Do we actually exist between ultimate boundaries?

Rubecula

The reason I ask is straight forward. Two items of theory have recently come together in my mind from things I have heard/seen/read and remembered while sitting at a desk in work.

Item 1. "Nothing can exist at the speed of light ... or above" Basically when anything tries to exceed the speed of light it becomes none existent. I can follow this as at the speed of light nothing can move around (such as atoms) as in so doing they would need to exceed the speed of light, even marginally.

Item 2. "Nothing can exist at Absolute Zero " This also follows on from the same idea. At absolute zero NOTHING moves at all. So electrons can not move, even photons can not move.

So are these the universal constants that "coral" our existence?

I would be intrigued as to what you think, especially as I can't actually ask a cosmologist or a quantum physicist.

shedweller

Your mention of absolute zero has me intrigued. I always thought that the atoms stopped vibrating at 0K but i never gave any more thought to the fact that the orbiting electrons might stop too. Is this true?

Re: light speed, well, i am nowhere near qualified to comment with any authority but having read Alastair Reynolds books i can honestly say it leads to interesting things!

If photons can travel at light speed then what are the quarks etc. doing inside? If they are orbiting within the photons then what laws do they follow?
Photons have smaller bits inside dont they?? Forgive me, i use spanners and socket sets in my line of work! And have kids; my brain is somewhat stifled and mushy. Sorry...

greedygoblin

Photons travel at the speed of light in a vacuum, right? So by definition, they have zero mass.

Rubecula

I am a bit like you shedweller, which is really why I posed the question. I have no idea.

It seems to me that exceeding lightspeed brings instant none existence but with a massive release of energy, whereas 0 Kelvin would also destroy all energy too.

I am probably wrong I realise, but it is a question that has niggled at me all week.

greedygoblin

On your second point Rubecula on nothing existing at absolute zero. Is this correct?

I'm no quantum physicist, but to me that means something is at zero Kelvin. Or from a quantum mechanics point of view, something at absolute zero would be in it's ground state (i.e. all the electrons would occupy the lowest energy level possible). So matter would still exist, or as shedweller put it, stuff would stop vibrating.

Edit: Although I do get where you are coming from. If something has zero energy at absolute zero, and photons of light are defined as packets of energy, then do they cease to exist?

Roquentin

we are just billions and billions of carbon atoms stuck together in a way in which we can realize we are stuck together

ps200306

Rubecula wrote: »

Item 1. "Nothing can exist at the speed of light ... or above" Basically when anything tries to exceed the speed of light it becomes none existent. I can follow this as at the speed of light nothing can move around (such as atoms) as in so doing they would need to exceed the speed of light, even marginally.

Item 2. "Nothing can exist at Absolute Zero " This also follows on from the same idea. At absolute zero NOTHING moves at all. So electrons can not move, even photons can not move.

So are these the universal constants that "coral" our existence?

I would be intrigued as to what you think, especially as I can't actually ask a cosmologist or a quantum physicist.

The two ideas you are grappling with here come from different (and thus far mostly irreconcilable) branches of physics. I think I would slightly dispute your language where you say "when anything tries to exceed the speed of light it becomes none existent". Nothing can exceed the speed of light. There is no question of anything become non-existent. The speed of light is simply an upper boundary. The reason (or, at least, one way of describing it) is that the common background against which we measure the speed of anything is a fixed space as imagined by Newton. But it turns out there is no such thing as Newton's fixed space. Space and time are part of a single continuum, as expressed by Hermann Minkowski. You travel through space and time simultaneously. At low speeds, it seems obvious that when your momentum increases (momentum being classically defined as your mass times your velocity) you travel through more space in less time. But at higher speeds, your incremental velocity for each increase in momentum starts to fall off. As you approach the speed of light, you cease to get any velocity increase for an increase in momentum.

Or, at least, that's the way it looks to an observer looking at you from their "stationary" frame of reference. If you are the person moving with these higher and higher momenta, things look different. Suppose you're shooting toward a distant star. The star can never appear to you to be approaching at more than the speed of light, but the distance to the star begins to appear shorter and shorter. At the limit of the speed of light, the whole universe in your forward direction is as flat as a pancake. You reach the distant star in no time. So if, before you set out, you measured this distant star as being 100,000 light years away on the other side of the galaxy, then you accelerated rapidly to as close as made no difference to the speed of light, it would seem to you that you had travelled faster than light according to your earlier measurement. But an observer you had left behind on earth would see you taking (at least) 100,000 years.

Your other line of thinking is that "Nothing can exist at Absolute Zero". Again, I would say the language is not quite correct -- it is fairer to say that there is no such thing as absolute zero. This conclusion comes from the Heisenberg Uncertainty Principle, which in turn comes from a more generalised theorem in quantum mechanics.

