The Block Universe and The Flow of Time

Discussions on classical and modern physics, quantum mechanics, particle physics, thermodynamics, general and special relativity, etc.

Re: Instant Results

Postby rajnz00 on May 23rd, 2020, 12:28 am 

Faradave » May 22nd, 2020, 11:53 pm wrote:Through most of his work in optics light was thought to transmit instantly.


I would be very surprised if Newton thought the speed of light was infinite. His explanation of Snell's law of the diffraction of light was the ratio's of the speed of light through different mediums. And even Galileo knew the speed of light was finite.
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Re: Quotes from Sabine Hossenfelder

Postby rajnz00 on May 23rd, 2020, 2:33 am 

http://backreaction.blogspot.com/2008/0 ... -then.html

Needless to say, my believe that the past, present and future exist in the same sense goes back to time being a coordinate in Minkowski-space and not a parameter. Since some people commented on this in the previous post with mentioning the problem of time in General Relativity, let me emphasize I didn't say it follows that nature can't be a succession of present moments for this reason [2]. I'm just saying that very possibly this is the origin of my personal opinion, and I occasionally wonder how far our education influences the opinions we hold on philosophical questions [3].


(Emphasis mine)

http://backreaction.blogspot.com/2008/0 ... verse.html

In my earlier post Every Now and Then I explained why I think the most plausible explanation for our perception of the now being different from the past and the future is due to the ability of our brains to store memory. I thus believe in the 'block universe' in which there is nothing special about the now, and the past and the future exists in the same way as the present moment.

Nevertheless, I want to point out this isn't more than a believe of mine that I personally find plausible. Especially, I do not think it follows from Special Relativity, as some comments indicated - and as also Petkov argues in his paper.

(Emphasis mine)
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Re: The Block Universe and The Flow of Time

Postby DragonFly on May 23rd, 2020, 2:49 pm 

rajnz00 » April 12th, 2020, 7:15 am wrote:People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion.” Albert Einstein


This is a fine thread, Rajnz.

Using philosophy to build up to to the mode of time, we first have to note that what basically 'IS' has no option but to be, ever, since there can be no alternative, such as 'non-existence', which cannot even be meant or said, and so I've put it in quotes.

It seems, then, that it can only transmute/transition in such a way that it can always return to any of these states of itself, as kind a topological transformation, which 'turning' we call the laws of nature.

More so, it appears that it can never be still, as being energetic, for its temporary patterns can never last longer than an instant. While we call these 'changes', overall it must ever remain as itself.

So, in summary, that one can deduce, I would tend to banish Beginning, End, Nought, Stillness, Infinity, Apart, Originality, Free Will, and He.
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Re: The Block Universe and The Flow of Time

Postby rajnz00 on May 23rd, 2020, 4:22 pm 

DragonFly » May 23rd, 2020, 2:49 pm wrote:....

Using philosophy to build up to to the mode of time, we first have to note that what basically 'IS' has no option but to be, ever, since there can be no alternative, such as 'non-existence', which cannot even be meant or said, and so I've put it in quotes.

It seems, then, that it can only transmute/transition in such a way that it can always return to any of these states of itself, as kind a topological transformation, which 'turning' we call the laws of nature.

More so, it appears that it can never be still, as being energetic, for its temporary patterns can never last longer than an instant. While we call these 'changes', overall it must ever remain as itself.

So, in summary, that one can deduce, I would tend to banish Beginning, End, Nought, Stillness, Infinity, Apart, Originality, Free Will, and He.


Wouldn't that mean that nothing exists? That everything is an illusion? That would explain everything, but I don't find that a satisfying explanation.
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Re: The Block Universe and The Flow of Time

Postby DragonFly on May 23rd, 2020, 4:32 pm 

rajnz00 » May 23rd, 2020, 3:22 pm wrote:Wouldn't that mean that nothing exists?


There is the Eternal Permanent and that's it.


