Question

If we compared the spectrum of a black hole with the spectrum of a blackbody emitter, when both have the same temperature, what difference would we see?

a) The black hole spectrum is continuous
b) The black hole spectrum has emission lines
c) Both spectra are identical
d) The black hole spectrum is shifted to higher energies

Answer 1

Both the spectrum of a black hole and that of a blackbody emitter at the same temperature would appear identical, as both would emit a continuous blackbody spectrum, which includes radiation across all wavelengths.

Step-by-step explanation:

If we compare the spectrum of a black hole with the spectrum of a blackbody emitter, both at the same temperature, the correct answer is c) Both spectra are identical. The reason for this is that black holes are predicted to emit radiation known as Hawking radiation, which is thermal and has a blackbody spectrum. A blackbody, including a black hole at a certain temperature, will radiate energy across all wavelengths of the electromagnetic spectrum.

Moreover, the radiation of a blackbody peaks at a particular wavelength, which is dependent on the temperature of the blackbody. This principle also applies to black holes emitting Hawking radiation, hence their spectra would resemble that of an ideal blackbody at the same temperature. This also means that the spectrum would be continuous without any emission lines.