Models for making sense of relativity - physical space vs physical spacetime

[Tim88]

With new emphasis in bold red:

OOPS - I found an unspotted error in my example [..] it's of course not acceptable to have an error in the SR description when trying to explain the causes!

[..]

Now, to my surprise you still don't notice the issue but continue to support my original statement. This has nothing to do with philosophy and it is both pertinent and useful for SR, so I'll spin it off

 

Spinning off threads everytime you have difficulty with my statements isn't going to help. Fact is these details ARE INPORTANT. and should never be ignored when examining between models [..]

 

I stay on topic. If useful, the result will be fed back here for interpretations.

 

Note that we already decided to elaborate here on the initial synchronization. [edit:] I'll provide next the elaboration for the first interpretation.

Edited October 10, 2016 by Tim88

[Mordred]

I stay on topic as well. the Philosophy is a comparison between mathematical models. Its pointless to discuss the philosophy unless you understand those models and the math behind them.

[Tim88]

While I appreciate your good intentions, this means that you overlooked what I already stated in post #145 and even emphasized in post #151.

[Tim88]

Before posting an improved "car" example, time to search for some "loose ends"...

 

[...] One could then formulate everything in terms of this rest frame and look at what happens in other (inertial) frames.

But again, our modern understanding is that there is no aether and that field theory is the best understanding we have. [..]

 

 

It's quite unclear what the practical difference is between the assumption of "ether" and the assumption of "no ether but field".

I tend to interpret the last as either meaning that "spacetime doesn't exist, instead we have fields with properties in empty space" or even something like "spacetime has properties but it doesn't exist, so that nothing does have properties".

 

If something like either was meant, please input it in the "mother thread"!

[..] The block universe is a natural concept in special and general relativity, though as we like dynamics it is common and sometimes necessary to cut space-time into space and time. My own philosophical thoughts here - and many also hold the same thoughts - are that this cut should be avoided. Einstein tells us that space and time should be treated on equal footing. [..]

I think you meant Minkowski tells us that space and time should be treated on equal footing. Lorentz tells us that space and time are not the same physical entity (without objecting to the mathematical "equal footing"). Those differing views led to this topic, where the usefulness of 3D and 4D "ether" are compared. Can you or someone else clarify how dynamics works or why it exists, as you consider that there should be no cut between space and time - the "4D" view?

Some Einstein quotes:

 

<< From a "happening" in three-dimensional space, physics becomes, as it were, an "existence" in the four-dimensional "world". >>

(Albert Einstein. "Relativity: The Special and the General Theory." 1916. Appendix II Minkowski's Four-Dimensional Space ("World") (supplementary to section 17 - last section of part 1 - Minkowski's Four-Dimensional Space).

<< Since there exists in this four dimensional structure [space-time] no longer any sections which represent "now" objectively, the concepts of happening and becoming are indeed not completely suspended, but yet complicated. It appears therefore more natural to think of physical reality as a four dimensional existence, instead of, as hitherto, the evolution of a three dimensional existence. >>

(Albert Einstein, "Relativity", 1952).

<<...for us convinced physicists the distinction between past, present, and future is only an illusion, although a persistent one." >> ( Letter to Michele Besso family, March 21, 1955. Einstein Archives 7-245).

 

----------------------

Also, Karl Popper about his encounter with Einstein:

<< The main topic of our conversation was indeterminism. I tried to persuade him to give up his determinism, which amounted to the view that the world was a four-dimensional Parmenidean block universe in which change was a human illusion, or very nearly so. (He agreed that this had been his view, and while discussing it I called him "Parmenides".)...

[..]

Ah yes, these can be useful for the "4D" phrasing; although it's at first unclear to me how any of it can be helpful to make more sense of the equations. Notably "the concepts of happening and becoming are indeed not completely suspended, but yet complicated" suggests to me a possible unclarity.

It's a bit funny that Einstein provided good sources for both philosophical views - typically him.

[VandD]

 

Ah yes, these can be useful for the "4D" phrasing; although it's at first unclear to me how any of it can be helpful to make more sense of the equations.

Well, it's unclear to Einstein why you need presentism/aether/preferred frame of reference/etc to make more sense of the equations.

[Mordred]

Well, it's unclear to Einstein why you need presentism/aether/preferred frame of reference/etc to make more sense of the equations.

 

lol I don't know about Einstein but I never needed it. Even when I first started learning GR.

[Tim88]

Well, that's it; I will now repost your comments in the appropriate thread where Einstein explation why he needed it was summarized - the "mother thread".

Edited October 18, 2016 by Tim88

[Tim88]

OK, I now prepared a more elaborate summary of SR and classical effects, but I'll wait a few more days for feedback on the car example analysis and calculation.

 

Meanwhile it will be interesting to discuss and compare the views on "what really happens" in GR.