Quantum mechanics does not describe reality in terms of trajectories in a fixed background space at all. Instead it has a weird mathematical wave whose evolution (i.e. it's change in shape over time) describes the "expectation values" of properties like momentum. Expectation values are based on probabilities, and in the so-called "classical limit" things work out as we expect them too, on the average. If we calculate the expected position of an object over time, it follows a classical trajectory as long as we don't look too closely. (The mathematical wave function involves a combination of kinetic and potential energy called the Hamiltonian, so it takes into account the effects of things like gravitational or electric fields).

But there are these strange things called non-commuting operators, which describe pairs of properties which do not have well-defined values at the same instant. It seems very odd that we can't precisely measure certain properties together, but QM describes exactly how this works and what the limits of precision are. In the Heisenberg case, the two non-commuting properties are position and momentum. QM sets the lower limit on the product of the uncertainty of position and momentum at h/(4*pi) where h is Planck's constant.

If we were able to reach a state of zero energy, i.e. absolute zero, then a particle could be in an absolute fixed position (x) with absolutely no momentum (p). There would be no uncertainty in either quantity, so ΔxΔp = 0. But the uncertainty principle says that ΔxΔp ≥ h/(4*pi). There will always be some uncertainty in the position and momentum down at small scales where Planck's constant is significant. Since temperature is just the measure of random jiggling in the positions and momenta of atoms, it follows that there is no absolute zero.

One other point worth mentioning is about where you said "electrons cannot move". We've gotten rid of the idea that you can have definite combinations of certain properties, and therefore there is no absolute zero, but there are situations in which energy levels can be definite. These are very special configurations of the mathematical wave called "stationary states" where the Hamiltonian combination of energies never changes. Although the wave normally evolves over time, there are these standing wave configurations -- a bit like how you can sometimes see a vibrating guitar string appear "frozen", or you can tie one end of a skipping rope to a gate and wiggle the other end at a few special frequencies that produce non-moving wave patterns. The properties of electrons that are bound to atoms are described by stationary states of the mathematical wave and thus have definite energy values that do not change over time. So an electron orbiting an atomic nucleus can never be "frozen", even if absolute zero were a possibility. On the other hand, it can never spiral into the nucleus (as classical mechanics predicted) because that would involve pinning down its position more precisely than is allowed. So it is actually the combination of these definite energy states and the uncertainty principle that sets the size of atoms. Atomic nuclei are made of heavier particles that are allowed to be tied down more precisely, which is why they can occupy the nucleus.

N.B. Shedweller -- I think you are thinking of protons, which have mass, and contain quarks (rather than photons which are quanta of light).

gkell11

ps200306 wrote: »

The reason (or, at least, one way of describing it) is that the common background against which we measure the speed of anything is a fixed space as imagined by Newton. But it turns out there is no such thing as Newton's fixed space. Space and time are part of a single continuum..

That is quite a swindle you have going on there.

In the other thread I have managed to keep the issues focused on how to use different perspectives to account for planetary motions as they appear to us , as they move around the Sun and the structure of the solar system but it should be second nature by now that everything is accounted for from a moving Earth.

Newton went on a solo run with retrogrades by creating a hypothetical observer on the Sun to account for the apparent motions of the planets thereby creating his absolute/relative space and motion -

"For to the earth planetary motions appear sometimes direct, sometimes
stationary, nay, and sometimes retrograde. But from the sun they are always seen direct,..." Newton

So, people have,for the last century, gone on a jargon fest and called this an achievement and all because they had no idea what Newton was doing apart from wrecking havoc with basic and productive astronomical methods and insights -

"It is indeed a matter of great difficulty to discover, and effectually to distinguish, the true motion of particular bodies from the apparent; because the parts of that absolute space,in which those motions are performed, do by no means come under the observation of our senses. Yet the thing is not altogether desperate; for we have some arguments to guide us, partly from the apparent motions, which are the differences of the true motions" Newton

There is this tangled mess out there and perhaps a large proportion of the population like to keep it that way as it is one less thing to think about but a society without a functioning astronomical discipline is a self-obsessed one that lacks considerations for their surroundings and to fellow human beings.

People prefer fiction to fact and can even insert fictional observations to support a worthless view and perhaps that is the greatest crime against astronomy of all.

Do we actually inhabit 3 dimensions (3 space) or 4 (3 space and time) or 3 and a bit (where we manipulate 3 space dimensions and are effected by a grazing 4th time)?

