Re: Missing Galactic C,N,O - Aliens?

Rik van Riel (
Mon, 4 Oct 1999 12:24:09 +0200 (CEST)

On Fri, 1 Oct 1999, Robert J. Bradbury wrote:

> and evolve to the SI state. So either (intelligent)
> life evolving to an SI state is very very difficult
> *or* they aren't especially interested in "colonization"
> *or* our "snapshot" of the universe at this time is a
> very unique timeslice.

*or* the universe is simply very large and very empty.

That last idea is supported by the fact that inside atoms something like 99.99..% of the space is empty, and the same thing seems to hold for interplanetary, interstellar and intergalactic space. And the intercluster and intersupercluster numbers might be even worse...

So even if there is SI life in abundance, there's no reason why it should be near to us. Especially not if they haven't found a way to travel faster than light. (because, eg. it's not possible)

That is also my problem with SIs having launched sub-lightspeed probes to explore the universe. Even if they have launched a probe 100.000 years ago and the probe may have reached us by now, I don't see why they would hold interest in data from such a distance away.

The probe was launched 100.000 years ago when their knowledge of the universe and interests were quite different than what they are now and the data won't arrive until after another 100.000 years, when the SI will be completely different again.

Of course, this assumes that the SI continuousy evolves and changes, but then again, isn't that what intelligence is all about?

> I've been wondering about the Anthropic principle and all of
> the "magic" constants/rules in physics. In particular I've
> been considering the fact that carbon just happens to be
> a great material for wet-biolife *AND* hard-nanolife *AND*
> the laws of nuclear physics just happen to make it one
> of the materials produced in great abundance during stellar
> evolution. Now why *is* that the case?!?

Simple. The reasons that carbon is such a great material for biolife are that it was both capable of making many intramolecular connections and that it was available.
Life based on silicon would have been just as possible, assuming that both silicon and the 'complemetary' materials would have been available in the same quantities that C, N, and O are available.

The reason that carbon seems so great for nanolife is also a simple one. Since our world is so carbon-abundant, we need our nanolife to be able to primarily modify carbon structures. And what better to use for than than carbon itself?



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