Earth's Constant Hum Explained 336
MattSparkes writes "It has been known for some time that there is a constant hum that emanates from the Earth, which can be heard near 10 millihertz on a seismometer. The problem was that nobody knew what caused it. It has now been shown that it is caused by waves on the bottom of the sea, and more specifically 'by the combination of two waves of the same frequency travelling in opposite directions.'"
I shall be the first to say (Score:5, Funny)
Re:I shall be the first to say (Score:5, Funny)
The truth is the Earth is humming just because it doesn't know the words.
On mars the atmosphere shakes once every year (Score:3, Interesting)
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Constant Hum (Score:5, Funny)
Ohmmm (Score:2, Funny)
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Spelling, its only fun it you can mess with it.
Re:Constant Hum (Score:5, Funny)
Re:Constant Hum (Score:4, Funny)
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Not. (Score:2)
So that's what causes it (Score:5, Funny)
please (Score:5, Funny)
Alternate explanation (Score:2)
Re:Alternate explanation (Score:5, Funny)
Everybody knows this is Great Cthulhu snoring in his sleep
Now please lose 2D6 sanity points
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Re:Alternate explanation (Score:5, Funny)
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MAKE IT STOP!!!
I visited disneyworld once. That damned song scarred me for life.
Damn (Score:5, Funny)
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"So all this time I guess I should have put the tinfoil... in my shoes!"
I'm currently at university, and have had to endure hearing every other sentence ending with "in my pants!", so that might explain it...
Maybe it's just happy? (Score:5, Funny)
Re:Maybe it's just happy? (Score:5, Funny)
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Unfortunately they'll be butch instead of lipstick.
Re:Maybe it's just happy? (Score:4, Funny)
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On the other hand, my current cat is the opposite. Purring seems to have nothing to do with being happy. She will frequently walk up to me and just start purring, and generally stops once I start petting her.
So it's not really disinformation, it's partial information. Just like yours.
Wow (Score:5, Funny)
All this time, I just assumed it was because it couldn't remember the words.
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Actually the earth knows the words but was concerned that the RIAA might sue.
Why? (Score:2, Interesting)
Did ancient greeks know about this? (Score:5, Interesting)
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Hmmmmmmmm (Score:5, Insightful)
Re:Hmmmmmmmm (Score:5, Funny)
Re:Hmmmmmmmm (Score:4, Insightful)
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But wait! (Score:5, Interesting)
Wait a minute. How do we know that it's the waves that are causing the hum, and not the other way around? Perhaps the planet is still ringing from meteor impacts, and the hum is just the resonant frequency. The deep ocean waves may be just a side effect.
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Damping.
Note to mods: you misspelled "funny".
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That's what I love about science though, there's yet another thing to explain. I wonder what it will reveal?
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You could try religeon, they have *all* the answers, so long as you don't actually ask any questions....
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The exaust ports on the engines.... DUH!
Re:Hmmmmmmmm (Score:4, Informative)
The answer is "wind" this has been known at least a century, no need to put it in the article. Now you ask what makes wind. This to has been known for a long time, the basic answer at the bottom of all of this is uneven heating of the atmosphere by solar radiation. Why "uneven"? The Earth is not uniform all over it's surface? Why is that? Something about plate tectonics? Why is that? The core is liquid and the "lighter" crust floats on the liquid while the liquid circulates. You can go on forever.....
But seriously, wind blowing over water causes ripples, the hight and period of the riples depends on the speed of the wind and the "fetch". Fetch being the distance the wind has to act on the water.
Interesting, but wrong (Score:5, Funny)
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Re:Interesting, but wrong (Score:5, Funny)
Re:Interesting, but wrong (Score:4, Funny)
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IT'S BEES (Score:2)
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While we might accept the turtles, our wise men actually explain to us that the last turtle is actually standing on a dog that is chasing it's own tail - which explains the rotation.
Whales (Score:5, Funny)
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It stopped the other day (Score:5, Funny)
hertzs (Score:5, Informative)
http://en.wikipedia.org/wiki/Seismometer#Modern_r
Re:hertzs (stacking) (Score:3, Insightful)
So with enough stacking you can pretty much detect as low frequencies as you want if only the amplitude is strong enough to be detected by the seismometers, so my guess is that the limiting factor is not the 1 Hz, but lies in how small amplitudes these seismometers detect.
These suggested waves would hold quite an amount of energy so it does make sense that they are able to detect these to me.
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For example, if you want to predict the quality of your prediction of protein 3D structure, you can assume very simple approach, like all the aminoacid residues on
Balrog (Score:5, Funny)
Come one it is the intelligent shaking. (Score:4, Funny)
Global-scale flood tectonic cataclysm ring down. (Score:2)
Quick! Someone patent/copyright/trademark it! (Score:4, Funny)
PROFIT!
