blackbody questions (1 Viewer)

[Steven12]

is black body a theoretical concept or has people actually built it.

i know one black body is a furnace with a small opening, but is it theoretical?

also, is black body a perfect absorber or emmiter of radiation? or both?

plus , let me get this right, because black body is a perfect emitter, the thermally accerated charges will produce a continuous distribution of wavelengths, because it is slowly heated up. and because the thermal radiation are 100% re-emmited by the wall of black body. A really hot black body should contain spectrums across all wavelengths because the less intense wavelengths are not dissipated.


(but how does this have to have anything to do with UV catastrophe?, cos you just simply say that as wavelength decrease, frequence increase because of c=f(wavelength), and since E=hf,enegy increase without limit and that violate the law of conservation)but the equation of =hf was not proposed before the theory so i am not sure if i should insert that in.

 

[Xayma]

Although a perfect black body is theoretical they get very close using tungsten carbide tubes.

It is both a perfect emitter and perfect absorber of radiation.

 

[aim54x]

black body radiation has been studied, hence planck and quantised energy, but how do they do this if a prefect body has not been built???

 

[helper]

All objects act as black bodies. It is just a matter of how close to perfect. Looking at many objects give you a black body curve. All black body curves have the same characteristic drop off at the UV end so even though not perfect they can model what a perfect black body would look like.