Jeremy Cox asked:
If you fire an electron and a positron towards each other such that they just miss, would they orbit each other in such a way as to produce observable gravitational waves?
Side notes: My physics understanding has mostly been gained from what I learn in school (I'm in year 12). Regarding gravitational waves and antimatter my own reading of wikipedia, books and attending lectures is all I've got. Love your show, listened to many podcasts, including a bit on Gravitational waves, however I found this didn't provide me with any new knowledge. This one is the first one I'll listen to live.
We posed this question to Jeffrey Hangst from CERN...
Jeffrey - Absolutely. They make a system called positroneum which is a sort of a mini atom made of one positron and one electron, and that has been studied extensively. Also the spectrum of positron in positroneum has been studied. The problem with that thing is it doesnít live very long. About 140 nanoseconds in its long lived form so itís difficult to study. Anti-hydrogen is stable, that's why we want to go with that. Itís also a pure antimatter system. Positroneum is half matter, half antimatter.