Temp Limits: Speed of Light, Absolute Zero & Kinetic Energy

In summary, there is no limit on temperature based on the speed of light or the kinetic energy of molecules. Temperature is a function of energy, not velocity, and while there is an upper limit to an object's velocity, there is no such limit for energy. Absolute zero refers to the state of minimum motion, not a state of zero motion.
  • #1
pzona
234
0
Please excuse my lack of proper terminology, I've only just graduated high school so I'm by no means an expert on anything regarding physics.

My question is this: since there is a natural limit to the velocity of an object, the speed of light, and temperature is measured by kinetic energy of molecules of a substance, does that mean that the speed of light imposes a limit on how fast the molecules can move, and thus imposes a limit on the temperature? I'm not looking at it from a relativistic point of view, and I haven't really considered any of the consequences of the molecules approaching the speed of light, is this perhaps more important than I suspected?

On a semi-related note, is absolute zero a limit on the other end of the temperature spectrum? The way I see it, if all particle motion stops, this violates the uncertainty principle. So absolute zero cannot be reached, correct?
 
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  • #2
Neither of those statements is true. Absolute zero refers to the state of minimum motion, not a state of zero motion. Temperature is more accurately described as a function of energy, not velocity, and while there is an upper limit to an object's velocity, there is no such limit for energy.
 
  • #3
The temperature of a substance depends on the average kinetic energy of the molecules in the substance, (which depends on the square of the average velocity blah blah blah). While there is a limit on the velocity of the molecules (the speed of light), the theory of special relativity shows that there is no limit to an object's kinetic energy, thus there is no limit to temperature (for all we know). What I'm trying to say is that you shouldn't put a burrito in the microwave for more than seven minutes...

As for absolute zero, listen to Vanadium, he's more experienced than I.
 
  • #4
Vanadium 50 said:
... Temperature is more accurately described as a function of energy, not velocity, and while there is an upper limit to an object's velocity, there is no such limit for energy.

I think there's such a limit, at least in the gas phase. Consider the temperature of a mixture of gas. The temperature is expressed in term of gas molecule (or electrons & nuclei if it's too hot) velocity. The particles' velocity is limited so the temp is also limited isn't it?
 
  • #5
My understanding is the maximum temperature possible is Planck temperature.
 
  • #6
pixel01 said:
I think there's such a limit, at least in the gas phase. Consider the temperature of a mixture of gas. The temperature is expressed in term of gas molecule (or electrons & nuclei if it's too hot) velocity. The particles' velocity is limited so the temp is also limited isn't it?

No. As I said, temperature is a function of energy: it's proportional to kinetic energy, so while there is a velocity limit in SR, there is no kinetic energy limit.
 
  • #7
jobyts said:
My understanding is the maximum temperature possible is Planck temperature.

Why would this be true?
 
  • #8
Vanadium 50 said:
No. As I said, temperature is a function of energy: it's proportional to kinetic energy, so while there is a velocity limit in SR, there is no kinetic energy limit.

We have this formula: T = (2/3)*(1/k)*(mv^2)/2
v has a limit so you mean m can rise?
 
  • #9
You have the non-relativistic expression for kinetic energy in there and are attempting to use it to draw relativistic conclusions.
 

Related to Temp Limits: Speed of Light, Absolute Zero & Kinetic Energy

1. What is the speed of light and why is it considered a limit?

The speed of light is a fundamental constant in physics, denoted by the letter "c". It is approximately 299,792,458 meters per second in a vacuum. It is considered a limit because according to Albert Einstein's theory of relativity, nothing with mass can travel faster than the speed of light. This is because as an object's speed approaches the speed of light, its mass and energy increase infinitely, making it impossible to reach or surpass this limit.

2. What is absolute zero and why is it considered the lowest possible temperature?

Absolute zero is the lowest temperature that is theoretically possible, at which point the particles of matter have the least amount of energy and their motion stops completely. It is approximately -273.15 degrees Celsius or 0 Kelvin. It is considered the lowest possible temperature because it is the point at which all thermal motion ceases, and it is impossible to cool an object to an even lower temperature.

3. How does kinetic energy relate to temperature?

Kinetic energy is the energy an object possesses due to its motion. Temperature is a measure of the average kinetic energy of the particles in a substance. As the temperature of a substance increases, the kinetic energy of its particles also increases. This is because at higher temperatures, the particles have more energy and move faster, resulting in an increase in their kinetic energy.

4. Is there a maximum limit to kinetic energy?

No, there is no maximum limit to kinetic energy. As long as an object is in motion, it will have kinetic energy. However, there is a limit to the speed at which an object can travel, which is the speed of light. As an object's speed approaches the speed of light, its kinetic energy increases infinitely, making it impossible to reach or surpass this limit.

5. How do these temperature limits affect our understanding of the universe?

The speed of light and absolute zero are fundamental limits that shape our understanding of the universe. They play a crucial role in various theories, such as relativity and quantum mechanics. These limits also have practical implications, such as the maximum speed at which we can send information or the minimum temperature required for certain chemical reactions to occur. Our understanding of these limits continues to evolve as we make new discoveries about the universe.

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