Status of the block universe in the field of physics

roosh

I'm interested in finding out what the generally accepted status of the block universe concept is, within the mainstream of physics.

On the one hand, the idea that is propagated in the general mainstream is that the block universe is a logical necessity of Einsteinian relativity; that the block universe is the physical embodiment of the mathematics of Minkowski spacetime; that is, if the mathematics of Minkowski spacetime represent an underlying physical structure, then the block universe is it. This is an idea that seems to be shared by some, if not many.

On the other hand there are those who dismiss the block universe as nothing more than a philosophical concept, which makes no testable predictions, and so, has no place in the field of physics.

These two views are obviously poles apart, so I'm interested to learn if the impression that is created in the general mainstream - through series like NOVAs the Fabric of the Universe, and other documentaries - that the block universe is a logical necessity of Einstein's relativity, is representative of the mainstream view within the field of physics.

krd

I think I know the documentary you're talking about.

Lots of animations?.......And they do something like having a series of block shaped universes.

I do not know.

You'd have to wary of these pronouncements. There's an article in this months New Scientist making the claim that gravity is possibly entropy. Vlatko Vedral, professor of quantum information theory, Oxford.

Of course I think they have it arseways. Think of huge gas clouds, coalescing through gravity into stars, and then galaxies. The gas clouds are moving from high entropy to lower entropy. You don't see spiral galaxies unravelling into gas clouds again. Or planets crumbling into space dust. In theory this will happen at some point - that's the theory, if the 2nd law of Thermodynamics is absolute. In terms of entropy, gravity operates in the opposite direction to the 2nd law of thermodynamics. Gravity causes bodies to go from a higher entropy state to a lower one.

I don't like the 2nd law being a law. I don't think entropy always increases.

citrus burst

I don't really know what you mean by "block universe." Perhaps a small paragraph explaining the ideas might help.

Are you talking about the the mathematical coordinates (x,y,z,t) that make up spacetime? Or some other treatment of the universe as a whole...ie block?

In other threads you seem unhappy about coordinate systems and their use in physics and seem to think they imply some sort of breakdown in the whole process.

krd

citrus burst wrote: »

I don't really know what you mean by "block universe." Perhaps a small paragraph explaining the ideas might help.

I think he saw the same documentary I saw. And no, I had no idea what they were on about either. I think they had an animation where they had something like a dayglo fried egg on the side of a rectangular object - and supposedly, the dayglo fried egg was us - or our universe.

Are you talking about the the mathematical coordinates (x,y,z,t) that make up spacetime? Or some other treatment of the universe as a whole...ie block?

x,y,z,t, is just Euclidean space with a time vector. For m-theory you need more dimensions - you need a different kind of geometry. For things like membranes.

In other threads you seem unhappy about coordinate systems and their use in physics and seem to think they imply some sort of breakdown in the whole process.

x,y,z,t, will only work for Special Relativity. For General you need more. And x,y,z,t, will only work within a limited and defined frame of reference.

Geometries can be tricky - if you were a caveman, you might assume you were on a flat earth. Once you get to Einstein, not only do you realise that the earth is not flat, but round, but that space isn't fixed in Euclidean coordinates. Then this allows for wilder theories. If the caveman didn't realise the geometry of the earth, than we may not be realising geometries of reality that are hidden from us, just like the roundness of the earth was hidden from the caveman.

Listen.......I don't know.....I'm still hacking away at the books trying to get a purchase on it.

roosh

I genuinely thought people would be much more familiar with the concept. But for those who aren't, here is one installment of the the [4 part - I think] series I mentioned. NOVA's The Fabric of the Cosmos (I think I said universe): the illusion of time.

The block universe concept is illustrated around the 18m55s mark; I tried adding time tags to the video so it would queue up the relevant part, but I'm not sure if that works when embedding. I've added the link below the video, with the time tags, so it will be queued up for you on youtube.

NOVA|The Fabric of the Cosmos - block universe

citrus burst

So what you're asking is do we agree with the coordinate system used to label events? Do we think they are real parts of the universe?

im invisible

or is it that past present and future exist, have always existed, and will always exist...

roosh

citrus burst wrote: »

So what you're asking is do we agree with the coordinate system used to label events? Do we think they are real parts of the universe?

im invisible wrote: »

or is it that past present and future exist, have always existed, and will always exist...

I'm not entirely sure how to phrase the question properly, because I might not use the right terminology. I think im invisible is perhaps closer to the question that I am asking, because I don't think it is a question of whether or not co-ordinate labels exist a priori in nature; as Einstein said, they don't.


Agree?
It might be better to ask if you agree with some of the comments made by prof. Greene in the documentary. For example:

Firstly, is the representation, here, of the experience of time, for relatively moving observers, an accurate reflection of what Einsteinian relativity says should occur?


