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Cosmic rays and measuring

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Cosmic rays and measuring
Dichotomy
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Posted 08/16/07 - 08:54 PM:
Subject: Cosmic rays and measuring
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#1
Hello all,
If anyone knows. I'd like some idea of how scientists know for a fact that cosmic rays are a completely separate source of rays from the rest of the earth's sun's rays? On the surface it seems to me almost impossible to separately measure and identify the suns rays, from rays coming from elsewhere in the cosmos. I think this because the sun's rays are sent out in all directions, and would obviously mingle with any supposedly external cosmic rays.

I'd appreciate any laymans explanations that make sense.

cheers. smiling face

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TriXstaH
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Posted 08/23/07 - 01:35 PM:
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#2
It is simple actually. Two arguments :

If the sun is causing these rays ,you'd expect the rays to become more intense when you near the sun , and less intense when you get further away from the sun. Measurements show that cosmic radiation is independent of location and orientation.
Also, radiations can be blocked by certain materials such as lead. So, by using such materials in telescopes to block out the radiation from interfering sources, you can know for sure where the radiation is coming from.
perseus
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Posted 08/23/07 - 02:46 PM:
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This question reminds me of another cosmic phenomenon, Gamma ray bursts. A US satellite was launched in the 60s that was originally designed to detect gamma rays from potential Russian nuclear tests in outer space. There were so many Gamma ray burst detected, at first it was thought the Russians must be exploding them everywhere, until the truth finally dawned ! This turned out to be a great scientific discovery by a purely military mission.

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derekc153
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Posted 12/06/07 - 11:11 PM:
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Firstly, measuring cosmic rays sounds like the type of experiment one would do at night so as to minimize the "pollution" of one's data by the sun's radiation. If the moon is out, of course, some reflected light from the sun will still reach the detector. In this case, one can take a spectrum of the moon and subtract or divide it out of the other spectra of the night sky (dividing is probably better because the intensity of the radiation from the moon will be much greater than that of the other spectra, since it is much closer to us).

Secondly, when one takes a spectrum, one points the telescope at a certain portion of the sky. Some radiation may scatter off particles of air and into the detector, but the intensity coming from the part of the sky one is aiming at should be greater than this background noise.

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perseus
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Posted 12/07/07 - 09:06 AM:
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derek153

My understanding of cosmic rays is that they can only be generated in very high energy situations such as a supernovae and could be easily distinguished from the much lower energy alpha & beta particles emitted by the Sun and other normal stars, neither would these 'rays' be reflected like light rays. They could be deflected by magnetic fields however such as the Van Allen belt, that is why they seem to come from all over the sky and the sources are difficult to pinpoint. I think they can only be detected indirectly in the atmosphere by the way they generate electrons, photons, and muon's in a cascade that can reach ground level.

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