As for Presentism’s problem being so, then

The unborn future is inherent in the past,
It’s ‘will be’ is real, since no unreal contrast class,
As there’s no opposite to existence—no Nil;
It’s not just that future is going to exist.

The present now undergoes an updating,
In a fleeting swoosh that passes it away,
For the ‘now’ fades, consumed, as future becomes,
Yet, what will become past can’t just non-exist.

One of my videos: Now Here; No Where
https://www.youtube.com/watch?v=TTfbGc3Oka8
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Re: The Block Universe and The Flow of Time

Postby rajnz00 on May 23rd, 2020, 6:35 pm 

DragonFly » May 23rd, 2020, 4:32 pm wrote:There is the Eternal Permanent and that's it.

As for Presentism’s problem being so, then

The unborn future is inherent in the past,
It’s ‘will be’ is real, since no unreal contrast class,
As there’s no opposite to existence—no Nil;
It’s not just that future is going to exist.

The present now undergoes an updating,
In a fleeting swoosh that passes it away,
For the ‘now’ fades, consumed, as future becomes,
Yet, what will become past can’t just non-exist.


I don't think the future is inherent in the past, as in that it can be absolutely predicted by the past.

Presentism undergoes a dynamical updating?

Yes I think so. Constant new Events is this dynamical updating, that are created, or allowed to be created by the expanding Universe.

So reality is created anew at every Now?

Yes, I would say so. It’s a moving wave, which is probably the expansion of the Universe, which is expanding all around each one of us, creating space and time as it goes. The reality that we experience with our Nows.

The expansion is maybe the hardware where information is manipulated?

"Yet, what will become past can’t just non-exist."

I think it can, Even chairs and tables become old. They are not the chairs and tables they used to be. Events happen and pass. Memories fade. Unless there is a Universal memory keeping track of every event. And I don't think so. The evidence is that memories don't last forever and they fade with time.
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Re: The Block Universe and The Flow of Time

Postby rajnz00 on May 23rd, 2020, 6:47 pm 

Re davidm’s posts, I am not claiming his arguments are invalid, or that the Block Universe cannot exist, my argument is limited to showing that presentism, specifically in regard to Einstein’s train thought experiment, is not precluded by that experiment.
And I think I have successfully defended that argument.
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Re: The Block Universe and The Flow of Time

Postby davidm on May 23rd, 2020, 7:10 pm 

This seems to me to be a significantly weaker claim than what you started with. As for Sabine and the block universe, in the comments section of her block universe thread, someone wrote:

Ok sorry, now i get it, i think. You are saying that you don't have to connect existence with simultaneity within SR, because even if we had this hypothetical existence slicing (not the simultaneity plane) to define existence, then we wouldn't know the difference with the laws of SR.[/quote\

To which she replied:

Yes, you got it :-)


To me, this pretty clearly indicates she is endorsing the above-mentioned surface presentism, but only as a defeater for Petkov’s claim that SR by itself entails a block universe. The idea, again, is that there may well be a privileged absolute reference frame that cannot be detected from within SR (or any other current physics). And … yeah, that could be true, I guess, but again, if one goes this route, it is pure article-of-faith stuff — not science.

The important point to note, however, is that the presentist goes this route because he recognizes that SR does pose a major threat to presentism, and must be dealt with if presentism is to be vindicated. So is that now your stand? It sure didn’t seem to be your stand at the start of this thread.

Remember also that Sabine won’t commit to the existence of an apple, based on observing an apple.
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Re: The Block Universe and The Flow of Time

Postby rajnz00 on May 23rd, 2020, 8:15 pm 

davidm » May 23rd, 2020, 7:10 pm wrote:Remember also that Sabine won’t commit to the existence of an apple, based on observing an apple.


That sounds almost like a presentist, who would say that the apple of a second ago is not the apple of now.

That time passes could be an illusion. That the past ceases to exist could be an illusion.

Even that the future exists could be possible, though I find that much harder to believe, as 1. There is no accompanying illusion to sustain that and 2. There is zero evidence that the future exists, unlike the past, which has evidence that it, at least, at one time existed.

