B Is Time Relative? Understanding Special Relativity

[Noah332]

TL;DR Summary

What i mean is, for example, the zeroth law of thermodynamics states the if systems A and C are in thermal equilibrium with a system B, then A and C are in thermal equilibrium. Does this mean temperature is relative? Can relativity be applied to other aspects of physics and science in general?

Im just asking this general question.

 

[member 656954]

Temperature is a measure of the average heat or thermal energy of particles in a substance. There is a scale - Kelvin - for this, with absolute zero being a theoretical point where there is zero thermal energy (there is no known corresponding maximum temperature that I'm aware of).

So temperature is not 'relative' unless you are comparing items against each other, as your A, B, and C systems suggests.

As far as we can measure, the laws of thermodynamics and the definition of temperature apply equally across the universe.

Now relativity, if defined as "the state of being judged in comparison with other things and not by itself", is applied to other aspects of physics and science in general.

However, relativity, if taken in the context of Einstein’s theories of of Special Relativity and General Relativity, have a very specific meaning that it does not appear that you are referring to, or alluding to, here.

 

[Noah332]

I see where your getting at, but I am wondering if we rethought about things similar to how Einstein thought of relativity could that change our understanding of the universe and would that make it more easier to combine the standard model and GR?

 

[Drakkith]

I see where your getting at, but I am wondering if we rethought about things similar to how Einstein thought of relativity could that change our understanding of the universe and would that make it more easier to combine the standard model and GR?

Physicists have all kinds of thoughts and ideas that they mull over when trying to develop new theories or ways to merge old ones together. I assure you that anything you can think of has already been tried.

 

[nasu]

You may have the wrong idea about what theory of relativity is. Your example with temperatures does not have any relation to the purpose of the theory of relativity. It is not even an example of a "relative" quantity in the common sense of the therm.

 

[Noah332]

Physicists have all kinds of thoughts and ideas that they mull over when trying to develop new theories or ways to merge old ones together. I assure you that anything you can think of has already been tried.

Im sure it has but in case it hasnt I like to ask my questions. Another thought i just had is that since nothing can be colder than absolute zero isn't that the same as nothing can be faster than the speed of light.

 

[Drakkith]

Another thought i just had is that since nothing can be colder than absolute zero isn't that the same as nothing can be faster than the speed of light.

No.

 

[Noah332]

No.

Why? Its a physical threshold. What happens if you try to cool something below absolute zero?

 

[Noah332]

Why? Its a physical threshold. What happens if you try to cool something below absolute zero?

No.

If you bring the temperature to absolute zero atoms stop moving.

If you move at the speed of light time stops.

Seems similar to me.

 

[PeroK]

If you bring the temperature to absolute zero atoms stop moving.

If you move at the speed of light time stops.

Seems similar to me.

It's an interesting idea. If an object moves relative to you, owing to time dilation the thermal motion of its atoms ought to decrease (relative to you). And, if it gets close to the speed of light relative to you, then it might look like its temperature is close to absolute zero.

There are some interesting things online about how to define and measure the temperature of an object that is moving relative to you. E.g.

https://physics.stackexchange.com/questions/317775/does-temperature-depend-on-velocity-of-observer
You might also ask yourself. If you cool an object and that somehow equates to accelerating the object relative to you, what happens if you heat up an object?

 

[Noah332]

It's an interesting idea. If an object moves relative to you, owing to time dilation the thermal motion of its atoms ought to decrease (relative to you). And, if it gets close to the speed of light relative to you, then it might look like its temperature is close to absolute zero.

There are some interesting things online about how to define and measure the temperature of an object that is moving relative to you. E.g.

https://physics.stackexchange.com/questions/317775/does-temperature-depend-on-velocity-of-observer
You might also ask yourself. If you cool an object and that somehow equates to accelerating the object relative to you, what happens if you heat up an object?

That's a very interesting thought. It must slow down in relative terms.

You may have the wrong idea about what theory of relativity is. Your example with temperatures does not have any relation to the purpose of the theory of relativity. It is not even an example of a "relative" quantity in the common sense of the therm.

Temperature is definitely relative. hence the zeroth law of thermodynamics. If, in my example, A and B are in thermal equilibrium but B and C arent then C will feel a temperature difference, hence it would feel if A and B were hot or cold. ie. temperature is relative.

