Serious Question on Clocks & Time

roosh

This will probably seem like a really basic question, so my apologies if it does; I have asked it elsewhere, but as of yet, haven't really had an answer to it.

The question is: how does a clock measure the property [of the universe] called time?

I can see how a clock can be used as a standard unit of comparison, which forms the basis of a system of measurement, called time; but I can't see how a clock actually measures a universal property called time.

In a discussion elsewhere, someone mentioned that

If you couldn't measure the property of time with some system, then it wouldn't be a characteristic qualifying to be dealt with by science.

How is it meassured, with a clock, or otherwise?

pacquiao

Time is made up by us isn't it?

rccaulfield

It measures it by dividing the arrow of time we recognise by the law of entropy into different sections-seconds minutes days etc according to the planet your ons spin and orbit.

Morbert

roosh wrote: »

This will probably seem like a really basic question, so my apologies if it does; I have asked it elsewhere, but as of yet, haven't really had an answer to it.

The question is: how does a clock measure the property [of the universe] called time?

I can see how a clock can be used as a standard unit of comparison, which forms the basis of a system of measurement, called time; but I can't see how a clock actually measures a universal property called time.

In a discussion elsewhere, someone mentioned that

How is it meassured, with a clock, or otherwise?

It measures the relation between events that we call time. Time is not a substance.

roosh

rccaulfield wrote: »

It measures it by dividing the arrow of time we recognise by the law of entropy into different sections-seconds minutes days etc according to the planet your ons spin and orbit.

I also can't see how increasing disorder suggests that time exists, or to use the oft cited example, I can't see how the breaking of a cup only happening in one direction suggests that time exists.

But that may where my misunderstanding lies, in thinking that time is treated as an existential property of the universe; Morbert's post above suggests that that may be where the misunderstanding lies.

roosh

Morbert wrote: »

It measures the relation between events that we call time. Time is not a substance.

OK, so it is a system of measurement, not actually a property of the universe?

FISMA

roosh wrote: »

I also can't see how increasing disorder suggests that time exists, or to use the oft cited example, I can't see how the breaking of a cup only happening in one direction suggests that time exists.

With the "exists" concept, we're more in to metaPhysics and philosophy than Physics.

What IS time?

What IS it to exist?

Does time exist?

These are questions for Philosophy. Physics isn't going to answer "why." We're going to accept the observation and study it in the natural world.

Anyhow, we say that entropy gives a direction of time. Which is not to say that time is a vector, it's a colloquial statement. Time unfolds, reveals, whatever's itself in a "direction" that causes entropy to increase.

For some reason, things naturally get more and more disordered. Glasses break, the living room gets messy, and so on. It is natural, in our world, for disorder to increase.

There's no violation of Energy, Momentum, or other conservation laws if entropy spontaneously decreased. The problem is that this has never happened in the observable world in which we live.

Newton did not know what Gravity was, however, he was able to measure it.

For some time, we did not know what the electron was. However, we could measure its charge to mass ratio.

Likewise, I may not know what time is, but, perhaps, I am measuring it. The oscillations of Cesium seem to fit nicely with the second.

Also, time is relative. I believe that there's a superluminal realm "out there," somewhere. Time lines tend to get messy when we talk about faster than light speeds - effects occuring before the cause and such, infinite now's, et al.

Finally, I do not believe that time is a property of the Universe in the way we use the word "property" in Physics. I would say that time is a property of consciousness, or something that is yet outside what we now consider the natural world. Perhaps, someday, we'll bring it in to the natural world.

roosh

FISMA wrote: »

With the "exists" concept, we're more in to metaPhysics and philosophy than Physics.

What IS time?

What IS it to exist?

Does time exist?

These are questions for Philosophy. Physics isn't going to answer "why." We're going to accept the observation and study it in the natural world.

Anyhow, we say that entropy gives a direction of time. Which is not to say that time is a vector, it's a colloquial statement. Time unfolds, reveals, whatever's itself in a "direction" that causes entropy to increase.

For some reason, things naturally get more and more disordered. Glasses break, the living room gets messy, and so on. It is natural, in our world, for disorder to increase.

There's no violation of Energy, Momentum, or other conservation laws if entropy spontaneously decreased. The problem is that this has never happened in the observable world in which we live.

Newton did not know what Gravity was, however, he was able to measure it.

For some time, we did not know what the electron was. However, we could measure its charge to mass ratio.

Likewise, I may not know what time is, but, perhaps, I am measuring it. The oscillations of Cesium seem to fit nicely with the second.

Also, time is relative. I believe that there's a superluminal realm "out there," somewhere. Time lines tend to get messy when we talk about faster than light speeds - effects occuring before the cause and such, infinite now's, et al.

Finally, I do not believe that time is a property of the Universe in the way we use the word "property" in Physics. I would say that time is a property of consciousness, or something that is yet outside what we now consider the natural world. Perhaps, someday, we'll bring it in to the natural world.

We can drop the concept of existence, and simply ask how time is measured, or how does time "reveal" itself.

Yes entropy may occur in only one direction, but how is that indicative of time; how is a cup breaking and not reassembling indicative of time?

With gravity and electrons something is [presumably] being measured, the charge to mass ratio in the case of the latters; with time it appears as though there is only the assumption that something is being measured by a clock.

To my mind, the oscillations of Caesium don't actually measure anything, because it is the oscillations of Caesium which are actually being measured.

Just having a quick read up on Caesium clocks and it appears as though the reason the oscillations of Caesium seem to fit nicely the second is because the second is defined in terms of the oscillations of Caesium.

roosh

one manifestation of the issue is the assertion that gravity and/or velocity has an effect on time i.e. that time can slow down or speed up depending on either; this suggests that "time" interacts with the physical world somehow.

Morbert

roosh wrote: »

OK, so it is a system of measurement, not actually a property of the universe?

The clock would be the system of measurement. Time would be the relation between events. Or to put it more rigorously: There is a metric that relates all events in the universe to each other. This metric is the spacetime metric.

one manifestation of the issue is the assertion that gravity and/or velocity has an effect on time i.e. that time can slow down or speed up depending on either; this suggests that "time" interacts with the physical world somehow.

That is almost right. It is instead the claim that the gravitational field *is* spacetime. I.e. The geometry that tells you clocks in space run at different rates is the same geometry that tells you objects accelerate towards the earth.

roosh

Morbert wrote: »

The clock would be the system of measurement. Time would be the relation between events. Or to put it more rigorously: There is a metric that relates all events in the universe to each other. This metric is the spacetime metric.



That is almost right. It is instead the claim that the gravitational field *is* spacetime. I.e. The geometry that tells you clocks in space run at different rates is the same geometry that tells you objects accelerate towards the earth.

How does a clock measure the relation between events; or the metric? Is it not the case that events are related to a clock, e.g. the number of oscillations of caesium between events are measured, and represent the number of seconds between events.

That clocks run at different rates depending on gravity or velocity suggests that gravity and/or velocity affect the physical process of a clock, not time.

How is a gravitational field anything other than a gravitational field; where does time enter into it?

Morbert

roosh wrote: »

How does a clock measure the relation between events; or the metric? Is it not the case that events are related to a clock, e.g. the number of oscillations of caesium between events are measured, and represent the number of seconds between events.

Take the stationary caesium oscillation as an example. Consider one event as a point in oscillation, and another event as the same point in the next oscillation. The distance between these events would be a unit of time. We can use this distance to build standardised clocks. Do you believe time is any more or less real than space?

That clocks run at different rates depending on gravity or velocity suggests that gravity and/or velocity affect the physical process of a clock, not time.

If this were true, you would expect gravity to affect different physical properties differently. Clocks based on the ping of a photon, and clocks based on caesium oscillations would all be affected differently. Yet what we observer is the same time dilation for all clocks. Why?

How is a gravitational field anything other than a gravitational field; where does time enter into it?

The spacetime metric tensor is the gravitational field.
http://en.wikipedia.org/wiki/Metric_tensor_(general_relativity)

A basic introduction from Astronomy Cafe
http://www.astronomycafe.net/gravity/gravity.html

"Perhaps the most unusual thing about gravity we know about is that, unlike the other forces of nature, gravity is intimately related to space and time. In fact, space and time are viewed by physicists, and the mathematics of relativity theory, as qualities of the gravitational field of the cosmos that have no independent existence. Gravity does not exist like the frosting on a cake, embedded in some larger arena of space and time. Instead, the 'frosting' is everything, and matter is embedded and intimately and indivisibly connected to it. If you could turn off gravity, it is mathematically predicted that space and time would also vanish!"

Our original theories posited gravity as something separate to spacetime, but those theories did not make correct predictions, and are only used today as approximations.

roosh

apologies for the delay in replying; I'm just in the process of moving over to South Korea, so I haven't had a chance to type up a full reply. I'll post it as soon as I get an opportunity.

MoogPoo

Got a good book on time in easons. From Eternity to Here. - A quest for the ultimate theory of time, by Sean Carroll. Its sort of a popular science book but is an interesting read, he starts defining time in different ways by relating it to periodic events in the universe like orbits and oscillations of crystals and defining it to be a scale or to be a measure of intervals. Then talks about Special Relativity and things to show how time differs from the newtonian view and goes on to some deeper things like gravity, time-travel and stuff... No real maths in it, he does mentions tensors and Riemannian Geometry but just states properties and has pictures. Great read though if your interested.

roosh

Reconciliation
There are a number of things I have difficulty reconciling, so it might be helpful to try and set out what some of those are.

Firstly, "time is not a substance"; by this I understand that time has no physical properties, which I understand as meaning that it is not something which can be measured?

Secondly, if it is not a substance, how then, can it be said to "bend", "twist", "speed up", "slow down", "warp", etc.? Also if time isn't physical how can gravity and motion appear to have tangible effects on it.

I also have trouble reconciling the notions of past and future with the use of a clock to measure time - I'm not entirely sure how to formulate it at present, but hopefully I can be more clear.

I also have trouble with the notion that gravity is space and time, because if space and time are not physical then how can they be gravity or vice versa, because gravity has physical effects.

The excluded middle
To my mind there are two possible solutions for what the nature of time is; either it is a system of measurement which does not have any intrinsic existence, or it is a physically existing "entity". I am open to correction on that though.

If time is a system of measurement, with no intrinsic existence, then it cannot speed up or slow down, it cannot bend or warp, and it cannot itself be measured - being the measuring system. This is how I personally see time. A clock which ticks slower because it is under the influence of gravity doesn't suggest that time is moving slowly, and that events which have that clock as their timepiece aren't further in the past than events measured using a faster ticking clock. It suggests that gravity impacts the physical mechanics of the clock to make it tick slower or faster.

The alternative is that time is a physically existng entity, force, property, call it what you will, and can be measured. It is this notion which gives rise to the dilemma of showing how a clock measures the physical property called time.

Is there an alternative that I have missed?

Morbert wrote: »

Take the stationary caesium oscillation as an example. Consider one event as a point in oscillation, and another event as the same point in the next oscillation. The distance between these events would be a unit of time. We can use this distance to build standardised clocks. Do you believe time is any more or less real than space?

The Caesium clock only counts the number of oscillations though, doesn't it? There is no "distance" between the events which is measured, the distance is only imagined. That's not to say that the oscillations happen at the same moment, but just that the idea that the "distance" between the oscillations as a unit of time appears to be a re-ification of a concept.

I don't have any trouble with the idea of clocks per se, and the idea that a standard unit can be used for the purpose of comparison or measurement, the trouble I have is with what is actually being measured.

As for the existence of space, I haven't given it the same consideration, but I would imagine a similar argument could be put forward; as I say though, I haven't tried considering it to the same extent.

Morbert wrote: »

If this were true, you would expect gravity to affect different physical properties differently. Clocks based on the ping of a photon, and clocks based on caesium oscillations would all be affected differently. Yet what we observer is the same time dilation for all clocks. Why?

Would you necessarily expect gravity to affect different physical properties differently? The classic example of the bowling ball and the feather falling at the same rate springs to mind.

The thing is, all clocks are acted upon by gravity uniformly and all clocks don't tick at the same rate; so a uniform change in gravity should affect all clocks the same no? But I wouldn't be sure to be honest.

In the example you give, is a second for the photon clock defined in terms of caesium oscillations or the ping of a photon?

Morbert wrote: »

The spacetime metric tensor is the gravitational field.
http://en.wikipedia.org/wiki/Metric_tensor_(general_relativity)

A basic introduction from Astronomy Cafe
http://www.astronomycafe.net/gravity/gravity.html

"Perhaps the most unusual thing about gravity we know about is that, unlike the other forces of nature, gravity is intimately related to space and time. In fact, space and time are viewed by physicists, and the mathematics of relativity theory, as qualities of the gravitational field of the cosmos that have no independent existence. Gravity does not exist like the frosting on a cake, embedded in some larger arena of space and time. Instead, the 'frosting' is everything, and matter is embedded and intimately and indivisibly connected to it. If you could turn off gravity, it is mathematically predicted that space and time would also vanish!"

Our original theories posited gravity as something separate to spacetime, but those theories did not make correct predictions, and are only used today as approximations.

It just seems like a non-sequitor that gravity is not only gravity, but also space and time, or spacetime.

Morbert

roosh wrote: »

Reconciliation
There are a number of things I have difficulty reconciling, so it might be helpful to try and set out what some of those are.

Firstly, "time is not a substance"; by this I understand that time has no physical properties, which I understand as meaning that it is not something which can be measured?

Secondly, if it is not a substance, how then, can it be said to "bend", "twist", "speed up", "slow down", "warp", etc.? Also if time isn't physical how can gravity and motion appear to have tangible effects on it.