I'll now present the "Absolute Space" view of reality for some basic observations on Earth.

 

The gravitational fields of all mass (incl. the "relativistic mass" from radiation and EM fields) is in this view assumed to have absolute effects on the speed of light as well as on clock frequencies, as follows.

GRAVITY PROBE A (Vessot). An atomic clock is sent up to high altitude after which it comes down in almost free fall.

a. At the start, the clock ticks at the same speed as clocks on Earth.

b. At its highest point, the clock is nearly in rest but less affected by the Earth's gravitational field: a higher potential energy corresponds to a higher clock frequency than that of clocks on the ground - gravitational time dilation was measured.

c. When falling down, just before impact the clock is again at the same hight but at high speed. Here the remaining effect was purely SR time dilation, and so the ground station measured a reduced clock rate after subtracting the assumed "classical" Doppler effect. It's maybe worth noting that for the theoretical case that the ground is in "absolute rest", the SR effect relates to "absolute" kinetic energy, in contrast to the GR effect which relates to gravitational potential energy.

GRAVITATIONAL LENSING

a. Light bending. When light passes nearby a star such as the Sun, the gravitational field bends the light towards the star somewhat like an optical lens, due to a gradient in propagation speed; the tricky point here is that according to GR, the effect is anisotropic. As a matter of fact, Einstein used the Huygens construction for predicting the effect (the corresponding Wikipedia article fails to inform the readers on this point and suggest quite the contrary).

b. Gravitational time delay. Radiation that passes near to a heavy mass such as the Sun will not only bend but also delay. This is immediately understood as due to the slower propagation speed in the gravitational field (it's interesting to notice that the corresponding Wikipedia article mentions the slowdown of light that is denied in the other one).

I hope that the advantage of using not only a mathematical model but also an intuitive, conceptual model for understanding is obvious from the given examples (incl. the car; and I'll also post on the rotating disc). As a matter of fact, a good model enables to notice errors in papers and books that others may not notice.

However, as more people here fancy the Minkowski 4D blockuniverse interpretation (or a variant), I'm looking forward to hear the alternative explanations of GR effects by means of the Absolute Spacetime model.

Edited October 22, 2016 by Tim88

[koti]

I've read about half through this thread so far. I'd like to thank Tim88 for this thread and especially Studiot, Mordred and ajb for your effort in it. Even posts like #52 by Mordred are usefull to me despite the fact that I lack the math to fully appreciate it. It is all exhilarating to read.

Edited October 23, 2016 by koti

[Mordred]

your welcome, there is some excellent details in this thread.

[Tim88]

Thanks koti, it's good to know that there are some onlookers!

 

But what's the block universe explanation of those GR effects??

 

So, I regret that this thread apparently didn't attract a convinced Minkowski block universe adept, who promotes the idea that time and space correspond to a single physical thing called "spacetime" (seeing the two words "space" and "time" in a text connected like that, is for me an indication that the writer adheres to that concept - and therewith subtly influences possibly unaware readers).

 

Maybe the following can pull any lurking true Minkowskiist out of his/her hiding.

 

[..] The block universe is a natural concept in special and general relativity, though as we like dynamics it is common and sometimes necessary to cut space-time into space and time. My own philosophical thoughts here - and many also hold the same thoughts - are that this cut should be avoided. Einstein tells us that space and time should be treated on equal footing. [..]

And I replied:

 

I think you meant Minkowski tells us that space and time should be treated on equal footing. Lorentz tells us that space and time are not the same physical entity (without objecting to the mathematical "equal footing"). Those differing views led to this topic, where the usefulness of 3D and 4D "ether" are compared. Can you or someone else clarify how dynamics works or why it exists, as you consider that there should be no cut between space and time - the "4D" view?

 

As this was not clarified (or did I overlook it?), I'll include in the elaboration in my next post how the dynamics of inertia are conceptually explained with Absolute Space.

 

I now start to think that dynamics cannot be reasonably explained by the block universe, in which everything is "frozen" into eternal existence!

 

By the way, I noticed another "loose end":

Mordred on 8 October 2016 - 04:39 PM

 

High speed velocity addition ALONE is enough to prove a 4d universe.

I'll also include velocity "addition" in my elaborated explanation of SR by means of the 3D "ether".

Edited October 23, 2016 by Tim88

[Memammal]

I was trying to figure out what you were after, what you were insinuating with your previous post. It has now become clear. You seem convinced that these GR effects are irreconcilable with the block universe model, correct? Why do you think that?

[Tim88]

I certainly don't think that GR effects are incompatible with block universe! I referred to something completely different. The lack of clarification of how dynamics is caused by a "frozen" 4D merge of space and time should not be surprising; for how can "block universe" conceptually explain dynamics, if "time" is another physical dimension like length?