If so, would you agree with the following?

prof.Greene wrote:

once we know that your now can be what I consider the past; or your now can be what I consider the future; and your now is every bit as valid as my now; then we learn that the past, must be real, the future, must be real; it could be your now; that means past, present, and future, all equally real

prof.Greene statement

I don't think the duration of their existence is an important question here, it's simply a question of whether or not you agree that [what you consider to be] the past still exists and if [what you consider to be] the future already exists; and if such is necessitated by Einsteinian relativity.


Does it follow?
I'll also paraphrase what someone else said in a discussion on the same subject; firstly, would you agree that time dilation is a real effect, that time actually slows down for relatively moving observers; as opposed to the slower ticking clock simply being an optical illusion.

Would you agree that only the block universe concept allows for time dilation to be a real, as opposed to an optical, effect; that is, if time dilation is real, then it follows that what I consider to be the past could be yours, or someone elses, present, and the same with my future; from this follows the block universe concept?

Morbert

The deepest statement that can be made about any physical law is a mathematical statement. Any ontology attached to the law is, at best, irrelevant to the physical understanding of that law. Physicists are instead interested in the mathematical structure best suited to relating postulates and principles to observation.

Currently, relativity is most commonly understood in the language and reasoning of 4-spaces (i.e. spacetime, 4-momentum, etc). What this "means" is not what scientists answer. They instead, for example, ask if the extra-dimensional mathematical structures that krd mentioned are what are needed to ensure that conformal transformations of the intrinsic metric of a world-volume are unobservable, thus providing a framework that is consistent with both relativity and quantum theory.

roosh

Morbert wrote: »

The deepest statement that can be made about any physical law is a mathematical statement. Any ontology attached to the law is, at best, irrelevant to the physical understanding of that law. Physicists are instead interested in the mathematical structure best suited to relating postulates and principles to observation.

Currently, relativity is most commonly understood in the language and reasoning of 4-spaces (i.e. spacetime, 4-momentum, etc). What this "means" is not what scientists answer. They instead, for example, ask if the extra-dimensional mathematical structures that krd mentioned are what are needed to ensure that conformal transformations of the intrinsic metric of a world-volume are unobservable, thus providing a framework that is consistent with both relativity and quantum theory.

To interpret mathematical statements, one must first learn what the symbols refer to through the medium of everyday language; in that sense, mathematical statements must be translatable into everyday language. For example, the idea of extra dimensions is meaningless, without some idea what a dimension is.

In some of our other discussion you would seem to strongly advocate the block universe concept; would you say that it is a necessary consequence of Einsteinian relativity and the concept of Relativity of Simultaneity?

For example, would you agree that relativity of simultaneity implies that what I consider to be the present could be what another, relatively moving observer considers to be the past, or indeed future; and if both are are equally real, equally valid, or equally phyiscal, that this necessitates some form of block universe; that, in the absence of such a concept, the phenomenon of time dilation is merely an optical effect?

bogwalrus

I watched that video you posted and it made a a lot of sense to me.

The fact that time is "moments" and all that rather then a "flow" makes sense to me also.

What i'm wondering is if the above is true what is the timing between each moment as there would have to be a space before every point no?

as in;

Now (space) Now (space) now (space)


Could it be that its all at quantum level meaning time is then associated with matter in some way.

(sorry i'm a complete noob but think my point kinda makes sense)

Morbert

bogwalrus wrote: »

I watched that video you posted and it made a a lot of sense to me.

The fact that time is "moments" and all that rather then a "flow" makes sense to me also.

What i'm wondering is if the above is true what is the timing between each moment as there would have to be a space before every point no?

as in;

Now (space) Now (space) now (space)


Could it be that its all at quantum level meaning time is then associated with matter in some way.

(sorry i'm a complete noob but think my point kinda makes sense)

The series of "nows" are continuous. This is similar to the real number system, where there are no gaps between numbers.

The manner in which spacetime is sliced is arbitrary to a large extent. To see how a now relates to other nearby "nows" for any given slicing scheme, we use something called a "metric" that locally connects nows to each other.

Morbert

roosh wrote: »

To interpret mathematical statements, one must first learn what the symbols refer to through the medium of everyday language; in that sense, mathematical statements must be translatable into everyday language. For example, the idea of extra dimensions is meaningless, without some idea what a dimension is.

In some of our other discussion you would seem to strongly advocate the block universe concept; would you say that it is a necessary consequence of Einsteinian relativity and the concept of Relativity of Simultaneity?

For example, would you agree that relativity of simultaneity implies that what I consider to be the present could be what another, relatively moving observer considers to be the past, or indeed future; and if both are are equally real, equally valid, or equally phyiscal, that this necessitates some form of block universe; that, in the absence of such a concept, the phenomenon of time dilation is merely an optical effect?