I also have trouble reconciling the notions of past and future with the use of a clock to measure time - I'm not entirely sure how to formulate it at present, but hopefully I can be more clear.

I also have trouble with the notion that gravity is space and time, because if space and time are not physical then how can they be gravity or vice versa, because gravity has physical effects.

Time is not a substance. By this I mean it is not matter, or a property of matter. But time is physical. By this, I mean the relation between events characterised by a manifold and a metric can exhibit dynamical variables, such as curvature.

The excluded middle
To my mind there are two possible solutions for what the nature of time is; either it is a system of measurement which does not have any intrinsic existence, or it is a physically existing "entity". I am open to correction on that though.

If time is a system of measurement, with no intrinsic existence, then it cannot speed up or slow down, it cannot bend or warp, and it cannot itself be measured - being the measuring system. This is how I personally see time. A clock which ticks slower because it is under the influence of gravity doesn't suggest that time is moving slowly, and that events which have that clock as their timepiece aren't further in the past than events measured using a faster ticking clock. It suggests that gravity impacts the physical mechanics of the clock to make it tick slower or faster.

The alternative is that time is a physically existng entity, force, property, call it what you will, and can be measured. It is this notion which gives rise to the dilemma of showing how a clock measures the physical property called time.

Is there an alternative that I have missed?

Time is a relation between events, characterised by a metric. We use a system of measurement to quantify time. Time is physical but it is not a property of an event. It is a property of the manifold of all events.

"Time slowing down" can an unhelpful description of time dilation because it implies some river or substance of time, which was abandoned centuries ago.

The Caesium clock only counts the number of oscillations though, doesn't it? There is no "distance" between the events which is measured, the distance is only imagined. That's not to say that the oscillations happen at the same moment, but just that the idea that the "distance" between the oscillations as a unit of time appears to be a re-ification of a concept.

I don't have any trouble with the idea of clocks per se, and the idea that a standard unit can be used for the purpose of comparison or measurement, the trouble I have is with what is actually being measured.

As for the existence of space, I haven't given it the same consideration, but I would imagine a similar argument could be put forward; as I say though, I haven't tried considering it to the same extent.

"Distance" is just a word I used to specify an interval. I could also say time characterises a "relation" between the first event and the second. This is not a reification since time is not defined as anything more. What I am trying to convey is that the structure of events codified by space and time does not permit presentism, the idea that a collection of simultaneous events is all that exists.

Would you necessarily expect gravity to affect different physical properties differently? The classic example of the bowling ball and the feather falling at the same rate springs to mind.

The thing is, all clocks are acted upon by gravity uniformly and all clocks don't tick at the same rate; so a uniform change in gravity should affect all clocks the same no? But I wouldn't be sure to be honest.

In the example you give, is a second for the photon clock defined in terms of caesium oscillations or the ping of a photon?

As an aside: You would expect gravity to affect different physical systems differently. A clock is a periodic system, so we would expect gravity to effect clocks differently. An hour glass would measure time faster in the presence of a strong gravitational field than a clock based on photons.

But more importantly, gravitational time dilation is not due to the strength of gravity experienced. If you and I were in a uniform gravitational field (I.e. if we both experienced the same amount of gravitational force) but in different locations along the gradient, our clocks would disagree. This means, if we both had hour glasses, and they both experienced the exact same same gravitational force, they would still register different intervals of time.

pacquiao

Thought this would aid in the discussion.


The Fabric Of The Cosmos: Illusion of Time (2011)

S39E06
http://www.mrbrownee...om/?id=ZEMASUQ5

Program Description

Time. We waste it, save it, kill it, make it. The world runs on it. Yet ask physicists what time actually is, and the answer might shock you: They have no idea. Even more surprising, the deep sense we have of time passing from present to past may be nothing more than an illusion. How can our understanding of something so familiar be so wrong? In search of answers, Brian Greene takes us on the ultimate time-traveling adventure, hurtling 50 years into the future before stepping into a wormhole to travel back to the past. Along the way, he will reveal a new way of thinking about time in which moments past, present, and future—from the reign of T. rex to the birth of your great-great-grandchildren—exist all at once. This journey will bring us all the way back to the Big Bang, where physicists think the ultimate secrets of time may be hidden. You'll never look at your wristwatch the same way again.


I did not upload this, I take no credit, I just found the megaupload link elsewhere and decided to post it.

roosh

cheers, watched it the other day

pacquiao wrote: »

Thought this would aid in the discussion.


The Fabric Of The Cosmos: Illusion of Time (2011)

S39E06
http://www.mrbrownee...om/?id=ZEMASUQ5

Program Description

Time. We waste it, save it, kill it, make it. The world runs on it. Yet ask physicists what time actually is, and the answer might shock you: They have no idea. Even more surprising, the deep sense we have of time passing from present to past may be nothing more than an illusion. How can our understanding of something so familiar be so wrong? In search of answers, Brian Greene takes us on the ultimate time-traveling adventure, hurtling 50 years into the future before stepping into a wormhole to travel back to the past. Along the way, he will reveal a new way of thinking about time in which moments past, present, and future—from the reign of T. rex to the birth of your great-great-grandchildren—exist all at once. This journey will bring us all the way back to the Big Bang, where physicists think the ultimate secrets of time may be hidden. You'll never look at your wristwatch the same way again.


I did not upload this, I take no credit, I just found the megaupload link elsewhere and decided to post it.

roosh

This extract might be helpful in outlining the issue.

“I recently went to the National Institute of Standards and Technology in Boulder,” says [Seth] Lloyd. (NIST is the government lab that houses theatomic clock that standardizes time for the nation.) “I said something like, ‘Your clocks measure time very accurately.’ They told me, ‘Our clocks do not measure time.’ I thought, Wow, that’s very humble of these guys. But they said, ‘No, time is defined to be what our clocks measure.’ Which is true. They define the time standards for the globe: Time is defined by the number of clicks of their clocks.”

Rovelli, the advocate of a timeless universe, says the NIST timekeepers have it right. Moreover, their point of view is consistent with the Wheeler-DeWitt equation. “We never really see time,” he says. “We see only clocks. If you say this object moves, what you really mean is that this object is here when the hand of your clock is here, and so on. We say we measure time with clocks, but we see only the hands of the clocks, not time itself. And the hands of a clock are a physical variable like any other. So in a sense we cheat because what we really observe are physical variables as a function of other physical variables, but we represent that as if everything is evolving in time

"Time may not exist" [page2]

Morbert wrote: »

Time is not a substance. By this I mean it is not matter, or a property of matter. But time is physical. By this, I mean the relation between events characterised by a manifold and a metric can exhibit dynamical variables, such as curvature.

Sorry, that was my misinterpretation.

Morbert wrote: »

Time is a relation between events, characterised by a metric. We use a system of measurement to quantify time. Time is physical but it is not a property of an event. It is a property of the manifold of all events.

The system of measurement, or the clock, provides a quantity which we designate as "time", but the quanity that it provides is the number of caesium oscillations, not a quantity of "physical time".

If we caricature the operations of a caesium clock as: a man sitting on a chair counting the number of oscillations as they appear in front of him. One pops into view, he counts one, and it disappears again; then another one pops into view, he counts two, and it disappears again; and so on.

Here, the "relation" between events is only an imagined one. The man observes them in a sequence, but each one ceases to exist after he counts it. To say that one event exists in the past is simply to imagine that it does.


Alternatively, if we imagine that each event is on a conveyor belt such that, as it comes into view he counts it and it continues along the conveyor belt without disappearing, or ceasing to exist. Again, there is no past/present/future relationship, other than in the imagination of the counter. As an event occurs i.e. as he counts the object on the conveyor belt, it continues to exist in the present, but he retains the memory of it having passed him and designates is as being "in the past" - again, this is only imagined, because the object continues to exist in the present and the physical relationship between it and the other events is entirely spacial, not temporal. The temporal relationship is imagined, on the basis of his capacity for memory.

Morbert wrote: »

"Time slowing down" can an unhelpful description of time dilation because it implies some river or substance of time, which was abandoned centuries ago.

The notion of a universal rive of time may have been abandoned, but the vestiges of it appear to remain in what could be labeled as "tributary time"; such that there is a river of time for each observer, which can combine with the rivers of other observers and also split off from them.

Morbert wrote: »

"Distance" is just a word I used to specify an interval. I could also say time characterises a "relation" between the first event and the second. This is not a reification since time is not defined as anything more. What I am trying to convey is that the structure of events codified by space and time does not permit presentism, the idea that a collection of simultaneous events is all that exists.

The re-ification doesn't lie in the fact that time is defined as anything more, rather that the "relation" is.

Morbert wrote: »

As an aside: You would expect gravity to affect different physical systems differently. A clock is a periodic system, so we would expect gravity to effect clocks differently. An hour glass would measure time faster in the presence of a strong gravitational field than a clock based on photons.

But more importantly, gravitational time dilation is not due to the strength of gravity experienced. If you and I were in a uniform gravitational field (I.e. if we both experienced the same amount of gravitational force) but in different locations along the gradient, our clocks would disagree. This means, if we both had hour glasses, and they both experienced the exact same same gravitational force, they would still register different intervals of time.

How do you mean in different locations along the gradient; what does the gradient measure; do the time dilation calculations work for hour glasses also?

Also, just on a previous question, is the second for a [pinging] photon clock defined in terms of the ping of a photon or the oscillations of caesium?

Morbert

roosh wrote: »

This extract might be helpful in outlining the issue.

"Time may not exist" [page2]


The system of measurement, or the clock, provides a quantity which we designate as "time", but the quanity that it provides is the number of caesium oscillations, not a quantity of "physical time".

If we caricature the operations of a caesium clock as: a man sitting on a chair counting the number of oscillations as they appear in front of him. One pops into view, he counts one, and it disappears again; then another one pops into view, he counts two, and it disappears again; and so on.

Here, the "relation" between events is only an imagined one. The man observes them in a sequence, but each one ceases to exist after he counts it. To say that one event exists in the past is simply to imagine that it does.

Alternatively, if we imagine that each event is on a conveyor belt such that, as it comes into view he counts it and it continues along the conveyor belt without disappearing, or ceasing to exist. Again, there is no past/present/future relationship, other than in the imagination of the counter. As an event occurs i.e. as he counts the object on the conveyor belt, it continues to exist in the present, but he retains the memory of it having passed him and designates is as being "in the past" - again, this is only imagined, because the object continues to exist in the present and the physical relationship between it and the other events is entirely spacial, not temporal. The temporal relationship is imagined, on the basis of his capacity for memory.

Firstly, you are using the term "physical" wrong. The spacetime metric, a platonic mathematical device, describes the physical relation between events. Time, like chaos, is physical even if it is an emergent phenomenon. What you should be saying is time might not be a dynamical variable, but rather a parameter generated by the Hamiltonian constraint under the ADM formalism of General Relativity.

Secondly, I have said before that there is no issue with time as an emergent parameter, as opposed to a dynamical variable. The issue is with the notion of presentism you keep asserting. There is no single present. The present is also an emergent phenomenon, and different observers will disagree over it.

The notion of a universal rive of time may have been abandoned, but the vestiges of it appear to remain in what could be labeled as "tributary time"; such that there is a river of time for each observer, which can combine with the rivers of other observers and also split off from them.

What? This isn't the case at all. Time for each observer is a measure of the length of segment of their worldine, the locus of events that make up their history.

The re-ification doesn't lie in the fact that time is defined as anything more, rather that the "relation" is.

How is the relation re-ified?

How do you mean in different locations along the gradient; what does the gradient measure; do the time dilation calculations work for hour glasses also?

Say we both have infinitely precise hour glasses. You are on the top floor of a building and I am on the bottom floor. Let's also say there exists a uniform gravitational field, so that my hourglass feels the exact same gravitational force (m*g) as yours does. Newton mechanics says both hour glasses will measure the same amount of time. Relativity says yours will measure a greater amount of time.

Also, just on a previous question, is the second for a [pinging] photon clock defined in terms of the ping of a photon or the oscillations of caesium?

The second is conventionally defined in terms of caesium oscillations.

krd

Morbert wrote: »

The second is conventionally defined in terms of caesium oscillations.

Something that's been bothering me. What if you use a sound wave as a clock?

What if you took middle C, on a piano, as your measure of time. That 440 cycles would be your piano second.

If you were on a train, and it was travelling fast enough, a stationary observer in front of the train, might hear D (587.330 Hz). And you wouldn't need to be moving that fast.

This bothers me - because it creates huge time dilations.

Morbert

krd wrote: »

Something that's been bothering me. What if you use a sound wave as a clock?

What if you took middle C, on a piano, as your measure of time. That 440 cycles would be your piano second.

If you were on a train, and it was travelling fast enough, a stationary observer in front of the train, might hear D (587.330 Hz). And you wouldn't need to be moving that fast.

This bothers me - because it creates huge time dilations.

It does not create time dilation at all. Time dilation is independent of any mechanical principle you base your watch on, as it is due to the geometry of spacetime. A piano clock gives false reading not because of the geometry of spacetime, but because it is affected by air.

krd

Morbert wrote: »

It does not create time dilation at all. Time dilation is independent of any mechanical principle you base your watch on, as it is due to the geometry of spacetime.

A piano clock gives false reading not because of the geometry of spacetime, but because it is affected by air.

And light through a vacuum, doesn't give a false reading?

Sound can only propagate through a gaseous medium. But with the Doppler effect, the change in frequency is instantaneous - it's not a graded change. The frequency does not increase between the source and the observer.