Reason that I ask a bit is that we can control our passage through the space dimensions by just moving but we can not control our passage through the time dimension (we can slow it down relative to others but not stop it, speed it up or move backwards)

gkell11

Deleted User wrote: »

Do we actually inhabit 3 dimensions (3 space) or 4 (3 space and time) or 3 and a bit (where we manipulate 3 space dimensions and are effected by a grazing 4th time)?

Reason that I ask a bit is that we can control our passage through the space dimensions by just moving but we can not control our passage through the time dimension (we can slow it down relative to others but not stop it, speed it up or move backwards)

You got that idea from 1898 in the well known novel called 'The Time Machine'

"‘Now, it is very remarkable that this is so extensively overlooked,’ continued the Time Traveller, with a slight accession of cheerfulness. ‘Really this is what is meant by the Fourth Dimension, though some people who talk about the Fourth Dimension do not know they mean it. It is only another way of looking at Time. There is no difference between time and any of the three dimensions of space " Wells 1898

http://www.bartleby.com/1000/1.html

The trick was to use Newton's idiosyncratic version of the Equation of Time and fabricate a fiction that has served many film scripts based on time travel.

"Absolute time, in astronomy, is distinguished from relative, by the equation of time. For the natural days are truly unequal, though they are commonly considered as equal and used for a measure of time; astronomers correct this inequality for their more accurate deducing of the celestial motions.The necessity of which equation, for determining the times of a phænomenon, is evinced as well from the experiments of the pendulum clock, as by eclipses of the satellites of Jupiter." Newton

Nobody I know presently other than myself has the ability to navigate through the tangled mess so that even if there were honest people who are curious to know how humanity ended up following the precepts of a science fiction story based on the idea that humans can control time by moving quicker,it would take a great deal of explaining. The real swindle is back in the late 17th century where the unresolved issue between the predictive and interpretative sides of astronomy were allowed to fall out of kilter with catastrophic consequences.

I have sentimental reasons for trying to promote Ireland at the forefront of genuine astronomy instead of that worthless jargon fest inherited from other times and people who knew no better and couldn't discern what Sir Isaac tried to do and how he did it.

'Spacetime' indeed ! - a college prank by any other name created for academics by academics.

mickmackey1

We don't need a moderator we need a shrink :pac:

gkell11

mickmackey1 wrote: »

We don't need a moderator we need a shrink :pac:

If you can get from the Equation of Time as Newton's absolute/relative time to the cartoon notion of time travel then good for you but it is far removed from anything normal as people understand time and space. Poor Newton was trying to define timekeeping and not time itself and only a dope would ignore that -

"Absolute time, in astronomy, is distinguished from relative, by the equation of time. For the natural days are truly unequal, though they are commonly considered as equal and used for a measure of time; astronomers correct this inequality for their more accurate deducing of the celestial motions.The necessity of which equation, for determining the times of a phænomenon, is evinced as well from the experiments of the pendulum clock, as by eclipses of the satellites of Jupiter." Newton

If you want me to explain what the Equation of Time does and how it factors into the 24 hour system and the Lat/long system then just let me know or the historical/technical details which refer the average 24 hour day to constant rotation -

" Here take notice, that the Sun or the Earth passes the 12 signs,or makes an entire revolution in the ecliptic in 365 days, 5 hours 49 min. or there about, and that those days, reckon'd from noon to noon,are of different lenghts; as is known to all that are vers'd in Astronomy Now between the longest and the shortest of those days, a day may be taken of such a length, as 365 such days, 5. hours &c. (the same numbers as before) make up, or are equal to that revolution: And this is call'd the Equal or Mean day, according to which the Watches are to be set; and therefore the Hour or Minute show'd by the Watches, though they be perfectly just and equal, must needs differ almost continually from those that are shew'd by the Sun, or are reckon'd according to its Motion. But this Difference is regular, and is otherwise call'd the Equation of Time ," Huygens

http://adcs.home.xs4all.nl/Huygens/06/kort-E.html

Most academics and their pupils live in a world of their own making for if things were right the discussion would be that Huygen's falls short in referring the Equation of Time to the annual motion of the Sun through the Zodiac insofar as the actual original reference used the motion of a star behind the Sun and its emergence as a marker for the Earth's orbital position in space and around the Sun.