 

[phinds]

Temperature is definitely relative. hence the zeroth law of thermodynamics. If, in my example, A and B are in thermal equilibrium but B and C arent then C will feel a temperature difference, hence it would feel if A and B were hot or cold. ie. temperature is relative.

Yes, but that has absolutely nothing to do with Einstein's Theory of Relativity (either SR or GR).

 

[ZapperZ]

That's a very interesting thought. It must slow down in relative terms.

Temperature is definitely relative. hence the zeroth law of thermodynamics. If, in my example, A and B are in thermal equilibrium but B and C arent then C will feel a temperature difference, hence it would feel if A and B were hot or cold. ie. temperature is relative.

You have a bit of a skewered idea on why a different line of thought appears in science, and in physics in particular.

If you look at Einstein and the history of physics, he came up with the idea of Special Relativity not because he was bored and decided "Hey, what if...?" out of nowhere. There was a very clear impetus for him coming up with the idea because of the problems of Maxwell equations not be covariant under Galilean transformation. In other words, there was a problem at that time, and he was trying to approach it from a different perspective. And then, when he came up with a new idea, he did one very important thing. He showed mathematically that this new idea converges with the old description.

Unfortunately, you never gave a clear impetus for why you'd want to think of temperature having the same "relative" concept. You simply can't invoke "Well, what if... since we already have relativity...", without specifying what exactly is the problem that would be solved if we look at thermodynamics from the different perspective. In other words, what is the worth of our time to delve into this? What does it do? What does it solve? Can it clean windows in record time?

There are infinite number of ideas out there that one can explore. The question is, while it may be interesting, but is it important? Those two criteria are not necessarily mutually inclusive.

Zz.

 

[Noah332]

That's a very interesting thought. It must slow down in relative terms.

Temperature is definitely relative. hence the zeroth law of thermodynamics. If, in my example, A and B are in thermal equilibrium but B and C arent then C will feel a temperature difference, hence it would feel if A and B were hot or cold. ie. temperature is relative.

You may have the wrong idea about what theory of relativity is. Your example with temperatures does not have any relation to the purpose of the theory of relativity. It is not even an example of a "relative" quantity in the common sense of the therm.

here is another thought that relates to GR, if I take a balloon filled with air, and let's assume this balloon can't pop or melt , and we heat it up from the outside. the balloon will change its geometry in spacetime. If we instead of heating the balloon we pump air in the balloon it will still expand its geometry in spacetime. No? the balloon doesn't know or care how the spacetime around it was affected only that it is now changed.

This idea is similar to Einsteins thought that triggered GR. A man in freefall doesn't feel his own weight.

 

[Noah332]

You have a bit of a skewered idea on why a different line of thought appears in science, and in physics in particular.

If you look at Einstein and the history of physics, he came up with the idea of Special Relativity not because he was bored and decided "Hey, what if...?" out of nowhere. There was a very clear impetus for him coming up with the idea because of the problems of Maxwell equations not be covariant under Galilean transformation. In other words, there was a problem at that time, and he was trying to approach it from a different perspective. And then, when he came up with a new idea, he did one very important thing. He showed mathematically that this new idea converges with the old description.

Unfortunately, you never gave a clear impetus for why you'd want to think of temperature having the same "relative" concept. You simply can't invoke "Well, what if... since we already have relativity...", without specifying what exactly is the problem that would be solved if we look at thermodynamics from the different perspective. In other words, what is the worth of our time to delve into this? What does it do? What does it solve? Can it clean windows in record time?

There are infinite number of ideas out there that one can explore. The question is, while it may be interesting, but is it important? Those two criteria are not necessarily mutually inclusive.

Zz.

That is true thank you for this.

I am hoping if i put my stupid ideas out to people who know more about the subject than me maybe it will spark some idea in them.

but also, my thoughts are within the realm of relating the standard model and GR. maybe if we rethink things in terms of GR maybe we can combine them in a previously unthought of way. for example according the GR objects of energy change the geometry of spacetime. atoms have energy, why isn't it that they are change the geometry of spacetime around it in a similar way the sun does?

 

[PeroK]

That's a very interesting thought. It must slow down in relative terms.

