Hello.. Can someone tell me what sources in the Universe produce anti-matter? Do black-holes, stars? stellar explosions? I can assume if these things are large in number...there should be a lot of anti-matter floating around in the Universe. I know a lot of it gets destroyed in the interstellar medium..but because the medium is "thin" there should still be a lot of anti-matter out there floating around. Also, there should be a lot in the vicinity of the Earth as well. And if so...could you not simply harvest or collect it up in a big way to be used as fuel or for other purposes? Thanks for any and all responses. Bye. G.