- #1
Ravyan Asro
- 8
- 0
if two bodies are in thermal equilibrium in one frame, will they be in thermal equilibrium in all frames? also, does the temperature of a body depend on the frame from which it is observed?
Yes temperature is calculated as a macroscopic quantity but there are microscopic corollaries hence statistical mechanics. The zeroth law should hold as often as the 1st,2nd,3rd laws do. The rotation and velocity of particles in their micro and macro configurations are determined in probability by the partition function.tommyxu3 said:Temperature is the macroscopic performance of the motion of molecules, so I believe it may rely on the frame the observers stay, but I'm not sure if the zeroth law of thermodynamics still works anytime...
It is not.cree_be_mee said:The temperature is defined as the average kinetic energy of the particles.
It is very important to be precise here, particularly if it comes to thermodynamics in the relativistic realm. Temperature is by definition a scalar (or more precisely a scalar field if you generalize it to local thermal equilibrium). Historically, this was not always the case. That's why you find in the older literature other ideas about the thermodynamic quantities. Here, I refer to the modern definition. I'm not sure, when it was precisely established. A lot has been done by van Kampen. I can only recommend to learn the modern definition, because it is pretty confusing in the old way (the same holds true for various old-fashioned concepts about relativistic mass or even transverse and longitudinal mass).cree_be_mee said:It's exactly the transitive property of mathematics. If a=b and b=c, then a=c.
The temperature is defined as the average kinetic energy of the particles. The frame is taken to be one instance of measurement. The relative temperatures depend on the equilibrium state of the system. Is it closed or open? Is the ambient temperature ~close to the temperature of the system of particles?
True. I agree to this.mfb said:It is not.
Temperature in special relativity is actually a tricky concept, and there is more than one approach to define it. Thermal equilibrium of co-moving objects (zero relative velocity) is the same in all reference frames, however.
The Zeroth law of thermodynamics states that if two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other. This law establishes the concept of temperature and allows for the definition of a temperature scale.
The Zeroth law was added to the three existing laws of thermodynamics because it was deemed to be more fundamental and necessary in order to define temperature. It was given the name "Zeroth" because it was added after the first, second, and third laws were already established.
The Zeroth law is the basis for the definition of temperature, which is a key factor in the first and second laws of thermodynamics. The other laws also help to explain the behavior and properties of systems in thermal equilibrium, as defined by the Zeroth law.
An example of the Zeroth law in action is when you put a hot cup of coffee in a room temperature environment. The coffee will eventually cool down to reach the same temperature as the room, due to the transfer of heat energy between the two systems. This demonstrates thermal equilibrium, as defined by the Zeroth law.
The Zeroth law applies to many real-world situations, such as the regulation of body temperature in living organisms, the functioning of refrigerators and air conditioners, and the design and efficiency of engines and power plants. Understanding and applying the Zeroth law is essential in many fields, including engineering, biology, and chemistry.