From: email@example.com (Henry Spencer)
Subject: Re: Cosmic ray-bans and the Local Interstellar Medium
Date: Wed, 8 Jul 1998 15:31:32 GMT
In article <firstname.lastname@example.org>,
>What is the minimum protection needed to stop cosmic rays and
>gamma rays resulting from cosmic ray impacts? An inch of lead?
>Ten feet of concrete?
Depends on what you mean by "stop". Neutrino detectors, some of them a
kilometer down in solid rock, still have to put a substantial effort into
distinguishing neutrino arrivals from noise produced by cosmic-ray hits.
It's worth remembering that the mass of Earth's atmosphere is about
10t/m^2, so anything that's going to add significantly more shielding
is going to have to be measured in tons per square meter.
>By how much is it estimated that cosmic rays would increase
>if the heliosphere were stripped away down to the orbit of
>the earth? What is the estimated cosmic ray exposure in
>interstellar space, outside the heliosphere, as compared
>to levels on the earth now?
Last I heard, there were only vague ideas about this. It's never been
Being the last man on the Moon is a | Henry Spencer email@example.com
very dubious honor. -- Gene Cernan | (aka firstname.lastname@example.org)