Temperature is definitely relative. hence the zeroth law of thermodynamics. If, in my example, A and B are in thermal equilibrium but B and C arent then C will feel a temperature difference, hence it would feel if A and B were hot or cold. ie. temperature is relative.

One problem with your idea is that light, which does travel at the speed of light, would be at absolute zero. So, the light from the Sun would cool us down. But, of course, sunlight not only keeps us warm, but ultimatley is the source of all energy on Earth.

 

[Noah332]

One problem with your idea is that light, which does travel at the speed of light, would be at absolute zero. So, the light from the Sun would cool us down. But, of course, sunlight not only keeps us warm, but ultimatley is the source of all energy on Earth.

but that's because we don't move at the speed of light. so this change in momentum as the photon particles interact with us cause the appearance of a temperature increase

 

[ZapperZ]

That is true thank you for this.

I am hoping if i put my stupid ideas out to people who know more about the subject than me maybe it will spark some idea in them.

but also, my thoughts are within the realm of relating the standard model and GR. maybe if we rethink things in terms of GR maybe we can combine them in a previously unthought of way. for example according the GR objects of energy change the geometry of spacetime. atoms have energy, why isn't it that they are change the geometry of spacetime around it in a similar way the sun does?

That still doesn't answer on WHY one would want to do such a thing.

Again, as I've said, it may be "interesting" (to you), but why is it important? What does it solve or make simpler or clearer?

This, you have not clarified.

Zz.

 

[Noah332]

That still doesn't answer on WHY one would want to do such a thing.

Again, as I've said, it may be "interesting" (to you), but why is it important? What does it solve or make simpler or clearer?

This, you have not clarified.

Zz.

I will have to ponder on this. Thank you

 

[Noah332]

One problem with your idea is that light, which does travel at the speed of light, would be at absolute zero. So, the light from the Sun would cool us down. But, of course, sunlight not only keeps us warm, but ultimatley is the source of all energy on Earth.

What I mean is not that light because it moves at the speed of light is cold, its that because light is moving at the speed of light everything around it seems cold. This temperature difference causes us to feel the heat of the light.

Imagine you are a light beam moving from the sun to the earth. your traveling at .9c, time would slow down, hence atoms and molecules around you would inturn slow down. when molecules slow down they become cold. Therefore if you were to slow down time and touch an object it would appear cold.

 

[ZapperZ]

What I mean is not that light because it moves at the speed of light is cold, its that because light is moving at the speed of light everything around it seems cold. This temperature difference causes us to feel the heat of the light.

Imagine you are a light beam moving from the sun to the earth. your traveling at .9c, time would slow down, hence atoms and molecules around you would inturn slow down. when molecules slow down they become cold. Therefore if you were to slow down time and touch an object it would appear cold.

This is faulty physics that you invented. Light beam does not move at 0.9c. It has to be "c". It is not an arbitrary choice.

And if you think you can transform to light's frame of reference, I'd like you to point out to me what physics you are using to do that, because SR/GR does not allow such a transformation.

Zz.

 

[PeroK]

What I mean is not that light because it moves at the speed of light is cold, its that because light is moving at the speed of light everything around it seems cold. This temperature difference causes us to feel the heat of the light.

Imagine you are a light beam moving from the sun to the earth. your traveling at .9c, time would slow down, hence atoms and molecules around you would inturn slow down. when molecules slow down they become cold. Therefore if you were to slow down time and touch an object it would appear cold.

You started with an interesting idea and now you are having to reinvent physics and deny experimental facts to support it!

In any case, these forums are for discussing science, not your personal theories about how science ought to be.

 

[Noah332]

You started with an interesting idea and now you are having to reinvent physics and deny experimental facts to support it!

In any case, these forums are for discussing science, not your personal theories about how science ought to be.

How do you mean? this isn't about what science ought to be. I haven't reinvented anything. Just think logically. If you slow down time do atoms hold there heat relative to you? If you are standing next to a boiling pot of water and you somehow stopped time, if you touched the boiling water would it feel hot?

 

[Noah332]

This is faulty physics that you invented. Light beam does not move at 0.9c. It has to be "c". It is not an arbitrary choice.

And if you think you can transform to light's frame of reference, I'd like you to point out to me what physics you are using to do that, because SR/GR does not allow such a transformation.