 

With my earlier "car example" I forgot to discuss the basics which are already pertinent for classical mechanics.

 

So here's a retake, starting with dynamics.

 

Physical effects such as inertia and time dilation can be modeled as caused by an underlying 3D background (non-material "ether" / "vacuum" / "Absolute Space"), but a more widespread view is that they are caused by a 4D background in which "space" and "time" form a single entity (block universe / "Absolute Spacetime"). One might ask, what is the practical difference? For a start, both models are proposed as CAUSING the space-time metric.

I'll elaborate how the Absolute Space model in "action" pretends to create classical as well as relativistic effects; additions by others are welcome (I will include a few by Mordred for the "car" example), and I invite those who adhere to the Absolute Spacetime model (Minkowski block universe) or similar, to post the corresponding alternative explanations to make sense of our observations.

ABSOLUTE SPACE model of reality:

There is supposed to be a 3D "background" that affects and determines our measurements; Absolute Space is directly associated with distances and lengths. Different from classical mechanics, measurements of distances and lengths are affected by Absolute Space.

In contrast with distances, time is a measure for the progress of physical processes; however our measurements of time are similarly affected by Absolute Space. Inertial frames (postulated to be in uniform translational motion relative to Space) can be set up just as in Newton's mechanics.

 

Similarly as in the old theory, the state of motion (speed) cannot be detected although a change of motion with respect to Space can be detected, since Space literally induces an inertial effect at a change of motion.

 

1. Newton argued for this with his BUCKET EXPERIMENT: in this model of reality, the inertial force is explained as the result of the water's co-acceleration with the bucket relative to Space.

[edit]: compare also De Sitter and dark energy: cosmology is not "my thing", but if I correctly understand it, even in an otherwise empty universe, rotation of an object should result in inertial effects. In what follows we'll use Occam's razor and assume that whatever it is that causes inertia, it's not moving relative to Absolute Space. Concepts such as cosmological expansion may impose refinements that are not fundamental for the explanations.

 

Inertia can even be understood in a straightforward manner as self induction for the simple case of the electron (QM improves on this quantitatively); this fact suggests the possibility that one day a unified theory may be found that explains all inertia as due to change of field energies.

 

Other improvements to Newton's Space following from Maxwell and Lorentz are that radiation does not propagate like particles but as waves (or, since QM, like wavelets), so that its speed is determined by the Space that it propagates through; and that matter is affected by motion just the same as Heaviside's moving EM fields.

In addition, effects of ROTATING DISCS are similarly easy to intuitively understand by means of Absolute Space:

2. SAGNAC EFFECT. For simplicity, let's first pretend that the axle is at rest in Space. If now laser light is sent along the rim in both directions, the light will, just like any real wave, propagate at a fixed speed through Space. During that time the detector will move away from the one ray and towards the other ray, so that the interference is a function of rotation speed relative to Absolute Space.

3. EHRENFEST PARADOX. Lorentz contraction only occurs in the direction of motion.
If the disc would be at rest in Space, then a measuring chord will be slightly contracted as it is laid along the rim, but not as it is laid along the diameter. Consequently the circumference will appear to be more than 2pi times the diameter (and there isn't any paradox to start with).

The combined effects of Lorentz contraction, time dilation and relativity of simultaneity (as elaborated in the upcoming extended car example post), assure that the same phenomena occur with rotating discs in any inertial reference system.

[edit: changed numbering]

Edited October 23, 2016 by Tim88

[koti]

Tim88...I don't want to disrupt the flow of this thread and alienate the guys who really know what they are talking about but I think there are some issues in your below post which I'd like to adress:

 

Thanks koti, it's good to know that there are some onlookers!
Oh I bet there are more than just me as this thread is very interesting

 

But what's the block universe explanation of those GR effects??

 

So, I regret that this thread apparently didn't attract a convinced Minkowski block universe adept, who promotes the idea that time and space correspond to a single physical thing called "spacetime" (seeing the two words "space" and "time" in a text connected like that, is for me an indication that the writer adheres to that concept - and therewith subtly influences possibly unaware readers).

I don't think that we need the growing block universe concept to promote the idea of spacetime. Adherence to the spacetime concept is the root of Einstein's genius and we will need much more than what you propose to undermine that concept which works so well on so many levels. I might be wrong but I have a notion that you are trying to look for holes in GR ?

 

Maybe the following can pull any lurking true Minkowskiist out of his/her hiding.

 

And I replied:

 

As this was not clarified (or did I overlook it?), I'll include in the elaboration in my next post how the dynamics of inertia are conceptually explained with Absolute Space.

 

I now start to think that dynamics cannot be reasonably explained by the block universe, in which everything is "frozen" into eternal existence!

