Apparently I am not watching enough PBS SpaceTime because I still do understand what a "gravitational atom" might be.
They are not implying a particle that causes gravity right? Because I thought it is pretty well accepted there isn't a "gravaton" like there are photons.
They also don't mean atom-sized black-holes, so I still don't get it.
Hoping Matt does an episode on this so I can grasp it.
> I thought it is pretty well accepted there isn't a "gravaton" like there are photons.
Different branch of physics that we can't quite mesh with GR yet. A graviton is the quantized "piece" of gravity, like phonon is for sound/mechanical waves, or photons for EM. It exists as much as a photon or any other "messenger particles" exists, in that it's a useful mathematical model. It's not something we have isolated/observed with equipment though.
In an atom, the electrons orbiting the nucleus are only allowed to be at discrete energy levels (the energy levels are "quantized"). In a classical model of an orbit, the energy level of a spaceship orbiting a planet can be thought of as the speed it has that allows it to orbit at a certain altitude, assuming no friction or other effects. Velocity is energy in that case (E=m*v^2 in classical mechanics). Unlike electrons in an atom, the spaceship can be in any one of a continuous range of energy levels (up to escape velocity).
The proposal in the article is (I think) that bosons orbit certain black holes in quantized energy states, like electrons would orbit an atomic nucleus.
As far as I know the existence of the graviton is 100% up in the air, not well accepted either way.
But yeah, particles in energy levels gravitationally bound to a black hole in a similar way electrons are electrically bound to a nucleus.
I think they are more drawing an analogy between the atom one or more black holes with a cloud of particles around them. Black holes are quantum mechanical and so the resulting system could behave much like an atom, including having things that look like energy levels. The universe rhymes.