The constituency of the air, dictates the speed of sound. But it's still relative motion that effects the frequency in a Doppler shift. If the person on the train has a sound clock that uses C, and the observer has a sound clock, that uses C - both clocks will be out of synch with very little motion. But, to both observers, neither of their clocks would speed up or slow down* - to both observers, their personal clocks would tell correct time. Unless, of course, as the train slows down - the Doppler shift/gap closes and synchronises both clocks???????

Any periodic system can be used as a clock - a spring, a sound wave, the discharge from a crystal.

*if the speed of motion pitched up the tone to D, both observers would hear each others clocks in D. I'm still confused. If I could do the maths, I'd probably see a screaming error in my thinking. But it had never struck me until this moment - that someone on a train, hears all sounds from the outside world as a mixture of pitched up and pitched down sounds.

roosh

Morbert wrote: »

Firstly, you are using the term "physical" wrong. The spacetime metric, a platonic mathematical device, describes the physical relation between events. Time, like chaos, is physical even if it is an emergent phenomenon. What you should be saying is time might not be a dynamical variable, but rather a parameter generated by the Hamiltonian constraint under the ADM formalism of General Relativity.


Secondly, I have said before that there is no issue with time as an emergent parameter, as opposed to a dynamical variable. The issue is with the notion of presentism you keep asserting. There is no single present. The present is also an emergent phenomenon, and different observers will disagree over it.

How am I using the term "physical" wrong? I'm using it in it's most simplistic form as being something which is measurable; are messers Lloyd and Rovelli also using it incorrectly?

The assertion is that time is the physical relation between events, but the physical relation between events [if it exists] is spatial, not temporal; not only that but if it exists, it only exists in the present. The error lies in the double definition of the physical relation between those events i.e. as being both spatial and temporal, when only the spatial can be demonstrated.

Time, which encompasses the notions of "past" and "future", "emerges" on the basis of an observers capacity for memory and projection i.e. it is imagined. There is no evidence to suggest that either the past or the future exist, unless they are assumed to exist a priori.

As was outlined above, with the caricature of the Caesium clock, only the spatial relationship between "events" can be demonstrated; the "temporal" relation i.e. between any two of the past, present, and future, is only imagined, or assumed.

The reason that space and time appear to be so intertwined is because we derive our idea of time from observing the change that physical objects undergo; because we can remember a "past state" and can imagine an object in a "future state", we get the impression of linear time; but both "past" and "future" are only imagined, as the impression of linear time.

Morbert wrote: »

What? This isn't the case at all. Time for each observer is a measure of the length of segment of their worldine, the locus of events that make up their history.

Firstly, the notion of a worldline, extending from the past, through the present, and into the future, only arises when the past and the future are assumed to exist.

Secondly, if all observers were at rest relative to each other, their worldlines would converge and very closely resemble the [partially] abandoned idea of a universal river of time; where the worldlines diverge, due to the relative motion of the observers, they would resemble tributaries.

Morbert wrote: »

How is the relation re-ified?

The "temporal relation" is reified off the back of the spatial relationship, when only the spatial relationship can be demonstrated.

Morbert wrote: »

Say we both have infinitely precise hour glasses. You are on the top floor of a building and I am on the bottom floor. Let's also say there exists a uniform gravitational field, so that my hourglass feels the exact same gravitational force (m*g) as yours does. Newton mechanics says both hour glasses will measure the same amount of time. Relativity says yours will measure a greater amount of time.

That's assuming that there is a uniform gravitational force; if the scenario was exaggerated, with one of us atop a mountain, that wouldn't be the case would it?

Morbert wrote: »

The second is conventionally defined in terms of caesium oscillations.

I know the "official" second is defined in terms of Caesium oscillations, but I thought I read somewhere [wikipedia I think] that each other kind of atomic clock has it's own definition of a second - which would make sense seeing as a hydrogen maser won't "measure time" in terms of Caesium oscillations.

Given the likely difference between the measurement of a second according to different clocks, I'm just wondering if the gravitational time dilation is the exact same for each clock, in terms of Caesium oscillations, or is it merely proportional?


What a clock does
If we just picture what a clock actually does, it should become apparent that time is not a physical property being measured.

In the Caesium clock, the repetitive oscillations of the Caesium atom (forgive the crude explanation) are counted; not time. The relation between the events isn't quantified either, the number of oscillations is simply counted.

Change is then measured in terms of this naturally occuring, repetitive frequency (which itself has time in it's definition), such that we compare the change to the number of oscillations counted e.g. we started the car at the same time as we started counting the number of oscillations, and it took us X number of oscillations to get from A to B.

We designate the number of oscillations as being the "time", but a physical property called "time" is never measured. At no point along that journey did anything occur in the past, or the future.

Morbert

krd wrote: »

And light through a vacuum, doesn't give a false reading?

No. The electromagnetic field is lorentz invariant. This has been established by theory, and affirmed by thousands of increasingly meticulous and sophisticated experiments. Furthermore, it has even been established on the quantum level, with quantum field theory being the most successfull physical theory to date: a theory that incorporates spacetime.

Sound can only propagate through a gaseous medium. But with the Doppler effect, the change in frequency is instantaneous - it's not a graded change. The frequency does not increase between the source and the observer.

The constituency of the air, dictates the speed of sound. But it's still relative motion that effects the frequency in a Doppler shift. If the person on the train has a sound clock that uses C, and the observer has a sound clock, that uses C - both clocks will be out of synch with very little motion. But, to both observers, neither of their clocks would speed up or slow down* - to both observers, their personal clocks would tell correct time. Unless, of course, as the train slows down - the Doppler shift/gap closes and synchronises both clocks???????

Any periodic system can be used as a clock - a spring, a sound wave, the discharge from a crystal.

*if the speed of motion pitched up the tone to D, both observers would hear each others clocks in D. I'm still confused. If I could do the maths, I'd probably see a screaming error in my thinking. But it had never struck me until this moment - that someone on a train, hears all sounds from the outside world as a mixture of pitched up and pitched down sounds.

Again, this is clearly an artefact of the poor choice of clock with no well-defined standard. Any periodic system can be used as a clock, just as any sheet of plywood can be used as a hang-glider. Good, robust, standardised clocks, whether they be photon clocks, or caesium clocks, or processes like muon decay, all equally register time dilation, exposing its underlying, geometrical (or chronometrical) origin.

Morbert

roosh wrote: »

How am I using the term "physical" wrong? I'm using it in it's most simplistic form as being something which is measurable; are messers Lloyd and Rovelli also using it incorrectly?

The assertion is that time is the physical relation between events, but the physical relation between events [if it exists] is spatial, not temporal; not only that but if it exists, it only exists in the present. The error lies in the double definition of the physical relation between those events i.e. as being both spatial and temporal, when only the spatial can be demonstrated.

Time, which encompasses the notions of "past" and "future", "emerges" on the basis of an observers capacity for memory and projection i.e. it is imagined. There is no evidence to suggest that either the past or the future exist, unless they are assumed to exist a priori.

As was outlined above, with the caricature of the Caesium clock, only the spatial relationship between "events" can be demonstrated; the "temporal" relation i.e. between any two of the past, present, and future, is only imagined, or assumed.

The reason that space and time appear to be so intertwined is because we derive our idea of time from observing the change that physical objects undergo; because we can remember a "past state" and can imagine an object in a "future state", we get the impression of linear time; but both "past" and "future" are only imagined, as the impression of linear time.

Firstly, the notion of a worldline, extending from the past, through the present, and into the future, only arises when the past and the future are assumed to exist.

I have explained this many times now: There is no single present. You are assuming time is an artificial factor space of all events, with a physically distinguished 3D hypersurface of simultaneous events as "the present" that is "real". This does not match up to experiment. Instead, the relation between events exhibits a Minkowski geometry, where different observers' presents are at angles to one another, so that my present can contain events that happen 150 years into your future. When considering all observers together, we see that the "future" is just as real as the past.

Secondly, if all observers were at rest relative to each other, their worldlines would converge and very closely resemble the [partially] abandoned idea of a universal river of time; where the worldlines diverge, due to the relative motion of the observers, they would resemble tributaries.

That is not true in the slightest. If all worldlines converged, we would all be in the same place. Furthermore, even if we were all at rest with respect to one another, spacetime exhibits curvature, so that our clocks would still label time differently.

The "temporal relation" is reified off the back of the spatial relationship, when only the spatial relationship can be demonstrated.

Einstein (among others) demonstrated that the temporal relation is on equal footing with the spatial relation, and that only by considering the two as a facet of the same thing, do we get a clear picture of the invariant physical world. It is how we formulated quantum field theory, with an abundance of experimental support.

That's assuming that there is a uniform gravitational force; if the scenario was exaggerated, with one of us atop a mountain, that wouldn't be the case would it?

Yes it would. In fact, let's exaggerate it further. Let's say I'm at the cusp of a black hole and you're far away from it, out of danger. I would witness your clock tick much faster. In fact, I would witness the rest of the universe age millions of years in what my clock labels as a few seconds. Similarly, you would see my clock nearly frozen, with no sand falling through the hourglass, despite being in a strong gravitational field.

I know the "official" second is defined in terms of Caesium oscillations, but I thought I read somewhere [wikipedia I think] that each other kind of atomic clock has it's own definition of a second - which would make sense seeing as a hydrogen maser won't "measure time" in terms of Caesium oscillations.

Given the likely difference between the measurement of a second according to different clocks, I'm just wondering if the gravitational time dilation is the exact same for each clock, in terms of Caesium oscillations, or is it merely proportional?

There is no difference. A second is standardised so that a caesium atom or a photon clock will both agree on what a second is.

Clock stuff

See my above statements about the shortcomings of presentism.

roosh

Morbert wrote: »

I have explained this many times now: There is no single present. You are assuming time is an artificial factor space of all events, with a physically distinguished 3D hypersurface of simultaneous events as "the present" that is "real". This does not match up to experiment. Instead, the relation between events exhibits a Minkowski geometry, where different observers' presents are at angles to one another, so that my present can contain events that happen 150 years into your future. When considering all observers together, we see that the "future" is just as real as the past.

I fully accept that the experiments have given rise to a model which is at odds with "presentism", but incorporated in the experiments is the assumption that time is physical and that a clock measures time. The proposition that time is not physical will not, I would imagine, change the experimental results, bcos clocks would still be used as a method of comparison, but the model of the universe would change.

EDIT: More concisely, the experimental evidence itself is not add odds with "presentism", it's the interpretation of that evidence that is; an interpretation which is based on a questionable assumption.


What needs to be demonstrated is the physical, temporal relation between events i.e. between past and present, or present and future, and how a clock measures that relation.

It has been outlined above how a clock does not demonstrate this relationship.

Morbert wrote: »

That is not true in the slightest. If all worldlines converged, we would all be in the same place. Furthermore, even if we were all at rest with respect to one another, spacetime exhibits curvature, so that our clocks would still label time differently.

Presumably the worldlines of all observers in the same universe cannot be completely divergent, as this would suggest that each observer occupies their own universe. I would imagine that space-time is the "glue that binds them together"; presumably space-time to must have a worldline, or else is the sum of all worldlines - the block universe itself can be likened to a body of water.

This is just incidental however, how a clock demonstrates the physical relationship between past and present, or future and present is the critical issue.

Morbert wrote: »

Einstein (among others) demonstrated that the temporal relation is on equal footing with the spatial relation, and that only by considering the two as a facet of the same thing, do we get a clear picture of the invariant physical world. It is how we formulated quantum field theory, with an abundance of experimental support.

Did he demonstrate how the clock issue raised here is resolved?

Morbert wrote: »

Yes it would. In fact, let's exaggerate it further. Let's say I'm at the cusp of a black hole and you're far away from it, out of danger. I would witness your clock tick much faster. In fact, I would witness the rest of the universe age millions of years in what my clock labels as a few seconds. Similarly, you would see my clock nearly frozen, with no sand falling through the hourglass, despite being in a strong gravitational field.

OK, but we wouldn't be under a uniform gravitational field would we i.e. we wouldn't experience the same "degree of gravity".

This may of course all be academic, and largely is, because it has never been tested to that extent; and it follows from the arguably unverified assumption that time is physical and that a clock measures it.

Morbert wrote: »

There is no difference. A second is standardised so that a caesium atom or a photon clock will both agree on what a second is.

I'll try and dig out that article - assuming I didn't dream it up; but how can it be standardised so that both agree? There must presumably be, at least, a very, very slight degree of discrepancy, because they presumably don't "tick" at exactly the same rate.

Morbert wrote: »

See my above statements about the shortcomings of presentism.

I fully accept the points being made, but there is the issue of how a clock demonstrates a physical relation between past and present to be resolved.

Morbert

roosh wrote: »

I fully accept that the experiments have given rise to a model which is at odds with "presentism", but incorporated in the experiments is the assumption that time is physical and that a clock measures time. The proposition that time is not physical will not, I would imagine, change the experimental results, bcos clocks would still be used as a method of comparison, but the model of the universe would change.

EDIT: More concisely, the experimental evidence itself is not add odds with "presentism", it's the interpretation of that evidence that is; an interpretation which is based on a questionable assumption.

What needs to be demonstrated is the physical, temporal relation between events i.e. between past and present, or present and future, and how a clock measures that relation.

It has been outlined above how a clock does not demonstrate this relationship.

<snip>

This is just incidental however, how a clock demonstrates the physical relationship between past and present, or future and present is the critical issue.

<snip>

Did he demonstrate how the clock issue raised here is resolved?

<snip>

I fully accept the points being made, but there is the issue of how a clock demonstrates a physical relation between past and present to be resolved.