Easy to explain (Score:4, Funny)
Which sea? (Score:2)
(re: my user handle)
Throbbing (Score:2, Insightful)
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It's more like "bang the drum softly". Once every ten seconds.
So are there any biological processes that are using this omnipresent beat for a clock frequency? Do any of the intracellular membranes we are familiar with quiver in resonance with the Earth beat? Would it be possible to predict the shape of such a biological structure?
I'm guessing that life has found a way to take advantage of this constant beat to organize sequences of activity. If that it so, there would be health consequences for astrona
I have an idea (Score:5, Interesting)
OK, I didn't say it was a *good* idea
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Sorry, folks. (Score:2)
But seriously, how much power would it take to put such a vibration into the air, and how far would it travel? I'm just picturing the hair on my head blowing this way and that way with the changes in sound pressue.
OK, next question... (Score:2)
Constant Hum Explained (Score:2)
Well this proves it... (Score:5, Funny)
Venus is the hot one and will turn out to be gay (natch, I mean Venus?)
Earth is the um, down-to-earth one - full of life.
Mars - the cold and distant one - always at war with the other members
Jupiter - slightly overweight - jolly
Saturn - Gaudy over-compensator wears lots of jewelry and rings - looks up to Jupiter
Hot headed Mercury - left in a huff to form his own band - his manager is the real star though.
Uranus was an asshole and left before fame came.
Neptune - always blue, committed suicide after what happened to Pluto...
Pluto? Well, Pluto was thrown out when it was discovered he never could sing.
Re:Well this proves it... (Score:4, Funny)
All those cartoons paid off! ! (Score:2, Funny)
Not quite right (Score:4, Interesting)
Tesla noticed this and build a little tool which hit on the harmonic frequency and kept accelerating the oscillation with a device he built until there were "earthquakes" observed all around, and he had to cut short a trip to run home and turn it off. Indeed in manufacturing speakers you try to get this frequency down below audioble range as you don't want the speaker to resonate and alter the sound it's supposed to generate.
It's a very common mistake made by many when they observe a symptom (not realizing there is a real why behind it.)
this is what I found (Score:5, Interesting)
IDA (International Deployment of Accelerometers) [ucsd.edu] used to detect the hum.
Article in Nature (1979) [nature.com] assesses if IDA can be used to detect very low frequency seismic data. Looking at the figure 1 of amplitude(?) ("MD counts" at Rarotonga station not shown on the current IDA map [ucsd.edu]) I can see the aftershocks in 2 hour intervals after the Indonesia earthquake, but the subj frequencies could be detected only by obtaining the spectrum (Fig.2) at mHz range which frankly looks like white noise - irregular beats.
Most interesting figure is Fig.3 which shows the 0.43-0.52mHz of the _processed_ spectrum measured at six different stations around the world at Hour 25 and on. The Alaska station (CMO) has much clearer spectrum compared to the closest (?) RAR station.
All of it must have meant something for a seismologist which I am not.
possible energy source? (Score:3, Interesting)
Obligitory Friends (Score:2)
Phoebe: Oh my God turn him off!
Sorry... (Score:2)
triangulation doesnt work for hum (Score:4, Informative)
For continuous signals you can find source by cross-corelating long pieces of signal from multiple locations. I first saw this in ambient noise submarine location, but the seismologists have now adopted it for analyzing some kinds of difficult signals like hum.
Re:10 millihertz (Score:5, Informative)
10 milliHertz = 10 * 1/1000 waves per second
=> 0.01 waves per second
* 60 => 0.6 waves per minute
* 60 => 36 waves per hour
divide by 2 (Score:2)
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Wave mechanics surf.
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Re:constant hum (Score:5, Funny)
Ohhhh yes :) (Score:5, Funny)
You SO win the prize for 'AC reply that is most obviously by the original poster, ever'
A winner is you!
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Re: telepathic "she"
Ok, you're probably right - but you should be aware that a significant percentage of people now randomly use either "he" or "she" as a generic pronoun for an unknown person, or alternate the two in a document that calls for multiple instances of such usage. We do it in order to step away from the sexist "he" as a default, and to avoid the awkward "he/she" (which frankly doesn't flow very well.)
This still discriminates against genderless objects.
One should say "S/h/it" instead.
Won't somebody think of the machines?
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Wrong notation (Score:2)
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Nope, it actually comes out very slightly flat of E(-11)... 185.1 half-steps below A4.
Of course, at such low frequencies, even a tiny measurement error can make a huge difference... If we had just 11mHz, that drops the note by almost a full step.
(Incidentally, for those curious on how to calculate this, just take log2(Hz/440)*12. That will equal the number of half-steps away from (middle) A4, at 440Hz (thus the magic constant given above).