It is not a necessity. We could all be jars connected to an asynchronous network. The mathematical symbols only need to pertain to observable phenomena, and do not need to be direct representations of any "physical noumena", which is almost an oxymoron.

If I am dragged into philosophy, however, I do feel the block universe is the cleanest and clearest representation of the formalism. And I certainly don't feel the presentism is in any way a necessary explanation of either the mathematics or our observations and experiences.

[edit] - Fixed a sentence that was saying the opposite of what I wanted it to say.

roosh

Morbert wrote: »

It is not a necessity. We could all be jars connected to an asynchronous network. The mathematical symbols only need to pertain to observable phenomena, and do not need to be direct representations of any "physical noumena", which is almost an oxymoron.

If I am dragged into philosophy, however, I do feel the block universe is the cleanest and clearest representation of the formalism. And I certainly don't feel the presentism is in any way a necessary explanation of either the mathematics or our observations and experiences.

[edit] - Fixed a sentence that was saying the opposite of what I wanted it to say.

Are they the two alternatives, either we are jars connected to an asynchronous network or the block universe is correct?

Even if we are jars in a network, the experience created by that is something we have come to label "the physical world", from which we derive our mathematics and logic; so even if we are all in jars, would the block universe be the logical conclusion of the mathematics of relativity; regardless of it's ontology?

Morbert

roosh wrote: »

Are they the two alternatives, either we are jars connected to an asynchronous network or the block universe is correct?

No.

Even if we are jars in a network, the experience created by that is something we have come to label "the physical world", from which we derive our mathematics and logic; so even if we are all in jars, would the block universe be the logical conclusion of the mathematics of relativity; regardless of it's ontology?

If by logical conclusion you mean a logical necessity: No.

roosh

Morbert wrote: »

No.

OK, it just seemed that you were presenting it as a two horse race.

Morbert wrote: »

If by logical conclusion you mean a logical necessity: No.

OK, so the block universe isn't a logical necessity of Einsteinian relativity; is the idea that my past, present, and future all co-exist, a logical necessity?

Morbert

roosh wrote: »

OK, so the block universe isn't a logical necessity of Einsteinian relativity; is the idea that my past, present, and future all co-exist, a logical necessity?

Again, it is not a logical necessity. Just as presentism is not a logical necessity.

roosh

Morbert wrote: »

Again, it is not a logical necessity. Just as presentism is not a logical necessity.

Presentism isnt a logical necessity, its the only position that is supported by the evidence of our empirical experience, that isn't based on circular reasoning. It's an experiential fact, as opposed to a logical necessity.

It seems that either presentism must be true, or some formalism whereby our past and future are existential must be true; because, essentially, presentism is just what is left when our past and future don't exist.

Relativity of Simultaneity
The concept of RoS is something central to relativity, but the term "Relativity of Simultaneity" is meaningless unless we can expand on what it refers to in the physical world.

Now, we know that it means that "events which are simultaneous in one reference frame can be non-simultaneous in another". The question which arises from this is, what does that mean in a physical sense. It's possible that the events observed by one observer are just an optical illusion, while those observed in a different reference frame are the "true events"; this is denied under Einsteinian relativity, so we need to explore what the consequences are.


Past and future
You've said on numerous occasions that RoS implies that events I consider to be in the past i.e. "my past", could be someone elses present. You've stated that their perspective is equally valid, so from this can we no reasonably conclude, that events which I consider the past, must physically exist; that is, they must continue to physically exist?

If so, then have we not established that some form of block universe is a necessary consequence of RoS.

krd

roosh wrote: »

Past and future
You've said on numerous occasions that RoS implies that events I consider to be in the past i.e. "my past", could be someone elses present. You've stated that their perspective is equally valid, so from this can we no reasonably conclude, that events which I consider the past, must physically exist; that is, they must continue to physically exist?

No. Your past physical presence will not continue to exist. But the image will.

If I'm on a planet precisely 50,000 light years away from earth. If in precisely 50,000 years time I find earth with a telescope, and I find you, I will be able to see you, as you are today. But in reality, you'll be long gone.

roosh

krd wrote: »

No. Your past physical presence will not continue to exist. But the image will.

If I'm on a planet precisely 50,000 light years away from earth. If in precisely 50,000 years time I find earth with a telescope, and I find you, I will be able to see you, as you are today. But in reality, you'll be long gone.

That would be my interpretation also, but relativity would appear to disagree; because that me, that you say would be long gone, could be part of someone elses present [apparently], not just in the sense of an image, apparently.

Morbert

roosh wrote: »

Presentism isnt a logical necessity, its the only position that is supported by the evidence of our empirical experience, that isn't based on circular reasoning. It's an experiential fact, as opposed to a logical necessity.

It seems that either presentism must be true, or some formalism whereby our past and future are existential must be true; because, essentially, presentism is just what is left when our past and future don't exist.