Nobody says a clock demonstrates spacetime. Instead, scientists say experiments ranging from the the speed of light in laboratories, to stellar aberration, to clock synchronisations at different velocities and locations, to ether detection (and the lack thereof), to relativistic doppler shift analyses etc. all affirm a minkowski spacetime structure. And presentism is inconsistent with minkowski spacetime.

Scientists and philosophers were suggesting that time and space were not entities, independent from things, long before Einstein. Gottfried Leibniz and Ernst Mach were two prominent examples (the latter actually influenced Einstein). So the idea that time is not real is not new, and is not implicitly assumed by experimenters. What Einstein and Minkowski argued was that space is relative and time is relative, but that there exists a structure of "space-time" that is invariant and physical. This structure is what experiments look for. They do not assume it is true. Instead, they work out what would happen if it was true or false, and then look for the respective phenomena that affirm or falsify it.

Presumably the worldlines of all observers in the same universe cannot be completely divergent, as this would suggest that each observer occupies their own universe. I would imagine that space-time is the "glue that binds them together"; presumably space-time to must have a worldline, or else is the sum of all worldlines - the block universe itself can be likened to a body of water.

It would not suggest separate universes. And spacetime does not have a worldline. Spacetime is the block universe, and contains all worldlines.

OK, but we wouldn't be under a uniform gravitational field would we i.e. we wouldn't experience the same "degree of gravity".

This may of course all be academic, and largely is, because it has never been tested to that extent; and it follows from the arguably unverified assumption that time is physical and that a clock measures it.

It does not follow from the assumption that a clock measures time. It is predicted that the relationship between clock ticks is described by a geometrical structure that exhibits time dilation and length contraction, among other counter-intuitive notions. And it has not been tested "to that extent", but it has been thoroughly tested, and not not only has it qualitatively agreed with relativity, but quantitatively too.

How does presentism, for example, account for relativistic doppler shifts, or gravitational time dilation?

himnextdoor

I'm pretty sure that an hour-glass will show a much larger degree of time-dilation than a caesium clock under either acceleration or gravity which could be regarded as the same thing.

Any clock can be described in terms of a device that is counting events. Physical events. Acceleration/gravity affect all physical events. For instance, a pendulum clock would probably stop altogether during free-fall whereas a digital-watch would remain comparatively accurate under the same conditions.

Really, accurate time-keeping has been a struggle against natural forces. Candle-clocks can be affected by the wind; water-clocks can be affected by atmospheric conditions; clockwork-clocks are affected by movement and pendulum-clocks even more so.

Even electronic-clocks based on counting oscillations of a crystal are limited by the fact that the crystal is actually, physically bending and flexing at a rate based on its physical parameters. This means that a crystal that has undergone 'contraction' due to acceleration will have changed its resonant frequency.

Now we have atomic clocks and so forth and they are not affected to the same extent by conditions that place serious limitaion the the types of clock mentioned above.

But they do operate within physical laws and acceleration/gravity cause physical effects.

When a rocket takes off, it is accelerated from the rear and becomes slightly shorter; the front of the rocket lags the rear as information cannot be instantaneously transmitted and received. Surely this is the same as saying that the density of the materials comprising the rocket (and everything on board) undergoes an increase in density; atomic nuclei become closer to each other? It seems obvious that time-keeping would be affected under such conditions.

Then consider the case where the force of acceleration is applied at the front due to gravity, say. (Or because the rocket motor is attached to the nose of the rocket which would be wholly impractical of course.) If the rocket was heading into a black-hole, for instance, then the rocket would undergo 'stretching'; the rear would lag the front and the density of the rocket would be slightly lowered.

So there are two scenarios; two rockets accelerating in the same direction but one is powered from the rear whereas the other is powered from the front. Same rate of acceleration, same direction but one is stretched and the other is compressed; in one the density is decreased and in the other it is increased.

What I'm having trouble understanding is, why should we think that there is an actual thing called time that is affected by acceleration/gravity rather than think that acceleration/gravity have a physical effect (which they do) on time-keeping instrumentation? I mean, couldn't a change in density have thermal implications that could influence the integrity of the clock?

Morbert

himnextdoor wrote: »

I'm pretty sure that an hour-glass will show a much larger degree of time-dilation than a caesium clock under either acceleration or gravity which could be regarded as the same thing.

Any clock can be described in terms of a device that is counting events. Physical events. Acceleration/gravity affect all physical events. For instance, a pendulum clock would probably stop altogether during free-fall whereas a digital-watch would remain comparatively accurate under the same conditions.

Really, accurate time-keeping has been a struggle against natural forces. Candle-clocks can be affected by the wind; water-clocks can be affected by atmospheric conditions; clockwork-clocks are affected by movement and pendulum-clocks even more so.

Even electronic-clocks based on counting oscillations of a crystal are limited by the fact that the crystal is actually, physically bending and flexing at a rate based on its physical parameters. This means that a crystal that has undergone 'contraction' due to acceleration will have changed its resonant frequency.

Now we have atomic clocks and so forth and they are not affected to the same extent by conditions that place serious limitaion the the types of clock mentioned above.

But they do operate within physical laws and acceleration/gravity cause physical effects.

When a rocket takes off, it is accelerated from the rear and becomes slightly shorter; the front of the rocket lags the rear as information cannot be instantaneously transmitted and received. Surely this is the same as saying that the density of the materials comprising the rocket (and everything on board) undergoes an increase in density; atomic nuclei become closer to each other? It seems obvious that time-keeping would be affected under such conditions.

Then consider the case where the force of acceleration is applied at the front due to gravity, say. (Or because the rocket motor is attached to the nose of the rocket which would be wholly impractical of course.) If the rocket was heading into a black-hole, for instance, then the rocket would undergo 'stretching'; the rear would lag the front and the density of the rocket would be slightly lowered.

So there are two scenarios; two rockets accelerating in the same direction but one is powered from the rear whereas the other is powered from the front. Same rate of acceleration, same direction but one is stretched and the other is compressed; in one the density is decreased and in the other it is increased.

What I'm having trouble understanding is, why should we think that there is an actual thing called time that is affected by acceleration/gravity rather than think that acceleration/gravity have a physical effect (which they do) on time-keeping instrumentation? I mean, couldn't a change in density have thermal implications that could influence the integrity of the clock?

Morbert wrote:

Good, robust, standardised clocks, whether they be photon clocks, or caesium clocks, or processes like muon decay, all equally register time dilation, exposing its underlying, geometrical (or chronometrical) origin.

Morbert wrote:

Time dilation is independent of any mechanical principle you base your watch on

I don't think people understand the level of rigour that goes into detecting time dilation. It is not a case of "Some clocks tick slowly, therefore time dilation." The more robust and precise a mechanism is, the more it agrees with predictions of relativity.

http://en.wikipedia.org/wiki/Time_dilation#Experimental_confirmation

Let me try a different approach. If you want to suggest that time dilation is just the mechanical deformation of clocks, you must answer 2 questions:

Why do completely different mechanisms, like photon clocks, atomic oscillations, relativistic doppler shifts, and the varieties of particle decay observed in accelerators all register the same level of time dilation?

Why do completely different mechanisms register an amount of time dilation as if spacetime had a relativistic, minkowski structure?

himnextdoor

Morbert wrote: »

Let me try a different approach. If you want to suggest that time dilation is just the mechanical deformation of clocks, you must answer 2 questions:

Why do completely different mechanisms, like photon clocks, atomic oscillations, relativistic doppler shifts, and the varieties of particle decay observed in accelerators all register the same level of time dilation?

Why do completely different mechanisms register an amount of time dilation as if spacetime had a relativistic, minkowski structure?

Thank you for your patience Morbet but can I point out that experimental data actually registers different values of time-dilation and in the case of the Hafele-Keating experiment, direction, east to west or west to east seems to determine whether clocks 'speed up' or 'slow down'? Doesn't this support an 'ether' conjecture'?

But getting back to the point, let me suggest a (possibly overused) train scenario.

Suppose that there is a large box on a carriage that is attached to a train which is at rest. At the centre of the box is a machine which 'fires' tennis-balls in two directions, forward and backward with respect to the train. The balls are 'fired' simultaneously such that the balls bounce off the two opposite walls with the same energy and an optical device detects them as they bounce back toward their origin. When the detector detects a ball, it causes another to be fired.

In this idealised situation, the balls arrive and are detected after they bounce and the arrangement is such that the ball-pairs are synchronised when the train is at rest. So, in essence we have two clocks that use returning balls as a time-base,

Now, I know that photons are different from tennis-balls but lets just take it from the point of view of Newtonian physics.

How will the 'synchronisity' of the balls be affected by the train accelerating?

Well, the first thing to note is that the path to the wall will be lengthened in the forward direction while the path will be shortened in the backward direction but what is the effect on how the 'energy' of each ball is dissipated?

Of course, the balls bounciing off the front wall will lose energy to the wall whereas the balls bouncing off the back wall will gain energy from the wall; the 'forward clock' will slow down and the 'backward clock' will speed up.

What I'm trying to say is that in classical physics, energy transfer (ball to wall, wall to ball) is affected by acceleration. Momentum is still conserved but the behaviour of the ball is altered and the clocks run faster or slower.

If we consider photons instead of tennis-balls then the effect would be that 'forward travelling' photons are red-shifted whilst 'backward travelling' photons are blue-shifted.

Does this make sense?

If acceleration (or gravity) has an effect on energy distribution then how can the 'ether' concept be dismissed?

'Why do completely different mechanisms, like photon clocks, atomic oscillations, relativistic doppler shifts, and the varieties of particle decay observed in accelerators all register the same level of time dilation?'

Because, in the end they all utilise 'photonic' properties and electron transitions, and photon emmision and absorption, are affected in the same way by acceleration/gravity.

And in the case of muon decay, stopping a particle that is undergoing acceleration due to gravity should have an effect on the decay time; it becomes 'stressed' when collided with a block of iron. Acceleration inhibits the dissipation of energy and deceleration promotes it.

Again, why should we think that 'time' as opposed to 'a clock' is affected by gravity or acceleration.

Enkidu

himnextdoor wrote: »

'Why do completely different mechanisms, like photon clocks, atomic oscillations, relativistic doppler shifts, and the varieties of particle decay observed in accelerators all register the same level of time dilation?'

Because, in the end they all utilise 'photonic' properties and electron transitions, and photon emmision and absorption, are affected in the same way by acceleration/gravity.

Decays don't use photonic properties and they are affected in the exact same way. In fact all physics, regardless of the mechanism is affected the same.

Morbert

himnextdoor wrote: »

Thank you for your patience Morbet but can I point out that experimental data actually registers different values of time-dilation and in the case of the Hafele-Keating experiment, direction, east to west or west to east seems to determine whether clocks 'speed up' or 'slow down'? Doesn't this support an 'ether' conjecture'?

They all register the same level time dilation: a level predicted by relativity. The East-West difference is due to the motion of the laboratory clock with respect to the centre of the earth.

'Why do completely different mechanisms, like photon clocks, atomic oscillations, relativistic doppler shifts, and the varieties of particle decay observed in accelerators all register the same level of time dilation?'

Because, in the end they all utilise 'photonic' properties and electron transitions, and photon emmision and absorption, are affected in the same way by acceleration/gravity.

And in the case of muon decay, stopping a particle that is undergoing acceleration due to gravity should have an effect on the decay time; it becomes 'stressed' when collided with a block of iron. Acceleration inhibits the dissipation of energy and deceleration promotes it.

As Enkidu has already pointed out, this is categorically untrue. The processes in particle accelerators (not merely muon decay) do not involve photonic properties, and they all behave as predicted by special relativity and quantum theory. Why would particle decay processes happen to all exhibit time dilation, and why would they agree with the time dilation exhibited by atomic clocks? Remember that we are not merely talking about a qualitative "slowing", but a slowing by a specific amount predicted by relativity.

Furthermore, regarding photonic properties, why would gravity, acceleration, and velocity affect all atomic and optical clocks equally? The oscillation frequencies involved are very different. The energy levels involved are very different, yet they all quantitatively support time dilation. Not to mention relativistic Doppler shifting, specifically the transverse Doppler effect.

To illustrate my point, consider your train scenario:

Suppose that there is a large box on a carriage that is attached to a train which is at rest. At the centre of the box is a machine which 'fires' tennis-balls in two directions, forward and backward with respect to the train. The balls are 'fired' simultaneously such that the balls bounce off the two opposite walls with the same energy and an optical device detects them as they bounce back toward their origin. When the detector detects a ball, it causes another to be fired.

In this idealised situation, the balls arrive and are detected after they bounce and the arrangement is such that the ball-pairs are synchronised when the train is at rest. So, in essence we have two clocks that use returning balls as a time-base,

Now, I know that photons are different from tennis-balls but lets just take it from the point of view of Newtonian physics.

How will the 'synchronisity' of the balls be affected by the train accelerating?

Well, the first thing to note is that the path to the wall will be lengthened in the forward direction while the path will be shortened in the backward direction but what is the effect on how the 'energy' of each ball is dissipated?

Of course, the balls bounciing off the front wall will lose energy to the wall whereas the balls bouncing off the back wall will gain energy from the wall; the 'forward clock' will slow down and the 'backward clock' will speed up.

What I'm trying to say is that in classical physics, energy transfer (ball to wall, wall to ball) is affected by acceleration. Momentum is still conserved but the behaviour of the ball is altered and the clocks run faster or slower.

If we consider photons instead of tennis-balls then the effect would be that 'forward travelling' photons are red-shifted whilst 'backward travelling' photons are blue-shifted.

Does this make sense?

If acceleration (or gravity) has an effect on energy distribution then how can the 'ether' concept be dismissed?