Are you refering to "block universe" or the "growing block universe" as these are pretty much very different concepts as far as I know ?
I have a notion that the block universe concept is flawed. The idea that future events are part of a done deal is far fetched to me. A notion that nature cramped "that" much information into reality during the big bang and that ridiculous amount of information is stuck with us at every moment in time is hard for me to accept. As far as I'm aware the block universe got replaced with the growing block universe concept which is more user friendly at least in the sense that it doesn't state that future exists.

 

By the way, I noticed another "loose end":

I'll also include velocity "addition" in my elaborated explanation of SR by means of the 3D "ether".

[Tim88]

Tim88...I don't want to disrupt the flow of this thread and alienate the guys who really know what they are talking about but I think there are some issues in your below post which I'd like to adress:

 

Koti that's fine, as there isn't much discussion!

 

Oh I bet there are more than just me as this thread is very interesting

I hope so; I use this thread in order to divulge some of my metaphysical insights that helped me to get a better feeling for physics, and to compare them with the insights of others.

 

 

I don't think that we need the growing block universe concept to promote the idea of spacetime. Adherence to the spacetime concept is the root of Einstein's genius and we will need much more than what you propose to undermine that concept which works so well on so many levels. I might be wrong but I have a notion that you are trying to look for holes in GR ?

I was primarily referring to the standard "frozen" block universe.

 

As I now understand it, "growing" block universe (of which I had never heard until starting this topic) has a specific problem that michel spotted and strikingly named "double time": in order to explain our consciousness of "now", an additional "now" time must be added! However, I got the impression -thanks to ajb and Mordred- that also the standard, "frozen" block universe variant suffers from a need for "double time" if it wants to explain dynamic effects.

 

And I'm not looking for holes in GR nor would I want to undermine the space-time matrix as a mathematical tool; quite to the contrary, in view of one century of debates in philosophical literature, the starting assumption here is that both discussed interpretations are in agreement with the basics of SR and GR. At different times, Einstein promoted each interpretation.

 

If you click on the references in the first post of this thread, you will see that it's wrong to say that "Adherence to the spacetime concept is the root of Einstein's genius" - if with that you are referring to what is properly called Minkowski block universe. The confusion may have come to you by the news media.

 

 

Are you refering to "block universe" or the "growing block universe" as these are pretty much very different concepts as far as I know ?

I have a notion that the block universe concept is flawed. The idea that future events are part of a done deal is far fetched to me. A notion that nature cramped "that" much information into reality during the big bang and that ridiculous amount of information is stuck with us at every moment in time is hard for me to accept. As far as I'm aware the block universe got replaced with the growing block universe concept which is more user friendly at least in the sense that it doesn't state that future exists.

 

Indeed a "growing block universe" may be more easy to digest.. but it doesn't seem to help much in better explaining things, and it's a kind of mixed bag that seems to try to merge the Lorentz ether + real time with the Minkowski block universe.

PS. here's a little related "antidote" in the battle against the now obvious indoctrination, the effects of which keep interfering with this discussion:

 

"according to general relativity, the experimenter could set his laboratory rotating by leaning out a window and firing his 22-caliber rifle tangentially. Thereafter the delicate gyroscope in the laboratory would continue to point in a direction nearly fixed relative to the direction of motion of the rapidly receding bullet. [..] It is clear that what is being described here is more nearly an absolute space in the sense of Newton rather than a physical space in the sense of Berkely and Mach".

- C Brans - H Dicke, Mach's Principle and a Relativistic Theory of Gravitation, Physical Review, 1961

 

These GR experts appeared to have been unaware of the Minkowski block universe interpretation; in any case they didn't mention it.

[michel123456]

(...)

 

As I now understand it, "growing" block universe (of which I had never heard until starting this topic) has a specific problem that michel spotted and strikingly named "double time": in order to explain our consciousness of "now", an additional "now" time must be added! However, I got the impression -thanks to ajb and Mordred- that also the standard, "frozen" block universe variant suffers from a need for "double time" if it wants to explain dynamic effects.

 

(...)

I don't know if "double time" is a problem. It is surely bizarre but mathematically, and physically, seconds squared are being used without discussion. It is however conceptually difficult that there could be a 2nd Time topping Time. Even in String Theory, when eleven dimensions are introduced, it is explained that all dimensions are spatial and only one is time. And I wonder why.

------------------

And I think that in the 4D Block Universe, something must be introduced to explain the dynamics. I disagree with the concept of time being a "persistent illusion". Something physical is happening. Something like a "double time" is needed in this concept too.

-------------------

And I repeat my nonsense: what element proves us that the past is "frozen"? That it still exist somehow in the past cone?