Zz.

wow dude. ok, so you are traveling at c and time stops. If you are standing next to a boiling pot of water if you touched the boiling water would it feel hot?

 

[ZapperZ]

wow dude. ok, so you are traveling at c and time stops. If you are standing next to a boiling pot of water if you touched the boiling water would it feel hot?

But that is what I warned you about transforming to the light's reference frame! I told you to watch out for that big hole in the ground, and you still fell into it! (My students will get a chuckle out of that phrase.)

If you are moving at c, what physics did you use? You can't use the consequences predicted by SR, because in SR, the speed of light is ALWAYS "c" in any frame. So again, what physics did you use to be able to describe your world when you're moving at c?

Zz.

 

[PeroK]

How do you mean? this isn't about what science ought to be. I haven't reinvented anything. Just think logically. If you slow down time do atoms hold there heat relative to you? If you are standing next to a boiling pot of water and you somehow stopped time, if you touched the boiling water would it feel hot?

You can't slow down time, you can't stop time. That's your invention. Changes, like heat transfer, require the passage of time.

 

[Noah332]

But that is what I warned you about transforming to the light's reference frame! I told you to watch out for that big hole in the ground, and you still fell into it! (My students will get a chuckle out of that phrase.)

If you are moving at c, what physics did you use? You can't use the consequences predicted by SR, because in SR, the speed of light is ALWAYS "c" in any frame. So again, what physics did you use to be able to describe your world when you're moving at c?

Zz.

Im talking about if you are moving at the speed of light, forget the light beam for a second and please don't talk down to me. I am trying to just discuss this with people in a nice way. if you disagree please say so and tell me why and let's come to a conclusion together not one where your students chuckle at me.

this is a thought experiment. and if you think logically it makes sense. if you move at the speed of light or close to the speed of light doesn't time slow down? and if time slows down around you wouldn't it make sense that things would feel colder to you?

 

[phinds]

Im talking about if you are moving at the speed of light

Not possible

if you move at the speed of light or close to the speed of light doesn't time slow down?

Absolutely not.

I suggest you stop posting nonsense and read some actual physics.

 

[Noah332]

You can't slow down time, you can't stop time. That's your invention. Changes, like heat transfer, require the passage of time.

thats Einsteins invention. its called time dilation. In order for the speed of light to remain constant in all inertial frames of reference then time has to be able to slow down. as well as space needs to expand. hence the idea of spacetime and it curving.

"Gravitational time dilation is a form of time dilation, an actual difference of elapsed time between two events as measured by observers situated at varying distances from a gravitating mass. The higher the gravitational potential (the farther the clock is from the source of gravitation), the faster timepasses. "

https://en.wikipedia.org/wiki/Gravitational_time_dilation

when you are near a black hole's event horizon the closer you get the slower time gets.

This is part of GR.

 

[Noah332]

Not possible

Absolutely not.

I suggest you stop posting nonsense and read some actual physics.

I know it isn't possible but people do physics where they make assumptions that you are moving at .9c all the time. how is this different

https://worldbuilding.stackexchange...practical-problems-of-near-light-speed-travel

 

[phinds]

thats Einsteins invention. its called time dilation. In order for the speed of light to remain constant in all inertial frames of reference then time has to be able to slow down. as well as space needs to expand. hence the idea of spacetime and it curving.

"Gravitational time dilation is a form of time dilation, an actual difference of elapsed time between two events as measured by observers situated at varying distances from a gravitating mass. The higher the gravitational potential (the farther the clock is from the source of gravitation), the faster timepasses. "

https://en.wikipedia.org/wiki/Gravitational_time_dilation

when you are near a black hole's event horizon the closer you get the slower time gets.

This is part of GR.

All of this is incorrect. You are confusing time dilation with differential aging due to different paths through spacetime. Yes, if you synchronize two clocks and then move them apart, either having one go deeper into a gravity well or move at a high speed, and then you bring them back together, they will show differnt times. This is NOT "time slowing down" (or speeding up), it is differential aging. EVERYTHING see time move at one second per second, regardless of where it is in a gravity well or how fast it is moving relative to something else.

Your misconception about time changing rates is a very common one, but that doesn't make it right. Again, I suggest you study the actual physics.