You poor folk don't need a shrink, you are just wasting your time following idiots like Newton who never had a feel for astronomy and its principles including the Equation of Time. Again, 'stolen honor' at the expense of astronomy where most of you are content to live out a lie.

gkell11

gkell11 wrote: »

You got that idea from 1898 in the well known novel called 'The Time Machine'

Ahhhh no. In fact I stated that we can not actually change our passage through time

gkell11

Deleted User wrote: »

Ahhhh no. In fact I stated that we can not actually change our passage through time

If you are talking 'time travel' in any shape or form,including 'slowing time down' then you are taking it straight from a late 19th century fictional novel (rather than an early 20th century formal version via relativity ) where you can read all about the 4th dimension where space and time combine, it doesn't matter that it is a narrative necessity to move a wonderful fictional story along but I thought you might be interested in discovering how a decade later they actually proposed it as fact by doing to Newton what Newton did to everyone else.

"‘Scientific people,’ proceeded the Time Traveller, after the pause required for the proper assimilation of this, ‘know very well that Time is only a kind of Space" Wells, 'The Time Machine

I suggest you read the final chapter of that book so you can have a good laugh at the jargon fest created by the guys in the early 20th century and who took these things like 'time travel' seriously.

http://www.bartleby.com/1000/13.html

Haha you don't understand a simple comment, how are you supposed to understand time

riffmongous

We need more discussion of tachyons here!

gkell11

Deleted User wrote: »

Haha you don't understand a simple comment, how are you supposed to understand time

Poor fools try to make timekeeping look like time and if you all are going to make a fuss about doing away with Newton's absolute time in order to fit it in with a 'Time Machine' narrative then it appears the actions of wayward kids and not adults.

"Absolute time, in astronomy, is distinguished from relative, by the equation of time. For the natural days are truly unequal, though they are commonly considered as equal and used for a measure of time; astronomers correct this inequality for their more accurate deducing of the celestial motions.The necessity of which equation, for determining the times of a phænomenon, is evinced as well from the experiments of the pendulum clock, as by eclipses of the satellites of Jupiter." Newton

So maybe the world has to suffer another 100 years of meaningless drivel meant to torture the wider population with some notion of intellectual superiority however a genuinely intelligent person will be drawn back into what Sir Isaac was actually trying to do as he fiddled around with the Equation of Time and its role in timekeeping.

Goodness me !, don't you all love your cult bubble world where you all get to play masters of time.

ps200306

Deleted User wrote: »

Do we actually inhabit 3 dimensions (3 space) or 4 (3 space and time) or 3 and a bit (where we manipulate 3 space dimensions and are effected by a grazing 4th time)?

Reason that I ask a bit is that we can control our passage through the space dimensions by just moving but we can not control our passage through the time dimension (we can slow it down relative to others but not stop it, speed it up or move backwards)

You can think of it as four dimensions, but they are not all mutually orthogonal. The three space dimensions are orthogonal, that is, you can move along each axis independently or any combination of the three together. But the time axis is not only somewhat folded into the others, the degree of folding is affected by the speed of the observer. (You probably know that volumes have been written about not only the theory but the experiments that confirm this so, no, it's not a crackpot idea of Newton or H.G.Wells).

I'm sure you've seen the idea of a light cone which attempts to show a single event on the space and time axes. Time is on the vertical axis, and space is on the horizontal. Every event has some set of spacetime coordinates, (x,y,z,t) from which the cone then spreads out into the past and future. Space is three-dimensional, of course, but we only have room to show two on this picture - in reality the light cone is the edge of an expanding 3D sphere but we can't show that.



The edge of the cone has a special meaning. That represents a ray of light travelling from the event into the future (or a ray of light travelling toward the event from the past, on the lower half of the cone). Since nothing can travel faster than light, the edge of the cone represents the boundary of spacetime that could possibly be affected by this event (or that could possible have affected it from the past, in the lower cone). So the region of spacetime inside the light cone is a causally connected region.

It follows that any real object starting at the tip of this cone must take a path through spacetime inside the future light cone. Only light rays can travel along the edge of the cone, and those trajectories are called "light-like". Trajectories inside the cone are called time-like, while those outside are called space-like (but you can never follow one of those).

Now, because of the effect of velocity, not all observers will agree on the spacetime coordinates of any given event. But because they all see light travelling at the same speed, they do agree on where the edge of the light cone is. This is good news for causality. It means that one observer can never see one event causing another, while another observer sees the second event causing the first.

This is probably all old hat, so to come back to the question and see exactly how things look different for different observers, we can simplify the light cone picture even further to just show one dimension of space:



Ignore the blue lines for a moment. We've got a single space axis, x. We've got the edge of our light cone (which in a single space dimension is now a "light triangle") marked in red. Our vertical axis is still time, but we've just scaled it appropriately for this picture. We want the edge of the cone to represent a light ray which, in time t travels a distance x = ct where c is the speed of light. So if our red line is going to be at a 45 degree angle, we have to scale the time axis by c, so we label it ct.

