system
Given the following post, respond as if you're commenting on Reddit:
human
If atoms only emit light with specific (discrete) values for wavelengths, why do bodies emit a continuous spectrum of radiation?

The notions of the emission spectrum kind of collided with the black-body radiation information I had...

If you heat a body, like tungsten wire in a light bulb, it acts like a black-body and you get the classic continuous spectrum... But that body is made up of atoms, and atoms only release discrete radiation when an electron goes back to a lower energy level (E=hf=hc/l)... So how can you get that continuous spectrum of wavelengths from atoms that release light with discrete wavelength values?
gpt
A black body is an idealized model, like a perfect vacuum or a frictionless surface. It is an approximation which holds up well in many cases, but actual things deviate from the black-body model.

The hypothetical black body is a substance that absorbs all light perfectly, and emits light in a well-defined spectrum depending on its temperature, ie. blackbody radiation. A single hydrogen atom is therefore a poor candidate for applying the black-body model, because it only absorbs some wavelengths of light and generally does not behave much like a black body on its own.

But if you took a huge ball of hydrogen, like the sun for example, and heated the whole thing up to 6000 kelvin, it follows the black-body model quite well. At this temperature, we happen to get the spectrum we are familiar with from the sun.

It is still the case that photons are emitted from electrons changing energy states. But energies of electrons are not limited only to their quantum numbers. There are also vibrational energy states, so if you have a gas of really hot hydrogen atoms bouncing around, there will be a lot of kinetic energy that will result in electrons being bounced around, emitting light accordingly. This is somewhat independent of what particular material it is, and then you have blackbody radiation :)