SR and the passage of time

[guyger]

Does time pass in SR?

Rietdjik(1967)-Putnam(1968)-Sider (2001) Petkov (2006) ..Russell, Penrose and others, claim that SR proves "Eternalism".

That is; The world is an eternal (a-temporal) 4-dimensional spacetime manifold in which all events exist and the notion of passage of time, in other words a moving Now (a global hyper-surface of simultaneous "now events") moving towards the future is a psychological illusion. To quote Geroch;

There is no dynamics within space-time itself: nothing ever moves therein; nothing happens; nothing changes[...] one does not think of particles as ‘moving through’ space-time, or as ‘following along’ their world-lines. Rather, particles are just ‘in’ space-time, once and for all, and the world-line represents, all at once, the complete life history of the particle Geroch (1978 p. 20-21)

Is that physically substantial or only philosophically?

[michel123456]

To me it is not philosophical only.

The approach says that when time passes by, you continue to "exist" somewhere in the past. And the same for the future: it says that you are already "existing" in the future. This approach says that you are not a 3D human being living its life, it says you are a 4D "extended human being from its birth to its death". It says that from this 4D Reality, the thing you are perceiving is only 3D objects + the "illusion of time " coming from the 4th dimension.

 

My pet theory says it is wrong.

One of my argument could be that if the 4th dimension exists (aka Time), then why would it be perceived as an "illusion"? Time is that thing that allows motion to take place, time is the same real as distance.

 

For example, do you know Flatland?

Flatland is described as a 2D Flat world. But since events are able to happen in Flatland, time exists in Flatland. Which means that Flatland is a 3D world (2D of Space + 1D of Time).

The 3D of Flatland can be represented by a cube sliced in a succession of flat surfaces. Each surface representing a moment of NOW.

Ok you can do that, and build a 3D cube of solid wood with all points of all events happening in Flatland.

So what?

Is that time? Have we explained anything?

The question remains: what is the process that makes one slice slide to the other? Is it an illusion? Is that it?

 

Why is one slice able to observe the past slices and not the future ones? What is the process that gives the direction to the sliding? And the direction of the oservable?

And also: are the slices of NOW exactly flat? (hint: no they are not)

And also: can a specific point on a slice observe all the events of all past slices? (hint: no) And why?

And also, do all the slices continue to "exist"? Why are we so sure of that?

[Sensei]

To me it is not philosophical only.

The approach says that when time passes by, you continue to "exist" somewhere in the past. And the same for the future: it says that you are already "existing" in the future. This approach says that you are not a 3D human being living its life, it says you are a 4D "extended human being from its birth to its death". It says that from this 4D Reality, the thing you are perceiving is only 3D objects + the "illusion of time " coming from the 4th dimension.

 

My pet theory says it is wrong.

One of my argument could be that if the 4th dimension exists (aka Time), then why would it be perceived as an "illusion"? Time is that thing that allows motion to take place, time is the same real as distance.

 

For example, do you know Flatland?

Flatland is described as a 2D Flat world. But since events are able to happen in Flatland, time exists in Flatland. Which means that Flatland is a 3D world (2D of Space + 1D of Time).

The 3D of Flatland can be represented by a cube sliced in a succession of flat surfaces. Each surface representing a moment of NOW.

Ok you can do that, and build a 3D cube of solid wood with all points of all events happening in Flatland.

So what?

Is that time? Have we explained anything?

The question remains: what is the process that makes one slice slide to the other? Is it an illusion? Is that it?

 

Imagine we have "world" that's 2D array 2x2 fields.

Possible states are:

 

10

00

 

01

00

 

00

10

 

00

01

 

And mixtures of these.

 

Now we have frames going from:

10

00

 

it's changing to

01

00

 

it's changing to

00

01

 

it's changing to

00

10

 

Then everything repeats. Somebody observing it above, will say "1" is moving in circle.

 

Time in this example is index to frame, one full set of states.

 

Let's make it a bit harder: 3x3 array

 

100

000

000

 

let's assume that "1" can move only by one row/column, in 1 frame/time unit,

then jumping from above frame, to frame:

 

000

000

001

would be violation of our "law" of speed limit.