Relativity of Simultaneity
The concept of RoS is something central to relativity, but the term "Relativity of Simultaneity" is meaningless unless we can expand on what it refers to in the physical world.

Now, we know that it means that "events which are simultaneous in one reference frame can be non-simultaneous in another". The question which arises from this is, what does that mean in a physical sense. It's possible that the events observed by one observer are just an optical illusion, while those observed in a different reference frame are the "true events"; this is denied under Einsteinian relativity, so we need to explore what the consequences are.


Past and future
You've said on numerous occasions that RoS implies that events I consider to be in the past i.e. "my past", could be someone elses present. You've stated that their perspective is equally valid, so from this can we no reasonably conclude, that events which I consider the past, must physically exist; that is, they must continue to physically exist?

If so, then have we not established that some form of block universe is a necessary consequence of RoS.

And now that your initial question has been answered and you have reverted to the usual philosophical quackery, I consider this thread finished, and invite you to continue the quackery in the thread in the philosophy forum.

roosh

Morbert wrote: »

And now that your initial question has been answered and you have reverted to the usual philosophical quackery, I consider this thread finished, and invite you to continue the quackery in the thread in the philosophy forum.

The thread is a question on the status of the block universe in the field of physics; to see if it is generally accepted as being a logical necessity of Einsteinian relativity or not. While your opinion is valued, it is open to whoever else wishes to contribute.

In other discussions you have been championing the idea of the block universe; to the extent that it could be forgiven for having thought that you were of the opinion that it was a logical necessity. Indeed, in this thread the alternative you gave to the block universe was that we are all in jars connected to a network.

I'm not sure what we can take form your comment that the block universe is the "cleanest and clearest" formalism, but it would seem to have positive connotations for the block universe concept.

Philosophy
It's debatable whether the discussion should be furthered in the philosophy section, because it ultimately pertains to a clarification of the concept of relativity of simultaneity.

As such, the concept itself is meaningless without some clarification of the underlying philosophical concepts; for example, if we say that events which are simultaneous in one reference frame can be non-simultaneous in another, that is meaningless without further clarification. Are the non-simultaneous events optical illusions or are they physical? If we answer physical, then it has different physical implications.

Indeed, without clarification of what is meant, it could be taken that we are not distinguishing between LET or Einstein's relativity. Given the uniformity of the results of LET and SR, unless we clarify certain, core, philosophical concepts, then we are as much talking about one as the other. Whether that is a question of physics or philosophy is, itself, debatable.

Morbert

roosh wrote: »

The thread is a question on the status of the block universe in the field of physics; to see if it is generally accepted as being a logical necessity of Einsteinian relativity or not. While your opinion is valued, it is open to whoever else wishes to contribute.

In other discussions you have been championing the idea of the block universe; to the extent that it could be forgiven for having thought that you were of the opinion that it was a logical necessity. Indeed, in this thread the alternative you gave to the block universe was that we are all in jars connected to a network.

I'm not sure what we can take form your comment that the block universe is the "cleanest and clearest" formalism, but it would seem to have positive connotations for the block universe concept.

Philosophy
It's debatable whether the discussion should be furthered in the philosophy section, because it ultimately pertains to a clarification of the concept of relativity of simultaneity.

As such, the concept itself is meaningless without some clarification of the underlying philosophical concepts; for example, if we say that events which are simultaneous in one reference frame can be non-simultaneous in another, that is meaningless without further clarification. Are the non-simultaneous events optical illusions or are they physical? If we answer physical, then it has different physical implications.

Indeed, without clarification of what is meant, it could be taken that we are not distinguishing between LET or Einstein's relativity. Given the uniformity of the results of LET and SR, unless we clarify certain, core, philosophical concepts, then we are as much talking about one as the other. Whether that is a question of physics or philosophy is, itself, debatable.

Purely ontological considerations are irrelevant to physics. The deepest physical statement you can make is a statement pertaining to observed phenomena (usually a mathematical law or principle).

In other discussions I have been "championing" the idea that presentism is in no way a logical necessity of physics, and that there are no obstacles to interpreting spacetime as existing ontologically.

roosh

Morbert wrote: »

Purely ontological considerations are irrelevant to physics. The deepest physical statement you can make is a statement pertaining to observed phenomena (usually a mathematical law or principle).

Quite possibly, although language is usually necessary to arrive at an understanding of the maths and to meaningfully interpret it; for example what the nature of time is that is represented by 't' in the relevant equations; either way the mathematics must represent the underlying physicality of the universe, and depending on how the maths is interpreted we can draw different conclusions about that underlying structure.

Morbert wrote: »

In other discussions I have been "championing" the idea that presentism is in no way a logical necessity of physics, and that there are no obstacles to interpreting spacetime as existing ontologically.