From the perspective of an observer travelling at a speed V, the space and time axes get "folded" as I mentioned. These are represented by the blue lines, labeled x' and ct'. Now, although these axes are not orthogonal, we plot the coordinates of an event in the usual way -- move parallel to the x' axis to draw the space coordinate, and parallel to the ct' axis to draw the time coordinate, as shown by the dashed lines here for event 1:



The weird thing now is that different observers can see events happening in different orders. By moving along the ct axis and looking across parallel to x, you can see four events happening in the order 0,2,3,1. But for the observer moving at speed V, along the ct' axis they happen in the order (0,3) simultaneously, followed by (2,1) simultaneously. But crucially, for both observers only events 0 and 2 are inside the light cone, so only they can be causally related and they are in the same order for both observers, so causality is preserved and you still can't go back in time and kill your parents before you were born.

(Diagram 1 from Wikipedia, 2 and 3 from Relativity, Gravitation and Cosmology by RJA Lambourne).

(edit: I checked my use of the word "orthogonal" later, and I think some would challenge it).

gkell11

ps200306 wrote: »

(You probably know that volumes have been written about not only the theory but the experiments that confirm this so, no, it's not a crackpot idea of Newton or H.G.Wells).

Don't be naughty. There is a feedback loop between relativity and Newton's attempt to define time,space and motion for everyone in the audience so you are required to explain what it is that was questionable about those notions of absolute/relative time ,space and motion in terms that Sir Isaac presented these things rather than making it a setup for your spacetime voodoo.

It just so happens that I can get behind the complicated maneuvering of Newton long enough to see what he was trying to do and how he did it but once relativity came along and expanded on the nonsense Newton and his followers dumped into astronomy then it is an unfortunate layer of contrived rubbish to deal with.

What a daunting task !, what a catastrophic mess ! - described as a supreme human achievement when it is all damage and chaos. The real damage was done back at the Galileo affair when the Church jettisoned its astronomical heritage and left a crucial point unresolved which in turn led to the emergence of the 'predictions' gang in the late 17th century and then the cartoon cult of the early 20th century.

If people want to be real time travelers using history then they had better start going through the wreckage that is astronomy and start to pick up the pieces by untangling this awful mess created by academics and for academics.

ps200306

The implications of Special Relativity are among the best tested of any scientific theory and it has many terrestrial, not just astronomical, applications. I've no interest in your crackpot scientific conspiracy notions and having seen you lay waste to another thread don't intend to encourage your persistent trolling either. To anyone else who wants to take up the baton, I'll just warn them that your modus operandi is to never get beyond posting the same vague anti-scientific allusions over and over again.

gkell11

ps200306 wrote: »

The implications of Special Relativity are among the best tested of any scientific theory and it has many terrestrial, not just astronomical, applications.

Spoken like a true cultist and an intellectual lightweight as the whole idea here is to get the respondent to attack relativity rather than probe exactly what Sir Isaac was trying to do by defining time,space and motion for everyone. I neither admire nor respect the ruse so no, this is not about conspiracies real or imagined but pure technical and historical developments that existed long before Newton and his followers distorted the principles of solar system structure,planetary dynamics and how timekeeping meshes with the great cycles of the Earth .

If you are an expert on time,space and motion then qualify this idea that there are more rotations than 24 hour days in a circuit of the Earth around the Sun ? -

"During one orbit around the Sun, the Earth rotates about its own axis 366.26 times, creating 365.26 solar days" Main Earth article Wikipedia

It is a human right that every child learn that all the experiences of one rotation of the Earth occurs within each 24 hours so that one rotation follows the next just as Friday follows Thursday,Saturday follows Friday and they never,ever fall out of step. The stupid notion that they do fall out of step is due to your cult managing to conjure notions out of thin air and I assure you the Equation of Time (Newton's idiosyncratic absolute/relative time) plays a role in keeping days and rotations in step.

When all you guys calling yourselves astronomers here can account for the Sun rising and setting within each 24 hours due to one rotation of the Earth,including February 29th, then and only then can you think of yourselves as experts in time,space and motion otherwise it is all unthinking behavior and voodoo.

ps200306

gkell11 wrote: »

Spoken like a true cultist and an intellectual lightweight...

You could've just presented your contrary case that Relativity is not among the best tested of all scientific theories. Instead you've just resorted to petty name calling. The only response that will elicit from me is another post reported for moderation. Make sure to add it to your list of complaints of victimisation when the time comes.

gkell11 wrote: »

If you are an expert on time,space and motion then qualify this idea that there are more rotations than 24 hour days in a circuit of the Earth around the Sun ?

