The Passage of Time

[momuuu]

Now that's a very out of context usage of the principle of entropy and doesn't actually show much understanding. You can actually derive the definition of entropy without ever mentioning anything related to time. In truth the only relation it has with time is that it sort of assumes time is moving forward.

[Goodspeed]

I was a bit confused by the mention of the 2nd law of thermodynamics as well. Seems off topic

[oats13]

@momuuu "In truth the only relation it has with time is that it sort of assumes time is moving forward." as in a completely direct association with time you mean?

as in - @oats13 "conventionally you need a linear concept of time in order for the second law of thermodynamics to make a certain kind of sense" you mean?

Time is specifically mentioned in all of the major early contributors to the theory and it is completely on topic because on the one hand there is this idea where time is somehow non-fundamental like within a simulation where you 'speed it up' and you can't perceive it because you don't have to increase all the forces as well ( it is just like a video) or it is fundamental or emergent from a specific actual physical universe (perhaps the only one possible) in which you would notice if it were 'sped up'-

So it's like the op is similar to the chicken and egg question which is answerable according to whether it is a chickens' egg or just any egg.

Spank asked why time was important and so I linked it to an important idea with which it is fundamentally associated- I'm not a physicist but I am a Philosopher of sorts having made some contribution to some published works- this topic overlaps with ontology as callen said earlier- so long as we don't start doing cliched blackboard style equations i'm fine with it.

[momuuu]

You should read a textbook about entropy and then read your first post about it oats. You're spewing out nonsense.

[Laurence Drake]

Imagine time as a dimension. The OP is basically saying: "woah what if time moved twice as fast along the axes but everything also happened twice as fast!?" which is a meaningless statement since it doesnt mean anything. Wow, what if you know time passed twice as fast so every second 2 seconds would pass but the earth also rotates and moves twice as fast!? Spoiler, then everything would be the same and we've just constructed something that's just redefining the definition of a second. Time is actually just a measure for how long certain processes take, like how long it takes for the earth to rotate along its axis, how long it takes for a certain particle to decay, how long it takes for an object to fall on the ground from a certain height, how long it takes usain bolt to run 100m. If we speed time up and everything along it, then nothing happened. Usain bolt isn't faster, particles don't decay faster, an object still falls equally fast, we still perceive time the same way. So yes, one could speed up time but it wouldn't mean anything because literally everything in the universe would still be the same. It's a construct that doesn't add anything, can't be measured and simply complicates our understanding of the world if we would asssume it to be true. In other words, it's a useless construction.

Now if we phrase it like this: If we simulate something, we can speed up the simulation. That would be a more clear formulation. Thats really all the original post is saying, but it has a misplaced "wow mind is blown" aspect to it. In any case, yes you can speed up a simulation, just like how you can speed up a youtube video.

Can you speed up the radioactive decay of radium nuclei?

[oats13]

It would be highly amusing to my younger self but I actually don't like this kind of thing anymore. People can google time and the second law of thermodynamics for themselves.

[Laurence Drake]

phpBB [video]

[Goodspeed]

It would be highly amusing to my younger self but I actually don't like this kind of thing anymore. People can google time and the second law of thermodynamics for themselves.

There is no relation other than the obvious relation between time and any change including change in entropy. By mentioning the 2nd law specifically, you made it sound like the relation goes deeper than that. Maybe that's just how I interpreted it and wasn't your actual meaning, but hopefully you can understand why it seemed that way to me.

[momuuu]

conventionally you need a linear concept of time in order for the second law of thermodynamics to make a certain kind of sense and the second law is considered to be very important and then some- if we understand time better then we can possibly better understand any laws of physics- that's a very general way of putting it.

There is no contradiction between measurement and meaning, they both have value in the practical and emotional 'realms' as it were, and we live in both.

So lets look closely at you writing "you need a linear concept of time in order for the second law of thermodynamics to make a certain kind of sense".

Now one could phrase the second law in terms of entropy, which states that for a process the change in entropy is equal (for a reversible process) or larger than (for an irreversible process) than the change in heat divided by the temperature. The common "the entropy must always increase" happens when one applies this to a closed system, where the change in heat is zero. In that case, the change in entropy for a process is larger or equal to zero. In other words, in a closed system the entropy always increases. Now if you say the universe is a closed system, then the entropy indeed always increases.