Edited October 23, 2016 by michel123456

[Tim88]

[..] As I now understand it, "growing" block universe (of which I had never heard until starting this topic) has a specific problem that michel spotted and strikingly named "double time": in order to explain our consciousness of "now", an additional "now" time must be added! However, I got the impression -thanks to ajb and Mordred- that also the standard, "frozen" block universe variant suffers from a need for "double time" if it wants to explain dynamic effects.[..]

Oops I was thinking about the one variant while I wrote about the other, and so it got mixed up...

 

I intended to write that, as I now understand it, "growing" block universe has a specific problem that michel spotted and strikingly named "double time"; if I correctly recall it was in order to account for the advancing past. However, both the "block" and "advancing" interpretations should anyway explain our consciousness of a progressing "now", and I got the impression -thanks to ajb and Mordred- that both block universe variants also suffer from a need for "double time" if they want to explain dynamic effects.

 

I don't know if "double time" is a problem. It is surely bizarre but mathematically, and physically, seconds squared are being used without discussion. It is however conceptually difficult that there could be a 2nd Time topping Time. Even in String Theory, when eleven dimensions are introduced, it is explained that all dimensions are spatial and only one is time. And I wonder why.

------------------

And I think that in the 4D Block Universe, something must be introduced to explain the dynamics. I disagree with the concept of time being a "persistent illusion". Something physical is happening. Something like a "double time" is needed in this concept too.

-------------------

And I repeat my nonsense: what element proves us that the past is "frozen"? That it still exist somehow in the past cone?

 

Yes, I agree. Those negative issues make block universe concepts look unappealing to me.

 

Still, the focus here is more on useful features of the block universe.

So far I discern two clearly useful features for making sense of relativity (but only for specific aspects): a 1-1 relationship with the standard mathematical presentation, and the rather neat "odometer".

If nobody comes here to clarify how otherwise a block universe model of reality is useful for explaining relativistic physics, then it will start to look rather poor and weak compared to Absolute Space... I did expect it to be a little more attractive than that!

Edited October 24, 2016 by Tim88

[Memammal]

Tim88, this is indeed a very informative thread. I think we just need to be careful to not confuse ourselves and others and in the process get lost among Newtonian dynamics, Newtonian time, Einsteinian time, "cosmological time", Planck time and/or Planck constants, our human construct of Earth bound reality vs that of outer space, etc. Unfortunately I have been side-lined (and still am) with other pressing matters, otherwise I would have attempted to contribute more constructively to this discussion. That being said, it appears that you have questioned certain specific comments made by ajb & Mordred and it will probably be better if they themselves respond to those points.

 

Let me just quickly throw this in. We have a human construct of reality that is unavoidably link to our specific, albeit dynamic eco system. We sense time in the passing of day to night, from tide to tide, from season to season while we are bound by our dense atmosphere that provides us with an intimate sense of classical mechanics. Now let us (quickly) consider the concept of time. Imagine the way Mayflies (24 hour living span) versus a giant barrel sponge Xestospongia muta​ (approx. 2,400 years living span) would perceive time here on Earth. Think about it. Let us further imagine a human who is born on an intergalactic space craft on route to a galaxy far, far away. Imagine said person's sense of time and dynamics in a totally dark, totally weightless environment (consider for example said astronaut pushing him/herself in a direction and his/her illusion of movement...what is moving in relation to the other?).

 

It was Einstein who revolutionised the way scientists perceive time, no? Four-dimensional Euclidean spacetime, Minkowski space and the block universe model(s) resulted from it. In order for readers of this thread to get to grips with some of the fundamental basics of the various approaches that have been raised, I suggest the following background reading:

 

Absolute space and time​ (this article contrasts the classical views nicely with that of Einstein)

Minkowski space​

Relativistic dynamics

 

​And until I have more time to try and explain the various kinds of block universe models and the somewhat misleading interpretation of "frozen events" (as if it prohibits movement...opposed to change), let me leave you with a link to an article about a recent attempt by some of the world's most renowned physicists to reconstruct the block universe model (which seems to be very fitting to the thread):

 

A Debate Over the Physics of Time

According to our best theories of physics, the universe is a fixed block where time only appears to pass. Yet a number of physicists hope to replace this “block universe” with a physical theory of time.

 

Let me also add these:

Time, Free Will and the Block Universe (copied from other threads)

Growing Block Universe

 

* Edited to correct a grammar error *

Edited October 25, 2016 by Memammal

[studiot]

A few thoughts on the subject, especially since Tim has placed this discussion in 'philosophy'.

 

 

 

We are hostages to our own language, experience and preconceptions in considering this.

 

What do we mean when we propose that the 'block universe' is frozen or has existence?

 

Both are point concepts applied to something that is not a 'point' but substantial in extent, if not indeed infinite.

 

Because of this we look favourably upon the block concept because it avoids the twin difficulties of explaining how things come into and wink out of 'existence' as the moving finger writes and moves on.