Swap the position of the walls with the emitter and you get the opposite effect. The clock at the front of the train would now speed up. The clock at the back of the train would now slow down. Or place the the apparatus such that the path of the balls are perpendicular to the acceleration of the train. The discrepancy would disappear. Here we have a clock that registers different frequencies based on trivial rearrangements. This does not happen with robust, optical and atomic clocks. They do not arbitrarily register different frequencies. All versions agree to incredibly high accuracy, and all agree with special relativity to incredibly high accuracy.

So the questions remain: Why do different processes (atomic and optical clocks, particle decay etc.) register the same level of time dilation? And why do they all register the level of time dilation predicted by special relativity?

himnextdoor

:cool:

Morbert wrote: »

They all register the same level time dilation: a level predicted by relativity. The East-West difference is due to the motion of the laboratory clock with respect to the centre of the earth.

From what I understand, experimental observations have produced data which has varied from 10% accuracy in the fifties, to 1% accuracy in the sixties and in 2005 the NPL performed the Hafele and Keating experiment which produced results within 4% accuracy of Einstein's predictions. If the theory came about through observation then the theory would be slightly different.

But this is nit-picking.

Let me be clear; I do not deny that gravity/acceleration have the effect that time-dilation attempts to address but I do question what it is that is actually being measured.

And I accept that the east-west thing is sufficiently understood in terms of the relative motion of the centre of gravity.

Could I ask your opinion of something: It seems well documented that the data released from the Hafele and Keating experiment were actually different to data obtained from the experiment, that the original results were adjusted. Some claim that the adjustments were made using dubious reasoning. Do you think that this is true?

The reason I ask is that, in my opinion, science that is based on politics is bad science. Would you agree?

Morbert wrote: »

As Enkidu has already pointed out, this is categorically untrue. The processes in particle accelerators (not merely muon decay) do not involve photonic properties, and they all behave as predicted by special relativity and quantum theory. Why would particle decay processes happen to all exhibit time dilation, and why would they agree with the time dilation exhibited by atomic clocks? Remember that we are not merely talking about a qualitative "slowing", but a slowing by a specific amount predicted by relativity.

Yes, thank you Enkido. I think you are both being a little unfair here, I was talking about 'clocks' and as far as I know there are no time-keeping devices based on muon decay. Caesium-clocks and light-clocks rely on photonic properties and it is these kinds of clocks that are used in the detection of time-dilation.

Furthermore, muon detection relies on the use of photo-multipliers and photo-multipliers do make use of photonic properties.

Anyway, what is a photon if not a packet of energy? Muon decay is an energetic process and so must be subject to photonic properties.

But to answer your question, I think that 'time-dilation' can be explained in terms of impedance; anything in a gravitational field or undergoing acceleration becomes 'stressed', 'under tension', so to speak. Why?... Because of resistance; resistance to change. Change requires energy expenditure; to stand up, sit down, lie down all require an exchange of energy and all because of gravity. It is gravity that stresses human joints. Every time we move we suffer wear and tear due to gravity, change occurs and energy is expended. I reckon you get the picture.:)

When systems interact, degradation happens; the universe is a process of decay. All matter has a 'life-span'.

Of course, I am talking about matter in terms of large scale systems of energy; atoms, molecules, microscopic-life, animals, planets, stars are all fated to destruction and all because gravity causes wear and tear. All systems of energy have a tendency to decay.

So why shouldn't the same thing apply at a sub-atomic scale? Sub-atomic particles can be thought of as systems whose components are comprised of energy that interact with each other creating structures defined as particles. In stable particles the components are balanced, relatively speaking, and in unstable particles there is a mismatch which results in the decay of that particle.

Let me offer another analogy by way of yet another idealised thought experiment. Imagine the fundamental particles as a set of toothed cogs that come in three distinct sizes; large, medium and small. Each size comes in two flavours; ten teeth per centimetre and fourteen teeth per centimetre, say. That is six types of cog so far. Each cog is fitted with a drive mechanism that gives it spin and there are two speeds available, one rpm and two rpm, let us say, which brings the number of different types of cog to twelve. Next, suppose that the cogs are magnetised in order to represent charge; the y-axis of the cog is a cylindrical bar-magnet and half the cogs have their north-pole up and the other half have their north-pole down. That is now twenty-four types of cog. Finally, all of these cogs are designed to have symmetry along their x-axis and to float on water such that the bottom surface of the cog is barely in contact with the water (so that we can disregard the forces generated in the water itself... for now). This means that they can be 'flipped' which will affect the spin direction and the 'charge'.

Let us say that we have two-thousand of each type and that they will each begin to operate upon contact with water. All we need now is a pool of water large enough to accommodate millions of such cogs and we can start ramdomly throwing our forty-eight thousand cogs into the water.

What would happen? The motors would start and roughly half will spin in a clockwise direction and the rest will spin in the opposite direction. They'd bob about randomly and eventually, they'll start making contact with each other. Think of the possible combinations; where charge is the same, north meets north of south meets south, repulsion occurs but if their spins are in opposite directions, the repulsion would be gentle whereas where the spins are the same, the repulsion would be violent. In the cases where charges are opposite and two cogs are attracted to each other equal spin would cause the two cogs to rotate about a common centre whereas opposite spin would cause 'soft merging' and the pair would simply move in a new direction according to their momentum.

Factor in the two different tooth-pitches, two different speeds and three different sizes (representing different masses), consider that three or four cogs could interact, and more, and the number of possible interactions becomes enormous.

However, some combinations will persist, be stable, for longer periods than others which can be considered unstable.

Can you imagine such a model and visualise how the cogs might 'arrange' themselves over time?

And back to muon decay. A muon might be represented as one large cog and three small ones that have been thrown together as a result of a collision between two stable systems. The instability comes about because one small cog is spinning at the slower rate and as soon as the system comes together it is doomed to break down shortly thereafter.

But what effect would acceleration have on the rate of 'decay'?

The reason that our mechanical muon is unstable is because there will come a point where like magnetic poles will be brought into contact and this will cause one cog to be ejected from the system at a rate determined by the magnetic field. If the muon is being accelerated in the direction in which the repulsive force is acting then the rate at which the muon decays is retarded. The cogs disengage which means that spin no longer plays a role in the decay but because one side of the rejected cog remains in close proximity to an opposite pole, it stays loosely connected to the system until either unstable oscillations inpart enough momentum to fire the particle out of the system or the system decelerates.

Naturally this would suggest that if a muon is accelerated in a direction opposite to the direction in which the repulsive force is acting then decay would be speeded up; acceleration would cause the system to move away from the rejected particle, assisting the force of repulsion.

I have a vivid picture in mind and I hope I am conveying it. Does this model work in a crude way at least?

If I make the cogs into corrugated spheres with the same properties outlined above, submerge trillions upon trillions of them in a vast tank of water and take into account the forces imparted into the water, don't I have, at the very least, a crude model of the quantum world?

Morbert wrote: »

Furthermore, regarding photonic properties, why would gravity, acceleration, and velocity affect all atomic and optical clocks equally? The oscillation frequencies involved are very different. The energy levels involved are very different, yet they all quantitatively support time dilation. Not to mention relativistic Doppler shifting, specifically the transverse Doppler effect.

Simple. Under acceleration, the orbital shells of atoms, all atoms, becomes distorted. They tend toward being a kind of 'comet' shape as the rate of acceleration increases. This causes the orbital path of the electron to become elongated and the distance travelled by the electron in each revolution is increased and the average velocity of the electron is decreased as is spends more time in the outer orbital.

In the case of caesium, this means that the probability that an electron makes a transition is increased and sure enough, the clock ticks slightly faster.

Oh, and the change of average velocity of an electron in any given shell is directly proportional to the spectral-shift. It can go down as well as up. At very high acceleration the orbital-shell can become so 'compressed' at the bow that electrons approach very close to the nucleus where escape velocity increases exponentially.

Also, could you give me an example of an 'optical-clock' that has shown the effects of time-dilation in the real world?

Morbert wrote: »

To illustrate my point, consider your train scenario:

Swap the position of the walls with the emitter and you get the opposite effect. The clock at the front of the train would now speed up. The clock at the back of the train would now slow down. Or place the the apparatus such that the path of the balls are perpendicular to the acceleration of the train. The discrepancy would disappear. Here we have a clock that registers different frequencies based on trivial rearrangements. This does not happen with robust, optical and atomic clocks. They do not arbitrarily register different frequencies. All versions agree to incredibly high accuracy, and all agree with special relativity to incredibly high accuracy.

Yes, that is true of course but caesium clocks do not operate that way; orbital paths are affected the same way regardless of direction of acceleration; acceleration provides energy to the system which raises the probability of a transition occurring.

As far as I know optical clocks cannot be used in high velocity and high altitude experiments as they require very stable conditions if they are to operate at all and could not provide reliable data. Although I suppose two such clocks could be synchronised, one is the tick to the other ones tock, with one clock at high altitude and the other below sea-level. The 'mark to space ratio', or phase-change could be analysed to obtain data helpful in understanding time-dilation a little better.

And light clocks that operate by 'bouncing' photons are not really useful in the study of time-dilation for the reasons you gave above.

Morbert wrote: »

So the questions remain: Why do different processes (atomic and optical clocks, particle decay etc.) register the same level of time dilation? And why do they all register the level of time dilation predicted by special relativity?

In conclusion then, we are actually only interested in atomic clocks and particle decay here, aren't we?

I think we have dealt with atomic clocks; acceleration has an effect on atoms and can consequently have an effect on photon emission/absorption. The rate of acceleration can be said to modify the probability curve of all events undergoing acceleration and a consequence of this must be that a device that counts events of a cyclic nature will be subject to alteration through acceleration regardless of its construction.

For instance, a digital wrist-watch which operates on the basis of crystal oscillations relies on the size and shape of the crystal. Under acceleration the part of the crystal that faces the direction of motion experiences compression which slightly changes the dimensions of the crystal whilst at the same time modifying the way the crystal bends and flexes. It seems logical and reasonable to think frequency of the crystal would increase in a manner proportional to the rate of acceleration. However, you would have to take into account what the effect of acceleration would have on capacitance. Capacitors are often used in conjunction with crystals and 'tune' the frequency to the counter. But capacitance is inversely proportional to the distance between the plates. And the lower the capacitance, the higher the frequency.

Under acceleration capacitive plates would increase their cross-sectional are in almost all orientations to a greater or lesser degree and cross-sectional-area is proportional to capacitance. There are only two possible, limited areas where capacitance can be reduced due to acceleration; the plates would have to be oriented one behind the other with respect the direction of acceleration. Only in this arrangement would the plates experiences a force that tends to increase the distance between them. So it is entirely possible that a digital-watch might speed up or slow down depending on its position during acceleration.

So maybe the construction of the time-keeping device is relevant when it comes to the question of time-dilation.

Particle decay evidences time-dilation. Or rather, the effect that acceleration has on atomic clocks startlingly correlates with the effect that acceleration has on particle decay. That's fair, isn't it?

A muon has a life-expectancy of about 2.2 microseconds but under acceleration the probability of a muon decaying after more time (or over a longer distance) increases. But also, the probability of faster decay rates are also increased.

As I outlined above, acceleration has equivalence with charge. I visualise a decaying particle a collection of fundamental particles that are temporarily 'entangled', in wildly chaotic orbits, bombarding each other with energy until one is emitted away from the system. Sometimes, absorbing energy can stabilise the system too.

Acceleration imparts energy. As the muon is pulled toward the centre of gravity it becomes deformed, comet-shaped. Now the decay has to occur at the front so that the resultant particles can conserve momentum and continue their downward journey.

The interior of the muon is filled with forces that are interacting with each other and a standing wave appears growing as it makes its way around the centre of mass and the muon begins to resonate. Then it shakes itself to pieces.

Under acceleration, if the motion of this standing-wave is away from gravity (through reasons of momentum) then it will experience 'retardation' as it make its way around the top of the muon (toward the tail of the comet) in an elongated path. The result: The muon takes longer to decay.

However, if the motion of the standing is toward gravity then the wave will experience 'advancement'; energy is gained from acceleration and the muon decays sooner.

I see a problem here though; could a muon be accelerated at a rate that would prevent it from decaying altogether.

Suppose a muon is created in the viscinity of a black-hole and was accelerating toward it at near light-speed. Could the accelerating force of a black-hole retard the muon's decay to infinity?

I reckon that it is possible that some muons never get to decay before they are spontaneously converted into pure photonic energy shining toward the centre of the black-hole where they encounter other photons in head-on collisions which yield energy with 100% efficiency.

The thing is though, perhaps the rate of particle decay can be speeded up or slowed down through acceleration. There is nothing to say that a muon cannot decay more quickly through the same mechanism that causes muons to decay more slowly.

So, muon decay yields data that has a similar structure to the data yielded by light-clocks and digital-watches; dependence on orientation and direction of motion with respect to the accelerating force.

And it is not time that is affected; it is how energy is conserved that is affected. Spectral-shifts have to occur because if a photon came back with the same 'colour' it left with the photon would have had to have either speeded up in one direction or, worse, slowed down in the other and there is no way that can happen without violating conservation laws. Spectral shifts indicate energy lost or gained through acceleration and again, that has nothing to do with time and more to do with how energy is distributed.

So, when it comes down to it, atomic-clocks are the only viable means we have for obtaining data concerning time-dilation. Or is it simply the case that acceleration causes a certain type of clock to tick faster?

In the same way that increasing the water-pressure in a garden sprinkler system results in a faster water output, couldn't it be that caesium clocks tick faster because acceleration provides extra energy to electrons at all tested orientations.

