Have you ever gone outside on a cold, clear night to watch a meteor shower and witness a super-bright fireball racing across the sky so brilliantly that you could swear you could hear it? Turns out the sizzling noise might not have been all in your head after all…but rather on it. (And here’s science to prove it.)
Meteors—aka “shooting stars”—have anecdotally been known to exhibit sounds to viewers on the ground for a long time: faint hissing, humming, buzzing, or popping noises that accompany bright fireballs (meteors brighter than magnitude -4) but don’t seem to make logical sense, especially considering that the light from the meteors you see is reaching your eyes nearly instantaneously from an event occurring at least 50 miles up. There’s simply no way a sound generated by a meteor at the source would be heard at the same time as it’s seen, or even closely afterwards—if it were even loud enough to cross the distance.
Yet the sounds are often reported, and they do occur simultaneously. It has been suggested that bright meteors can create electromagnetic transmission in radio wavelengths—which travel as quickly as light does—and meteor showers can be “heard” by radio receivers. But our ears don’t pick up radio wavelengths, so the audible sounds must be from something else.
In 2016, researchers from Sandia National Laboratories conducted experiments on this phenomenon. They discovered that various low-conductivity materials can serve as “photoacoustic transducers,” picking up electromagnetic radiation coming from the bright pulsing light of the fireball itself and transmitting faint sounds that can be detected by human ears.
These materials can be anything that might be close to the observer like dry leaves, dark-colored fabrics, and even hair—the frizzier, the better.
“It seems significant that people with frizzy hair are reported to be more likely to hear concurrent sound from meteors. Intuitively, frizzy hair should be a good transducer for two reasons. Hair near the ears will create localized sound pressure, so it is likely to be heard. Also, hair has a large surface-to-volume ratio which maximizes sound creation.” (Source)
This sort of photoacoustic reaction was observed as far back as 1880 by Alexander Graham Bell, but it’s only now that it’s been directly connected with the long-purported noises of meteors.
So the next time a good meteor shower is coming and you want to try to hear some shooting stars, find a nice, quiet place away from the city lights with a good view of the sky, wear something dark…and you might want to get yourself a perm.
Source/read more: Sandia National Laboratories