On Sun, 20 Aug 2017 16:54:58 +0100, Mike Coon wrote:

I take your point about the scale over which lensing works. But why is
the effect not similar to using a high-gain aerial, which is common
enough?


Whatever. I appreciate N Cook's suggestion was just a joke which some
here seem to have overlooked. The idea is a total non-starter if anyone
tried to do it in practice, which I very very very much doubt.



--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.