 

But if it's

000

010

000

 

Then

000

000

001

No speed limit law is violated.

 

State in one frame changes to state in other frame.

 

If you're looking at video/movie, nothing really moves on the TV/cinema screen.

Just different frames are drawn one by one 50/60 frames per second.

If player software will be randomizing index to frame, movie won't make any sense.

The same is with 2D/3D games we play on computer screen.

Do these players-3d objects, actually move?

They jump from one location:

x += vx * delta_time;

y += vy * delta_time;

z += vz * delta_time;

x,y,z is player position

vx,vy,vz is player speed in m/s

delta_time = time taken to render single frame in s (for proper synchronization, how fast/slow computer is generating frames)

 

Why is one slice able to observe the past slices and not the future ones?

Photons from event are send in the all (or one direction in minimum).

And if they're absorbed by detector (f.e. eye) we see what happened.

If event emitted just one photon, and you absorbed it, then nobody else will know about this event, only you.

 

What is the process that gives the direction to the sliding?

Conservation of energy, conservation of momentum, speed limit. etc.

 

And the direction of the oservable?

Thing that will happen in future, didn't released photons during event yet. So how do you want to see it?

 

And also, do all the slices continue to "exist"? Why are we so sure of that?

That depends on interpretation.

See above pet explanation of frames-all possible states to build.

Does frame

10

00

always existed, or it started existing when I wrote it on keyboard?

 

ps. It can be interpreted this way. Regardless of my personal opinion about the subject.

Edited October 25, 2015 by Sensei

[guyger]

Thank you verymuch guys.

Food for thought.

[david345]

These are you tube videos explaining the subject from string theorist Brian Green and theoretical physicist Sean Carroll. Most physicists believe we live in a block universe. Some uneducated internet trolls may disagree. They often use arguments such as "physics doesn't know everything therefore my theory is just as good." It isn't. That is why physicists don't use their theories. It is best to listen to the professionals.

 

 

[MigL]

" Uneducated internet trolls who disagree " ???

That's a little harsh.

 

What Michel123456 presented with his dimensional reduction ( Flatland ) analogy and what Sensei presented with his digital states analogy, are no different than the block universe.

All are models which can be used to make predictions.

Some models may make more accurate predictions.

Some models may apply to a broader range of boundary conditions ( circumstances ).

 

But are they reality ?

No, they are models describing some aspect of 'reality', whatever that may be.

 

And we may never know; we certainly accept this limitation in QM.

Is a quantum particle described best by the wave model or the particle model ?

They are both useful models in the right circumstances, but neither is reality.

Edited October 25, 2015 by MigL

[david345]

They are pet theories by non physicists such as yourself. Your argument comes straight off the wikipedia page for politicization of science.

 

"Researcher William R. Freudenburg and colleagues have noted that where decisions and action are required, science can offer valuable degrees of certainty, however, it can never offer a guarantee.^[4] John Horgan describes how this point is sometimes intentionally ignored as a part of what he calls an "Orwellian tactic".^[5] Organizations sometimes seek to shift all discussion on some issues away from 'conclusions are most scientifically likely' to 'even the more probable conclusion is still uncertain.'

Chris Mooney has claimed these tactics are used to gain more attention for views that have been undermined by scientific evidence. In his view, the media ends up in a misguided pursuit of "balance" which results in undue weight in reporting."

Edited October 25, 2015 by david345

[MigL]

I beg to differ.

I have a physics degree and am familiar with the block universe model.

 

But you, being better than the rest of us, should know that science is all about what can be proven and repeated.

So tell us how you can prove that your future already exists !

[david345]

Once again you are resorting to the method mentioned in the previous post.

[Sensei]

These are you tube videos explaining the subject from string theorist Brian Green and theoretical physicist Sean Carroll.

String theory has not been proven.

 

Not even experiment confirming it has been performed.

 

Most physicists believe we live in a block universe.

What physicist BELIEVE really does not matter. No matter what is name of him/her.

Matters what physicist can prove or disprove.

Performing the real experiment, not on white table.