I'm quite familiar with the concepts of mean time, and the equation of time, and if they were even remotely relevant to this thread I might take you up on it. Special Relativity as discussed here concerns inertial frames of reference and has nothing to do with your rotating frames, and even less to do with the accidents of the earth's orbital ellipse. As I said elsewhere, you're quite free to start your own threads on the topics that interest you.

(Oops. Scratch that. I think you've just been banned :pac:).

ps200306

ps200306 wrote: »

You can think of it as four dimensions, but they are not all mutually orthogonal. The three space dimensions are orthogonal, that is, you can move along each axis independently or any combination of the three together. But the time axis is not only somewhat folded into the others, the degree of folding is affected by the speed of the observer. (You probably know that volumes have been written about not only the theory but the experiments that confirm this so, no, it's not a crackpot idea of Newton or H.G.Wells).

I'm sure you've seen the idea of a light cone which attempts to show a single event on the space and time axes. Time is on the vertical axis, and space is on the horizontal. Every event has some set of spacetime coordinates, (x,y,z,t) from which the cone then spreads out into the past and future. Space is three-dimensional, of course, but we only have room to show two on this picture - in reality the light cone is the edge of an expanding 3D sphere but we can't show that.



The edge of the cone has a special meaning. That represents a ray of light travelling from the event into the future (or a ray of light travelling toward the event from the past, on the lower half of the cone). Since nothing can travel faster than light, the edge of the cone represents the boundary of spacetime that could possibly be affected by this event (or that could possible have affected it from the past, in the lower cone). So the region of spacetime inside the light cone is a causally connected region.

It follows that any real object starting at the tip of this cone must take a path through spacetime inside the future light cone. Only light rays can travel along the edge of the cone, and those trajectories are called "light-like". Trajectories inside the cone are called time-like, while those outside are called space-like (but you can never follow one of those).

Now, because of the effect of velocity, not all observers will agree on the spacetime coordinates of any given event. But because they all see light travelling at the same speed, they do agree on where the edge of the light cone is. This is good news for causality. It means that one observer can never see one event causing another, that for another observer couldn't possibly have happened because of speed of light limitations.

This is probably all old hat, so to come back to the question and see exactly how things look different for different observers, we can simplify the light cone picture even further to just show one dimension of space:



Ignore the blue lines for a moment. We've got a single space axis, x. We've got the edge of our light cone (which in a single space dimension is now a "light triangle") marked in red. Our vertical axis is still time, but we've just scaled it appropriately for this picture. We want the edge of the cone to represent a light ray which, in time t travels a distance x = ct where c is the speed of light. So if our red line is going to be at a 45 degree angle, we have to scale the time axis by c, so we label it ct.

From the perspective of an observer travelling at a speed V, the space and time axes get "folded" as I mentioned. These are represented by the blue lines, labeled x' and ct'. Now, although these axes are not orthogonal, we plot the coordinates of an event in the usual way -- move parallel to the x' axis to draw the space coordinate, and parallel to the ct' axis to draw the time coordinate, as shown by the dashed lines here for event 1:



The weird thing now is that different observers can see events happening in different orders. By moving along the ct axis and looking across parallel to x, you can see four events happening in the order 0,2,3,1. But for the observer moving at speed V, along the ct' axis they happen in the order (0,3) simultaneously, followed by (2,1) simultaneously. But crucially, for both observers only events 0 and 2 are inside the light cone, so only they can be causally related and they are in the same order for both observers, so causality is preserved and you still can't go back in time and kill your parents before you were born.

(Diagram 1 from Wikipedia, 2 and 3 from Relativity, Gravitation and Cosmology by RJA Lambourne).

(edit: I checked my use of the word "orthogonal" later, and I think some would challenge it).

Looks like I have some light reading to do ha. This was all just something that I was thinking about myself, having read about the experiments of time perception Vs velocity, never saw anything about a light cone!!

ps200306

Deleted User wrote: »

Looks like I have some light reading to do ha. This was all just something that I was thinking about myself, having read about the experiments of time perception Vs velocity, never saw anything about a light cone!!

I might have overdone the answer. :pac:
I suppose one of the main points was that as well as time and distance measurements being affected by velocity so is event ordering -- look up "the relativity of simultaneity". Wikipedia has this cool animated gif that maybe shows how the spacetime axes are altered for different observers better than my previous diagram. Note the light cone (grey background) -- this event reordering can only happen for non-causally-connected events.

I've got the biology and computer science qualifications, may as well get a rounded education ha

gkell11

ps200306 wrote: »

You could've just presented your contrary case that Relativity is not among the best tested of all scientific theories. Instead you've just resorted to petty name calling. The only response that will elicit from me is another post reported for moderation. Make sure to add it to your list of complaints of victimisation when the time comes.


