- #1
bwana
- 82
- 2
- TL;DR Summary
- is there evidence of relativistic change in processes occurring at the level of large populations of particles
In most experiments of SR, we look at atomic and subatomic particles or the frequency of EM radiation.
The Haefele-Keating experiment looked at the resonance of cesium atoms stimulated by a certain EM frequency
https://en.wikipedia.org/wiki/Hafele–Keating_experiment
The Ives-Stillwell experiment looked at Doppler shift
https://en.wikipedia.org/wiki/Ives–Stilwell_experiment
The lifetimes of muons and other particles were investigated in other experiments.
https://en.wikipedia.org/wiki/Experimental_testing_of_time_dilation
But consider the mundane process of diffusion. Does diffusion occur more slowly in a container moving close to relativistic velocity? I guess doing this experiment is technically very difficult. But haven't we developed tools improved enough to allow this?
Or consider the Carnot cycle. Or perhaps something even more fundamental- heat transfer between two bodies. A simple experiment would consist of an insulated (adiabatic) container. In this container are two separate containers of water separated by a gap of air. Each container has a thermocouple to measure its temperature. One container is then heated to a specific temperature. The containers are brought into contact and the time it takes for the temperature equilibration is measured and a curve is generated. If this experiment is done on an airplane (like the Hafele–Keating_experiment) we should expect different rates of cooling compared to the ground experiment as well as the direction of flight compared to the ground (as in the Hafele–Keating_experiment)
But the theory of relativistic thermodynamics is still controversial
https://www.nature.com/articles/s41598-017-17526-4
The initial treatment by Planck and Einstein suggested
\begin{array}{ccc}T^{\prime} =\frac{T}{\gamma }\,, & S^{\prime} =S, & p^{\prime} =p\,,\end{array}where γ = (1 − (w/c))−1/2 is the Lorentz factor, c is the speed of light, and primed quantities correspond to the thermodynamic measurements in I’. These results mean that a body should appear cooler for a moving observer, but both entropy and pressure are relativistic invariants.
But even to this day, there is no consensus about how to theoretically treat relativistic thermodynamics. Even when the theory is written down, I can make no sense of it.
https://arxiv.org/abs/gr-qc/9803007
https://link.springer.com/article/10.1007/s10701-020-00393-x
https://www.researchgate.net/post/Why-is-relativistic-thermodynamics-not-included-in-the-general-physics-textbooks-and-special-theory-of-relativity-textbooks
But most of these treatises look at the question trying to understand whether a body “looks hotter or colder” from the point of view of the other. My question has more to do with the intrinsic thermodynamic behavior of a process at relativistic speeds.
But really, the theory has to fit the data. So where are the data?
The Haefele-Keating experiment looked at the resonance of cesium atoms stimulated by a certain EM frequency
https://en.wikipedia.org/wiki/Hafele–Keating_experiment
The Ives-Stillwell experiment looked at Doppler shift
https://en.wikipedia.org/wiki/Ives–Stilwell_experiment
The lifetimes of muons and other particles were investigated in other experiments.
https://en.wikipedia.org/wiki/Experimental_testing_of_time_dilation
But consider the mundane process of diffusion. Does diffusion occur more slowly in a container moving close to relativistic velocity? I guess doing this experiment is technically very difficult. But haven't we developed tools improved enough to allow this?
Or consider the Carnot cycle. Or perhaps something even more fundamental- heat transfer between two bodies. A simple experiment would consist of an insulated (adiabatic) container. In this container are two separate containers of water separated by a gap of air. Each container has a thermocouple to measure its temperature. One container is then heated to a specific temperature. The containers are brought into contact and the time it takes for the temperature equilibration is measured and a curve is generated. If this experiment is done on an airplane (like the Hafele–Keating_experiment) we should expect different rates of cooling compared to the ground experiment as well as the direction of flight compared to the ground (as in the Hafele–Keating_experiment)
But the theory of relativistic thermodynamics is still controversial
https://www.nature.com/articles/s41598-017-17526-4
The initial treatment by Planck and Einstein suggested
\begin{array}{ccc}T^{\prime} =\frac{T}{\gamma }\,, & S^{\prime} =S, & p^{\prime} =p\,,\end{array}where γ = (1 − (w/c))−1/2 is the Lorentz factor, c is the speed of light, and primed quantities correspond to the thermodynamic measurements in I’. These results mean that a body should appear cooler for a moving observer, but both entropy and pressure are relativistic invariants.
But even to this day, there is no consensus about how to theoretically treat relativistic thermodynamics. Even when the theory is written down, I can make no sense of it.
https://arxiv.org/abs/gr-qc/9803007
https://link.springer.com/article/10.1007/s10701-020-00393-x
https://www.researchgate.net/post/Why-is-relativistic-thermodynamics-not-included-in-the-general-physics-textbooks-and-special-theory-of-relativity-textbooks
But most of these treatises look at the question trying to understand whether a body “looks hotter or colder” from the point of view of the other. My question has more to do with the intrinsic thermodynamic behavior of a process at relativistic speeds.
But really, the theory has to fit the data. So where are the data?