Helium Balloon Popping Sounds
Most recent answer: 09/12/2013
- Kevin Gross (age 52)
Goshen, IN, USA
This story is amazing and fun to think about. Don't take our ideas on it too seriously, because we never heard of anything like it. Basically, we suspect you're right.
How could the balloon float stably? That's not too weird, since the air near the ceiling can be a little warmer and less dense than the air near the floor. So the balloon can float at the mid-density height. I suppose that would be particularly likely if there are air-conditioning vents in or near the floor, as in my house.
A colleague (Mike Stone) tells me that it's common for electrically isolated objects to pick up rather large voltages from static charge. (Maybe some sort of ion generation in an air-conditioner filter could play a role here.). So the balloon could pick up static charge.
Then we get to the part where the discharge makes a series of very loud noises. Sparks always make some noise. Maybe having the spark shake the balloon gives it much better coupling to sound waves than you'd get for just a bare spark between rather rigid objects. So these sparks are unusually loud.
If I were you I'd try to reproduce the whole thing, and even try making a video. If that's possible, then we can consider what might be done to test the idea. (E.g. does a thin conducting polymer coat on the balloon have a big effect, ...) I believe that there's no danger to anyone, so long as the balloon doesn't get sucked into a fan or some such normal problem.
Mike W.
(published on 09/12/2013)