I filed the conversation away in my memory, and then finally got a chance to write about it for (drumroll, please) NOVA’s blog! Suffice to say this was a fun article to write: I started it without knowing a lot about the topic, and ended feeling like I had learned something. Hopefully it’s as interesting to read as it was to write.
While astronomical sources may be good accelerators, that doesn’t mean the cosmos is full of good colliders. Our Earth-bound experiments are designed to focus beams of protons or other particles into tight “bunches” (that’s the technical term!), then send those bunches slamming into each other from opposite directions. That sort of thing is rare in space: A cloud of gas left after a supernova may be full of fast-moving protons, but direct collisions are not very common.
However, Earth itself is part of the Universe’s collider, the accidental “target” for beams of cosmic rays from deep space. [Read more...]