What makes the loudest noise? I think it's an H bomb, but my girlfriend thinks it's a big volcano. Or is it our argument about this question? Please help!
-- Andy, South Park
Our neighbors two dogs make the loudest noise. They also take the prize for the most endless, pointless, and soul-killing noise, especially after midnight. That's my answer and I'm sticking to it. But I suppose you want science. How boring. We're not in a position to predict what potentially could make the loudest noise, choosing from all the noisy things in the world. But we'll base our answer on what the science guys say has been the loudest noise heard on the planet during recent, fairly reliable recorded history. And that was no puny man-made thing; it was a volcano. In August of 1883 the three-volcano island chain of Krakatoa (in Indonesia, between Java and Sumatra) blew up with such force that the sound of it was reliably heard 3000 miles away in Australia and Mauritius. Concussion air waves were felt in London on four separate days, after circling the globe a few times. So much crap was spewed into the atmosphere that the weather was drastically changed for at least the next year. Krakatoa didn't actually go up in one big boom; it started slowly, with seeping gasses, mud flows, and earthquakes, like most other eruptions. Speculation has it that after enough fissures and cracks appeared in the mountain's side, sea water got into the central pit of lava, turned to steam, and finally blew up all but one tiny crescent of the island. It also set off the obligatory tsunamis and other ancillary disasters. True to form, the island is slowly rebuilding itself, so if it hurries up, maybe Krakatoa itself can end the girlfriend-boyfriend spat. It had a minor spit-up in 2001.
Today's scientists calculate that the explosion was the equivalent of 200 megatons of TNT, seven times the energy release of the bomb we dropped on Hiroshima. The largest bomb built by us genius homo sapiens was in Russia during the Cold War and it was only 50 megatons. We're sure the CIA heard it blow, but I doubt they heard it in London. So until the bomb brains wire together a real humdinger, we can probably anticipate that the next loudest sound will come from some natural explosion like a volcano, given the magnitude of the forces nature can conjure up. Maybe it will be the big supervolcano they claim is sitting under Yellowstone just waiting to have it's messy, noisy day. We may not be around long enough to appreciate it.