Tagged Questions
0
votes
1answer
64 views
How to understand the thermal radiation?
I am studying the thermal radiation (Stefan–Boltzmann law) by myself
$$P = \epsilon \sigma A T^4$$
here $\epsilon$ is the emissivity, $\sigma$ is Stefan-Boltzmann constant, $A$ is the surface area ...
0
votes
1answer
45 views
Electromagnetic field to cool a substance?
I saw somewhere that an electromagnetic field would cause a substance to let off thermal energy, ultimately resulting in the substance to cool really quickly.
If this is possible, does the strength ...
3
votes
2answers
291 views
How to interpret Stefan-Boltzmann's law?
The Stefan-Boltzmann equation states $e=\sigma T^4$, but how do we interpret this?
Is this completely wrong: A body of size $s^2$ generates the radiation/temperature $T^4$ for a given size and a ...
0
votes
2answers
117 views
Temperature of a black-body in LEO on the dark side of the Earth
Questions about the temperature of something in space are often very hard to pin down (example), since there is radiative transfer to/from many different regions in the field of view at dramatically ...
4
votes
0answers
131 views
How do I measure the temperature of a tiny water droplet?
How do I accurately (+/- 0.1 degrees Celsius or better) measure the temperature of a small (5 to 50 microliter) water droplet without noticeably affecting its temperature?
The mass of a thermistor or ...
4
votes
4answers
1k views
Light emitted by an object according to its temperature
According to this picture
the light emitted by an object depends on its temperature.
That makes perfect sense when we heat a metal. As its temperature raises we see it red at first, then orange, ...
6
votes
1answer
610 views
What’s the relationship between thermal radiation and Johnson thermal noise?
All objects above absolute zero emit radiation due to random collisions between the atoms they are made of. The spectrum of radiation emitted varies according to the temperature of the object, I ...
