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Author Topic: Does time exist at a quantum level?  (Read 6513 times)

Offline thedoc

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Does time exist at a quantum level?
« on: 01/11/2013 09:30:04 »
Cleon w  asked the Naked Scientists:
   I know that those who claim to understand these things, suppose that there are up to ... I think the current guesstimate is 13 ... Dimensions at the sub atomic level, most of which fold up so small that they only exist at the sub atomic level.

I find myself wondering whether it is possible that a converse could also be true ... Is it possible that time either does not exist, or it exists but in a different form ... at the sub atomic level?

The reason I ask this is that the absence of time at that level neatly explains the various quantum anomalies.

Lets face it, we do know that time can behave strangely even at our scale.

I'd be interested to know what you guys think of this thought

Regards
Cleon White


What do you think?
« Last Edit: 01/11/2013 09:30:04 by _system »


 

Offline Supercryptid

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Re: Does time exist at a quantum level?
« Reply #1 on: 02/11/2013 21:12:05 »
If time did not exist on a subatomic level, that would make half-lives of unstable subatomic particles difficult to explain.
 

Offline Pmb

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Re: Does time exist at a quantum level?
« Reply #2 on: 02/11/2013 21:57:08 »
If time did not exist on a subatomic level, that would make half-lives of unstable subatomic particles difficult to explain.
If time doesn't exist then the worldline of a particle in a 2D spacetime (t,x) would be a point.

Pete
 

Offline CliffordK

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Re: Does time exist at a quantum level?
« Reply #3 on: 03/11/2013 01:00:16 »
Unfortunately "time" is something that has often been discussed, but poorly defined.

Aren't electrons considered subatomic particles?  Assuming they are discrete entities, then they have periodic movement around atoms, and thus time.  Are we able to measure electron location, speed, and direction?  Or was that something that was considered impossible to measure?

Nonetheless, on the subatomic scale, an electron's orbit should be similar to using a planet or moon's orbit to measure time.

Many of our clocks also depend on periodic vibrations on the atomic scale.

What about velocity, acceleration, and distance?  A positron may be emitted in a certain direction, and endure for a certain period of time while traveling a certain distance before inevitable destruction.
 

Offline Ethos_

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Re: Does time exist at a quantum level?
« Reply #4 on: 03/11/2013 01:49:11 »
Planck time is equal to: 5.391 e^-44 sec. According to theory, there can be no event, in nature, occurring at shorter intervals than this value. One can surmise then, that time is digital and must advance in multiples of Planck time. This means that time does not advance at a continuous rate as one might think. Time does not, in analogous terms, flow as if it were a river. It stutter-steps along, from one Planck unit to the next. What does this mean in practical terms? For we humans, nothing, we will never notice, these units are just too small. However, for the quantum world, where particles can reside in two different places at once, it's a critical necessity. There are a few scientists that have even suggested that each unit of Planck time generates it's own particular universe, separate and singular from the one before and the one that follows. Very strange indeed!
« Last Edit: 03/11/2013 03:27:00 by Ethos_ »
 

Offline woolyhead

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Re: Does time exist at a quantum level?
« Reply #5 on: 03/11/2013 19:27:08 »
Rovelli's idea about quantum gravity finds that time exists in Planck sized loops. So does space in this theory. I'd like to know what exists between these loops. I wonder if it's sub space, ie what was here before the big bang. In the book "Quantum Gravity" by Carlos Rovelli, Cambridge Monographs on Mathematical Physics he gives 9 different meanings of the word "time" and describes each one. The best everyday meaning I can find is Thermodynamic Time. Everything obeys the law of thermodynamics, ie time never goes backwards even though the laws of physics are not usually dependent on the direction of time. But his quantum gravity time loops are the most interesting for me. I didn't know there is supposed to be a whole universe inside each loop, however. Since there are time loops and they are separate from space loops, wouldn't the universe inside any loop be devoid of either space or time? How would it function? I know you are not claiming that things are like this. Are we even talking about the same definition of time here? Which definition are you discussing?I fully agree with you that the absence of time at some level would be very useful for explaining some anomalies in quantum physics. For example Bell's hypothesis being wrong, ie Aspect's experiment. The spin relationship of entangled particles is noticed to be unaltered, even on the picrosecond time scale,  no matter what is done to alter one of them, no matter how far apart the particles are. The problem then is "how did the distant particle know when to change its spin?" My idea is that as well as spacetime there is subspace, in which the speed of light is infinite.
« Last Edit: 09/11/2013 18:51:22 by woolyhead »
 

Offline yor_on

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Re: Does time exist at a quantum level?
« Reply #6 on: 09/11/2013 00:08:46 »
You can't do any observations at Planck scale, as far as I know that is? A arrow is consistent with change though, and assuming that a scale is a representation of something able to be defined as 'always being there' even through a 'ideal magnification', as of a light quanta (which we define as a point particle:) then I don't know, you should be free to assume a change happening at all scales there, possibly? If we define it such as all observations break down at Planck scale though, then a arrow is consistent with how we think of decoherence, they sort of goes hand in hand as you go up in scale.
 

Offline JP

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Re: Does time exist at a quantum level?
« Reply #7 on: 09/11/2013 03:07:06 »
Planck time is equal to: 5.391 e^-44 sec. According to theory, there can be no event, in nature, occurring at shorter intervals than this value.

While you're right about the length of Planck time, all that we know is that our theories don't extend to sub-Planck time scales.  We don't know what happens below those scales, so its all speculation.

But back to answering the original post: time does certainly exist on the quantum scale.  In fact, quantum mechanics works by describing events in space and time.
 

Offline Ethos_

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Re: Does time exist at a quantum level?
« Reply #8 on: 09/11/2013 05:03:37 »
Planck time is equal to: 5.391 e^-44 sec. According to theory, there can be no event, in nature, occurring at shorter intervals than this value.

While you're right about the length of Planck time, all that we know is that our theories don't extend to sub-Planck time scales.  We don't know what happens below those scales, so its all speculation.

But back to answering the original post: time does certainly exist on the quantum scale.  In fact, quantum mechanics works by describing events in space and time.
Your observation is certainly true my friend, nevertheless, the facts also depends on how we describe time. When we talk about time, we tend to think of it as a singular aspect of the natural order when it is not. Time can't be divorced from it's ever present partner; Space. In fact, one might say that it is a false assumption to consider one without the other. They are intrinsically inseparable. Instead of "space and time", it would be more correct to say: Space-time. The continuum of dimensional events.
« Last Edit: 09/11/2013 05:15:51 by Ethos_ »
 

Offline Skyli

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Re: Does time exist at a quantum level?
« Reply #9 on: 09/11/2013 20:35:55 »
I'm not much of an engineer and even less of a mathematician but the idea of minima of time - Plank time - seems like something that could be tested at a relatively macroscopic level.

Take a set of opaque discs along an axis and have each disc spinning counter to its two neighbours. While the disks are stationary put a tiny hole in each such that a photon/electron source can pass through the entire set.

By adjusting the rate of spin of each disk independently one would be able to ensure that the holes lined up for "5.3*10-44" seconds using 15 disks, assuming each spins around 10,000 rpm. In that case one would not be able to get a photon through the set.

In practice one would also have to take the time it would take a photon to traverse this apparatus into consideration but could it work?

Or should I avoid trying to fix the washing machine?


 

Offline yor_on

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Re: Does time exist at a quantum level?
« Reply #10 on: 11/11/2013 22:20:31 »
One Planck time, 10-43 seconds, is the time it takes for a 'photon', or light, to propagate one Plank length 10−35 meters. That's a fairly short distance.
 

Offline woolyhead

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Re: Does time exist at a quantum level?
« Reply #11 on: 16/11/2013 20:36:40 »
Planck time is equal to: 5.391 e^-44 sec. According to theory, there can be no event, in nature, occurring at shorter intervals than this value.

While you're right about the length of Planck time, all that we know is that our theories don't extend to sub-Planck time scales.  We don't know what happens below those scales, so its all speculation.

But back to answering the original post: time does certainly exist on the quantum scale.  In fact, quantum mechanics works by describing events in space and time.
Except that time doesn't feature in quantum theory.
 

Offline yor_on

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Re: Does time exist at a quantum level?
« Reply #12 on: 17/11/2013 11:49:24 »
Oh, time feature in all experiments. Better call that a hypothesis.
 

Offline chiralSPO

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Re: Does time exist at a quantum level?
« Reply #13 on: 17/11/2013 20:40:03 »
If time doesn't feature in quantum mechanics, then why did I have to study the time-dependent Schrödinger equation for so long?

We do have to think of time differently on a quantum scale than in the macro scale. Effects of quantization and uncertainty can be contrary to our own perception of time, but that doesn't mean it doesn't exist. Notions of cause and effect can be irrelevant under certain circumstances.
« Last Edit: 17/11/2013 20:43:33 by chiralSPO »
 

Offline yor_on

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Re: Does time exist at a quantum level?
« Reply #14 on: 28/11/2013 14:11:00 »
There's a side to defining a arrow that's really confusing. (thankfully the definition of Planck scale leave it all sort of fuzzy).

But consider this. As soon as you make a experiment you must involve your local time keeping, and that one exist, for you and for me too. Doesn't matter there at what scale you define your experiment. I'm free to hypothise scales under Plank scale too, still involving my local time keeping. That's what frames of reference crave, you measuring relative your local definitions, and there your arrow of time (wrist watch) always will exist.

Although, from a purely local definition, not involving comparing between frames of reference, you can reach another definition. And in that one light can't make more than one Planck length, in one Planck time. After that the physics we know 'breaks down'.

And to me, that is a 'Planck clock', ticking one Planck Length, in one Planck time. So it becomes the ultimate, locally definable, 'clock' I can physically imagine. We can't measure at that scale though so it is a theoretical limit.
=

Another point worth mentioning is that sometimes Plank scale constants are used to hypothesize a 'defined universal invariant scale'. That one is true, but as all constants I know of ultimately should be traceable back to ones local definition, then using relativity comparing frames of reference, we reach a definition in where it must be a locally true statement, but 'globally', as in comparing your frame, local time, etc, against another, untrue. That as we then will find time dilations and all sorts of 'contractions/extensions' confusing the issue.

So it is true locally, but not 'globally' in a comparison. Unless you refer to your time and distance measurements as illusions, also invalidating all repeatable experiments. The way to define a repeatable experiment, is to use a local definition, then stipulating that the laws of physics is equivalently valid, locally defined, for/in all frames of reference. As soon as you move from that local definition to comparing your frame of reference to another, you should need to consider time dilations Lorentz contractions, etc.

One can think of it this way. Using a local definition, a Plank length, or Plank time, is just as 'locally equivalent' a Planck length/time at a event horizon, as it is on Earth, for you measuring it locally, being 'on site' so to speak. Locally you should find this definition to hold everywhere. But it won't hold if you instead define it 'globally', comparing your 'Plank length' to what you compute to be 'his Plank length, including relativistic effects over frames of reference, as speed and mass.' (not 'fitting' your results for that other frame through Lorentz transformations)

What it boils down to is whether you accept your measurements to be real, or not? When you talk about a constant you must define it as real, and 'repeatable' (locally measured). And that's the way we built physics.
« Last Edit: 28/11/2013 16:47:41 by yor_on »
 

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Re: Does time exist at a quantum level?
« Reply #14 on: 28/11/2013 14:11:00 »

 

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