[ExI] L5 society and infections

[Keith Henson]

On Sat, Mar 21, 2020 at 8:03 AM spike jones via extropy-chat <
extropy-chat at lists.extropy.org> wrote:

snip

> That problem turns out to be far more difficult than it sounds.  An
> atmosphere is a great way to filter some kinds of particularly harmful
> radiation.

I know this area moderately well.  Do you have a pointer to "some
kinds of particularly harmful radiation."

> A sheet of metal creates a bunch of secondary particles when
> struck by high-energy particles.  To filter out the bad stuff requires a
> lot of material.

It takes 6 m of polyethylene to get the radiation down to 20 mS/yr.
About 10 m of rock will suffice.  This is what killed power satellites
being constructed by humans.  The smallest rotating habitat took
60,000 tons of shielding.

Keith

> This makes me think we must have a way to use material
> already out there, such as from the asteroid belt.