 

Some uneducated internet trolls may disagree. They often use arguments such as "physics doesn't know everything therefore my theory is just as good."

But the most of time these people doesn't even know of decay modes of particles.. Nor can list them..

Comparison completely failing.

 

That is why physicists don't use their theories.

Silly comment.

 

You must use your own theory formulas with the real set of data to be sure result matches with reality..

That's what differs them from 'uneducated internet trolls', that skip this stage.

 

It is best to listen to the professionals.

No matter how professional you are,

you're limited to set of experimental data, especially if you're not experimental physicists.

You must rely on data provided by 3rd party people.

If they will make error while calculation, you will get wrong data.

And all calculations basing on them will be also wrong.

 

The thing is any professional does not know what he/she does not know.

New experimental data could completely disagree with established knowledge.

 

Imagine you are early XX century scientist. Atom was thought to be indestructible. You learned it in school.

And then somebody finds out it's not true. It can annihilate. It can decay. etc.

Your whole understanding of world is smashed..

For the most of people such turn around 180 degrees is very hard. As they used to what they learned.

Edited October 25, 2015 by Sensei

[david345]

It now appears you are simply posting long posts in an attempt to bury the arguments put forth by professional scientists. (Not just those who claim to have degrees while offering no proof). At some point you must present a theory that is better then our best theory. So far all you have done is say "Relativity makes some predictions. My theory makes some predictions. Neither are 100% proven therefore both are equally as good." That's not going to cut it.

 

These physicists are professors at prestigious universities. Einstein, Russel, Penrose, and many other highly accomplished physicists have supported the block universe view. You are simply a internet commenter. Neither you nor I know everything about the subject. This is why it is best to listen to the professionals and not the opinion of some internet commenter pushing "fringe" theories.

[Sensei]

Nobody in this thread has been publishing his own theory as far as I can see.

What michel123456 said in #2 post is rather objection, than theory.

 

It now appears you are simply posting long posts in an attempt to bury the arguments put forth by professional scientists.

The most famous neutrino scientist of the world (the most of physicists know his name, so I will skip it),

when I showed him couple years ago my applications which are analyzing the all data of 3142 stable and unstable isotopes (my own database), instantly wanted to have my applications, to use by whole university..

As it's immediately showing and sorting which materials, which isotopes of which elements, are the best neutrino detectors...

(and which isotope is stable, and which is unstable, and decay by which mode)

 

Command-line early version was presented in this thread:

http://www.scienceforums.net/topic/83451-radioactive-decay-and-information-split-from-what-is-real-in-physics/?p=808149

 

I wrote similar apps, for fusion, radioactive decay and neutrinos, basing on the same database.

How it compares to your achievements as 'professional scientists'.. ?

 

I could send 10 patents for new neutrino detectors in a day, if I would like to..

 

(Not just those who claim to have degrees while offering no proof). At some point you must present a theory that is better then our best theory. So far all you have done is say "Relativity makes some predictions. My theory makes some predictions. Neither are 100% proven therefore both are equally as good." That's not going to cut it.

 

These physicists are professors at prestigious universities. Einstein, Russel, Penrose, and many other highly accomplished physicists have supported the block universe view. You are simply a internet commenter. Neither you nor I know everything about the subject. This is why it is best to listen to the professionals and not the opinion of some internet commenter pushing "fringe" theories.

You must be really young. Quantum physics student?

They're sometimes under incredible, god-fearing influence of professors.

Whatever professor tells, is treated by them as absolute truth.

Undeniable and not questionable dogma..

Edited October 25, 2015 by Sensei

[MigL]

No-one is arguing against the block universe model, on the contrary it is an extremely valuable model.

That being said ALL of GR is a model, and the very fact that it doesn't apply at certain limits, means it is an incomplete model.

Who knows ( I certainly don't, neither do you, nor any of the eminent physicist you mentioned ), maybe the whole geometric model may have to be scrapped to reconcile it with QM ?

The only criteria we have to go by is whether the model is a good fit for what we measure.

If that seems 'old fashioned' to you and relies too much on proof, then I guess I'm an internet troll who claims to have a degree while offering no proof.

