Well, there are thousands and thousands of physics and astronomy terms out there, and I'm not even aware of all of them that exist. In-world, Kankonian would obviously have a word for "Hawking radiation", but out-of-world, I just haven't created it yet.
I would also point out that physics is one of my weak spots for knowledge/vocabulary. Other weak spots include IT, military, vehicles, and video games. My strong points in knowledge/vocabulary include organisms (and the taxonomy thereof), the periodic table, music, recreational drugs, food and drink, astronomy, anatomy, medicine, psychology, politics, religion, and linguistics.