I heard the ding of an impact against the diamond shield. It was definitely a pebble. Pieces of metallic debris make a different noise. The chances of hitting that tiny rock were vanishingly small—just like the rock itself, which had now vanished in a little puff of even smaller pieces. Given the vast amount of emptiness that both objects had been moving through, the math made impact look impossible. It wasn’t, though. We still hit the pebble. That collision had become a fact, and not just a fractional possibility. After something happens, the probability of it happening is one.
