Relativistic Particles: Reaching Absolute Temperature?

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Discussion Overview

The discussion revolves around the concept of relativistic particles and their relationship to absolute temperature, exploring the implications of a particle existing in a state of zero potential energy. Participants engage with the mathematical formulations presented and the underlying physical principles, including the Lagrangian mechanics of relativistic particles.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant proposes that a particle with zero potential energy must be at rest, suggesting that this implies it has reached absolute temperature.
  • Another participant points out that the equations presented lack a time derivative, indicating that the velocity of the particle remains constant in the absence of external potential, which they argue is a case of inertia.
  • Some participants challenge the application of classical reasoning to relativistic particles, asserting that the Lagrangian should not be defined as the difference between kinetic and potential energy.
  • There is a discussion about the implications of differentiating constants and the potential existence of an integration constant in the equations presented.
  • Participants request clarification on the differences between relativistic and classical Lagrangian mechanics, with references to external resources for further reading.

Areas of Agreement / Disagreement

Participants express disagreement regarding the validity of the original claims about relativistic particles and the application of classical mechanics. There is no consensus on the correctness of the mathematical formulations or the physical interpretations presented.

Contextual Notes

Some limitations in the discussion include unresolved mathematical steps and the dependence on specific definitions of potential and kinetic energy in the context of relativistic mechanics.

Somali_Physicist
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Hello fellow physicists.Recently I imagined a particle far away from everything (infinitely away) such that there is no potential energy affecting the particle.

Ep = 0
Ek = mc2δ : δ = (1-v2/c2)-1/2
L = EP- Ek
= -mc2δ
∂L/∂v = vE0/c2 *δ^3 where E0 = mc2
d( ∂L/∂x)/dt = 0

vE0/c2 *δ^3 = 0
mvδ3 = 0
I'm not 100% sure if next lines are correct
p = mvδ
∴ pδ2 = 0

p = 0 ⇒ m = 0 or v = 0
δ = 0
(1-v2/c2)-1/2 = 0
v = c ⇒ m =0

Inconclusion a particle with zero potential is at velocity = 0 , what does this mean? a particle unmoving means absolute temperature has been reached!

vrms = (3RT/m)1/2
T = mvrms*1/3R
T ⇒ 0 as Ep ⇒ 0

Other solution states
Light or massless particles travel in a purely kinetic environment. I will update this with reference to both its wave like instances as well as its photon like instances.

Please criticize this as I wish to learn.
-SomaliPhysicist.
 
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Somali_Physicist said:
d( ∂L/∂x)/dt = 0

vE0/c2 *δ^3 = 0
mvδ3 = 0
You lost a time derivative here.
All the following equations should have a time derivative. The expressions are all constant in time, which means the velocity is constant for a single particle with no external potential. This is just inertia.
 
Somali_Physicist said:
d( ∂L/∂x)/dt = 0

vE0/c2 *δ^3 = 0
Apart from you trying to apply classical reasoning to an a priori relativistic particle, this is just wrong.

Also, the Lagrangian of a relativistic particle is not given by ##E_k - E_p##. See https://en.wikipedia.org/wiki/Relativistic_Lagrangian_mechanics
 
mfb said:
You lost a time derivative here.
All the following equations should have a time derivative. The expressions are all constant in time, which means the velocity is constant for a single particle with no external potential. This is just inertia.
Time derivative of 0 = 0 right?
∂L/∂x = ∂(-mc2δ)/∂x = 0
 
Somali_Physicist said:
Time derivative of 0 = 0 right?
∂L/∂x = ∂(-mc2δ)/∂x = 0
Yes, but the time derivative of any constant is also 0. You therefore cannot conclude that what you are differentiating to get zero necessarily is zero. You are missing the integration constant.
 
Orodruin said:
Yes, but the time derivative of any constant is also 0. You therefore cannot conclude that what you are differentiating to get zero necessarily is zero. You are missing the integration constant.
Oh , so there is a constant?
∂L/∂x = C

Also could you give a quick summary on the difference between relativistic langragian and classical.

Is it simply because:
S= ∫Lδdτ
 
Somali_Physicist said:
Also could you give a quick summary on the difference between relativistic langragian and classical langragian.Is it just taking into account coordinates?
This is all described on the Wikipedia page I linked to in post #3. I suggest that you read it carefully and come back if you have further questions. We cannot write you a textbook.
 
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Orodruin said:
This is all described on the Wikipedia page I linked to in post #3. I suggest that you read it carefully and come back if you have further questions. We cannot write you a textbook.

And with that, this thread is closed as the OP is speculation based on mistaken premises.
 
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