A more accessible way to phrase the second law is that heat does not flow spontaneously from warm to cold. This is where a sense of time is, for if we would revert time then one could so a cool body warm up from the heat of the air spontaneously (that would be, playing back a hot body cooling from the warmth of the air) which is indeed not in agreement with the 2nd law of thermodynamics. So yes, time is probably not reverted. Basic causality suggests time is not reverted anyways so I dont see that much value in this statement.

Then here is the flaw in your thinking: You somehow introduce that the 2nd law of thermodynamics requires a linear concept of time. It frankly does not. Whether time accelerates exponentially or is accelerated at one point to another or whatever form the flow of time theoretically would have doesn't affect this 2nd law. As long as heat doesn't randomly start flowing from cold to warm (that is basically as long as time moves forward) then the 2nd law of thermodynamics is just fine.

There are also some other remarks to make: In this thought experiment, the universe isn't a closed system so the entropy can actually decrease aswell. Also, the 2nd law of thermodynamics is simply an empirical law, it's not as much of a universal undeniable truth, its merely how we measured the universe to sort of work. That way we measure it could also be the result of our universe moving at a very rapid time pace to an outside observer, in theory at least.

[Dolan]

One thing: The 2nd law of thermodynamics (2LoT) is a statistical law, which means it's true on average, but doesn't have to be true in every case.

Another thing: I might have posted this before, but are you guys aware that the 2LoT doesn't hold so well at a microscopic level?

Violations of this law at a microscopic level have already been reported experimentally:

http://rsc.anu.edu.au/~sevick/groupwebp ... 50601(2002).pdf
(DOI: 10.1103/PhysRevLett.89.050601)

https://rsc.anu.edu.au/~sevick/groupweb ... 004%29.pdf
(DOI: 10.1103/PhysRevLett.92.140601)

Classical thermodynamics doesn't apply at a microscale. Basically we can say that entropy runs in reverse at this level and that motion can follow reversible trajectories. At a small scale, molecular nano-machines can actually generate work by taking heat from the environment, consuming entropy.

[oats13]

It would be highly amusing to my younger self but I actually don't like this kind of thing anymore. People can google time and the second law of thermodynamics for themselves.

There is no relation other than the obvious relation between time and any change including change in entropy. By mentioning the 2nd law specifically, you made it sound like the relation goes deeper than that. Maybe that's just how I interpreted it and wasn't your actual meaning, but hopefully you can understand why it seemed that way to me.

Well, when I was doing physics (admittedly 25 years ago) the second law was regarded as being the only law that required directionality of time, I'm aware that some quite rare processes in particle physics are now supposed to share this quality but I really wouldn't know about them. I said also that " if we understand time better then we can possibly better understand any laws of physics- that's a very general way of putting it." This is in reference to some theories outside of the convention that DO go beyond what you call the "obvious" so in that way I'm balancing my statement and I can see then that is why it seems like I was saying myself that the "relation goes deeper than that" when I was simply trying to communicate to spank that this was by no means a complete picture.

The whole quote is-

"@spanky4ever- conventionally you need a linear concept of time in order for the second law of thermodynamics to make a certain kind of sense and the second law is considered to be very important and then some- if we understand time better then we can possibly better understand any laws of physics- that's a very general way of putting it."

I'm quite clearly addressing a convention about the arrow of time and the second law and how it makes "a certain kind of sense" not a kind of sense that is certain. I'm then stating that the second law is important which is plainly in reply to spanks question and I'm then qualifying the sentence with "that's a very general way of putting it" - I don't see what is controversial about this sentence.

spank asked a simple question as to what the use any of this is and so I gave her what I thought was the most important thing that was attached to time and I expressed that as a 'linear concept' and herein lies the nub of the problem I think.

@momuuu "Then here is the flaw in your thinking: You somehow introduce that the 2nd law of thermodynamics requires a linear concept of time. It frankly does not. Whether time accelerates exponentially or is accelerated at one point to another or whatever form the flow of time theoretically would have doesn't affect this 2nd law. "

Firstly it was apparent in which way I meant time because you re-state it yourself " In truth the only relation it has with time is that it sort of assumes time is moving forward" but you dismissed this idea wholesale previously- "You're in over your head here I fear. I don't even think the second law of thermodynamics has something to do with time tbh."