In terms of pure empirical observation, all we ever observe is the present moment; any theory which requires an observer to conclude that their past and future are, ontologically, on an equal footing with their present, requires that observer to assume the conclusion, and is representative of a circularity inherent in the theory.

Morbert

roosh wrote: »

In terms of pure empirical observation, all we ever observe is the present moment; any theory which requires an observer to conclude that their past and future are, ontologically, on an equal footing with their present, requires that observer to assume the conclusion, and is representative of a circularity inherent in the theory.

And any interpretation which requires an observer to conclude that an unobservable set of dynamic relations is responsible for the universal speed of light requires that observer to assume the conclusion, and is representative of a circularity inherent in the interpretation.

Again, nobody is saying it's a logical necessity.

roosh

Morbert wrote: »

And any interpretation which requires an observer to conclude that an unobservable set of dynamic relations is responsible for the universal speed of light requires that observer to assume the conclusion, and is representative of a circularity inherent in the interpretation.

Again, nobody is saying it's a logical necessity.

As opposed to the unobservable set of dynamics that can lead to physical objects being both, physically, contracted and uncontracted?

Bearing in mind that "the geometry of the relation between events" isn't an adequate explanation, because "geometry" is just the mathematical representation of the relation between events; it doesn't explain how this "relation between events" can allow for the same object to be both physically contracted and not contracted; that is, how a clock can tick slower than itself, or how Albert's brain can be both contracted and not contracted - physically. Also, it doesn't explain how the geometry of the relation between events can exhibit contraction, without affecting the underlying physical structure of the object.


EDIT: as for the block universe being a logical necessity, or not, without the concept of the block universe, what you've got is presentism and a very different interpretation of RoS.

Morbert

roosh wrote: »

As opposed to the unobservable set of dynamics that can lead to physical objects being both, physically, contracted and uncontracted?

That is a straw man.

Bearing in mind that "the geometry of the relation between events" isn't an adequate explanation, because "geometry" is just the mathematical representation of the relation between events; it doesn't explain how this "relation between events" can allow for the same object to be both physically contracted and not contracted; that is, how a clock can tick slower than itself, or how Albert's brain can be both contracted and not contracted - physically. Also, it doesn't explain how the geometry of the relation between events can exhibit contraction, without affecting the underlying physical structure of the object.


EDIT: as for the block universe being a logical necessity, or not, without the concept of the block universe, what you've got is presentism and a very different interpretation of RoS.

No. The coordinate labels are mathematical and unphysical. The relation between events exhibiting hyperbolic geometry is physical.

I am now almost certain that you are no longer interested in understanding relativity, and are instead only interested in peddling bad philosophy. I am holding this opinion because you have resurrected an old objection of yours that I categorically addressed previously. Your failure to understand the kinematic interpretation of relativity must therefore be deliberate.

roosh

Morbert wrote: »

That is a straw man.

No. The coordinate labels are mathematical and unphysical. The relation between events exhibiting hyperbolic geometry is physical.

This is just a restatement of the same point, about the geometry of events.

Again, "geometry" is just the mathematical representation of the relation between events; it doesn't explain how this "relation between events" can allow for the same object to be both physically contracted and not contracted; that is, how a clock can tick slower than itself, or how Albert's brain can be both contracted and not contracted - physically. Also, it doesn't explain how the geometry of the relation between events can exhibit contraction, without affecting the underlying physical structure of the object; or how an object can go from uncontracted according to an observer at rest relative to it, and then, according to the same observer, contracted when it starts moving relative to him - yet still uncontracted itself.

All the statement says is that it does, it doesn't say how it does; that we must attribute to some mysterious dynamics.

Morbert wrote: »

I am now almost certain that you are no longer interested in understanding relativity, and are instead only interested in peddling bad philosophy. I am holding this opinion because you have resurrected an old objection of yours that I categorically addressed previously. Your failure to understand the kinematic interpretation of relativity must therefore be deliberate.

And again you choose to ignore an important point; the fact that, if you don't have a block universe, you've got presentism.

It might be worth mentioning that your "categoric addressing" of the point is still the subject of debate in the thread on absolute motion; your "categoric addressing" of presentism was to use the block universe as the "categoric refutation"; but as we can see from the other thread, it is far from the categoric refutation it was built up to be.

Also, don't confuse the fact that kinemaitcs chooses to ignore the cause of relative motion with the idea that relative motion doesn't have a cause.

Morbert

roosh wrote: »

This is just a restatement of the same point, about the geometry of events.

Again, "geometry" is just the mathematical representation of the relation between events; it doesn't explain how this "relation between events" can allow for the same object to be both physically contracted and not contracted; that is, how a clock can tick slower than itself, or how Albert's brain can be both contracted and not contracted - physically. Also, it doesn't explain how the geometry of the relation between events can exhibit contraction, without affecting the underlying physical structure of the object; or how an object can go from uncontracted according to an observer at rest relative to it, and then, according to the same observer, contracted when it starts moving relative to him - yet still uncontracted itself.