 

[phinds]

I know it isn't possible but people do physics where they make assumptions that you are moving at .9c all the time. how is this different

https://worldbuilding.stackexchange...practical-problems-of-near-light-speed-travel

It's different because you have moved from the possible (.9c) to the impossible (c)

 

[ZapperZ]

Im talking about if you are moving at the speed of light, forget the light beam for a second and please don't talk down to me. I am trying to just discuss this with people in a nice way. if you disagree please say so and tell me why and let's come to a conclusion together not one where your students chuckle at me.

this is a thought experiment. and if you think logically it makes sense. if you move at the speed of light or close to the speed of light doesn't time slow down? and if time slows down around you wouldn't it make sense that things would feel colder to you?

If you travel close to the speed of light with respect to another reference frame, your clock and time is no different than what it is now! You have not understood SR! Proper time and Proper length remain no different than if you are "not moving"! So no, your time doesn't slow down!

Zz.

 

[Noah332]

If you travel close to the speed of light with respect to another reference frame, your clock and time is no different than what it is now! You have not understood SR! Proper time and Proper length remain no different than if you are "not moving"! So no, your time doesn't slow down!

Zz.

but time around me has?

 

[phinds]

but time around me has?

This is really beginning to sound like you are just trolling us. You have been told several times now that there are NO circumstances in which your time "slows down" in your own frame of reference (the time around you).

 

[Noah332]

This is really beginning to sound like you are just trolling us. You have been told several times now that there are NO circumstances in which your time "slows down" in your own frame of reference (the time around you).

I am not trolling anyone. I really appreciate peoples inputs i don't know enough about this stuff and explanation are welcome. Id like to learn more but all u have are my thoughts. If you guys would, instead of getting mad at me for not being as smart as you, help me understand where i am going wrong why it would be really helpful. Just saying NO in bold and saying my students would chuckled at you, doesn't help. I hope you don't bully everyone who isn't as smart as you.

 

[jbriggs444]

but time around me has?

Moving clocks are measured to run slow when measured against an array of stationary clocks synchronized according to your standard of rest.

Your clocks are measured to run slow when measured against an array of moving clocks synchronized according to their standard of rest.

Both moving and stationary clocks measure one second per second by definition. Time is what a clock measures.

As has been suggested, you really need to learn special relativity before speculating about it.

 

[ZapperZ]

but time around me has?

I don't know what this mean.

If you are going to invoke something, don't you think you should understand that "thing" first? We are going backward several steps here and ending up trying to teach you Special Relativity, which you should have known already if you are going to apply it to make "temperature" relative just like SR.

Now this is even before I query you if you are aware of the statistical nature of thermodynamics and the origin of the definition of this quantity called "temperature"?

It is nice and simple to make speculation and play this "What if...?" game. But that works only in the pedestrian sense, and maybe it works in other forums. But PF, if you have looked around, has a significantly higher standards than that. If we entertain all the "What ifs..." of the worlds, we won't be doing anything else on here but put out fires. This is true if the person making that kind of speculation started off not even understanding what is being used. We typically end up like this, trying to go one step forward, but ending up making 2 or 3 steps back, trying to explain our explanation. I'm sure even you can already see how frustrating that can be.

I strongly suggest you shore up your understanding of (i) Special Relativity and (ii) thermodynamics and statistical mechanics first before trying to see if you can push what you wrote in your very first post.

Zz.

 

[Drakkith]

If you slow down time do atoms hold there heat relative to you? If you are standing next to a boiling pot of water and you somehow stopped time, if you touched the boiling water would it feel hot?

You can't stop time, so the question is not answerable.

As for temperature being relative, well, it's not. It's a measure of the internal energy of a system (such as a collection of gas particles). This internal energy does not change if you or the system is accelerated since the kinetic energy of the system is not part of the internal energy. The fact that objects can be at different temperatures does not mean that temperature is relative, it only means that there isn't a single temperature that an object can have. (using 'relative' in the context it is used in SR and GR)

For something to be relative, it requires that there be no discernible difference in the laws of physics at the different values that something can take. For example, no matter how much you accelerate an object, no experiment you can do on that object from its reference frame will tell you how fast you are going. You must reference an outside object. And, depending on what that outside object is doing, you can very easily measure different values for your velocity.