Or, that there is permanence could be an illusion. We do have the illusion of permanence. A caterpillar can change almost in front of our eyes, but my car looks pretty much the same today as yesterday when I drove in it. But just like the river of Heraclitus, where we never step into the same river twice, that is an illusion. It does change slowly, imperceptibly, from event to event.

The difference between our Nows and those of a stone is that we have the added facility of recording our Nows with our consciousness, during our lifetimes. It’s almost like that provides crosschecks of events in spacetime.

Therefore, I think that living is a significant event in time. There is a profound difference between being alive and being dead.

Similarly that apple, that we buy from the market, hold in our hand and even bite into, changes imperceptibly from moment to moment. Only being in our Here/Now it’s existence is intersecting with our existence so we can be sure it exists along with us, in our moments.

To me for the past to exist, we would have to have more than Universal time, but a universal memory. If I hit a stone with a hammer n times and walk away, those events would have to be recorded and the records kept permanently

Just my thoughts on the fly.
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Re: The Block Universe and The Flow of Time

Postby DragonFly on May 23rd, 2020, 8:56 pm 



I don't think the future is inherent in the past, as in that it can be absolutely predicted by the past.

As a side note for you all: I just discovered a great new show, called DEVS, that explores this.


Presentism undergoes a dynamical updating?

Yes I think so. Constant new Events is this dynamical updating, that are created, or allowed to be created by the expanding Universe.

So reality is created anew at every Now?

Yes, I would say so. It’s a moving wave, which is probably the expansion of the Universe, which is expanding all around each one of us, creating space and time as it goes. The reality that we experience with our Nows.

The expansion is maybe the hardware where information is manipulated?


Dark energy’s the fuel that keeps on giving.


"Yet, what will become past can’t just non-exist."

I think it can, Even chairs and tables become old. They are not the chairs and tables they used to be. Events happen and pass. Memories fade. Unless there is a Universal memory keeping track of every event. And I don't think so. The evidence is that memories don't last forever and they fade with time.


That all may return is akin to all History.

The sun is not the same sun as it was a trillionth of a second ago, although to us the semblance of the ‘sun’ remains.

There are, strictly speaking, no objects that are identical with themselves over time, and so perhaps the temporal sequence probably remains open.

Nature would then then no longer seen as clockwork, but only as a ‘possibility gestalt’, the whole world occurring anew each moment; however, the deeper reality from which the world arises, in each case, acts as a unity in the sense of an indivisible ‘potentiality’, which can perhaps realize itself in many possible ways, it not being a strict sum of the partial states.

It appears to us, though, that the world consists of parts that have continued on from “a moment ago”, and thus still retain their identity in time; yet, matter likely only appears secondarily as a congealed potentiality, a congealed gestalt, as it were.
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Re: The Block Universe and The Flow of Time

Postby rajnz00 on May 24th, 2020, 12:57 am 

DragonFly » May 23rd, 2020, 8:56 pm wrote:

I don't think the future is inherent in the past, as in that it can be absolutely predicted by the past.

As a side note for you all: I just discovered a great new show, called DEVS, that explores this.

I’ll try and watch DEVS sometime

Random thoughts
The Block Universe makes no sense. My end and yours already exist? Not only that but that of the whole Universe?

After the Big Bang, space and time was created. This creating is still going on and may well never end, so how can we know the end?

Creation itself means something new. Space that didn't exist before, time that didn't exist before. How can it be known what's in the new creation(s)?

In fact we don’t even know the beginning. Everything breaks down an infinitesimal second before the beginning.

We don’t know the beginning and we don’t know the end, so how can we have a Block Universe?

Another time, another place, my friend. I think you are in a more idyllic island than I am.
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Re: The Block Universe and The Flow of Time

Postby davidm on May 24th, 2020, 7:06 pm 

The evidence for a block universe, of course, is the special theory of relativity, such evidence having been spelled out in this thread, and in the many papers I have linked. This is why we see presentists turning cartwheels trying to reformulate a coherent presentism (point presentism, cone presentism, surface presentism) because they understand the challenge that SR poses to presentism.

