Now this is cool: an orbiting gamma-ray telescope has detected the creation of antimatter by earthly thunderstorms.
This is strange and delightful. I’m a little taken aback that people apparently predicted this quite a long time ago. (And it’s in the literature, so they really did.)
Since I spent my graduate student days thinking about high energy radiation processes, I can’t help but speculate about this.
Postulating the creation and annihilation of antimatter as a method for generating all gamma rays within a thunderstorm strikes me as putting the cart before the horse. It makes much more sense to me that a preexisting gamma above the electron pair-creation threshold would be the source of the positrons, which then create a secondary population of gammas via pair annihilation. One can imagine Compton scattering scenarios that would boost a lower-energy X-ray photon up to the pair-creation threshold, thus starting the process. (We already know thunderstorms can produce X-rays.) But if the antimatter is the original source of the gammas, you have to speculate about a pair-creation process that doesn’t already invoke such high energy photons—which is much more difficult at these energies.
But what do I know. I write books about Nazis.
I’m tickled that this discovery was made by the Fermi telescope. When I was in grad school, it was called GLAST (for Gamma-Ray Large Area Space Telescope), and it hadn’t been launched yet. I wrote about the potential impact of GLAST observations in my thesis. If I had stayed in the field, I would have loved to incorporate GLAST/Fermi data into further iterations of that research.