Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Ron Hughes on 19/04/2010 17:15:16

Title: Is there a limit on time?
Post by: Ron Hughes on 19/04/2010 17:15:16
Time is malleable. As a clock falls into a gravity well it slows with respect to an observer that is stationary with the gravity well. If a clock is accelerated it slows with respect to a stationary observer. Is there a limit as to how slow or fast time can flow? In the case of slow time, no matter if you put all the energy and mass of the entire Universe into a black hole, the flow of time would still not completely stop it could only approach zero. So the limit in this case is unobtainable. Is there a limit in the other direction. I would think the same condition would apply, that it could approach infinitely fast.
Title: Is there a limit on time?
Post by: LeeE on 20/04/2010 19:56:19
You seem to be thinking of a temporal equivalent of 'c' and the phenomenon of relativistic time dilation suggests that there is a maximum speed of time, for with relativistic time dilation the rate of time would become zero if the rate of spatial displacement became 'c', which in turn suggests a maximal rate of time if the rate of spatial displacement could be reduced to zero.
Title: Is there a limit on time?
Post by: Ron Hughes on 21/04/2010 17:50:30
No Lee, I don't think you understand what I mean. You have a biological clock that will tick on average seventy five years. The Universe has a clock, according to mainstream physics, that will tick for about 10^30th years, this is the theoretical life span of the electron and proton. This is almost an infinite amount of time compared to yours. For the sake of this discussion lets theorize that the radiation our universe turns into, will expand into a larger Universe identical to ours in makeup and that we are a part of this larger Universe. Our Universe was created by the collision of two charged particles in this larger Universe whose clock runs almost infinitely slower than ours.As you can see this scenario could be carried out infinitely forever in both directions. So time in the larger Universes would just keep getting slower and slower while in the other direction time would just keep getting faster and faster. That is why I claim time has no limits in either direction.
Title: Is there a limit on time?
Post by: LeeE on 21/04/2010 22:32:38
Your original question made sense to me but as soon as you start positing:

Quote
For the sake of this discussion lets theorize that the radiation our universe turns into, will expand into a larger Universe identical to ours in makeup and that we are a part of this larger Universe. Our Universe was created by the collision of two charged particles in this larger Universe whose clock runs almost infinitely slower than ours

...then you're on your own.

There's no way of either verifying or disputing this position, so there's no way to argue it, either for or against.
Title: Is there a limit on time?
Post by: Murchie85 on 22/04/2010 01:19:08
Hi LeeE,

I wanted to latch on to your comment and see if you could help answer something for me. If for example spacial displacement in theory was possible to reach zero and hence the rate of time would be at a maximal. Would that imply that for example no displacement in the atoms of the object in question, thus meaning zero kinetic energy and then 0degrees kelvin..... thus zero volume :S Hope its just a simple missunderstanding
Title: Is there a limit on time?
Post by: LeeE on 22/04/2010 17:15:07
On the face of it there would seem to be a correlation between 0 K and zero kinetic energy, and thus to the rate of time, but then it's believed that a system at 0 K would still have QM zero-point energy and so molecular motion would not cease at 0 K, and so presumably, neither would time stop.

However, I don't quite see how zero volume comes into it (which is not to say that zero volume/area/length objects/particles cannot exist, for in n-dimensional environments, other than our own 4-D space-time, they would seem to be inevitable).
Title: Is there a limit on time?
Post by: yor_on on 23/04/2010 00:04:03
Time is motion, at least 'times arrow' is. Everything that measures time move in some way as far as I know. Temperature is also motion, without any motion at all zero temperature as I think :) But we can't go there as HUP makes it impossible. The things making sense to us all exist inside Planck time, except possibly virtual particles?

I don't expect there to be a 'limit' to time, there is to its arrow though as the fastest we can 'move' classically is the speed of light in a vacuum. But it seems also very plastic if the idea of 'Unruh radiation' and 'Rindler observers' are as I understands them. Then you have different universes depending on your relative motion, where virtual particles become real particles for those traveling at those velocities. And if that is true then you as easily can argue that what you changed is not motion, but times arrow. And changing that you will observe a different universe.

And if that is true it makes sense differing between 'time' and its arrow, well, as I see it. Entropy then? Well its a measure of movement too, isn't it? That Gluon soup waiting, will it have movement then?
Don't know?
Title: Is there a limit on time?
Post by: Murchie85 on 23/04/2010 10:57:39
Hi Leee thanks for that, I wasn't sure if there was still quantum motion at 0k, the reason I mentioned zero volume is for I remember one of the things being taught at college chemistry/phyiscs with regards to the gas laws is as temperature reaches zero its volume decreases and theoretically at zero degrees kelvin then the volume also must equal zero.
It may have been a simple analogy in how volume changes with temperature but i thought it fitting ot ask.
Title: Is there a limit on time?
Post by: LeeE on 24/04/2010 01:46:07
Hmm... now that's interesting.  I can't say I've ever given much time or thought to the gas laws.

The first thing that occurs to me is that they only make sense at the molecular level, but the inference that the volume of a molecule will reduce to zero at 0K implies a collapse into a singularity because the molecule has a non-zero rest-mass i.e. it would become a microscopic Black Hole.  However, being so small, the BH will have a very high temperature and will almost immediately evaporate...  into what?

Another thing I'm wondering about is that if you're considering the kinetic energy of a single molecule, with the kinetic energy being a measure of the spatial speed of the molecule, to what is that measurement [of spatial speed] relative?  A single gas molecule then, would appear to have different levels of kinetic energy, and potentially exist in different states, depending upon your point of view.
Title: Is there a limit on time?
Post by: Atomic-S on 24/04/2010 04:34:28
The gas law PV = nRT, which implies zero volume at zero temperature, is a macroscopic approximation that is wholly inappropriate to describe condensed matter at the molecular level. Matter at 0K would continue to occupy about the same volume as ti does at 1K or 10K or (certain gasses excepted) 100K. At 0K, matter continues to have considerable kinetic energy, due to the fact that electrons cannot fall below certain levels due to the Pauli exclusion principle. What you do have at 0K is the system in its lowest quatum energy state.