[extropy-chat] Suicide the Green way

[spike]

________________________________________
From: extropy-chat-bounces at lists.extropy.org
[mailto:extropy-chat-bounces at lists.extropy.org] On Behalf Of Robert Bradbury
Sent: Monday, November 20, 2006 8:42 PM
To: ExI chat list
Subject: Re: [extropy-chat] Suicide the Green way


On 11/20/06, Anders Sandberg <asa at nada.kth.se> wrote:
... Maybe we will go to the stars
on gold foil?

The mirror on the JWST is Be so it can't be that bad.  I would be curious to
know why low resistance beats lightness -- do the photons charge the sail? 

Robert


Robert, it's from Maxwell's equations.  Recall that when a material reflects
a photon, the photon induces a circular magnetic field in the material.  In
general better conductors make better reflectors.  Regarding gold, my
understanding is that the reason it makes a good solar sail material is not
that it is such a great reflector but rather that it can be made into
thinner sheets than anything else.

spike