That is equivalent to saying it has nothing to do with time but it specifically requires a flow and as far as I know anything with a flow needs to go 'forwards' in time, hence 'unscrambled eggs'.

Something is the opposite of nothing last time I checked, which is why in my first post in this thread I said "On the metaphysical- The axis from which we draw our graph of reality on the paper called time are existing and not existing."

You then amended your criticism to that of the use of the word linear- firstly I was actually talking about the 'concept'- if you want to argue the toss about the word linear then fine but that is another conversation (in fact I have an idea for a shape that I would happily discuss if that conversation happened) but I think it was apparent that I was referring to 'the arrow of time', if it wasn't clear then it is now.

"There are also some other remarks to make: In this thought experiment, the universe isn't a closed system so the entropy can actually decrease as well. Also, the 2nd law of thermodynamics is simply an empirical law, it's not as much of a universal undeniable truth, its merely how we measured the universe to sort of work. That way we measure it could also be the result of our universe moving at a very rapid time pace to an outside observer, in theory at least."

That is the whole point- originally I was posting to support your observations that none of this was possible in the real world and that it was even more complicated than had previously been discussed and that one would have to simplify the concept within the thought experiment to a degree which would basically be self-evident in order to have any meaning.

Therefore the op presents a shape-of A and B with B subdividing again where A is the thought experiment and B is a universe where time has some kind of 'essential' relationship with basically anything in that universe and the subdivision is a universe where time doesn't have that relationship, is either non-existant, or basically 'last in the queue of all things' so to speak.

Like the chicken and the egg it depends on which particular question one is asking- I'm not 100% sure which question @Jam is asking.

[Jam]

One thing: The 2nd law of thermodynamics (2LoT) is a statistical law, which means it's true on average, but doesn't have to be true in every case.

Another thing: I might have posted this before, but are you guys aware that the 2LoT doesn't hold so well at a microscopic level?

Violations of this law at a microscopic level have already been reported experimentally:

http://rsc.anu.edu.au/~sevick/groupwebp ... 50601(2002).pdf
(DOI: 10.1103/PhysRevLett.89.050601)

https://rsc.anu.edu.au/~sevick/groupweb ... 004%29.pdf
(DOI: 10.1103/PhysRevLett.92.140601)

Classical thermodynamics doesn't apply at a microscale. Basically we can say that entropy runs in reverse at this level and that motion can follow reversible trajectories. At a small scale, molecular nano-machines can actually generate work by taking heat from the environment, consuming entropy.

Yeah well:

https://tinyurl.com/kddpv5v

https://tinyurl.com/otfhbm4

[Dolan]

I get the joke, but I don't think those studies are a case of "we can prove anything with a bit of statistics manipulation" sort of thing. I wouldn't be so dismissive of research just because a big % of it is crap.

What they found could be really useful in nanomachines. You know, stuff that could be used in many ways in medicines, materials science, products etc.

[Jam]

I get the joke, but I don't think those studies are a case of "we can prove anything with a bit of statistics manipulation" sort of thing. I wouldn't be so dismissive of research just because a big % of it is crap.

What they found could be really useful in nanomachines. You know, stuff that could be used in many ways in medicines, materials science, products etc.

I wasn't actually criticizing your articles, just making a cheap joke. Sorry.

[deleted_user]

♫ Every thousand years
This metal sphere
Ten times the size of Jupiter
Flies just a few yards past the Earth
You climb on your roof
And take a swipe at it
With a single feather
And you do it once every thousand years
Until you've worn it down
To the size of a pea
Yeah, I'd say that's a long time
But it's only half a blink in the place we're going to be ♫

[Horsemen]

♫ Every thousand years
This metal sphere
Ten times the size of Jupiter
Flies just a few yards past the Earth
You climb on your roof
And take a swipe at it
With a single feather
And you do it once every thousand years
Until you've worn it down
To the size of a pea
Yeah, I'd say that's a long time
But it's only half a blink in the place we're going to be ♫

Don’t bump old, bad threads

Also Built to Spill’s older albums need to be on Spotify as well