Daily Archives: July 14, 2012

Nuclear Explosions are Loud

Yesterday Huxley and I were out on the porch checking out the incoming thunderheads. Then we heard thunder. Huxley immediately ran over to the door and pulled it shut.

“We don’t want thunder going in the house.”

Good idea. Who knows what it would do in there.

Anyway, everybody knows that when you see lightning, the thunder takes a while to get to your ears because lightning is percieved by us first from its light which travels at…the speed of light!…while lightning is percieved by us later from the sound it makes which travels at…the speed of sound! The latter is much much slower than the former.

So, when you see a video of an A-bomb or H-bomb explosion, either for real or as a dramatization, or for that matter, any kind of explosion, you should feel strange if the sound of the blast happens at the same exact time as the sight of the blast. We don’t, after all, see lightning and thunder coming at the same exact time when that is depicted on film or video. I think.

Now, this might make sense, depending on perspective. If the narrative mode is omniscient, I suppose one sees the blast and hears the blast because one is…well, omniscient. But an omniscient narrator may actually be hanging around with the characters who are experiencing the blast form a distant, so it still makes no sense.

Anyway, there is a YouTube video out there now that shows the unedited film of an atomic blast, and the sound is what it was at the time…a bunch of people chatting and then “KaBlam” and then “Holy Shit” and so on. It’s a long time between the blast (a bright flash of light) and the KaBlam. Here it is:

From the YouTube page:

Atomic bomb test ANNIE, March 17, 1953. This footage is interesting because the audio is more or less unedited. The timing between seeing the explosion and hearing the blast wave is off by a few seconds, which is how it would be in reality for an observer at that distance (because light travels much faster than sound). All together the audio is great here, so put on some headphones and experience it as if you were actually there.

“In an effort to calm public fears about weapons testing, Annie was an “open shot” — civilian reporters were permitted to view it from News Nob, 11 kilometers south of the shot-tower.

Hat Tip: Joe