Question

What is black body and what are black body radiation

Answer 1

An object that absorbs all radiationfalling on it, at all wavelengths, is called a black body. When a black body is at a uniform temperature, itsemission has a characteristic frequency distribution that depends on the temperature. Its emissionis calledblack-body radiation.

It is called black body because the device used for this experiment was black in color and experiment was impossible without it. This was a big shock because it changed the thinking about light in classical physics and regarded as first success of quantum mechanics.