( oh, so now proof is valuable ??? )

 

P.S.- or maybe its just your arrogant, condescending, dismissive attitude that bothers me.

[david345]

The only criteria we have to go by is whether the model is a good fit for what we measure.

If that seems 'old fashioned' to you and relies too much on proof, then I guess I'm an internet troll who claims to have a degree while offering no proof.

( oh, so now proof is valuable ??? )

.

That model is Relativity. It is the most well proven theory we have. If you watched the videos you would have seen that the block universe is also compatible with QM. It's possible relativity is wrong. It's possible pink unicorns exist. Congratulations you realized we don't know everything. Your argument brings nothing to the table.

 

P.S. I've seen you on here many times before. Every time someone disagrees you start crying about them being a cyber bully. You need to grow up. You are a liar, a fraud, and a crackpot . That is what bothers me.

 

Note: I did not accuse Michael and sensi of anything. Migl accused me of referring to them. I am simply responding to insults directed at me by Migl.

Edited October 25, 2015 by david345

[swansont]

You need to grow up. You are a liar, a fraud, and a crackpot . That is what bothers me.

 

!

Moderator Note

 

What bothers me is posts attacking people. You've done it in several posts in this thread.

 

1. Knock it off.

2. Don't respond to this modnote.

 

 

 

One a broader note, nobody is really addressing the topic raised in the OP. If you want to go off on a tangent, start a new thread.

 

[michel123456]

One a broader note, nobody is really addressing the topic raised in the OP

 

 

The OP asked

 

Does time pass in SR?(...)

Is that physically substantial or only philosophically?

 

As it seems from the debate, I understand that everyone here must think it is a matter of physics, not a philosophical issue.

[swansont]

As it seems from the debate, I understand that everyone here must think it is a matter of physics, not a philosophical issue.

 

!

Moderator Note

The part you replaced with ellipses is what the "Is that physically substantial or only philosophically?" refers to. IOW, the issue of a particle in space-time. Everybody has gone off on their own particular tangent, but nobody has addressed that question.

[StringJunky]

Time must pass otherwise there would be no need for frames of reference.

[michel123456]

Oh you mean you want us to address the following

 

Rather, particles are just ‘in’ space-time, once and for all, and the world-line represents, all at once, the complete life history of the particle.

 

 

One interpretation is that a particle is not a point-like object anymore, but rather a one-dimension object (a line) from which we can observe only a section (a point). The line-like particle is frozen in spacetime.

 

The other interpretation is that a particle is moving in spacetime and its world line is the path of this particle. The point-like particle moves in spacetime.

[studiot]

Well, I looked up 'eternalism' on Wikipedia, for want of somewhere better and I did not spot the exact quote of the OP, if it was listed.

 

The world is an eternal (a-temporal) 4-dimensional spacetime manifold in which all events exist

I would therefore ask where does this come from or is it the OP interpretation of something else?

 

The reason I ask is because it is self contradictory.

 

I call it self contradictory because it states that the world (do you mean universe?) is both A-temporal and spacetime.

 

Come on, it is one or the other it cannot be both.

[VandD]

Does time pass in SR?

Rietdjik(1967)-Putnam(1968)-Sider (2001) Petkov (2006) ..Russell, Penrose and others, claim that SR proves "Eternalism".

That is; The world is an eternal (a-temporal) 4-dimensional spacetime manifold in which all events exist and the notion of passage of time, in other words a moving Now (a global hyper-surface of simultaneous "now events") moving towards the future is a psychological illusion. To quote Geroch;

There is no dynamics within space-time itself: nothing ever moves therein; nothing happens; nothing changes[...] one does not think of particles as ‘moving through’ space-time, or as ‘following along’ their world-lines. Rather, particles are just ‘in’ space-time, once and for all, and the world-line represents, all at once, the complete life history of the particle Geroch (1978 p. 20-21)

Is that physically substantial or only philosophically?

 

 

A few 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).

 

 

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".... >> (Karl Popper, Unended Quest: An Intellectual Autobiography.Routledge Classics. Routledge. pp.148–150).