All the statement says is that it does, it doesn't say how it does; that we must attribute to some mysterious dynamics.



And again you choose to ignore an important point; the fact that, if you don't have a block universe, you've got presentism.

It might be worth mentioning that your "categoric addressing" of the point is still the subject of debate in the thread on absolute motion; your "categoric addressing" of presentism was to use the block universe as the "categoric refutation"; but as we can see from the other thread, it is far from the categoric refutation it was built up to be.

Also, don't confuse the fact that kinemaitcs chooses to ignore the cause of relative motion with the idea that relative motion doesn't have a cause.

You are bordering on incoherent at stage. The contention in the other thread is with the atemporal status of world lines, it was not any apparent "physically contracted and not contracted" because, as I said before, over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over, time dilation and length contraction, and simultaneity are all frame-specific descriptions of events. They are relative, just as the loudness of a radio is relative.

roosh

Maybe if I put it as a stand alone point you won't be able to continue ignoring it:

if you don't have a block universe, what you've got is presentism.

roosh

Morbert wrote: »

You are bordering on incoherent at stage. The contention in the other thread is with the atemporal status of world lines, it was not any apparent "physically contracted and not contracted" because, as I said before, over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over, time dilation and length contraction, and simultaneity are all frame-specific descriptions of events. They are relative, just as the loudness of a radio is relative.

Apologies, I took the point that you "categorically addressed" to mean the issue of presentism.

However, you still didn't "categorically address" the point about reciprocal contractions; you simply stated that the relation between events exhibits hyperbolic geometry; you haven't clarified how it comes to exhibit this hyperbolic geometry; for example, how a clock which is at rest relative to an observer can go from being physically uncontracted for both, to being physically contracted when it starts moving relative to that observer, but remain uncontracted itself. Saying that it displays parabolic geometry is simply a restatement of the thing that is being questioned.

And you're still trying to peddle that specious analogy!

Are you honestly trying to suggest that for two observers, at rest relative to each other, the loudness of the radio is subject to length contraction and time dilation; or that the length contraction and time dilation, which lead to relatively moving observers measuring the speed of light to be the constant c, is due to the motion of the light relative to the air?

Because, if not, your analogy isn't representative of the issue.

citrus burst

roosh wrote: »

However, you still didn't "categorically address" the point about reciprocal contractions; you simply stated that the relation between events exhibits hyperbolic geometry; you haven't clarified how it comes to exhibit this hyperbolic geometry; for example, how a clock which is at rest relative to an observer can go from being physically uncontracted for both, to being physically contracted when it starts moving relative to that observer, but remain uncontracted itself. Saying that it displays parabolic geometry is simply a restatement of the thing that is being questioned.

Because of the speed of light being the same in every reference frame.
And every reference frame being correct.

roosh wrote: »

Are you honestly trying to suggest that for two observers, at rest relative to each other, the loudness of the radio is subject to length contraction and time dilation; or that the length contraction and time dilation, which lead to relatively moving observers measuring the speed of light to be the constant c, is due to the motion of the light relative to the air?

No I think what he meant was that like the loudness of a radio, length contractions and time dilation are relative. ie they depend on the situation of the observer. In the case of a radio it will be louder to some standing right next to it relative to some one 5 meters away. Similarly length contractions and time dilation are relative to the velocity of the observer. Some one at rest will observe length contraction/time dilation for a relatively moving frame. That is a spaceship moving relative to an observer will be shorter as measured by the observer, then the spaceship as measured by someone on the ship. The shortness is relative to the speed of the ship as the loudness of the radio is relative to the distance from the radio.

Morbert

roosh wrote: »

Apologies, I took the point that you "categorically addressed" to mean the issue of presentism.

However, you still didn't "categorically address" the point about reciprocal contractions; you simply stated that the relation between events exhibits hyperbolic geometry; you haven't clarified how it comes to exhibit this hyperbolic geometry; for example, how a clock which is at rest relative to an observer can go from being physically uncontracted for both, to being physically contracted when it starts moving relative to that observer, but remain uncontracted itself. Saying that it displays parabolic geometry is simply a restatement of the thing that is being questioned.

As I said before (x10000), it is not a physical contraction or dilation. What is physical is the causal structure of events. This structure is hyperbolic. Take the time to study this structure. You will see that the difference between reference frames, and hence the difference between the length of an object, or the passage of time, is a hyperbolic rotation. It is no more physically mysterious than looking at a rubik's cube from different frames of reference and seeing different colours.

And you're still trying to peddle that specious analogy!

Are you honestly trying to suggest that for two observers, at rest relative to each other, the loudness of the radio is subject to length contraction and time dilation; or that the length contraction and time dilation, which lead to relatively moving observers measuring the speed of light to be the constant c, is due to the motion of the light relative to the air?