 

1D, 2D, 3D, 4D space/ spacetime etc.

 

They are all just glorified graphs or plots.

 

Think of someone drawing a very long graph of y = x².

 

Until she has reach a particular point on the graph, that point 'does not exist' in some sense, so has to come into existence,

 

and then

As she draws the curve if she either

 

1) Leaves behind a trace which contiuses (in some sense) to exist.

 

or

 

2) Edward Scissorhands comes along and snips it off or it 'ceases to exist in some sense'

 

or

 

3) What?

[Tim88]

[..] Let me just quickly throw this in. We have a human construct of reality that is unavoidably link to our specific, albeit dynamic eco system. We sense time in the passing of day to night, from tide to tide, from season to season while we are bound by our dense atmosphere that provides us with an intimate sense of classical mechanics. Now let us (quickly) consider the concept of time. Imagine the way Mayflies (24 hour living span) versus a giant barrel sponge Xestospongia muta​ (approx. 2,400 years living span) would perceive time here on Earth. Think about it. Let us further imagine a human who is born on an intergalactic space craft on route to a galaxy far, far away. Imagine said person's sense of time and dynamics in a totally dark, totally weightless environment (consider for example said astronaut pushing him/herself in a direction and his/her illusion of movement...what is moving in relation to the other?).

 

OK. Apparently such person will still have a sense of time; however it will be less developed, as there isn't much more than that person's internal "clock" to go on. Interestingly, yesterday I heard in a talk that even red blood cells have a biological clock, so that their conductivity changes with the hour of the day.

However, it's not clear how that is useful for explaining laws of physics...

 

 

It was Einstein who revolutionised the way scientists perceive time, no? Four-dimensional Euclidean spacetime, Minkowski space and the block universe model(s) resulted from it.

 

Ehm no, not really, and different scientists perceive time differently; even this thread is witness thereof. A lot of things are pushed into Einstein's shoes (as no doubt also with Newton), but that one was mostly not Einstein's doing. His philosophy was formed and influenced by the people he frequented such as Lorentz and Minkowski. But I read that according to his autobiography he was first of all influenced by Hume and Mach.

 

Not that it matters much for us; we must make up for ourselves what metaphysics we deem most plausible.

 

 

In order for readers of this thread to get to grips with some of the fundamental basics of the various approaches that have been raised, I suggest the following background reading:

 

Absolute space and time​ (this article contrasts the classical views nicely with that of Einstein)

Minkowski space​

Relativistic dynamics

 

​And until I have more time to try and explain the various kinds of block universe models and the somewhat misleading interpretation of "frozen events" (as if it prohibits movement...opposed to change), let me leave you with a link to an article about a recent attempt by some of the world's most renowned physicists to reconstruct the block universe model (which seems to be very fitting to the thread):

 

A Debate Over the Physics of Time

According to our best theories of physics, the universe is a fixed block where time only appears to pass. Yet a number of physicists hope to replace this “block universe” with a physical theory of time.

 

Let me also add these:

Time, Free Will and the Block Universe (copied from other threads)

Growing Block Universe

 

Wow, thanks! Of course, better would have been if you had made a synthesis yourself, but I understand that you also are busy.

I'll look at it and see what of that material can be used for showing how "block universe" metaphysics can be helpful for making sense of physics - if only to be fair.

A few thoughts on the subject, especially since Tim has placed this discussion in 'philosophy'.

 

I reasoned that since there is no sub forum for metaphysics, it's more appropriately put under "philosophy" than under "physics" - especially as it may be unavoidable to occasionally make short excursions into "pure philosophy" and discuss ideas from philosophers. However we're here really at the boundary of physics and philosophy, far from the arguably "empty" and "useless" philosophy that Feynman made jokes about.

 

 

We are hostages to our own language, experience and preconceptions in considering this.

What do we mean when we propose that the 'block universe' is frozen or has existence?

 

Both are point concepts applied to something that is not a 'point' but substantial in extent, if not indeed infinite.

 

Because of this we look favourably upon the block concept because it avoids the twin difficulties of explaining how things come into and wink out of 'existence' as the moving finger writes and moves on.

 

Well, I hoped (and still hope) to find out what those concepts mean for practical understanding, by more "hands on" explanations than the usual philosophical debates that tend to neglect practical usefulness. What's the use of either concept for developing intuitive understanding of the physics? That's the focus here.

 

 

1D, 2D, 3D, 4D space/ spacetime etc.

 

They are all just glorified graphs or plots.

 

Think of someone drawing a very long graph of y = x².

 

Until she has reach a particular point on the graph, that point 'does not exist' in some sense, so has to come into existence,

 

and then

As she draws the curve if she either

 

1) Leaves behind a trace which contiuses (in some sense) to exist.

