[meteorite-list] seti
From: Sterling K. Webb <kelly_at_meteoritecentral.com>
Date: Mon Nov 14 02:07:18 2005 Message-ID: <43783782.8D46AC86_at_bhil.com> Hi, There is a huge difference between detecting and discriminating an INDIVIDUAL radio signal from the Earth at interstellar distances on the one hand and merely detecting the totality of the Earth's radio signals at interstellar distances, on the other. Surrounding the Earth is a shell of EM transmissions out to a radius of 94 light years. At the outer edge of that shell is Marconi's transmission of the letter "S" in 1901. Faint. But at radii of 84 light years and again at 57 light years, quantum leaps in intensity occur. (That's the onset of commercial radio and commercial television respectively.) The TOTAL radio emissions of the Earth are TWICE AS BRIGHT AS THE SUN. Every radio astronomer within that inner 100 light year sphere (if there ARE any radio astronomers "out there") is confronted with the paradox of a normal type G star which has an optically invisible companion which has twice the luminosity in the radio spectrum as the visible star! Studies of the motion of the "invisible companion" would show it to be in orbit around the normal star. There is only one possible explanation of an optico-radio binary star. That is, that the normal star has a planet which is SCREAMING its head off in the radio spectrum! And it's only getting noisier with every passing year, louder and louder! As for directed transmissions, we already have interplanetary radar signals that are 10,000,000,000 times brighter than the Sun! As an interstellar neighbor, the Earth is kind of like that guy on the subway toting the 300 pound ghetto blaster! If you have any hope that the aliens haven't noticed us yet, you can forget all about them. Which is why I find the beautiful dream of SETI to be just that: a beautiful dream. A Kardashev Level Two civilization (one which utlizes the full energy resources of an entire solar system) should be roughly the radio luminosity of a QUASAR! It would be "visible" in the EM spectrum at 100,000 light years distant (if the civilization survived for that long). In 300 to 500 years, WE will (I hope) be a fledging Kardashev Level Two civilization. There will be millions of powerful comet-hunting radars in the Kuiper Belt and the Inner Oort Cloud, billions of radar beacons on every rock in the system, trillions of TV channels (how many re-runs of the ancient classics like The Brady Bunch?), and an inconceivable number of interplanetary cell phones (most of them on hold and playing space elevator music). Our solar system will probably be the brightest radio source in the Milky Way Galaxy. If there are any aliens out there, you know, great wise space-traveling advanced aliens, WHERE are their home systems and WHY are there no bright artificial radio sources? If there is an interstellar civilization or many such, you shouldn't be able to point a radio detector to the heavens without having your ears blown off. We should be awash in a cacophony of re-runs of the Arcturian "I Love Lucy" or the Tau Ceti "Milton Berle." I say this as a person who, for many years, DONATED more money to SETI than I spent on, say, buying meteorites, or even books, so I was not without hope in that dream. But I have concluded that it was just that... a dream. Sterling K. Webb ----------------------------------------------- Neil Caliva wrote: > Hi List, > > How far could our EM signals generated by humans be detected? > > Sorry if this is off topic!!! > > -NC Received on Mon 14 Nov 2005 02:06:42 AM PST |
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