Presentism fares even worse under general relativity. Closed time-like curves have been mooted that would be spacetime paths to the past. The physicist Paul Davies wrote a book, How to Build a Time Machine, in which he shows that in principle (though perhaps this will always remain beyond our technology) one might connect two disparate regions of spacetime with a wormhole, or even find an existing wormhole that does this, and use it to travel to the past. Of course, these scenarios require that the past exists in order to travel to it, and that the future exists in order to have a spacetime region to travel to the past from. General relativity give us the past, present and future on the required equal ontological footing. Of course, GR is in conflict with QM and may turn out to be incomplete.
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Re: The Block Universe and The Flow of Time

Postby rajnz00 on May 25th, 2020, 2:58 am 

davidm » May 24th, 2020, 7:06 pm wrote:The evidence for a block universe, of course, is the special theory of relativity,

By “evidence” you mean assertion. “The evidence for a block universe, of course, is the special theory of relativity” is an assertion, if I ever saw one.

I do not accept that either the past exists or the future.

Your response:
Eternalism vs. Presentism
Your position is called presentism — the idea that only the present exists. The past used to exist, but no longer does. The future will exist, but does not yet.

The competing position is eternalism — that the past, present and future all exist; they share equal ontological footing. Socrates exists; he is just temporally distant from me — (in an “earlier than” state). People in the far future exist; they are also just temporally distant from me, in a “later than” state. These sorts of temporal relations are called McTaggert’s B-series of time.


So you have defined Presentism above, (as well as eternalism), a definition I agree with. I shall call this definition 1.

This is what you need to be defending, if you are a presentist. The presentist claims that there are distant present events, everywhere in the universe, that occur simultaneously with the finger snap. This is presentism’s core foundational claim, the exact definition or [of] presentism.


I shall call this definition 2.

Now anyone can see that definition 2 is not the same as definition 1.

Definition 2 is defined as the very thing that SR says doesn’t happen. Hence presentism is refuted. Very nice.

If I substitute eternalism for presentism in definition 2, I would get “The eternalist claims that there are distant present events, everywhere in the universe, that occur simultaneously with the finger snap. This is eternalism’s core foundational claim, the exact definition or [of] eternalism.”

Now please tell us how eternalism is compatible with SR? I have perfectly crafted the definition of eternalism to be antagonistic to SR.

But how does davidm arrive at definition 2 from definition 1?

There is obviously an argument from definition 1 to definition 2. An argument is not evidence. The argument has to be examined.

Definition 2 is claimed to be derived from definition 1, through an argument.

I have made comments on both Petkov’s argument (and your argument about Einstein’s train experiment), as to why, on first principles, they are wrong.

Sabine Hossenfelder also didn’t think too highly of Petkov's argument.

Her definition of presentism:
Presentism means there is a notion of 'now' and it is only the 'now' that exists.
Short and sweet and the same as mine.

Her statements which I have quoted are pretty clear and unequivocal, but you have to reiterpret her to suit your narrative and get her to say what she is not saying.
PS
SR does not rule out a privileged, absolute at-rest frame — it only rules out that this frame can ever be found within SR itself.

Where did you get that from? The first postulate rests on the very denial of what you are claiming. Is this your own postulate?

I have used Einstein's thought experiment to give my argument, with the help of phyti and his spacetime diagram and argument, why presentism is perfectly compatible with SR. ( http://www.sciencechatforum.com/viewtopic.php?f=2&t=35865&p=350840&hilit=awareness#p350840 ).

It directly contradicts the reasoning in your argument. It is there for you to examine and refute. The argument is simple and short. No Jargon, refernces or labels.

Neither you nor anyone else has addressed it. Or pointed out any fallacies in the reasoning.

You can do so anytime you want.
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