 

or

 

2) Edward Scissorhands comes along and snips it off or it 'ceases to exist in some sense'

 

or

 

3) What?

 

Maybe you lost me here! It appears to be a discussion (by means of 3D Space + dynamic time concepts!) of someone drawing (and next cutting) mathematical curves...

 

I think that it's essential - as done by both Langevin in 1911 and Einstein in 1916 - to distinguish the mathematical formalisms (as well as their pictorial representations) from the metaphysical concepts that they were based on, or that we may infer from them. Was that perhaps not sufficiently elaborated in the "mother thread"?

By the way, also that thread was put here in "philosophy", probably with the same reasoning.

[studiot]

 

Tim 88

Maybe you lost me here!

 

 

Perhaps because once again you have totally ignored my single main and most important point.

 

Which was

 

 

studiot

Because of this we look favourably upon the block concept because it avoids the twin difficulties of explaining how things come into and wink out of 'existence' as the moving finger writes and moves on.

 

The rest was just exemplification and elaboration.

[Memammal]

OK. Apparently such person will still have a sense of time; however it will be less developed, as there isn't much more than that person's internal "clock" to go on. Interestingly, yesterday I heard in a talk that even red blood cells have a biological clock, so that their conductivity changes with the hour of the day.

However, it's not clear how that is useful for explaining laws of physics...

Probably so as it may be a result of evolutionary adaptation to our particular eco-system and as such not something that is likely to change within one generation. I was however attempting to provide an analogy of a person having to operate in deep space without any references/memories of conditions on Earth. That would be a totally different ball game, not so?

 

Of course, better would have been if you had made a synthesis yourself, but I understand that you also are busy.

The articles that I referenced are mostly short and concise, except the one re Minkowski space...that one is pretty detailed (for reasons that would be apparent). There are a few important aspects contained within those articles, some that you and michel have raised in recent posts, so well worth the read especially by casual readers of this thread. I will try to highlight and elaborate on some of them a bit later.

 

I'll look at it and see what of that material can be used for showing how "block universe" metaphysics can be helpful for making sense of physics - if only to be fair.

Lol. Yes, kindly be fair to what has become one of- if not the best explanation for our current understanding of physics...even though physicists generally have a love/hate relationship with it because of that darn fixed future feature.

[koti]

A few thoughts on the subject, especially since Tim has placed this discussion in 'philosophy'.

 

 

 

We are hostages to our own language, experience and preconceptions in considering this.

 

What do we mean when we propose that the 'block universe' is frozen or has existence?

 

Both are point concepts applied to something that is not a 'point' but substantial in extent, if not indeed infinite.

 

Because of this we look favourably upon the block concept because it avoids the twin difficulties of explaining how things come into and wink out of 'existence' as the moving finger writes and moves on.

 

1D, 2D, 3D, 4D space/ spacetime etc.

 

They are all just glorified graphs or plots.

 

Think of someone drawing a very long graph of y = x².

 

Until she has reach a particular point on the graph, that point 'does not exist' in some sense, so has to come into existence,

 

and then

As she draws the curve if she either

 

1) Leaves behind a trace which contiuses (in some sense) to exist.

 

or

 

2) Edward Scissorhands comes along and snips it off or it 'ceases to exist in some sense'

 

or

 

3) What?

 

When you say that we are hostages to our language, experience and preconceptions it rings a (unfortunately a rather pessimistic) bell in me - consider this;

Would Ed Witten be able to comprehend the math of the true nature of the universe that an advanced alien civilization would convey to him? Furthermore, if not...would he be able to learn?

I don't think we can be sure that he would be able to learn and I don't think we can be sure that anyone could.

 

BTW...Wouldn't there be an issue (at least a philosophical one) with the block universe concepts concerning the amount of information involved?

Considering the original block concept where the past, present and future are done events wouldn't that mean that at or right after the big bang spacetime would have to be "stuffed" with a ridiculuos amount of information?

Edited October 26, 2016 by koti

[Tim88]

Perhaps because once again you have totally ignored my single main and most important point.

 

Which was

 

 

Because of this we look favourably upon the block concept because it avoids the twin difficulties of explaining how things come into and wink out of 'existence' as the moving finger writes and moves on.

 

 

The rest was just exemplification and elaboration.

 

Indeed I forgot to ask you what you meant with that, as we already know that both concepts avoid the "twin difficulties". Such difficulties arise when one assumes that there is no background at all.

 

And as was elaborated on the last pages, it seems as if there isn't much more that the block universe concept helps with.

[..] BTW...Wouldn't there be an issue (at least a philosophical one) with the block universe concepts concerning the amount of information involved?

Considering the original block concept where the past, present and future are done events wouldn't that mean that at or right after the big bang spacetime would have to be "stuffed" with a ridiculuos amount of information?

