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posted by martyb on Tuesday April 18 2017, @08:26PM   Printer-friendly
from the check-your-fillings dept.

Meteors may emit radio waves as they burn up in the atmosphere. The radio waves could be converted to sound by vibrating objects near the ground, explaining why some observers "hear" meteors in real time despite the discrepancy between the speeds of light and sound:

For centuries, some observers have claimed that shooting stars or meteors hiss as they arc through the night sky. And for just as long, skeptics have scoffed on the grounds that sound waves coming from meteors should arrive several minutes after the light waves, which travel nearly a million times faster. Now, scientists have proposed a theory to explain how our eyes and ears could perceive a meteor at nearly the same time. The hypothesis might also explain how auroras produce sound, a claim made by many indigenous peoples living at high latitudes.

Meteors release huge amounts of energy as they disintegrate in the atmosphere. They also produce low frequency radio waves that travel at the speed of light. Some scientists have suggested that those radio waves produce the sound that accompanies meteors. The waves can cause everyday objects—including fences, hair, and glasses—to vibrate, which our ears pick up as sound between 20 and 20,000 Hertz. This phenomenon, called electrophonics, is a well-known principle: "The conversion from electromagnetic waves to sound waves ... is exactly how your radio works," says Colin Price, an atmospheric scientist at Tel Aviv University in Israel and co-author of the new study. "But in this case nature provides the conversion between electromagnetic waves and acoustic waves."

On the electrophonic generation of audio frequency sound by meteors (DOI: 10.1002/2017GL072911) (DX)

Photoacoustic Sounds from Meteors (open, DOI: 10.1038/srep41251) (DX)


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  • (Score: 2) by VLM on Tuesday April 18 2017, @09:03PM (5 children)

    by VLM (445) Subscriber Badge on Tuesday April 18 2017, @09:03PM (#496013)

    hiss as they arc through the night sky

    I've kept tropical fish for some decades and they pay a ridiculous amount of attention to their sky that being the top of the aquarium where I feed them.

    My point is that maybe snakes don't like getting eaten by hawks and some moving thing in the sky pissed them off mightily so they hiss, because other than being eaten theres not much they can do as a hawk swoops about. Just because some dude doesn't find the snake doesn't prove there wasn't a snake there recently.

    New generations are growing up knowing that hiss, thats a creeper not a meteor.

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  • (Score: 3, Interesting) by sjames on Tuesday April 18 2017, @09:24PM (4 children)

    by sjames (2882) on Tuesday April 18 2017, @09:24PM (#496025) Journal

    I have heard a meteor and I have heard a snake. They do not sound alike.

    • (Score: 2) by VLM on Wednesday April 19 2017, @12:45PM (3 children)

      by VLM (445) Subscriber Badge on Wednesday April 19 2017, @12:45PM (#496262)

      I have heard a meteor

      LOL you can't just drop that without any details.

      So do meteors sound like stand up comedy laughter or a large diesel engine or fairies or ...

      • (Score: 2) by sjames on Wednesday April 19 2017, @01:03PM (2 children)

        by sjames (2882) on Wednesday April 19 2017, @01:03PM (#496270) Journal

        More of a whoosh. Very similar to red noise.

        • (Score: 2) by VLM on Wednesday April 19 2017, @03:31PM (1 child)

          by VLM (445) Subscriber Badge on Wednesday April 19 2017, @03:31PM (#496357)

          Low freq atmospheric noise has a reddish spectrum (at higher freqs its more white noise spectral shape) so that's not unrealistic. Thats not even mythbusters "plausible" but more "not implausible"

          If you can hear a meteor you should have been able to hear omega stations. I hooked a tweeter up to a longwire antenna when I was much younger (omega shut down like 20 years ago) and I heard omega stations, very high freq beeps in the lower 10 khz range. In theory people who hear meteors should have been driven insane by hearing much stronger omega transmissions. Then again, maybe some tinnitus sufferers were successfully receiving omega pulses... That must have been pretty annoying to listen to 24x7.

          • (Score: 2) by sjames on Wednesday April 19 2017, @04:07PM

            by sjames (2882) on Wednesday April 19 2017, @04:07PM (#496382) Journal

            If you can hear a meteor you should have been able to hear omega stations.

            That presumes something in my ear was decoding and converting the signal. I have seen many meteors since, but have not heard them.

            Wideband vs very narrow makes a difference. For a narrow signal like OMEGA, you not only need something to just happen to have a non-linear response, but to be responsive to the center frequency (or close to it) The latter part is much more likely with a broad signal.

            Accidentally decoding OMEGA might explain an instance where I heard an incandescent light bulb "sing" for a minute or 2 just before it burned out.

            Probably irrelevant but I do have a bit of tinnitus and have for as long as I can remember.