Re: Why Would Aliens Hide?

Robin Hanson (
Wed, 17 Nov 1999 14:20:45 -0500

Robert Bradbury wrote:
> > So we should see at least P(n2) power intercepted from star 2.
>Only if it is of some benefit! We always come back to this
>point. Say m2 is enough for an AS-SI-JBrain. Is there any
>point to the construction of this if over the last billion+
>years, billions of JBrains have been constructed and they have
>"thought" everything that JBrains are capable of thinking?

Ten billion years seems far too short a time for a billion Jupiter Brains to compute everything they possibly could.

>what justifies the production of something that is only capable
>of thinking things that you thought ages and ages ago?

The space of possible things to think is so big that I'm sure there are many things a Jupiter Brain could think of that even much bigger brains that have been thinking for ten billion years would have never gotten around to.

>... Once you have decided
>to harvest everything that provides benefit in excess of the
>investment, then the question is whether there is any benefit to
>leaving behind "handicapped" JBrains. That sounds like a pretty
>sadistic thing to do. As a JBrain it is going to be pretty clear
>that you got somebody's leftovers.

OK, a show of a hands here; raise your hand if you think that being a Jupiter brain is such a pitiful existence that a merciful creator would never even create you in the first place (you're better off dead).

> > So in this model the only way to explain all those stars we see is
> > to say they all have very little metal near them, so little that even
> > when it is all used to intercept starlight, less than 1% of the light
> > is intercepted. This isn't true of our system, and I doubt it is true
> > of a great many.
>It takes a small fraction of the metal in a system like ours to harvest
>all of the sunlight (and hide the star in the visible region). It
>[probably] takes more metal than we have available even after
>dismantling all of the planets to *optimally* use the energy the
>sun is producing. So we can rapidly evolve to the low-SI level with
>a hidden star but may take eons to evolve to high-SI levels.

So it seems you agree that visible stars with metal planets, and which have been that way for a million years or more, almost surely don't have local civilizations. So the puzzle is, if there have been billions of other civilizations around for billions of years, why haven't they created "colony" civilizations around those stars?

>Do cockroaches question whether to reproduce? No. They do
>it because they are programmed for it. Do humans question
>whether to reproduce? Yes. Because they consciously question
>whether the benefits exceed the costs. ...
>Sure, a few of the textropians can go off and colonize nearby
>stars, but they are going to be *years* behind us on the SI
>evolutionary curve.

Consciousness is irrelevant. The question is, what strategies does evolution reward with more reproduction? Intelligent creatures can more quickly figure out what those strategies are, with less blind search, but it still remains that evolution selects for creatures that adopt strategies that induce more reproduction.

Given the time-scales of billions of years you invoke, why is it a problem if it takes a few thousand years to create a colony? How can it be evolutionarily better not to reproduce at all via colonies?

>You could set your sights on a bigger
>star (more energy), but that has a shorter lifetime and
>suffers from larger inter-SI node propagation delays ... You
>could shoot for a metal rich star that would have a resource
>base for faster post-SI evolution, but as soon as you got
>a few million moon-sized telescopes up and running you might
>discover the sky filled with individuals who have been
>pursuing your strategy for much, much longer. ...

If there were trillions of creatures attempting to colonize the universe, then maybe it wouldn't be worth the effort for you to try as well. But that would only be because you expected it to all be already colonized by the time you got there. You can't use this, however, as an argument why these stars never get colonized. Why aren't all these stars taken, and so now dark?

>Also, some of my claims regarding communications costs have raised
>some eyebrows. A very brief & rough summary of my thoughts in
>this area, and the references (what people really want) is now up at:

This is more relevant regarding your overall perspective:

Robin Hanson Asst. Prof. Economics, George Mason University MSN 1D3, Carow Hall, Fairfax VA 22030
703-993-2326 FAX: 703-993-2323