When a planet is 90 degrees from the Sun in the sky.
This is the study and respective theories on how the Universe is put together on a tiny sub-atomic scale. It’s the dream of many scientists to combine quantum theory with the theories that explain the large scale Universe in one unified theory.
A theoretical type of massive neutron star that is so dense that matter is broken down to its constituent particles. Quarks are the hypothetical constituent particles of subatomic particles, like neutrons.
A very distant active galaxy that emits large amounts of energy from its centre as electromagnetic radiation. The word is a contraction of ‘quasi-stellar radio source’.