And what about this scenario: Suppose the caesium atom was oriented so that the orbital path of the electron remained roughly equidistant from the centre of gravity. Wouldn't this have the effect of pulling the electron into a higher orbital shell, tending to fix it into a particular orbital? Wouldn't this tend to reduce the number of transitions? Could it be possible that caesium clocks could be oriented with respect to gravity in such a way as to tick more slowly than a clock on the same journey oriented such that it ticked faster?

Yes, acceleration has an effect on clocks and Einstein predicts it but time-dilation is actually simply 'a change in the rate of change due to acceleration'. Time doesn't exist except as a scale we measure rate of change against. I think it is a mistake to assume that time is a vector-like quantity that must be subject to change in order to achieve universal constants such as the speed of light, i.e., light cannot rush so time must speed up; light cannot tarry so time must stand still. (I must use that in a song.)

Time-dilation seems like a misleading term to me. Especially if the effect can be explained in terms of energy distribution and changes in rates of change and still confirm relativity. Acceleration causes an increase in energy potential and events can occur more quickly and some can be retarded; position and motion with respect to gravity determine which,

I don't know, perhaps quantum physics has a problem with that?

I have a bit of a problem too; my universe requires the existence of an ether as a source of energy and in the end, so too does relativity.

Or do I? :cool:

Morbert

himnextdoor wrote: »

:cool:

From what I understand, experimental observations have produced data which has varied from 10% accuracy in the fifties, to 1% accuracy in the sixties and in 2005 the NPL performed the Hafele and Keating experiment which produced results within 4% accuracy of Einstein's predictions. If the theory came about through observation then the theory would be slightly different.

But this is nit-picking.

Let me be clear; I do not deny that gravity/acceleration have the effect that time-dilation attempts to address but I do question what it is that is actually being measured.

And I accept that the east-west thing is sufficiently understood in terms of the relative motion of the centre of gravity.

Could I ask your opinion of something: It seems well documented that the data released from the Hafele and Keating experiment were actually different to data obtained from the experiment, that the original results were adjusted. Some claim that the adjustments were made using dubious reasoning. Do you think that this is true?

The reason I ask is that, in my opinion, science that is based on politics is bad science. Would you agree?

No, I would not agree. The calculations are explicit and transparent.

Yes, thank you Enkido. I think you are both being a little unfair here, I was talking about 'clocks' and as far as I know there are no time-keeping devices based on muon decay. Caesium-clocks and light-clocks rely on photonic properties and it is these kinds of clocks that are used in the detection of time-dilation.

Furthermore, muon detection relies on the use of photo-multipliers and photo-multipliers do make use of photonic properties.

Anyway, what is a photon if not a packet of energy? Muon decay is an energetic process and so must be subject to photonic properties.

But to answer your question, I think that 'time-dilation' can be explained in terms of impedance; anything in a gravitational field or undergoing acceleration becomes 'stressed', 'under tension', so to speak. Why?... Because of resistance; resistance to change. Change requires energy expenditure; to stand up, sit down, lie down all require an exchange of energy and all because of gravity. It is gravity that stresses human joints. Every time we move we suffer wear and tear due to gravity, change occurs and energy is expended. I reckon you get the picture.:)

When systems interact, degradation happens; the universe is a process of decay. All matter has a 'life-span'.

Of course, I am talking about matter in terms of large scale systems of energy; atoms, molecules, microscopic-life, animals, planets, stars are all fated to destruction and all because gravity causes wear and tear. All systems of energy have a tendency to decay.

So why shouldn't the same thing apply at a sub-atomic scale? Sub-atomic particles can be thought of as systems whose components are comprised of energy that interact with each other creating structures defined as particles. In stable particles the components are balanced, relatively speaking, and in unstable particles there is a mismatch which results in the decay of that particle.

Let me offer another analogy by way of yet another idealised thought experiment. Imagine the fundamental particles as a set of toothed cogs that come in three distinct sizes; large, medium and small. Each size comes in two flavours; ten teeth per centimetre and fourteen teeth per centimetre, say. That is six types of cog so far. Each cog is fitted with a drive mechanism that gives it spin and there are two speeds available, one rpm and two rpm, let us say, which brings the number of different types of cog to twelve. Next, suppose that the cogs are magnetised in order to represent charge; the y-axis of the cog is a cylindrical bar-magnet and half the cogs have their north-pole up and the other half have their north-pole down. That is now twenty-four types of cog. Finally, all of these cogs are designed to have symmetry along their x-axis and to float on water such that the bottom surface of the cog is barely in contact with the water (so that we can disregard the forces generated in the water itself... for now). This means that they can be 'flipped' which will affect the spin direction and the 'charge'.

Let us say that we have two-thousand of each type and that they will each begin to operate upon contact with water. All we need now is a pool of water large enough to accommodate millions of such cogs and we can start ramdomly throwing our forty-eight thousand cogs into the water.

What would happen? The motors would start and roughly half will spin in a clockwise direction and the rest will spin in the opposite direction. They'd bob about randomly and eventually, they'll start making contact with each other. Think of the possible combinations; where charge is the same, north meets north of south meets south, repulsion occurs but if their spins are in opposite directions, the repulsion would be gentle whereas where the spins are the same, the repulsion would be violent. In the cases where charges are opposite and two cogs are attracted to each other equal spin would cause the two cogs to rotate about a common centre whereas opposite spin would cause 'soft merging' and the pair would simply move in a new direction according to their momentum.

Factor in the two different tooth-pitches, two different speeds and three different sizes (representing different masses), consider that three or four cogs could interact, and more, and the number of possible interactions becomes enormous.

However, some combinations will persist, be stable, for longer periods than others which can be considered unstable.

Can you imagine such a model and visualise how the cogs might 'arrange' themselves over time?

And back to muon decay. A muon might be represented as one large cog and three small ones that have been thrown together as a result of a collision between two stable systems. The instability comes about because one small cog is spinning at the slower rate and as soon as the system comes together it is doomed to break down shortly thereafter.

But what effect would acceleration have on the rate of 'decay'?

The reason that our mechanical muon is unstable is because there will come a point where like magnetic poles will be brought into contact and this will cause one cog to be ejected from the system at a rate determined by the magnetic field. If the muon is being accelerated in the direction in which the repulsive force is acting then the rate at which the muon decays is retarded. The cogs disengage which means that spin no longer plays a role in the decay but because one side of the rejected cog remains in close proximity to an opposite pole, it stays loosely connected to the system until either unstable oscillations inpart enough momentum to fire the particle out of the system or the system decelerates.

Naturally this would suggest that if a muon is accelerated in a direction opposite to the direction in which the repulsive force is acting then decay would be speeded up; acceleration would cause the system to move away from the rejected particle, assisting the force of repulsion.

I have a vivid picture in mind and I hope I am conveying it. Does this model work in a crude way at least?

If I make the cogs into corrugated spheres with the same properties outlined above, submerge trillions upon trillions of them in a vast tank of water and take into account the forces imparted into the water, don't I have, at the very least, a crude model of the quantum world?

Muon decay is described by quantum field theory, where a muon field excitation is converted to electron and neutrino excitations via transient W boson excitations. There is nothing in the process which suggests it would behave in the manner you describe, and I can find no treatment which shows it would.

Also, we are talking about all forms of decay, of both cosmic particles, and those in particle accelerators.

Simple. Under acceleration, the orbital shells of atoms, all atoms, becomes distorted. They tend toward being a kind of 'comet' shape as the rate of acceleration increases. This causes the orbital path of the electron to become elongated and the distance travelled by the electron in each revolution is increased and the average velocity of the electron is decreased as is spends more time in the outer orbital.

In the case of caesium, this means that the probability that an electron makes a transition is increased and sure enough, the clock ticks slightly faster.

Oh, and the change of average velocity of an electron in any given shell is directly proportional to the spectral-shift. It can go down as well as up. At very high acceleration the orbital-shell can become so 'compressed' at the bow that electrons approach very close to the nucleus where escape velocity increases exponentially.

Again, I can find no such quantum mechanical treatment which supports your analogies. Please provide references.

There are interesting studies on acceleration and quantum systems. E.g. The implications of noninertial motion on covariant quantum spin. But nothing which would explain how time dilation could be mechanically induced.

And your analogy does not address velocity-induced time dilation observed in optical and atomic clocks, which also agree with relativistic doppler shift experiments.

Also, could you give me an example of an 'optical-clock' that has shown the effects of time-dilation in the real world?

Chou, C. W.; Hume, D. B.; Rosenband, T.; Wineland, D. J. (2010). "Optical Clocks and Relativity". Science 329 (5999): 1630–1633

Both gravitational and velocity time-dilation are demonstrated.

I think we have dealt with atomic clocks; acceleration has an effect on atoms and can consequently have an effect on photon emission/absorption. The rate of acceleration can be said to modify the probability curve of all events undergoing acceleration and a consequence of this must be that a device that counts events of a cyclic nature will be subject to alteration through acceleration regardless of its construction.

For instance, a digital wrist-watch which operates on the basis of crystal oscillations relies on the size and shape of the crystal. Under acceleration the part of the crystal that faces the direction of motion experiences compression which slightly changes the dimensions of the crystal whilst at the same time modifying the way the crystal bends and flexes. It seems logical and reasonable to think frequency of the crystal would increase in a manner proportional to the rate of acceleration. However, you would have to take into account what the effect of acceleration would have on capacitance. Capacitors are often used in conjunction with crystals and 'tune' the frequency to the counter. But capacitance is inversely proportional to the distance between the plates. And the lower the capacitance, the higher the frequency.

Under acceleration capacitive plates would increase their cross-sectional are in almost all orientations to a greater or lesser degree and cross-sectional-area is proportional to capacitance. There are only two possible, limited areas where capacitance can be reduced due to acceleration; the plates would have to be oriented one behind the other with respect the direction of acceleration. Only in this arrangement would the plates experiences a force that tends to increase the distance between them. So it is entirely possible that a digital-watch might speed up or slow down depending on its position during acceleration.

So maybe the construction of the time-keeping device is relevant when it comes to the question of time-dilation.

Particle decay evidences time-dilation. Or rather, the effect that acceleration has on atomic clocks startlingly correlates with the effect that acceleration has on particle decay. That's fair, isn't it?

A muon has a life-expectancy of about 2.2 microseconds but under acceleration the probability of a muon decaying after more time (or over a longer distance) increases. But also, the probability of faster decay rates are also increased.

As I outlined above, acceleration has equivalence with charge. I visualise a decaying particle a collection of fundamental particles that are temporarily 'entangled', in wildly chaotic orbits, bombarding each other with energy until one is emitted away from the system. Sometimes, absorbing energy can stabilise the system too.

Acceleration imparts energy. As the muon is pulled toward the centre of gravity it becomes deformed, comet-shaped. Now the decay has to occur at the front so that the resultant particles can conserve momentum and continue their downward journey.

The interior of the muon is filled with forces that are interacting with each other and a standing wave appears growing as it makes its way around the centre of mass and the muon begins to resonate. Then it shakes itself to pieces.

Under acceleration, if the motion of this standing-wave is away from gravity (through reasons of momentum) then it will experience 'retardation' as it make its way around the top of the muon (toward the tail of the comet) in an elongated path. The result: The muon takes longer to decay.

However, if the motion of the standing is toward gravity then the wave will experience 'advancement'; energy is gained from acceleration and the muon decays sooner.

I see a problem here though; could a muon be accelerated at a rate that would prevent it from decaying altogether.

Suppose a muon is created in the viscinity of a black-hole and was accelerating toward it at near light-speed. Could the accelerating force of a black-hole retard the muon's decay to infinity?

I reckon that it is possible that some muons never get to decay before they are spontaneously converted into pure photonic energy shining toward the centre of the black-hole where they encounter other photons in head-on collisions which yield energy with 100% efficiency.

The thing is though, perhaps the rate of particle decay can be speeded up or slowed down through acceleration. There is nothing to say that a muon cannot decay more quickly through the same mechanism that causes muons to decay more slowly.

So, muon decay yields data that has a similar structure to the data yielded by light-clocks and digital-watches; dependence on orientation and direction of motion with respect to the accelerating force.

And it is not time that is affected; it is how energy is conserved that is affected. Spectral-shifts have to occur because if a photon came back with the same 'colour' it left with the photon would have had to have either speeded up in one direction or, worse, slowed down in the other and there is no way that can happen without violating conservation laws. Spectral shifts indicate energy lost or gained through acceleration and again, that has nothing to do with time and more to do with how energy is distributed.

So, when it comes down to it, atomic-clocks are the only viable means we have for obtaining data concerning time-dilation. Or is it simply the case that acceleration causes a certain type of clock to tick faster?

In the same way that increasing the water-pressure in a garden sprinkler system results in a faster water output, couldn't it be that caesium clocks tick faster because acceleration provides extra energy to electrons at all tested orientations.

And what about this scenario: Suppose the caesium atom was oriented so that the orbital path of the electron remained roughly equidistant from the centre of gravity. Wouldn't this have the effect of pulling the electron into a higher orbital shell, tending to fix it into a particular orbital? Wouldn't this tend to reduce the number of transitions? Could it be possible that caesium clocks could be oriented with respect to gravity in such a way as to tick more slowly than a clock on the same journey oriented such that it ticked faster?

Yes, acceleration has an effect on clocks and Einstein predicts it but time-dilation is actually simply 'a change in the rate of change due to acceleration'. Time doesn't exist except as a scale we measure rate of change against. I think it is a mistake to assume that time is a vector-like quantity that must be subject to change in order to achieve universal constants such as the speed of light, i.e., light cannot rush so time must speed up; light cannot tarry so time must stand still. (I must use that in a song.)

