Earth emits an ear-piercing series of chirps and whistles that couldbe heard by any aliens who might be listening, astronomers havediscovered. The sound is awful, a new recording from space reveals.Scientists have known about the radiation since the 1970s. It iscreated high above the planet, where charged particles from the solarwind collide with Earth's magnetic field. It is related to thephenomenon that generates the colorful aurora, or Northern Lights. Theradio waves are blocked by the ionosphere, a charged layer atop ouratmosphere, so they do not reach Earth. That's good, because theout-of-this-world radio waves are 10,000 times stronger than even thestrongest military signal, the researchers said, and they wouldoverwhelm all radio stations on the planet. Theorists had long figuredthe radio waves, which were not well studied, oozed into space in anever-widening cone, like light from a torch. But new data from theEuropean Space Agency's Cluster mission, a group of four high-flyingsatellites, reveals the bursts of radio waves head off to the cosmos inbeam-like fashion, instead. This means they're more detectable toanyone who might be listening. The Auroral Kilometric Radiation (AKR),as it is called, is beamed out in a narrow plane, as if someone had puta mask over a torch and left a slit for the radiation to escape. Thisflat beam could be detected by aliens who've figured this process out,the researchers say. The knowledge could also be used by Earth'sastronomers to detect planets around other stars, if they can build anew radio telescope big enough for the search.
They could alsolearn more about Jupiter and Saturn by studying AKR, which should emitfrom the auroral activity on those worlds, too. "Whenever you haveaurora, you get AKR," said Robert Mutel, a University of Iowaresearcher involved in the work. The AKR bursts -- Mutel and colleaguesstudied 12,000 of them -- originate in spots the size of a large city afew thousand miles above Earth and above the region where the NorthernLights form.
aku tak tahu lah nak tepek cemana
tp aku rase yg nilah kot
aku rase ni bkn nya some sort of earth crying
i read one of the comments and its said : the reason it sounds like aeroplanes and cars is because there are 35,000 and 1 billion cars on the road every second.
Originally posted by lolaxpdc at 4-7-2008 12:07 PM
ek ele luar pade atmosfera bumi ni vacum kan?
dlm ruang vacum bunyi takle travel la...
so x relevant...case closed!!!
baca artikel betul-betul,diaorg refer kepada radio wave la dol...
Post time 4-7-2008 07:06 AM
变色卡
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