Originally posted by Pasti:
dehammer, let's keep the terminology correct. The device you mention is not a black-hole device it is caled a black-body radiation device. The difference between this device and a black-hole cannot be emphasized enough.
In my time, the device was not a cylinder, but a sphere (for the obvious reasons), and it was called the Ulbricht sphere. It was used to determine the thermal distribution of the spectral density of the radiation emitted by an optical black-body,you know,the ~T^4 dependence of the spectral density, and similar.
Ive heard it referred to as a black hole device, as it allowed light to enter but not escape. the sphere did as the light would refract a little in all directions and would eventually bounce. back out. the cylander did not allow that, as if the light went in to a direction no alined with the hole, it would hit a wall and then hit the cylander again.
perhaps that was not its official name.