Time-dilation seems like a misleading term to me. Especially if the effect can be explained in terms of energy distribution and changes in rates of change and still confirm relativity. Acceleration causes an increase in energy potential and events can occur more quickly and some can be retarded; position and motion with respect to gravity determine which,

I don't know, perhaps quantum physics has a problem with that?

I have a bit of a problem too; my universe requires the existence of an ether as a source of energy and in the end, so too does relativity.

Or do I? :cool:

As mentioned above, there is no treatment of particles which supports the above line of thinking. I would be interested in actually seeing the physics. I.e. The quantum-mechanical calculations, generalised to encompass all decay and atomic clock mechanisms, in which time dilation and relativistic affects can be derived.

In other words, could I see the calculations that

a) Show that all atomic, optical, and particle decay processes will register the same level of time dilation (both gravitational and velocity induced).

b) SHow that all atomic, optical, and particle decay processes register a level of time dilation predicted by relativity. (both gravitational and velocity induced)

himnextdoor

Morbert wrote: »

No, I would not agree. The calculations are explicit and transparent.



Muon decay is described by quantum field theory, where a muon field excitation is converted to electron and neutrino excitations via transient W boson excitations. There is nothing in the process which suggests it would behave in the manner you describe, and I can find no treatment which shows it would.

Also, we are talking about all forms of decay, of both cosmic particles, and those in particle accelerators.



Again, I can find no such quantum mechanical treatment which supports your analogies. Please provide references.

There are interesting studies on acceleration and quantum systems. E.g. The implications of noninertial motion on covariant quantum spin. But nothing which would explain how time dilation could be mechanically induced.

And your analogy does not address velocity-induced time dilation observed in optical and atomic clocks, which also agree with relativistic doppler shift experiments.



Chou, C. W.; Hume, D. B.; Rosenband, T.; Wineland, D. J. (2010). "Optical Clocks and Relativity". Science 329 (5999): 1630–1633

Both gravitational and velocity time-dilation are demonstrated.



As mentioned above, there is no treatment of particles which supports the above line of thinking. I would be interested in actually seeing the physics. I.e. The quantum-mechanical calculations, generalised to encompass all decay and atomic clock mechanisms, in which time dilation and relativistic affects can be derived.

In other words, could I see the calculations that

a) Show that all atomic, optical, and particle decay processes will register the same level of time dilation (both gravitational and velocity induced).

b) SHow that all atomic, optical, and particle decay processes register a level of time dilation predicted by relativity. (both gravitational and velocity induced)

Are you serious?

Firstly, all the information you provide shows that it is 'as if' time is variable.

That is like saying that acceleration and gravity are the same thing; they are not the same thing, except philosophically.

Falling under the influence of gravity is not the same thing as 'accelerating' through the application of energy; (which always comes from behind.) where is the force applied?

Being 'pushed' is not the same as being 'pulled' outside philosophy.

Gravitation acts from the front whereas acceleration , in the context of what we are talking about, acts from behind. There is a qualitive difference between the two; in the first case, the 'energy' is applied from the front and in the second it is applied from behind. Don't you understand the difference between 'front-wheel drive' and 'rear-wheel' drive?

I can't stress this enough; when acceleration occurs through gravity, there is stretching at the front, when acceleration is due to a rocket or a jet-engine, there is compression at the rear. Both result in an increase in velocity but the application (front to back, back to front) of the force affects probability in different ways.

This seems obvious.

Seriously, tell me... Where is the flaw in my reasoning? Without relying on faith, Morbet, where is the flaw?

You know, I think it is funny; in 1905 Eistein postulated things that noone could read about and you dismiss what seems to me to be reasonable on the basis tht you have not read about it.

Not very reassuring.

My model of a quantum-unverse, the one with those submerged spheres predicts that the poles will have a high 'gravitational' pull when compared to the equator; gravity, the speed of light, magnetism are all predicted in this model but you dismiss it!

What about the fact that this model offers an opportunity for 'self-organisation' - a characteristic of nature - and provides an explanation tjat assists in the understanding of quantum-fluctuations?

Why shouldn't this model be useful in understanding physics? What is wrong with it? It is a theory based on observation and I can't break it... can you?

The fact that experiments are done in order to investigate 'time-dilation' suggests that, at least to some extent, the 'jury is still out' on the 'how's and why's' these effects occur.

I said quite a lot in my previous post and I worked quite hard to produce it and for about twenty hours solid (I literally stayed up all night to talk to you), but you address nothing... I suggested that 'time-dilation' might be synonymous with 'change of rate of change' (which would be in the remit of climatology and 'chaos theory') but you ignore it... Why?

You have a picture of how the universe works, in your head... Are you correct? And Are you sure?

I bet you always come down to that thing that 'might be God'?

Well, I don't; and I thought this was the place to 'chat' about it...

Morbert

himnextdoor wrote: »

Are you serious?

Firstly, all the information you provide shows that it is 'as if' time is variable.

That is like saying that acceleration and gravity are the same thing; they are not the same thing, except philosophically.

Falling under the influence of gravity is not the same thing as 'accelerating' through the application of energy; (which always comes from behind.) where is the force applied?

Being 'pushed' is not the same as being 'pulled' outside philosophy.

Gravitation acts from the front whereas acceleration , in the context of what we are talking about, acts from behind. There is a qualitive difference between the two; in the first case, the 'energy' is applied from the front and in the second it is applied from behind. Don't you understand the difference between 'front-wheel drive' and 'rear-wheel' drive?

I can't stress this enough; when acceleration occurs through gravity, there is stretching at the front, when acceleration is due to a rocket or a jet-engine, there is compression at the rear. Both result in an increase in velocity but the application (front to back, back to front) of the force affects probability in different ways.

This seems obvious.

Seriously, tell me... Where is the flaw in my reasoning? Without relying on faith, Morbet, where is the flaw?

That is not how the equivalence principle works. Remaining stationary in a gravitational field is equivalent to acceleration. Accelerating in a gravitational field is equivalent to having no forces acting on you. The only "streching" that ever occurs is through the weyl tensor, which isn't present at the level of atoms and molecules, as the gravitational field is locally uniform. They would need to be near a region of extreme curvature, like the singularity of a black hole, to even begin to be "stretched". And even if they did, they would not form a comet shape.

You know, I think it is funny; in 1905 Eistein postulated things that noone could read about and you dismiss what seems to me to be reasonable on the basis tht you have not read about it.

Not very reassuring.

My model of a quantum-unverse, the one with those submerged spheres predicts that the poles will have a high 'gravitational' pull when compared to the equator; gravity, the speed of light, magnetism are all predicted in this model but you dismiss it!

What about the fact that this model offers an opportunity for 'self-organisation' - a characteristic of nature - and provides an explanation tjat assists in the understanding of quantum-fluctuations?

Why shouldn't this model be useful in understanding physics? What is wrong with it? It is a theory based on observation and I can't break it... can you?

The fact that experiments are done in order to investigate 'time-dilation' suggests that, at least to some extent, the 'jury is still out' on the 'how's and why's' these effects occur.

I said quite a lot in my previous post and I worked quite hard to produce it and for about twenty hours solid (I literally stayed up all night to talk to you), but you address nothing... I suggested that 'time-dilation' might be synonymous with 'change of rate of change' (which would be in the remit of climatology and 'chaos theory') but you ignore it... Why?

You have a picture of how the universe works, in your head... Are you correct? And Are you sure?

I bet you always come down to that thing that 'might be God'?

Well, I don't; and I thought this was the place to 'chat' about it...

While I commend the effort, you have not tendered what I asked.

I ask for two simple things: a) An explanation as to why all physical mechanisms exhibit the same level of time dilation (both the gravitational and velocity kind) b) Why it is a level predicted by relativity.

If you want ideas of cogs and spheres and vats of water to be a piece in your reply, fine, but you must relate it to the formal, quantum mechanical description of particle decay and atomic clocks, and you must show how the appearance of lorentz invariance emerges. Otherwise it is no more useful than saying particles are made of bunnies that get sad when there is acceleration.

In short, I cannot break your model because you have not tendered a model. It is not even wrong.

roosh

Apologies again; I've been fairly busy over the past couple of weeks and haven't had the time to give a considered reply to the latest post.

It could be the new year before I get the chance.

roosh

Morbert wrote: »

Nobody says a clock demonstrates spacetime. Instead, scientists say experiments ranging from the the speed of light in laboratories, to stellar aberration, to clock synchronisations at different velocities and locations, to ether detection (and the lack thereof), to relativistic doppler shift analyses etc. all affirm a minkowski spacetime structure. And presentism is inconsistent with minkowski spacetime.

Scientists and philosophers were suggesting that time and space were not entities, independent from things, long before Einstein. Gottfried Leibniz and Ernst Mach were two prominent examples (the latter actually influenced Einstein). So the idea that time is not real is not new, and is not implicitly assumed by experimenters. What Einstein and Minkowski argued was that space is relative and time is relative, but that there exists a structure of "space-time" that is invariant and physical. This structure is what experiments look for. They do not assume it is true. Instead, they work out what would happen if it was true or false, and then look for the respective phenomena that affirm or falsify it.



It would not suggest separate universes. And spacetime does not have a worldline. Spacetime is the block universe, and contains all worldlines.




It does not follow from the assumption that a clock measures time. It is predicted that the relationship between clock ticks is described by a geometrical structure that exhibits time dilation and length contraction, among other counter-intuitive notions. And it has not been tested "to that extent", but it has been thoroughly tested, and not not only has it qualitatively agreed with relativity, but quantitatively too.

How does presentism, for example, account for relativistic doppler shifts, or gravitational time dilation?

I just have difficulty seeing how time dilation is demonstrated. Spatial dimensions appear to be a lot more obvious than a temporal one, and to the [very] untrained eye it is difficult to see how the experiments actually demonstrate that there is one.

I understand that the mathematics of the theory calls for it, but I can't really see how the experiments verify that a temporal dimension exists, or that time is real. All of the experiments are carried out in the "present".

With regard to the above, I can see how the relationship between clock ticks is spatial, but I can't see how it is temporal.

himnextdoor

Morbert wrote: »

That is not how the equivalence principle works. Remaining stationary in a gravitational field is equivalent to acceleration. Accelerating in a gravitational field is equivalent to having no forces acting on you. The only "streching" that ever occurs is through the weyl tensor, which isn't present at the level of atoms and molecules, as the gravitational field is locally uniform. They would need to be near a region of extreme curvature, like the singularity of a black hole, to even begin to be "stretched". And even if they did, they would not form a comet shape.

Yes, I get that and it supports my point; freefall occurs when resistance to gravity equals zero. I think of a leaf attached to a branch of a tree in high winds. While it is attached it will flip and flop in a very violent way but when it is ripped from the branch it ceases to feel the wind and moves gracefully through the air.

Gravity is like the wind and the leaf's attachment to the branch would be like a force of acceleration. Yes?

As I say, I think this reinforces my model. Imagine a line perpendicular to earth extending out to infinity; a line of gravity. We can think of this line as a conveyor belt that has equally spaced buckets that convey a certain amount of space to eath. We can imagine how the end of the conveyor belt closest to the earth would be stretched causing the buckets to increase their distance from each other as they are accelerated toward earth by gravity. You could represent the buckets as a set of points on a graph relating 'space density', the number of buckets per unit distance, to the distance from earth.

This could lead us to conclude that, in effect, gravitational systems have a region of 'depleted space' surrounding them, if you see what I mean, and I recognise that I'm being simplistic here but I'm just trying to get an idea across.

This depleted area has a lower vacuum pressure (it sucks harder) than the surrounding space. Reasonable?

Also, if you plot the points according to their distance related to time, you get a graph that looks the opposite, the number of point increase as you approach earth; this relates to the energy of the 'depletion layer', if you will.

That seems straight forward to me; if we think of gravity as space flowing into mass creating a 'current' that increase the effect of space expasion in the direction of mass then we need to explain the relationship between mass and space. The conveyor belt delivers the fuel for gravity but what is mass doing with it? Why is mass so hungry?

Let me try by re-mentioning how expanding space can be thought out as a set of points that repel each other. I consider that all the energy of the Universe has its origin in this repulsive force. Assuming that the big bang was the process of creating these points and these points were all that was created then do we have enough to make the Universe operate as it does?

There are a couple of ways of thinking about the behaviour of these points; one is if we imagine all the points of the Universe as tiny balloons that expand equally and at the same time, then it is easy to see how the Universe expands in every direction; front moves away from back, left moves away from right, up moves away from down and in moves away from out. But how would they interact with each other on increasingly larger scales; what kind of structure can we expect?

Another way of thinking of points of space is as electrons. A vast number of electron all compressed into a point and the confinement force suddenly disappearing. Obviously, there is no stable state for such a system and we would expect them to spring apart with great energy, (due to their repulsive force, however that is derived), in an attempt to be equidistant from one another, which can never happen. Well, we can see how they would all part radially from the centre but we would be wrong to assume that there is no motion in any other direction.

If there is motion in any direction other than away from the centre the electrons would interfere with each other's paths which means internal structure would develop and systems would emerge.

The thing is, there is no arrangement of identical spheres such that the distribution of forces is equal in any direction, not just radially. The field that initially contained the electrons would shape the surface of the ball. If the surface of the ball forms a sphere then internally some electrons will be 'loose' inside forming pockets that have no reason to be equdistant from each other. The internal surfaces shrink; you can't organise a layer of identical spheres that would perfectly cover the internal surface of the outside layer and the next layer would be even more ill-fitting.

