re: How many telescopes can we have?

From: Robert J. Bradbury (
Date: Mon Feb 19 2001 - 20:22:46 MST

On Tue, 20 Feb 2001, Amara Graps wrote:

> WHEN will you learn to leave *us* something to play with?

"Well", he says kind of sheepishly, digging the toe of his
sneaker into the dirt, I did leave you all the carbon,
not to mention the gold and silver. Those are
8x10^25, 3.1x10^18 kg, 1.4x10^18 kg. Actually, in
looking at this, I realized that I didn't adjust from
number fraction to mass fraction, so these should be
taken as order-of-magnitude estimates only... :-(

And if 43 trillion channels is boring, you could limit
yourself to silver mirrors, but I'm assuming that that
is better used in the high temperature superconducting
cables in some of your computronium.

> BTW. Don't you think that you would need some sort of
> adaptive optics to stabilize that mirror?

Yes, the mirrors are stabilized by electrostatic forces
so they don't need too much mass. I need to read the source paper in
detail at some point (J. R. Angel et al, SPIE 4013 699-705 (2000)),
to see how much mass is really be required. I would imagine that
large flat sheets of ice (very abundant) reinforced with carbon
nanotubes internally would make a strong enough "base" sheet.
These could either be positioned on the outside of MBrains where
solar light pressure doesn't disturb them excessively or located
way out in space in locations such as the gravitational lensing
focal points of stars (hundreds of AU from the star).

The question is, can I image an individual dust particle at
10 light years with that much collecting area? (Pls don't
take it as a serious question.)


This archive was generated by hypermail 2b30 : Mon May 28 2001 - 09:56:45 MDT