Temperature is not like this. There is absolutely a difference as you heat up an object, and all observers, no matter how they are moving or what their own temperature is, will agree on what will happen. For example, all observers will see water boil and evaporate as it is heated up to and beyond its boiling point. The person who put the kettle on the stove doesn't need to reference another kettle nearby and compare it their own kettle to know the temperature increased. He can simply observe what happens to the water in the kettle.

Another example of a non-relative effect is acceleration. You can very easily measure the acceleration using an accelerometer. You don't need to look to another object and compare what it's doing to what your doing. No matter how other objects are moving and accelerating, all would agree that you are accelerating, they would agree on the magnitude of the acceleration, and they would agree on the direction of the acceleration.

 

[phinds]

I am not trolling anyone. I really appreciate peoples inputs i don't know enough about this stuff and explanation are welcome. Id like to learn more but all u have are my thoughts. If you guys would, instead of getting mad at me for not being as smart as you, help me understand where i am going wrong why it would be really helpful. Just saying NO in bold and saying my students would chuckled at you, doesn't help. I hope you don't bully everyone who isn't as smart as you.

No one has suggest that you are not as smart as anyone here, we have simply stated, with good reason, that you are less educated and that you are asking questions that require an understanding of the very basic physics involved and that you clearly do not have that understanding. For the third or forth time in this thread, I suggest that you stop posting and go back and study the basics.

 

[nasu]

Even your assumption that "temperature is relative" needs some explanation. Maybe you can explain what do you think "relative temperature" means. The sensations of cold and hot are "relative" in the sense that what one person calls cold may be hot for another or what we call warm weather in winter may be different than a warm summer day. But the sensation being relative does not mean that the temperature is relative. If you measure the temperature, everybody gets the same value no matter how good is his peripheral circulation or the season of the measurement. Before speculating about what new physics will emerge from the relativity of temperature we need to make sure there is such a thing (relative temperature) and what does it mean.

 

[Drakkith]

I am not trolling anyone. I really appreciate peoples inputs i don't know enough about this stuff and explanation are welcome. Id like to learn more but all u have are my thoughts. If you guys would, instead of getting mad at me for not being as smart as you, help me understand where i am going wrong why it would be really helpful. Just saying NO in bold and saying my students would chuckled at you, doesn't help. I hope you don't bully everyone who isn't as smart as you.

Forgive us, we get a lot of people who start off their time here at PF with posts similar to yours and then proceed to ignore everything that they're told about physics. So we've already started off on the wrong foot. Just bear with us and continue to show that you're willing to learn and I assure you that no one will accuse you of trolling.

 

[Noah332]

Forgive us, we get a lot of people who start off their time here at PF with posts similar to yours and then proceed to ignore everything that they're told about physics. So we've already started off on the wrong foot. Just bear with us and continue to show that you're willing to learn and I assure you that no one will accuse you of trolling.

Thank you for this. I hope I am not coming off as ignoring what I am told. I am willing to learn. but it seems like everyone here doesn't want to explain they just want to tell me I am wrong. and need to learn more and shut up.

 

[Noah332]

Even your assumption that "temperature is relative" needs some explanation. Maybe you can explain what do you think "relative temperature" means. The sensations of cold and hot are "relative" in the sense that what one person calls cold may be hot for another or what we call warm weather in winter may be different than a warm summer day. But the sensation being relative does not mean that the temperature is relative. If you measure the temperature, everybody gets the same value no matter how good is his peripheral circulation or the season of the measurement. Before speculating about what new physics will emerge from the relativity of temperature we need to make sure there is such a thing (relative temperature) and what does it mean.

fair enough, i will have to think about this thank you

 

[ZapperZ]

Thank you for this. I hope I am not coming off as ignoring what I am told. I am willing to learn. but it seems like everyone here doesn't want to explain they just want to tell me I am wrong. and need to learn more and shut up.

EVERYONE?

I told you why and what was wrong with what you wrote. I didn't just tell you it was wrong. Otherwise, my replies to you will be just one sentence!

Zz.

 

[Nugatory]

This thread is closed, as the entire discussion has been based on a misunderstanding of what special relativity says about time what temperature is.

The original poster may want to find a good introductory textbook on SR (my personal favorite is Taylor and Wheeler, but there are other good ones that other members will be able to recommend). We can help you over the inevitable hard spots.