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Listening to Leonids
Bill Kendrick writes: "An interesting article was posted by NASA about reports of people hearing Leonids as they burnt up in the atmosphere. And not 5 minutes later, like you'd expect, but instantly. Apparently this is thanks to very low frequency radio signals given off by the meteors as they burn."
...or Extremely Low Frequency for those that have never heard the term before.
:) I'm not sure if it's still in use today. Usually the government only shows you out-of-service tech on cable networks.
The nava used this to communicate with submarines on the other side of the earth by directing ELF signals directly through the earth's core. Saw it on Discovery once.
Simple materials like aluminum foil, thin wires, pine needles -- even dry or frizzy hair -- can intercept and respond to a VLF field.
I bet Weird Al was having the multimedia show of a lifetime!
Years ago when I was a kid I remember watching the Leonids. While watching them I distinctly remember hearing some of the larger ones doing this exact buzzing. I always figured it was just a bad memory or something. Nice to know I'm not crazy. :)
It did sound like a fizzing sound... Not very loud, but you would definately hear it.
One /. reader at Nasa close with his computer close to the antennas saw this earlier post and tried out the program.
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I remember reading about the same type of thing occuring during very intense northern lights. Same sort of thing, where the event and sound occured at the same time, and there couldn't possibly be time for the sound to travel the distance.
IRC, it was the same sort of thing, an ELF interaction directly in the brain.
So my thought is, could we use this for actual communication? Cause voices in someones head?
they talk about things like auroras, meteors, and nuclear blasts setting off these vlf radio signals... so maybe someone out there with more knowledge of the science of the energy levels required to set off these vlf radio frequencies will smack me down on this... but how friggin' cool would this be for gaming?
;-P
can you imagine playing a fps and getting hit by something that sets off objects in your room crackling and vibrating? maybe a tie-in is possible with this article
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I hear this sort of thing really pisses off whales.
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Stephen McGreevy, a professor at some college, IIRC, in California has been listening to Aurora Borealis' for years and has actually made recordings of some of the things he's heard and made CD's for retail sale. He also sells receivers to people so they can listen to the earth as well.
Related links:
His home page for VLF radio
The page he wants people to bookmark , cause his current provider bites.
His second CD
The VLF receiver page
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I'm amazed that they posted it. It seems as if most government agencies (NASA included) are using the 9/11 attacks as an excuse to pull information offline.
Please note that NASA has become increasingly unwilling to divulge information about what happens on the space station. Routine information such as the 'ships log' and audio feeds are no longer shared or available.
I apologize for this off-topic message, but more people should understand that this article, while fascinating, is nothing compared to the reams of important data that is being maliciously sequestered by an organization paid for with tax dollars. For every piece on meteor sounds, there are 10 pages of technical data on spaceflight, human research, and more that is being systematically hidden.
I predict that the information will become available through some type of Lexis-Nexus style pay system in the future so that you can have the privilege of paying for the data twice.
Bread and circuses, my friend. Look at the rest of the story, and make NASA give us what we own.
Now this isn't as cool as hearing meteors unaided with my ears. But while I was outside watching the Leonids here in Cupertino, I was also watching and listening to NASA's Meteor-radar with a linux program called baudline. There was a lot of activity that night, about a hit a second. Unfortunately I can't correlate the radar hits with the visuals since I live in California and the meteor radar is in other states (NM TX and AL). Still it was cool.
Right now the meteor radar is getting a hit about every 20 seconds. Sweet, I just saw a 70 second streak with a doppler shift of about 183 Hz. That is screaming at about 17X earth rotation! (If I wasn't so lazy I'd calculate that in MPH or m/s)
How did I do it? I just piped the real-time NASA stream into the standard input (stdin) of baudline, then equalized it with about 10 seconds of quietness, and then watched and listened away. I used this command line:
mpg123 -s http://icecast.msfc.nasa.gov:8000/forward-scat | baudline -stdin -channels 1 -overlap 100 -fftsize 2048 -mem 9 -record -samplerate 22050 -session meteor_radar
If the geocities site for baudline craps out, try again later, or try the mirror site. The downloaded md5sum for baudline_0.87_i686.tar.gz should be 72f949826ac81a461a8b4b5c5551f366
One thing several of my friends and I wondered about is why the meteors didn't all travel in the same direction? The velocity of the Earth during the shower was basically constant. The velocity of all the particles in the cloud of debris that make up the shower should be the same, otherwise the cloud would have dispersed generations ago. If the two velocities are the same, then the path of the meteors should have all been the same. But while most of the meteors clearly traveled from East to West in accordance with the rotation of the Earth, quite a few appeared to come from the North and South! Does anyone know what causes this?
The kitchen stove in the house I lived in in Moscow, Idaho when I was 12 would pick up a local radio station. It sounded very quiet, but if the room was still you could make out the words in the announcer's voice.
Curiously, it only started doing that the last couple months we lived there, and it was only that one station that was received, although there were several in the area.
Later on, I lived around the corner from a CB fanatic that had a quite illegal overpowered station in his home. He had a fifty foot antenna set up in his backyard. If he broadcast while we were listening to the stereo, it would blast the room with his racket.
I found that I could receive him clearly on a cheap 2 inch audio speaker that had one foot of wire soldered to each terminal and stretched out in opposite directions. That's it.
A neighbor took up a petition to ask the FCC to bust him but they never would.
I mentioned both of these phenomena to an electrical engineer once and he thought it shouldn't happen because there was nothing to rectify the signal. I'm not so sure how it could work, maybe impurities or oxidation in the metal forming a natural diode, or nonlinear effects from all the power, or something I don't know.
Someone previously asked if you could receive radio on dental braces. Yes you can, I've never heard it happen but I've heard of it happening to other people.
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According to this old ABCNews article, communications systems that work by bouncing radio signals off momentary streaks of ionized air created by meteorites have been in use for decades. I remember reading about a truck tracking system based on this. Kind of cool actually.
They work on the principle that if you send out a weak, omnidirectional radio signal it will randomly be reflected to the right target every so often by a streak of ionized air from one of the 80,000 or so meteorites that hit the atmosphere every second. If the target radio sends out a return signal quickly enough, it will be reflected back along the same path to the sender. The ionized streak of air lasts about a second, which is long enough to shake hands and send a little data back and forth, like a truck's position or an updated delivery schedule. Radio signals can be reflected several thousand miles this way.
In addition to what has already been posted, not every meteor you saw was neccessarily a Leonid. You can see one or two meteors an hour on any night. If it's dark enough.
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