I'm quite familiar with the concepts of mean time, and the equation of time, and if they were even remotely relevant to this thread I might take you up on it. Special Relativity as discussed here concerns inertial frames of reference and has nothing to do with your rotating frames, and even less to do with the accidents of the earth's orbital ellipse. As I said elsewhere, you're quite free to start your own threads on the topics that interest you.

(Oops. Scratch that. I think you've just been banned :pac:).

Moderation is there to maintain an indoctrination rather than a facility to exclude me for I am not even contending with Newton but explaining that the Equation of Time is a timekeeping feature which correlates the 24 hour AM/PM system to the natural noon cycle. The fact that Sir Isaac couches his description of the two components of the Equation of Time as absolute/relative time only indicates that those who preach the relativity nonsense like yourself operate in a trance hence it is a phenomenon or even an illness of the cult kind. In short, start to focus on the EoT and what it represents dynamically and you will have no time for nonsense of 'getting rid of absolute time'.

If you can get the world to believe that humans can control the Universe by moving faster (slowing down time) they most certainly can be made to believe that they can control the planet's temperature like a household thermostat of 'climate change' as they call it.

An indoctrinated individual loses the ability to correlate the actual description of absolute/relative time as the Equation of Time insofar as that astronomical facility existed long before Newton encrusted it with worthless terms, all the indoctrinated person does is chant that Newton believed in absolute time,relativity came along and rejected it and hey presto - 'time travel'.

People are uninterested in how rotations and 24 hour days keep in step with each other across the circuit of the Earth around the Sun hence they become uninteresting and mediocre. It may be a great to be a 'relativity expert' but in truth it is a form of intellectual slavery designed for academics and by academics therefore the problem is generational. It takes a sharp and ruthless mind to strip away the jargon which not only gives people the notion of 'time travel' but more importantly - loses the fact that the Earth's rotation is responsible for the Sun rising and setting each 24 hours.

What people are led to believe are supreme human achievements is actually a jargon filled cult hence my freedom and the intellectual slavery of others. I do care that children are collateral damage via the education system but that may change in time as the visual narratives of genuine astronomy make a return. Until then you lot are on the wrong side of human reasoning,human consideration and all those things which have a positive influence on a functioning society.

Zubeneschamali

ps200306 wrote: »

I'm quite familiar with the concepts of mean time, and the equation of time, and if they were even remotely relevant to this thread I might take you up on it.

No, that's not what gkell is getting at.

His problem is that the Earth spins once on it's axis every 23 hours 56 minutes and 4 seconds. This fact drives him completely bonkers for some reason.

Rubecula

OMG I opened a can of worms here (or should that be a can of string theories) I would say sorry, but I am not

I am learning all the time, but I am still confused

ps200306

Zubeneschamali wrote: »

No, that's not what gkell is getting at.

His problem is that the Earth spins once on it's axis every 23 hours 56 minutes and 4 seconds. This fact drives him completely bonkers for some reason.

Poor guy must feel he's being robbed of 3 minutes 56 seconds of craziness every day. :pac:

now online

Reading this thread with keen interest. Maybe someday I might even understand some of it!

gkell11

ps200306 wrote: »

Poor guy must feel he's being robbed of 3 minutes 56 seconds of craziness every day. :pac:

Kids wake up in a world where adults believe that the Earth is into the next full rotation after 23 hours 56 minutes hence the silly conclusion that there is one more rotation than there are 24 hour days in a year and that is pure cult behavior.

Reasonable people probably could figure out what the extra rotation and 24 hour day that is February 29th achieves in closing out four full circuits of the Earth around the Sun as the 1461st rotation which reduces by division and inference to 365 1/4 rotations in 365 1/4 days. There is a step by step approach of course that anyone can take and it is not difficult with visual imaging to demonstrate the fact.

About the same time as men were storming the GPO in 1916 in asserting our national independence ,the wider world were becoming intellectual slaves to an idea that the entire Universe will change for an individual depending on their speed or 'time travel' as it has become known however the trouble began centuries earlier when the real damage was done to astronomy.

So the price of 'spacetime' and all the other voodoo surrounding it is that humanity has lost the ability to correlate the average 24 hour day with the constant rotation of the Earth via the Lat/Long system and the Equation of Time. That is breathtaking by any standard turn it what way you will but I assure you all that when the Sun rises and sets within each 24 hours the cause behind it is one rotation of the planet. Sad but true that I have to present this most basic fact of all.

Popoutman

^ reported for being just plain wrong. Quite delusional, and please set your reader to ignore gkell11 - your sanity will be better off.

