Clearly true -- the estimates of nearby GRB (or other highly
energetic events) probably place some significant contraints
on the development of higher life forms. The Earth may simply
have been very very lucky.
Luck presupposes that someone was counting on the outcome. If it hadn't happened the way it did, we wouldn't be here pontificating.
> That's pretty safe of him (re: 5 mi diameter telescopes), to make
> an immense claim, and then present an unrealizable set of test
> conditions for it.
One can easily take technological progress and project it.
How? Could anyone living in 1950 have predicted the personal computer? Back in 1950, they were still working with room-sized computers.
Now, I know that science fiction writers predicted lots of things, from Jules Verne forward. But, what you're talking about is something on an entirely different level than a submarine or a personal computer.
E.g.
The revolution in telescope aperture" by M. Mountain and F. Gillett
Nature: V. 395: Supp: A23-A29 (1 Oct 1998).
But I've done the calculations --
At 0.29% (i.e. << 1%) of the mass available to a Dyson
shell civilization, they can construct 10^11 (i.e.
100 billion) telescopes with a collecting area of
~10^13 m^2 (i.e. lunar diameter) (assuming a density
of 1 kg/m^2 which is quite above the limits).
The point was not whether a 'Dyson Sphere' civilization could construct all the giant telescopes that they want, but whether they could construct (or would construct) the sphere to begin with.
The point then wandered over to, if such a civilization DID exist, one way to find it would be to look for the tell-tale signs of missing mass surrounding the dysonized star, for the sphere mass had to be constructed from (relatively local) materials.
So you have to get this -- advanced civilizations can observe
us at the level of reading license plates (or more!).
We are supposed to be able to read a newspaper with current satellite technology. Tell me, where the hell is Osama Bin Laden? Why not just do a face search of everyone in Pakistan, if it's that easy?
We are *so* puny compared to advanced (nanotechnology
enabled) civilizations that it makes no sense at all
for them to bother with us.
We just *might* be first -- in which case it is worth
studying these problems to understand how we might deal
with those who come next. *OR* we may be on the mid-point
of the development spectrum in which case it might be
useful to consider how we should "engage" the more evolved.
It doesn't take a rocket scientist to understand that if
we piss off a civilization a million years more advanced
than we are that we are *BURNT TOAST*.
A civilization 1 million years more advanced than we are would not be a problem. That's like saying that a band of chimpanzees could conceivably annoy a human civilization. Sure, the individual band might get wiped out if it steals too many bananas, but the chimp species wouldn't be threatened by the actions of that one band.
I'd imagine our true problems would be the civilizations 50-10,000 years ahead of us, in a situation analogous to what the Aztecs faced with the Spanish.
The real challenge then would be to learn how to catch up, fast, without alarming the superior civilization.
Robert
