Is Time Real? Proving Its Existence

[Dale]

Good way to put it.

DaleSpam, I haven't seen his technical papers. Do you have any references? .

Sorry about the delay. Here is his main site for his technical papers:
http://www.platonia.com/papers.html

I have not read all of them, only "Machs principle and the structure of dynamical theories", "Leibnizean time, Machian dynamics, and quantum gravity", and his fqxi essay. I didn't find any of them convincing, and he actually soured me on Machs principle too.

 

[Dale]

But that's just about things changing. One thing happens and then another and then an ice age comes along or two and animals die and turn to oil. That's not Time. That's stuff changing.

And how could stuff change without time?

Mathematically change is given by a derivative, e.g. df/dt where f is the thing changing and t is the thing with respect to which it changes. So conceptually the changes you refer to all presuppose time.

 

[Selraybob]

That's a bold statement on the surface but is just semantics.

I looked up 'semantics' just to make sure I knew what you were saying. And what I'm figuring is that all of this discussion on the topic is semantics. Every idea is about the definition and meaning of the word Time and how it fits with all of the science. So I don't understand what you were getting at.

That's a very weak excuse.

I know you're a lot smarter than me and way more educated, so that clearly means something. But I was only talking about your question about why this topic keeps coming up. No one should need an excuse to bring something up on physicsforums. Of maybe I'm wrong on that. I don't know. But dang, if scientists didn't question what everyone thinks is the absolute right way, we'd probably be still drilling holes in people's heads to get the demons out.

A lot of things do not makes sense AT FIRST, and then makes sense later after you learn a bit more!

Don't worry, Zapper, I'm still reading. And I'm going to do some reading on broken time-reversal symmetry, to see if that isn't just about something changing back when something else is changing forward. But I don't know yet, so I'll look.

Phenomena that have been characterized by broken time reversal symmetry are strong evidence for an inherent and intrinsic properties of time.

Like I said, I'll do some reading.

Saying that it is nothing more than a "counter" implies that you can't tell the difference between a quality and the SCALE used to quantify that quality.

I'm not picking on Time, but I think I'm saying that Time isn't a quality. And if you do want to start counting some change that happens over and over, the scale's going to be different. And it can be different depending on what you're counting. But what I'm figuring is that you're set that Time is some quality. So I think we're stuck disagreeing.

One could argue the same thing with space, charge, mass, etc. So why pick on "time"? "Space" is also a CHANGE in something, which is displacement.

Zz.

I looked up Displacement, and from first reading, that seems to be a count of space. Space isn't the change in displacement.

But then, you're smarter than me, like I said, and more educated I'm sure, so I'll keep reading and disagreeing until someone comes up with something that doesn't just come back to Time being all about the count of changes.

 

[GrayGhost]

And how could stuff change without time?

Well, that's what Julian Barbour (and others) are spending much of their life trying to explain. So far, no bananas :)

The goal (of some) is to define a 4d (or more) continuum already laid out start to end, then develop a description for the sequencing within it that gives rise to our notion of time in the way we experience it. Basically, to find an alternative way to describe change which does not require time, but gives rise to our existing concept of it. A tall order. I think it's a worthy quest, given it is not expected to change physics, but rather hopefully extend physics.

GrayGhost

 

[Dale]

Well, that's what Julian Barbour (and others) are spending much of their life trying to explain. So far, no bananas :)

The goal (of some) is to define a 4d (or more) continuum already laid out start to end, then develop a description for the sequencing within it that gives rise to our notion of time in the way we experience it. Basically, to find an alternative way to describe change which does not require time, but gives rise to our existing concept of it. A tall order. I think it's a worthy quest, given it is not expected to change physics, but rather hopefully extend physics.

I think that the problem for Barbour et al. is that physics is written in terms of differential equations wrt time. While you can cast it in terms of a 4d continuum, as long as you are differentiating there is something you are differentiating wrt. That something includes time. I think that they will need to eliminate differential equations from physics in order to accomplish their goal. A very tall order, as you say.

 

[stevenb]

Does time really Exist?

I'll tell you later.

 

[atomthick]

I think that the problem for Barbour et al. is that physics is written in terms of differential equations wrt time. While you can cast it in terms of a 4d continuum, as long as you are differentiating there is something you are differentiating wrt. That something includes time. I think that they will need to eliminate differential equations from physics in order to accomplish their goal. A very tall order, as you say.

Probably this will never be done. Differential laws (equations) bring much more value than the removal of time. Unlike integral laws (equations), differential laws give us the possibility to compute the next state of a system given it's previous states, which what is ultimate desire in physics.

 

[GrayGhost]

I think that the problem for Barbour et al. is that physics is written in terms of differential equations wrt time. While you can cast it in terms of a 4d continuum, as long as you are differentiating there is something you are differentiating wrt. That something includes time. I think that they will need to eliminate differential equations from physics in order to accomplish their goal. A very tall order, as you say.

Well, when you put it that way, it does seem unlikely. I suppose I should break down and look thru that book of his.

Even when attempting to cast differential equations in terms of a 4d continuum, there is still this "other thing" we know to be time. It's a natural contiguous progression of everything. We all assume it has a rate, and that it is steady. Minkowski's model suggests that the rate of proper time equates to the rate of light. Let's say hypothetically, that the rate of proper time was to change all of a sudden. OK, so imagine a Minkowski worldline diagram ... the stationary observer's horizontal line-of-simultaneity (LOS) advancing vertically, with other slanted worldlines here and there. No matter how much faster (or slower) we advance this LOS, nothing changes geometrically. And so how could we ever discern a change in time's rate, even if it did? This is analogous to saying ... how could we ever discern a change in light's speed? ... which reminds me of your other post where you addressed this mathematically. One reason many ask ... is time what we assume it to be?

I'm also wondering ... as one steps thru J Barbour's 4-scape of Platonia, how does he prevent a steppage into the past? That is, how does his Platonia prevent a reversal along a worldline?

GrayGhost

 

[nitsuj]

I looked up 'semantics' just to make sure I knew what you were saying. And what I'm figuring is that all of this discussion on the topic is semantics. Every idea is about the definition and meaning of the word Time and how it fits with all of the science. So I don't understand what you were getting at.

Without a doubt there is a concise/strict definition for time in physics, and I doubt that it is what I had said. However, what I said is true, and is from the context of perception of time, not physics.

That was what I was "getting at" using the word semantics.

 

[tennismike22]

Existence implies taking up space in our universe. Then simply put...NO.

 

[Dale]

That was what I was "getting at" using the word semantics.

Wow, a semantic argument about the word semantic. Impressive. Is that a meta semantic argument?

 

[nitsuj]

Wow, a semantic argument about the word semantic. Impressive. Is that a meta semantic argument?

lol,

yes it was,

 

[ZapperZ]

If this thread is now discussion the concept of time not based on physics, but based on "perception", then it no longer is a physics discussion. It is done.

Zz.