Because, if not, your analogy isn't representative of the issue.

"How can a radio be both physically loud and quiet at the same time? One of the observers of the radio must be more correct than the other."

krd

Morbert wrote: »

As I said before (x10000), it is not a physical contraction or dilation.

No, the contractions and dilations are physical. They're just very difficult for beings like us, who can only imagine 3 dimensions as projections onto 2 dimensional space, to witness, or even imagine. When we imagine 3d objects, it's always just a projection onto a 2d surface. We can know there is a 3rd dimension, but we never witness it directly, as we can't. Maybe we can witness three dimensions when we put objects in our mouths, or when we put parts of ourselves in someone else's mouth, but in terms of our eyes, or what we can see in our minds, we never see beyond two dimensions.

If you were some kind of godlike being, who could see the entire universe instantaneously, both the light, and by some magical instantaneousness everything else - in proper 4d - then you'd see the contractions and dilations.

roosh

roosh wrote: »

Maybe if I put it as a stand alone point you won't be able to continue ignoring it:

if you don't have a block universe, what you've got is presentism.

How wrong I was!

Maybe if I repost it, you won't ignore it?!



I'm considering your most recent post; it is certianly food for thought. But this is a separate point.

Morbert

krd wrote: »

No, the contractions and dilations are physical. They're just very difficult for beings like us, who can only imagine 3 dimensions as projections onto 2 dimensional space, to witness, or even imagine. When we imagine 3d objects, it's always just a projection onto a 2d surface. We can know there is a 3rd dimension, but we never witness it directly, as we can't. Maybe we can witness three dimensions when we put objects in our mouths, or when we put parts of ourselves in someone else's mouth, but in terms of our eyes, or what we can see in our minds, we never see beyond two dimensions.

If you were some kind of godlike being, who could see the entire universe instantaneously, both the light, and by some magical instantaneousness everything else - in proper 4d - then you'd see the contractions and dilations.

They're not physical. Length contraction is a frame-dependent phenomenon, and physics is independent of the chosen reference frame.

Morbert

roosh wrote: »

How wrong I was!

Maybe if I repost it, you won't ignore it?!

It's a completely irrelevant question.

roosh

Morbert wrote: »

It's a completely irrelevant question.

It wasn't a question, it was a statement; one which pertains to the question of whether or not the block universe is a logical necessity of Einsteinian relativity or not.

Either the 4D Minkowski spacetime represents a block universe or it represents a "presentist" universe.

Morbert

roosh wrote: »

It wasn't a question, it was a statement; one which pertains to the question of whether or not the block universe is a logical necessity of Einsteinian relativity or not.

Either the 4D Minkowski spacetime represents a block universe or it represents a "presentist" universe.

This is getting stranger and stranger.

Again, the question of whether or not there is such a dichotomy is irrelevant. What is relevant is presentism is not a logically necessary inference from relativity.

krd

Morbert wrote: »

This is getting stranger and stranger.

Again, the question of whether or not there is such a dichotomy is irrelevant. What is relevant is presentism is not a logically necessary inference from relativity.

I think I know where he's getting this......There's a guy on the internet who claims the "present" is its' own dimension. He claims it "explains everything" but it doesn't really. I think his explanation is that the plane of the present, from whichever direction you're looking at it in Euclidian space is facing towards you - so like a cartoon character, who's been flattened by a steam roller, you can't see them if they're turned on their side.

roosh

Morbert wrote: »

This is getting stranger and stranger.

Again, the question of whether or not there is such a dichotomy is irrelevant. What is relevant is presentism is not a logically necessary inference from relativity.

It's really quite simple, and not strange at all; either the block universe is a necessary consequence of Einsteinian relativity, or it is compatible with presentism; that is, either the idea, that past and future co-exist with the present, in 4D spacetime, is a logical necessity of Einteinian reltativity, or Einsteinian relativity is compatible with presentism; because presentism is simply the idea that past and future don't exist.

roosh

krd wrote: »

I think I know where he's getting this......There's a guy on the internet who claims the "present" is its' own dimension. He claims it "explains everything" but it doesn't really. I think his explanation is that the plane of the present, from whichever direction you're looking at it in Euclidian space is facing towards you - so like a cartoon character, who's been flattened by a steam roller, you can't see them if they're turned on their side.

I can't say that I'm familiar with said "guy on the internet", or his explanation. Presentism stems from the most fundamental fact of empirical observation, namely that no observer ever has or, dare I say, will ever be able to, make an observation that is not in the present moment. That means that there is no evidence that past and future co-exist in 4D spacetime, that doesn't require us to assume the conclusion.

It also stems from the idea that time doesn't exist; given that we have no way of measuring physical time; because nowhere in the process of a clock is something physical called time actually measured; this means time is more a system of measurement, as opposed to a physical property to be measured. There is no evidence for the existence of time that doesn't require us to assume, a priori, that time exists.