This would suggest that lateral motion is possible and that systems could emerge. And perhaps a gravity-like effect might occur.

I really didn't mean to be this wordy but I want to try and deal with the next of your comments. I just need to 'explain' where mass comes from.

The lateral motion of the electrons causes compression waves to propogate inside the sphere and the waves interact increasing the complexity of the waves. This results in the clumping of some electrons while for others it's the opposite effect and 'gaps' or 'holes' occur.

But the 'holes' caused by the complex motions of the electrons are seen as physical objects by them; the holes represent a region of 'lowered negativity', a reduction in repulsive force from that side and some local electrons will rush to fill that void from all sides, they nearly meet, repel each other and fly away leaving another hole which is filled by new electrons. If such holes persisted then there would effectively be a positive charge created by a wholly negative Universe.

Electrons are accelerating toward relative positivity where they interact and deflect each other away from the 'hole' toward a more negative region where they are deflected back again, accelerating until they have enough energy to leave the system (photons?); at resonance the system starts to oscillate regularly and the movement of electrons in that region becomes organised and stable; a swirling region of space that is manifest as bound energy and free energy. Space rushes into these holes due to relative density where it provides energy to maintain the hole and is expelled as another ripple contributing to the complex waves of the Universe.

Can you see that? Even loosely speaking? These holes are what we perceive as mass and gravity is the result af space 'flowing' into the hole creating a current on which other holes can travel.

One more addition; since the holes absorb energy in all directions (and emit it) as they get closer to each other the space around them becomes more depleted between the points of the hole that are closest together which tends to bind them together (weak force?) but the space rushing to nearby points creates a 'pinching' force which tends to keep the holes apart: there is always space between the holes. If the pressure causes this not to be so then the system breaks down creating a new system created by fusion.

So, what I am suggesting is that the most fundamental sub-atomic particle is simply a hole in space with characteristics as outlined above.

Morbert wrote: »

While I commend the effort, you have not tendered what I asked.

I ask for two simple things: a) An explanation as to why all physical mechanisms exhibit the same level of time dilation (both the gravitational and velocity kind) b) Why it is a level predicted by relativity.

If you want ideas of cogs and spheres and vats of water to be a piece in your reply, fine, but you must relate it to the formal, quantum mechanical description of particle decay and atomic clocks, and you must show how the appearance of lorentz invariance emerges. Otherwise it is no more useful than saying particles are made of bunnies that get sad when there is acceleration.

In short, I cannot break your model because you have not tendered a model. It is not even wrong.

Now I will consider the holes, which I will call 'Spoles' (space-holes:)) as actual objects in actual space.

The 'Spole' is a point where space, energy and mass are coupled and their very existence gives rise to a force that behaves like gravity. But more than this, spoles can interact to form larger scale systems; systems like quarks, maybe or electrons, etc. And it should be obvious that spoles can be viewed as the first objects to spin.

Spoles can be thought of as 'cavity resonators'.

Spoles are most stable when they are at rest. They 'like' to have an even distribution of force over their surface. This gives them a tendency to not move relative to space; they have mass. When they are motionless relative to space, they absorb energy evenly from the expansion force of space itself. When the spole moves relative to space it feels more repulsion in the direction of travel and less from behind; this acts as a kind of brake. If a spole is forced to travel then it feels compression at the front and this inhibits the flow of energy at the bow and at the rear, the spole receives less energy from space and energy flow is inhibited. When a spole moves relative to space, it becomes less efficient. It seems slower.

Cavity resonators are more efficient when they are spherical. Distortion of the shape gives rise to unwanted frequencies.

And it is because of the tendency of spoles to not moves that the Universe looks the same in every direction; the only desirable motion between spoles is due to expansion.

All things are made of spoles. In fact, apart from space, spoles are all that exist and spoles are actually nothing more than regions of depleted space due to the border with energy giving rise to mass, which for the purposes of this discussion can be defined as 'that which has a tendency to attract space'.

A system that involves lots of spoles appears a stong positive force to space outside causing space to rush toward the system in greater quantities as mass increases.

Now, time-dilation.

So we have a clock and we make it travel relative to space on an aeroplane. It's a caesium clock. As the clock travels, the spoles that make up the electrons reduce in efficiency which causes a delay in the transition. And by a certain percentage. The clock runs slow.

In a clockwork wristwatch travelling under the same conditions, the spring is made of spoles. The inefficiency in this case leads to a slower release of energy from the spring. By a similar percentage. The clock runs slow.

Consider the fact that the earth is in relative motion to space; at rest, the spoles in the clocks are in a state of constant lowered efficiency. So, make the plane fly in the opposite direction and the spoles adopt a more spherical and therefore a more comfortable state becoming more efficient and the clocks speed up.

It's not time that is effected in the 'time-dilation' phenomenon; time-dilation is the result of variations in the energy conversion efficiency factor of spoles due to movement relative to space. And since all clocks are made of spoles then all clocks will demonstrate the same degree of time-dilation.

The reason relativity predicts this effect is that since gravity is a direct consequence of spoles, the equations of relativity have inadvertently accounted for the spoles' behaviour to some extent. To relate gravity to mass is to relate gravity to a vast quantity of spoles.

I hope you'll forgive me for not referring to cogs and water-tanks here, and the fact that I have been very descriptive, but I think that this model strongly shows that (A), if all that existed was a single medium with the intrinsic characteristic of repulsion then that could result in a Universe that behaves just like this one and (B), the 'time-dilation' phenomena may be describeable without a single reference to time which after all may not actually exist.

So, if you were to say that bunnies were made of particles that get sad when they accelerate, you might not be far off the mark. :cool:

himnextdoor

roosh wrote: »

I just have difficulty seeing how time dilation is demonstrated. Spatial dimensions appear to be a lot more obvious than a temporal one, and to the [very] untrained eye it is difficult to see how the experiments actually demonstrate that there is one.

I understand that the mathematics of the theory calls for it, but I can't really see how the experiments verify that a temporal dimension exists, or that time is real. All of the experiments are carried out in the "present".

With regard to the above, I can see how the relationship between clock ticks is spatial, but I can't see how it is temporal.

I can't either. All ticks from all clocks are the result of deterministic processes. I think that acceleration affects determinism in the same way as sticking your head out of a moving car affects your breathing; it's harder to control the input and more energy is required for the output.

I believe that matter is 'happiest' when it is at rest with respect to spacial expansion. When matter moves relative to space, (and from the matter's point of view), it is as if space is expanding faster in the direction opposite to the direction of motion. But space isn't expanding quickly in that direction is it? This results in the matter 'seeing' a more perfect vacuum behind it than the vacuum in front which 'feels' like unequal pressure and this causes matter to expend some energy in order to equalise that pressure.

This unscheduled use of energy reduces the amount of energy available to normal atomic processes, efficiency is slightly reduced and the transitions of electrons in caesium clock become fewer.

It is exactly the same for particle delay.

Matter is most efficient when at rest relative to space; clocks will tick fastest when stationary with respect to spacial expansion.

I think that time-dilation should be called 'Acceleration Caused Energy Damping', (ACED ), and is due to energetic processes having to sacrifice efficiency in order not to violate either conservation law or thermodynamic law. It makes clocks tick slower; it reduces the rate at which particle decay processes become critical.

Capacitors charge, and discharge more slowly.

Also, for matter travelling close to the speed of light, it would appear to such matter that there was a near perfect vacuum behind and a lousy vacuum in front. The energy losses to atomic processes would be huge and further acceleration would result in the complete breakdown of that matter as it is expended as energy.

I don't think that time needs to come into it at all.

Morbert

roosh wrote: »

I just have difficulty seeing how time dilation is demonstrated. Spatial dimensions appear to be a lot more obvious than a temporal one, and to the [very] untrained eye it is difficult to see how the experiments actually demonstrate that there is one.

I understand that the mathematics of the theory calls for it, but I can't really see how the experiments verify that a temporal dimension exists, or that time is real. All of the experiments are carried out in the "present".

With regard to the above, I can see how the relationship between clock ticks is spatial, but I can't see how it is temporal.

I would reiterate the fact that the theory has passed every experimental test thrown at it (which is why there is such excitement at even the mere possibility the neutrino experiment revealing new physics). If the spacetime structure of relativity is not real, then we have a long list of unexplained coincidences. You would not only have to explain away all the time dilation results, but also all particle interactions observed in accelerators.

To put it succinctly: We believe the structure of space-time, as described by relativity, is real because no other framework has successfully described experimental results.

Morbert

himnextdoor: Your spoles explanation of time dilation implies we would observe different level of time dilation depending on when the experiment was carried out, as the change in direction of the earth's motion with respect to the hypothetical absolute space changes.

himnextdoor

Morbert wrote: »

himnextdoor: Your spoles explanation of time dilation implies we would observe different level of time dilation depending on when the experiment was carried out, as the change in direction of the earth's motion with respect to the hypothetical absolute space changes.

If by 'when' you are referring to time of day then yes, an aeroplane flying toward the sun on the western side of the earth would experience less 'dilation' that a plane on the eastern side travelling away from the sun.

That would be an interesting experiment wouldn't it; two planes on opposite sides of the planet travelling at the same speed and in the same direction show register slightly different amounts of dilation because of the sun's gravity.

Is that what you meant?

Morbert

himnextdoor wrote: »

If by 'when' you are referring to time of day then yes, an aeroplane flying toward the sun on the western side of the earth would experience less 'dilation' that a plane on the eastern side travelling away from the sun.

That would be an interesting experiment wouldn't it; two planes on opposite sides of the planet travelling at the same speed and in the same direction show register slightly different amounts of dilation because of the sun's gravity.

Is that what you meant?

Close. I meant different times of the year. If there is an absolute space, performing an experiment in winter should have an opposite effect compared to summer result, as the earth is travelling in the opposite direction. It should even be possible to observe velocity-induced time contraction.

himnextdoor

Morbert wrote: »

Close. I meant different times of the year. If there is an absolute space, performing an experiment in winter should have an opposite effect compared to summer result, as the earth is travelling in the opposite direction. It should even be possible to observe velocity-induced time contraction.

Ah yes, I see.

And I think I have to agree. As the earth travels against the direction of expansion it will experience a greater degree of dilation than if it were travelling in the same direction of expansion.

All orbiting bodies spend half their time moving toward a notional centre of the Universe and the other half toward the notional edge of the Universe and these factors would produce a different degree of deformation of spoles. Albeit a very slight difference.

But I would say that local gravity comprises the largest effect on planes flying over earth.

Perhaps if this effect was allowed for, we might get more accurate results from such experiments.

roosh

Morbert wrote: »

I would reiterate the fact that the theory has passed every experimental test thrown at it (which is why there is such excitement at even the mere possibility the neutrino experiment revealing new physics). If the spacetime structure of relativity is not real, then we have a long list of unexplained coincidences. You would not only have to explain away all the time dilation results, but also all particle interactions observed in accelerators.

To put it succinctly: We believe the structure of space-time, as described by relativity, is real because no other framework has successfully described experimental results.

The experimental evidence doesn't distinguish between Einsteinian relativity and Lorentzian relativity though, does it?

roosh

Given that the experimental evidence doesn't distinguish between Einsteinian and Lorentzian relativity, it would suggest that the explanation for how a clock measures time under Einsteinian relativity, is indeed just an assumption.

Morbert

roosh wrote: »

Given that the experimental evidence doesn't distinguish between Einsteinian and Lorentzian relativity, it would suggest that the explanation for how a clock measures time under Einsteinian relativity, is indeed just an assumption.

I will deal with this in the other thread

http://www.boards.ie/vbulletin/showthread.php?t=2056515158

I figure it will streamline the conversation.

roosh

Morbert wrote: »

I will deal with this in the other thread

http://www.boards.ie/vbulletin/showthread.php?t=2056515158

I figure it will streamline the conversation.

I'm not sure this is something which can be addressed in the other thread. It will inevitably come down to a question of the evidence, which equally supports Lorentzian relativity. Then it is a question of interpretation.

The point would still remain, however, that the given explanation of how a clock measures time is based on the assumption that a clock measures time.

bananarama22

roosh wrote: »

This will probably seem like a really basic question, so my apologies if it does; I have asked it elsewhere, but as of yet, haven't really had an answer to it.

The question is: how does a clock measure the property [of the universe] called time?

I can see how a clock can be used as a standard unit of comparison, which forms the basis of a system of measurement, called time; but I can't see how a clock actually measures a universal property called time.

In a discussion elsewhere, someone mentioned that

How is it meassured, with a clock, or otherwise?

Time is just a label, it is something to do with the electrons in a cesium atom afaik. Time essentialy does not exist, it is onlt a label which can be used to determine the time separating you from when you first read this post, until you came to to end of it. Time is relative and NOT absolute. The faster you move through space, the faster time moves for you.
This is given by the equation:



this is known as the Lorentz factor. As you can see, when your velocity is zero the gamma = 1, so you are moving through time at 1 times the amount that the obersver sees you. If you are moving at c (which is impossible from what we know) gamma goes to infinity ( lim -> 0, 1/x = infinity). So you will be going infinitely fast through time, and you will have an infinite mass, therefore infinite energy required to move you. Anyways, to conclude my ramblings, time is only an intrinsic property of space adn time weaved together into the fabric of existence. The faster you travel over space, the more you travel through time. For example, if I hope on a motorbike and travel around a roundabout at near the speed of light, you would be aging and growing old before my very eyes, time around me would be moving extremely quickly, for me, only a few seconds would have passed, but for you many many years will have passed. PM me if you wanna know more, this kind of stuff is a big passion of mine.