You can tell what the highest frequency of radiation an object will emit

[LogicalAcid]

By its temperature? I just want to know if I understand Wien's law right.

 

[zhermes]

No, Wien's law tells you the peak frequency---i.e. the frequency at which the most power is radiated, based on temperature.

 

[fluidistic]

No, Wien's law tells you the peak frequency---i.e. the frequency at which the most power is radiated, based on temperature.

I concur that the answer is no. However should your word "power" be changed by "intensity"?

 

[zhermes]

I concur that the answer is no. However should your word "power" be changed by "intensity"?

Yes, that would probably be a more clear way of phrasing it. However, the intensity is the power per unit solid-angle, frequency and area.

 

[LogicalAcid]

Yes, that would probably be a more clear way of phrasing it. However, the intensity is the power per unit solid-angle, frequency and area.

So basically, when we get colder and colder, our body in general having less kinetic energy, will start radiating lower intensity infrared. But we will never emit anything lower than infrared, we'd freeze to death many times over first right?

 

[zhermes]

Correct... note that the human body only has the range of a few degrees in which it can operate. Thus the range in peak-intensity of radiation would be minute.

 

[LogicalAcid]

Correct... note that the human body only has the range of a few degrees in which it can operate. Thus the range in peak-intensity of radiation would be minute.

Exactly, thank you!

 

[DaTario]

Let me add a comment. Suppose we are using a black body whose temperature is T at time t0 but after that it is isolated in empty space. In this situation it makes sense to talk about the highest frequency it can emit, for there is a photon whose frequency is such that, if the body emits it, its temperature will fall to zero kelvin. No highest frequency can be emited.
I am particularly not considering rest mass energy here.

Best wishes

DaTario