 

Interesting idea! Even if we assume that the "Space" part of Spacetime is finite, how about the eternal "time" part that is supposedly present and existing? That does sound huge, and "infinite" sounds as quite too much...

Probably so as it may be a result of evolutionary adaptation to our particular eco-system and as such not something that is likely to change within one generation. I was however attempting to provide an analogy of a person having to operate in deep space without any references/memories of conditions on Earth. That would be a totally different ball game, not so?

 

The articles that I referenced are mostly short and concise, except the one re Minkowski space...that one is pretty detailed (for reasons that would be apparent). There are a few important aspects contained within those articles, some that you and michel have raised in recent posts, so well worth the read especially by casual readers of this thread. I will try to highlight and elaborate on some of them a bit later.

 

Lol. Yes, kindly be fair to what has become one of- if not the best explanation for our current understanding of physics...even though physicists generally have a love/hate relationship with it because of that darn fixed future feature.

 

I don't know how you want to use reduced time consciousness for this discussion; but since that person's movements of arms and legs probably uses a kind of PID control (and that implies again activation of speed cells and "time" dynamics), I don't think that that would be a totally different "ball game".

 

And I really wonder if we did a poll, what percentage of people would vote for "block".

Edited October 26, 2016 by Tim88

[Memammal]

It was Einstein who revolutionised the way scientists perceive time, no? Four-dimensional Euclidean spacetime, Minkowski space and the block universe model(s) resulted from it.

Ehm no, not really, and different scientists perceive time differently; even this thread is witness thereof. A lot of things are pushed into Einstein's shoes (as no doubt also with Newton), but that one was mostly not Einstein's doing. His philosophy was formed and influenced by the people he frequented such as Lorentz and Minkowski. But I read that according to his autobiography he was first of all influenced by Hume and Mach.

 

Not that it matters much for us; we must make up for ourselves what metaphysics we deem most plausible.

Quoted from Absolute space and time​:

• In Einstein's theories, the ideas of absolute time and space were superseded by the notion of spacetime in special relativity, and curved spacetime in general relativity.​
• The theory of relativity does not have a concept of absolute time because there is a relativity of simultaneity. An event that is simultaneous with another event in one frame of reference may be in the past or future of that event in a different frame of reference, which negates absolute simultaneity.
• Even within the context of Newtonian mechanics, the modern view is that absolute space is unnecessary.
• Special relativity eliminates absolute time (although Gödel and others suspect absolute time may be valid for some forms of general relativity)^[16]...
• [This may be an important source as it could link back to quote from Michel: Something like a "double time" is needed in this concept too.]

• ...and general relativity further reduces the physical scope of absolute space and time through the concept of geodesics. There appears to be absolute space in relation to the distant stars because the local geodesics eventually channel information from these stars, but it is not necessary to invoke absolute space with respect to any system's physics.​​​

The above then also in reaction to:

If nobody comes here to clarify how otherwise a block universe model of reality is useful for explaining relativistic physics, then it will start to look rather poor and weak compared to Absolute Space...

 

And from Relativistic dynamics:

• Einstein rejected the Newtonian concept and identified t as the fourth coordinate of a space-time four-vector. Einstein's view of time requires a physical equivalence between coordinate time and coordinate space.
• The role of time was a key difference between Einsteinian and Newtonian views of classical theory.

As for this:

And I repeat my nonsense: what element proves us that the past is "frozen"? That it still exist somehow in the past cone?

I don't quite follow the logic behind this comment. How do you propose for the past to be changed, to be unfrozen? Surely you can understand that if you were able to observe a spacetime coordinate that sits somewhere in the "past", you will observe the exact same event..? What else?

 

BTW...Wouldn't there be an issue (at least a philosophical one) with the block universe concepts concerning the amount of information involved?

Considering the original block concept where the past, present and future are done events wouldn't that mean that at or right after the big bang spacetime would have to be "stuffed" with a ridiculuos amount of information?

Interesting idea! Even if we assume that the "Space" part of Spacetime is finite, how about the eternal "time" part that is supposedly present and existing? That does sound huge, and "infinite" sounds as quite too much...

With all due respect, it seems to me that you guys really do not grasp the model at all. The idea of the standard block universe model is that it is done and dusted, a complete package. It is also not dependent on us observing all of it (we observe what we have access to during our lifeline). It would not have existed in its current form if there was not enough "space". You might as well imply that there is not enough space for the universe..? So I don't quite follow your logic here (as with Michel). Let us consider the alternative. In stead of everything already existing, we have "new information" coming into existence ex nihilo every nanosecond; is that a more viable option? BTW, keep in mind that the BB was just one of many events/points within the bock universe.

 

OK, unfortunately I have to run again. I hope this would make some sense. FINAL EDIT

Edited October 26, 2016 by Memammal