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Why the Flow of Time Is an Illusion

nautil.us

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Re: Why the Flow of Time Is an Illusion

#151

Post by obastani »

aassddffasdf wrote: post #144
obastani wrote: post #96

Earlier quoted context omitted.

I'm not an expert, but I don't think that quote is quite right. There is still a notion of time, there is just no notion of a direction of time. For example, if you go deep into empty space, then one patch of space looks just like the next one. That doesn't mean there is no longer a physical concept of space. Similarly, just because one point in time doesn't look very different from the next, doesn't mean that there…

We are in a pocket of high order/ low entropy (not high entropy).

That's what I meant -- thanks for the catch!

Re: Why the Flow of Time Is an Illusion

#152

Post by cairo_x »

How easy is it for physicists to mistake their models for reality? Equations are ways of representing reality. They are not reality. They are literally abstractions. Yes, it's another way of seeing and thinking about a thing, but it is not the thing... at all. Like a description of 4d space. Isn't a thing in reality, it is an abstraction. The only things that are not abstractions WRT time are movement and matter. Period. When ever you start freezeframing and creating integrations (4d view of time), then you've crossed into the world of the abstract and the non-existent.

Re: Why the Flow of Time Is an Illusion

#153

Post by Retra »

supergarfield wrote: post #108
obastani wrote: post #96

Earlier quoted context omitted.

I'm not an expert, but I don't think that quote is quite right. There is still a notion of time, there is just no notion of a direction of time. For example, if you go deep into empty space, then one patch of space looks just like the next one. That doesn't mean there is no longer a physical concept of space. Similarly, just because one point in time doesn't look very different from the next, doesn't mean that there…

Speaking of this, does anyone know of an explanation for why the direction in spacetime in which entropy decreases is parallel to the time dimension (the one with a different sign in the relativistic metric) of spacetime? Maybe I'm missing something, but I've never seen a link made between the two.

Low entropy systems are likely to transition into high entropy systems, and the reverse is unlikely to occur. It is largely a statistical argument; low entropy states are by definition less likely to occur by chance than high entropy states.

(You might then ask why we care what happens 'by chance'; the answer is either that physics is fundamentally unpredictable, or that the scale of the universe so large that the influence of the whole on any particular subsystem must necessarily be modeled with noise.)

Re: Why the Flow of Time Is an Illusion

#154

Post by obastani »

supergarfield wrote: post #108
obastani wrote: post #96

Earlier quoted context omitted.

I'm not an expert, but I don't think that quote is quite right. There is still a notion of time, there is just no notion of a direction of time. For example, if you go deep into empty space, then one patch of space looks just like the next one. That doesn't mean there is no longer a physical concept of space. Similarly, just because one point in time doesn't look very different from the next, doesn't mean that there…

Speaking of this, does anyone know of an explanation for why the direction in spacetime in which entropy decreases is parallel to the time dimension (the one with a different sign in the relativistic metric) of spacetime? Maybe I'm missing something, but I've never seen a link made between the two.

I'm not sure, and this is a lot of speculation, but I feel like it has to do with the fact that mass/energy is conserved over time (but not in space) [1]. The mass now corresponds to the mass in the past/future, which, for example, allows memories to form. In any case, time is still a qualitatively different dimension than space.

[1] https://en.m.wikipedia.org/wiki/Conservation_law#Exact_laws

Re: Why the Flow of Time Is an Illusion

#155

Post by sridca »

cobbzilla wrote: post #68

I find this quote fascinating: "What I think that means is there is no holy era of time. It emerged. If, in the distant future, we find ourselves in a universe where all the stars have burned out, and all the black holes have evaporated, and all the radiation has been diluted by the dark energy that expanded our universe, and all we have is some very cold bath of photons here and there—basically thermal equilibrium;…

> there will be no sense of time anymore [...] This is the way the world ends

If there is no sense of time why does the world "end"?

> If that is true, then time never really ends, it just "slows down" a lot (not much can happen, and not terribly quickly) until the next sparkup, whereupon time speeds up dramatically (inflationary theory).

Time slowing down or speeding up is still a "sense of time". Moreover time slowing down or speeding up is a human perception, and not a fact of the universe.

Re: Why the Flow of Time Is an Illusion

#156

Post by sridca »

DiffEq wrote: post #129
cobbzilla wrote: post #68

I find this quote fascinating: "What I think that means is there is no holy era of time. It emerged. If, in the distant future, we find ourselves in a universe where all the stars have burned out, and all the black holes have evaporated, and all the radiation has been diluted by the dark energy that expanded our universe, and all we have is some very cold bath of photons here and there—basically thermal equilibrium;…

Here is the crux. Time IS motion. We measure this motion of objects relative to one another by comparing their motion to a standard set of things in motion called a clock. There is nothing else to time except that; but it is real, as real as anything, it is not an illusion.