I had a long thread a few years ago trying to educate this misguided individual in the past, and it's like trying to teach a wall to sing.

ps200306

gkell11 wrote: »

Kids wake up in a world where adults believe that the Earth is into the next full rotation after 23 hours 56 minutes hence the silly conclusion that there is one more rotation than there are 24 hour days in a year and that is pure cult behavior... There is a step by step approach of course that anyone can take and it is not difficult with visual imaging to demonstrate the fact.

I see from other threads you've trolled that you flit between your own prescribed "visual imaging" and admonishing people to get out and see for themselves, depending on which of your crazy views has just been trashed. I see also that you're a Newgrange fan. You might be interested in my Newgrange-style observations of Spica in April-May 2012 where I timed its arrival at a fixed sky location over a number of weeks. I dug the picture below out from my notes. I measured the length of one earth rotation to be the accepted value that you have rubbished, to within a margin of error of 6 seconds. So who's the cult now? :pac:

Rubecula

has this anything to do with the original question?

ps200306

Rubecula wrote: »

has this anything to do with the original question?

Nothing whatsoever -- gkell11 is a master of thread hijacking and obfuscation.

mickmackey1

ps200306 wrote: »

You might be interested in my Newgrange-style observations of Spica in April-May 2012 where I timed its arrival at a fixed sky location over a number of weeks. I dug the picture below out from my notes. I measured the length of one earth rotation to be the accepted value

Excellent project. I keep meaning to do something like this, it creates a kind of ethereal link with the ancients

ps200306

mickmackey1 wrote: »

Excellent project. I keep meaning to do something like this, it creates a kind of ethereal link with the ancients

Yeah it was great fun. I wanted to do it with no equipment other than a clock. I ended up investigating everything from light pollution to how much your head moves by random postural swaying. (So I suppose I used a couple of billion transistors and a globally connected network as well as the clock )

Popoutman

Slightly off topic, but an interesting exercise that could have been done with the technology available to the ancients.

It would have been possible for the ancients to determine that the planets were apparently bigger than the stars in our sky.
If you take e.g. a film canister with a hole in the end, mounted on a tripod, and you watch a star as it moves behind something hard and vertical like the side of a building or a cliff face, you can see that it'll take maybe a second or less to wink out. The film canister is used to ensure that the eye position doesn't move. If you were to reposition the film canister such that one of the planets was to move behind something similar, you'd see that the planet takes a longer time to disappear.

There was an article in Astronomy Now a long time ago going into detail on this.

ps200306

Popoutman wrote: »

Slightly off topic, but an interesting exercise that could have been done with the technology available to the ancients.

It would have been possible for the ancients to determine that the planets were apparently bigger than the stars in our sky.
If you take e.g. a film canister with a hole in the end, mounted on a tripod, and you watch a star as it moves behind something hard and vertical like the side of a building or a cliff face, you can see that it'll take maybe a second or less to wink out. The film canister is used to ensure that the eye position doesn't move. If you were to reposition the film canister such that one of the planets was to move behind something similar, you'd see that the planet takes a longer time to disappear.

There was an article in Astronomy Now a long time ago going into detail on this.

That's interesting, and one I'd like to try. I see from Wikipedia that the maximum angular diameters of the classical planets range from 13 to 66 seconds of arc. Jupiter at opposition would probably be the best choice at 50 seconds. The sky rotates 15 seconds of arc per second so Jupiter takes 3 seconds to disappear if the planet was moving perpendicular to the edge of the occluding object. How much of that would the eye be able to perceive, though? I'd expect the dimming to follow some kind of sinusoidal pattern (and that's just from the shape of the disc, ignoring complications like limb darkening and diffraction). Could we arrange a grazing occultation to stretch out the event in time? I'd imagine the biggest experimental challenge would be trying to line your planet and obstacle up in a very tiny field of view.

I presume the occultation of a star is almost instantaneous but I don't know what allowance has to be made for atmospheric distortion. Judging by the video below, the second slowed-down occultation seems to take less than half a second (15 frames of video), and that's by the moon which is moving only 1/30 times the speed relative to the star than a terrestrial object would be. But in that case the occluding object is above our atmosphere -- a twinkling star must be prone to dancing in and out of view momentarily where the object is earth-based.

ps200306

ps200306 wrote: »

Nothing whatsoever -- gkell11 is a master of thread hijacking and obfuscation.

Where are our mod overlords then? I imagine that more than one of his comments have been reported?

mickmackey1

ps200306 wrote: »

I see also that you're a Newgrange fan. You might be interested in my Newgrange-style observations

Looking at yet another clouded-out Newgrange yesterday, there must have been a lot of effing and blinding when the ancients were trying to construct the bloody thing :pac: