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Having 0 kinetic energy


questionposter

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Theoretically, if an object has 0 kinetic energy, then it would mean that it's time stops, but, that same thing is exactly what happens in measurements in quantum mechanics. When we measure a particle, we are measuring a single finite and "not moving" point, its just a point, and since it's just a point and it's can't be moving because it would mean that your measurement is somehow getting information of it's motion before photons reach our eyes, it has 0 kinetic energy, so couldn't the reason why there's all this measurement weirdness be because a million times a second we are technically "stopping time" and therefore giving something 0 energy, and since it doesn't have energy it can't be a wave since wave mechanics clearly show you need energy to generate a wave?

Or...something like this? Because we can't actually measure continuous motion, because that would mean that we would need to have an infinitely continuous stream of photons hitting your eyes, without any break, so instead we only measure motion at tiny intervals....

Can anyone make sense of what I'm trying to say?

Edited by questionposter
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I understand, that a quantum 'measurement' is equivalent to a 'wave-function collapse', e.g. free electrons 'collapsing onto' free protons, in space plasma, emitting a 'recombination' photon. The center-of-mass rest-frame is not necessarily the same, as the earth rest-frame.

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Theoretically, if an object has 0 kinetic energy, then it would mean that it's time stops,

 

 

I do not understand your reasoning.

 

Think about a particle in standard classical mechanics. Surely measuring a kinetic energy of zero means that the object is moving at zero velocity as measured by you?

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I do not understand your reasoning.

 

Think about a particle in standard classical mechanics. Surely measuring a kinetic energy of zero means that the object is moving at zero velocity as measured by you?

 

But everything is always moving, so everything has kinetic energy, but perhaps not continuously. I'm actually very surprised you haven't heard of this before. Since it's impossible to make something have 0 kinetic energy (at least continuously) and things are always moving, if something did have 0 kinetic energy it would have to mean time stops, that's the only time something would have 0 kinetic energy.

Edited by questionposter
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With respect to what?

 

Everything else. Pick an object in the universe...it has some kinetic energy. If it did have 0K, it would be at absolute 0.

But I guess if you don't like the notion of time stopping, perhaps the act of measuring technically makes something have absolute 0 for the measurement because we can't continuously measure that the measurement is moving (unless we have infinitely continuous photon telling us information which we don't), we can only measure that a measurement is a single point at a single time, which means no distance over time and no monentum to generate a wave governed by wave mechanics, which technically means means no kinetic energy and that the measurement has absolute 0.

Edited by questionposter
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Everything else. Pick an object in the universe...it has some kinetic energy.

 

The problem I have is that kinetic energy is a frame dependent notion.

 

For example, go outside and pick up a rock. Hold it steady. What is the kinetic energy of this rock?

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The problem I have is that kinetic energy is a frame dependent notion.

 

For example, go outside and pick up a rock. Hold it steady. What is the kinetic energy of this rock?

It looks like questionposter is saying that it is essentially the rock's temperature.

 

questionposter, you are coming at this with the notion that time is motion. It isn't.

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According to what theory?

 

I don't even remember what theory, I think it just might have been something I heard from a high school teacher for an either physics or chemistry class, but I guess there isn't much that actually happens at absolute 0. But basically, the logic is that since everything is always moving in some way, if something didn't move at all in any way, it would have to mean time has stopped.

 

The problem I have is that kinetic energy is a frame dependent notion.

 

For example, go outside and pick up a rock. Hold it steady. What is the kinetic energy of this rock?

 

Your eyes still pick up the information to suggest its moving, you just don't notice it because it's so small. In fact, your eyes are even picking up information right now to suggest that atoms have wave-like properties, but the properties are happening over such a small distance that we don't notice. Not only that, but the rock is rotating as the earth is rotating and is also rotating around the sun, galaxy, local cluster and Virgo super-cluster.

All of space has no kinetic energy so does it mean if we go there, we stop in time?

 

Space at least in general relativity IS time, so wherever we go in space, there is time, and in the new standard model, space may be consisting of incredibly small strands of energy. There's also those virtual particle pairs that keep appearing and dis-appearing.

Ok, so the idea is that zero temperature equals no time. :blink:

 

Does the measurement of a point of a particle go along continuously through time? I don't think so...that would imply we know what path it takes.

Edited by questionposter
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I don't even remember what theory, I think it just might have been something I heard from a high school teacher for an either physics or chemistry class, but I guess there isn't much that actually happens at absolute 0. But basically, the logic is that since everything is always moving in some way, if something didn't move at all in any way, it would have to mean time has stopped.

This is pretty much nonsense. Keep in mind that high school teachers don't have to know a lot about the subject they are teaching. This is particularly so for the more advanced parts of the subject matter.

 

Space at least in general relativity IS time

No, it's not. Time is not a spatial dimension.

 

Does the measurement of a point of a particle go along continuously through time? I don't think so...that would imply we know what path it takes.

:blink:

That's a non sequitur.

 

There are some physicists who conjecture that space and time are quantized. They are in the minority. The standard model and relativity are written in the form of differential equations. In other words, the underlying assumption is that space and time are continuous rather than discrete.

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The problem I have is that kinetic energy is a frame dependent notion.

 

For example, go outside and pick up a rock. Hold it steady. What is the kinetic energy of this rock?

 

about 288K? When he refers to kinetic energy having an effect on time it isnt necessarily net movement. The rock is vibrating in your hand but not to a noticeable degree. Temperature is to movement what distance is to displacement, I suppose. If I kick a ball 5m into the air and it lands where i kicked it from, distance travelled is 10m but displacement is 0m. If you hold a rock steady in your hand, its movement is 0 but its temperature (and therefore kinetic energy) is quite a bit more.

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Space at least in general relativity IS time, so wherever we go in space, there is time, and in the new standard model, space may be consisting of incredibly small strands of energy. There's also those virtual particle pairs that keep appearing and dis-appearing.

I know what quantum mechanics is. Anyway, I'm not talking of M theory or particles. I'm talking about SPACE, the space that surrounds the particles because if there wasn't space they wouldn't exist.

 

Anyway, time could be stopping for "a billion years" (yes, I know you can't measure time where there is no time) every mili-second and we would never know.

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I know what quantum mechanics is. Anyway, I'm not talking of M theory or particles. I'm talking about SPACE, the space that surrounds the particles because if there wasn't space they wouldn't exist.

 

Anyway, time could be stopping for "a billion years" (yes, I know you can't measure time where there is no time) every mili-second and we would never know.

 

Well, I don't know what to tell you guys. The electron you measure isn't a wave, it's a point, and since we are not getting infinitely continuous measurements of the point, we can not observe that the point is moving any distance over time or that it has any momentum or kinetic energy, so I guess if time stops, what is it relative to?

 

This is pretty much nonsense. Keep in mind that high school teachers don't have to know a lot about the subject they are teaching. This is particularly so for the more advanced parts of the subject matter.

Well, I wouldn't agree with that, it's not nonsense because they still have degrees in science and no one has at least knowingly reached absolute 0, so what happens at 0K is anyone's game.

 

No, it's not. Time is not a spatial dimension.

Well then what do you call "the fabric of space-time"? Einstein called space and time a single entity, so...

 

 

 

 

There are some physicists who conjecture that space and time are quantized. They are in the minority. The standard model and relativity are written in the form of differential equations. In other words, the underlying assumption is that space and time are continuous rather than discrete.

 

Well we can't measure space and time continuously even if things like time do actually flow continuously.

 

I know what quantum mechanics is. Anyway, I'm not talking of M theory or particles. I'm talking about SPACE, the space that surrounds the particles because if there wasn't space they wouldn't exist.

 

Anyway, time could be stopping for "a billion years" (yes, I know you can't measure time where there is no time) every mili-second and we would never know.

 

Well, I don't know what to tell you guys. The electron or proton or whatever piece of matter you measure isn't a wave, it's a point, and since we are not getting infinitely continuous measurements of the point, we can not observe that the point is moving any distance over time or that the point has any momentum or kinetic energy, so I guess if time stops, what is it relative to? Or I guess, can anyone think of a better explanation for what happens when we observe something as a point and.or what happens at 0K?

Edited by questionposter
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Well, I don't know what to tell you guys. The electron you measure isn't a wave, it's a point, and since we are not getting infinitely continuous measurements of the point, we can not observe that the point is moving any distance over time or that it has any momentum or kinetic energy, so I guess if time stops, what is it relative to?

Huh? You are mis-mixing and mismatching a bunch of disparate concepts here. It's best not to do that.

 

Time doesn't stop at absolute zero. You are starting with this as your premise. It is a false premise.

 

 

 

This is pretty much nonsense. Keep in mind that high school teachers don't have to know a lot about the subject they are teaching. This is particularly so for the more advanced parts of the subject matter.
Well, I wouldn't agree with that, it's not nonsense because they still have degrees in science ...

Take a look at this site, http://www.phy.ilstu.edu/pte/career.html. Scroll down to "Plan of Study in Physics Teacher Education at Illinois State University". Education in physics per se pretty much stops at the sophomore level physics classes. No thermodynamics, no statistical physics (essentially, advanced thermodynamics). High school science teachers need to learn the very basics of their subject matter, and that's about it.

 

 

 

and no one has at least knowingly reached absolute 0, so what happens at 0K is anyone's game.

Just as a massive particle can never reach the speed of light, nothing can ever reach absolute zero. Both are physically impossible. Your premise that time stops at absolute zero (it doesn't) is better stated as time slows down near absolute zero (it doesn't).

 

 

 

No, it's not. Time is not a spatial dimension.
Well then what do you call "the fabric of space-time"? Einstein called space and time a single entity, so...

I call "the fabric of space-time" a phrase that is widely used and widely abused in lay science literature. I don't like the phrase. That word "fabric" carries connotations from the lay meaning of the word that lead to misconceptions.

 

The temporal dimension is quite different from spatial dimensions. It's an essential part of the spacetime metric. The spacetime interval between two points in spacetime is [math]\Delta s^2 = \Delta r^2 - c^2\Delta t^2[/math]. If the temporal dimension was just another spatial dimension that subtraction would be an addition. Another way to look at the spacetime interval is as [math]\Delta s^2 = \Delta r^2 + (i \Delta t)^2[/math]. In other words, time is on an imaginary axis. Yet another way to look at spacetime interval is as [math]\Delta s^2 = \Delta t^2 - \Delta r^2/c^2[/math]. This effectively places the spatial dimensions on imaginary axes, leading to a quaternionic representation of spacetime.

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Your first and biggest mistake, questionposer, is that since nothing is at rest ( ie the rock you pick up isn't moving in your hand but it is moving along with the earth )hat there must be a fame where it is 'actually' at rest. But as AJB has stated,"With respect to what?'. The frame you postulate would be a preferred universal frame, and unfortunately GR doesn't allow for abslute space and preferred universal frames .

Edited by MigL
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Your first and biggest mistake, questionposer, is that since nothing is at rest ( ie the rock you pick up isn't moving in your hand but it is moving along with the earth )hat there must be a fame where it is 'actually' at rest. But as AJB has stated,"With respect to what?'. The frame you postulate would be a preferred universal frame, and unfortunately GR doesn't allow for abslute space and preferred universal frames .

 

If nothing is at rest, how do you explain the measurement of a point? Plus I thought quantum mechanics and general relativity were different anyway.

Edited by questionposter
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I didn't say there cannot be a frame where something is at rest, just that all frames are equally viable, None is preferred or universal. But you are right QM and GR operate in different domains with little overlap.

 

Also what do you mean by measurement of a point? According to Quantum theory we don't actually make any measurements below a certain limit because of the large energies involved. And the calculus is a differential analisys where subsequent information (position, momentum, etc. ) is derived from previous values. The continuity is inplied, not proven, as noone knows what happens at or below the Planck length.

 

Also keep in mind the difficulties that arise from considering particles as points. Renormalisability is, as far as I'm concerned, still just a trick ( others here may disagree ) and seems to become increasingly difficult with higher spin values ( 1/2 being easiest, 2 is impossible ). A finite size of particle seems to alleviate this problem and is one reason driving string theory.

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If nothing is at rest, how do you explain the measurement of a point?

You are making no sense here. What is your point?

 

 

Plus I thought quantum mechanics and general relativity were different anyway.

There are (so far). So why are you writing as if they do address the same concepts?

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I didn't say there cannot be a frame where something is at rest, just that all frames are equally viable, None is preferred or universal. But you are right QM and GR operate in different domains with little overlap.

 

Also what do you mean by measurement of a point? According to Quantum theory we don't actually make any measurements below a certain limit because of the large energies involved. And the calculus is a differential analisys where subsequent information (position, momentum, etc. ) is derived from previous values. The continuity is inplied, not proven, as noone knows what happens at or below the Planck length.

 

Also keep in mind the difficulties that arise from considering particles as points. Renormalisability is, as far as I'm concerned, still just a trick ( others here may disagree ) and seems to become increasingly difficult with higher spin values ( 1/2 being easiest, 2 is impossible ). A finite size of particle seems to alleviate this problem and is one reason driving string theory.

 

Well no energy means no wave, and when we measure something we are making it have no wave, which technically means that for the time we are measuring it we are making it have no energy.

I guess it might be some kind of extra-dimensional frame-of-reference where to us how we measure it is as if it has 0K for the time we observe it even though the particle itself continues to act like a wave.

Edited by questionposter
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