August 05, 2004

"MA'!!!!! The Bacon Stole My Bjork CD again!!!" well, why wouldn't it? if I were freezing, I'd like to listen to some good music too...
posted by Warrior 20 years ago
  • Soundwaves are one of those things that are always talked about, but never seem to come to market. I've seen several stories over the years about ultrasonic washing machines that use soundwavews and no detergent to clean clothes, but have yet to see one come to market. My tinfoil hat says it is a conspiracy, but who knows what the truth of the matter is...
  • Wouldn't these things be a bit of a danger if, say, there was a leak? I would imagine the dbs that these would use would be higher than most ears can handle.
  • They are ultrasonic, like sonograms, so they are so high pitched we can't hear them. I imagine if shooting those soundwaves at an unborn baby is save, they would be safe for everyone.
  • Ah. That explains it, thanks.
  • They are ultrasonic, like sonograms, so they are so high pitched we can't hear them. It was my understanding that these things worked by setting up a standing wave in a resonance chamber. The area around the sparse part of the wave gets cold, and the area around the dense part of the wave gets hot. To make a refrigerator work on that principle, I'd imagine you'd need a sound wave that was at least a couple of inches long - meaning an audible frequency. According to this paper [pdf], a typical working frequency might be about 300 hertz - definitely audible. I'm no expert, so I don't know what would happen if the pressure vessel sprang a leak. This Penn State FAQ points out that the working fluid is pressurized at 10 to 30 times atmospheric pressure, so the pressure vessel must be very strong in the first place. Maybe that strength requirement means leaks are so vanishingly unlikely that they're a non-issue, as far as safety goes. Maybe a leaky pressure vessel loses it's ability to maintain the high sound pressure level, making it fail-safe.
  • in the article it states that it's louder than thunder...hmmm, a leak is probably not advisable...however, in the case of a leak, couldn't you just run and unplug it?
  • it's like when my house alarm goes off. i just run and cover my ears till it stops.
  • Totally, totally sweet.
  • I scream for ice cream