Yes, it is the sense of time moving that is an illusion; Time itself is a fact, and can be measured.

Re: Why the Flow of Time Is an Illusion

#157

Post by Retra »

Zaphods wrote: post #127
TeMPOraL wrote: post #76

Earlier quoted context omitted.

> The idea that consciousness is an algorithm or a computer or a machine is an assumption that is extremely popular among people in the tech industry because it confirms their assumptions No, it's not because of that. It's because it is effectively a computer. Not in the vague sense of "it has stuffs connected to stuffs and there's electricity involved", but in the more specific sense that it takes inputs, produces c…

> It's because it is effectively a computer. Not in the vague sense of "it has stuffs connected to stuffs and there's electricity involved", but in the more specific sense that it takes inputs, produces complex outputs, has clearly identifiable hardware and indirectly identifiable software. It even has internal structure we're only beginning to understand, but that we know enough about to reasonably infer what comput…

Computers "imagine" things all the time. The fact that we do not use the word "imagine" to describe it is immaterial. Words to not dictate the behavior.

Re: Why the Flow of Time Is an Illusion

#158

Post by supergarfield »

jbay808 wrote: post #136
supergarfield wrote: post #108

Earlier quoted context omitted.

Speaking of this, does anyone know of an explanation for why the direction in spacetime in which entropy decreases is parallel to the time dimension (the one with a different sign in the relativistic metric) of spacetime? Maybe I'm missing something, but I've never seen a link made between the two.

As opposed to entropy decreasing as you travel, say, toward the galactic north? It's a good question. One answer could be the mostly spatially uniform initial conditions of the big bang. Also, a spatial entropy gradient would gradually diffuse over time to become uniform again. But in general, the arrow of time is a consequence of systems that store a memory of their pasts, which is possible because the past is lower…

Thanks for the answer. I mean exactly that! Thoughts on your thoughts:

> One answer could be the mostly spatially uniform initial conditions of the big bang.

That's fair, but in that case, to continue the galactic north analogy, is there a reason why the Big Bang couldn't have happened uniformly in the dimension-3 hyperplane of (time, plane of the milky way) instead of the space hyperplane?

> a spatial entropy gradient would gradually diffuse over time to become uniform again.

But wouldn't that be "diffuse over direction-of-decreasing entropy time", not "diffuse over relativistic-time-dimension time"? In that case, I don't think it would help.

Apologies if I'm missing your points or not making sense, I can't claim I understand any of this well. I just feel like I see a lot of circular arguments around this :).

Re: Why the Flow of Time Is an Illusion

#159

Post by Retra »

egjerlow wrote: post #63
EGreg wrote: post #47

Earlier quoted context omitted.

How do you know that what you say about consciousness isn’t just a language game you play where you define words in terms of other words that are hardly connected to anything? “What it is like to be a bat” “What it is like to experience something” After having seen descriptions of all the physical components of experience: “It is Qualia! What it is like to see red” Having been described all the differences between se…

I'm not really sure what you're arguing here. I would certainly say consciousness is 'something more', and that this something more has to be something non-material (or at least using 'materials' that have wildly different properties than what we observe using the scientific method). Theseus' ship is a problem for a purely materialistic explanation of consciousness, for, by that account, consciousness should be a fun…

Theseus' ship is not a problem for materialistic explanations of anything; it's a problem for anybody who thinks the nature of a thing is governed by the words used to describe it.

The fact that you would continue to call a ship the same after exchanging all its parts is not an ontological problem, it is a problem arising from the imprecise use of language or intention to use an approximate/aggregate notion of identity. (I would recommend studying topology for a more modern understanding of this.)

Re: Why the Flow of Time Is an Illusion

#160

Post by monkeydreams »

DiffEq wrote: post #129
cobbzilla wrote: post #68

I find this quote fascinating: "What I think that means is there is no holy era of time. It emerged. If, in the distant future, we find ourselves in a universe where all the stars have burned out, and all the black holes have evaporated, and all the radiation has been diluted by the dark energy that expanded our universe, and all we have is some very cold bath of photons here and there—basically thermal equilibrium;…

Here is the crux. Time IS motion. We measure this motion of objects relative to one another by comparing their motion to a standard set of things in motion called a clock. There is nothing else to time except that; but it is real, as real as anything, it is not an illusion.

> Time IS motion.

Relatively speaking, yes.

> There is nothing else to time except that; but it is real, as real as anything, it is not an illusion.

The article isn't claiming time is an illusion, only our perception of it flowing.

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