Maximus Alexander

roosh wrote: »

It also stems from the idea that time doesn't exist; given that we have no way of measuring physical time; because nowhere in the process of a clock is something physical called time actually measured; this means time is more a system of measurement, as opposed to a physical property to be measured. There is no evidence for the existence of time that doesn't require us to assume, a priori, that time exists.

Surely this is the same as saying that nowhere on a ruler is something physical called distance actually measured.

citrus burst

Maximus Alexander wrote: »

Surely this is the same as saying that nowhere on a ruler is something physical called distance actually measured.

I often wonder why people never question why things are spatially separated, yet always question why things are temporarily separate. I mean they wonder how time changes, gets from the past to the present to the future, so to speak, or t1 to t2. But they never wonder why two things are separated by a distance.

Nobody seems to question what distance actually is and what it means.

roosh

Maximus Alexander wrote: »

Surely this is the same as saying that nowhere on a ruler is something physical called distance actually measured.

Distance, I think, is a little trickier for us, psychologically, than is time; because spatial dimensions seem so obvious, whereas we only ever experience the present moment, and as such, no temporal dimension.

The point could be argued that "distance" too, is just conceptual, even if physical spatial dimensions aren't; but that wouldn't affect the point about how a clock measures time, or rather, how it doesn't measure a physical, temporal dimension.

roosh

citrus burst wrote: »

I often wonder why people never question why things are spatially separated, yet always question why things are temporarily separate. I mean they wonder how time changes, gets from the past to the present to the future, so to speak, or t1 to t2. But they never wonder why two things are separated by a distance.

Nobody seems to question what distance actually is and what it means.

I would say that "time" doesn't change at all; there is an ever changing present moment; what we refer to as "past" and "future" are just psychological constructs.

Would the Pauli exclusion principle add some clarity as to why things are spatially separated?

Maximus Alexander

roosh wrote: »

The point could be argued that "distance" too, is just conceptual, even if physical spatial dimensions aren't; but that wouldn't affect the point about how a clock measures time, or rather, how it doesn't measure a physical, temporal dimension.

I don't agree at all. A clock measures time in precisely the same sense that a ruler measures distance. A second is just as clearly a distance between two events as a meter is.

Let me put it to you this way:

Imagine yourself locked in the carriage of a train, which travels east forever. There is no way you can get out, there is no way you can take the controls to reverse the train.

Does everything to the west cease to exist because you are no longer there? Does only your current location in space exist?

No, you are separated from the west by both distance and time.

roosh

Maximus Alexander wrote: »

I don't agree at all. A clock measures time in precisely the same sense that a ruler measures distance. A second is just as clearly a distance between two events as a meter is.

Not really though; you can lay a ruler down beside a physical object and clearly see the beginning of the ruler and the end, or the physical dimension that is being measured; a clock only ever exists in the present moment so the only "time" you ever see is now; you don't see the clock extending from the past into the future and measure it thusly.

Maximus Alexander wrote: »

Let me put it to you this way:

Imagine yourself locked in the carriage of a train, which travels east forever. There is no way you can get out, there is no way you can take the controls to reverse the train.

Does everything to the west cease to exist because you are no longer there? Does only your current location in space exist?

No, you are separated from the west by both distance and time.

Imagine I'm not locked in a carriage and can see "the west" even though I'm traveling east forever; I can also see "the east" approaching me; the same cannot be said of time. That is, there is no empirical evidence that "past" and "future" exist, that doesn't require us to assume the conclusion.

But even within the carriage, I can see one end of the carriage, while standing at the other; here the spatial dimensions of the carriage appear to be self-evident; even if this is an illusion, the same cannot be said of time; we only ever experience the present moment.

Maximus Alexander

roosh wrote: »

Imagine I'm not locked in a carriage and can see "the west" even though I'm traveling east forever; I can also see "the east" approaching me; the same cannot be said of time. That is, there is no empirical evidence that "past" and "future" exist, that doesn't require us to assume the conclusion.

But even within the carriage, I can see one end of the carriage, while standing at the other; here the spatial dimensions of the carriage appear to be self-evident; even if this is an illusion, the same cannot be said of time; we only ever experience the present moment.

Do you accept that both Africa and America exist, despite the fact that you cannot see them both?

roosh

Maximus Alexander wrote: »

Do you accept that both Africa and America exist, despite the fact that you cannot see them both?

I can travel to both; and there's empirical evidence of their existence, that doesn't require me to assume the conclusion*.


*Putting aside any disucussion on whether countries actually exist.

Maximus Alexander

roosh wrote: »

I can travel to both; and there's empirical evidence of their existence.

You can not travel to both at once. So, if there is no empirical evidence for time, you cannot accept the fact that you have been to Africa as evidence for its existence.