Great Filter, Low Profile, Cryptocosmology

Robin Hanson (
Tue, 15 Oct 96 10:41:50 PDT

Steve Witham writes:
b>any non-noiselike character of a signal represents redundancy, a waste
>of bandwidth. ...
>all there is is information, and what we know about, even all we've
>guessed about (for instance, imagining molecules in blades of alien
>grass on alien planets scattered all over the universe), is a tiny
>droplet in a sea--but a completely flat, grey sea, because I'm talking
>about the completely unknown that is the vast majority of the
>information that's around us ... we don't know we're not looking at
>"alien" civilizations. We don't know that the whole universe isn't
>colonized. Life evolves to become efficiently-encoded information,
>which looks like sunlight and dirt. I think these are the most
>natural developments to expect. The default scenario. I would expect
>a colonized universe to look exactly like a barren one. So what was
>the Fermi "paradox" again?

If one looked at the inards of a very advanced computer, then if one
intercepted a "long" communications channel, where the cost to
transmit was large compared to computation costs at either end, then
yes it should look like random noise relative to a high entropy state
of that channel. But this observation is a long way from showing that
the innards of this computer should look like the stars and dirt we
see. As you point out, all that sunlight streaming away seems

I'd expect an advanced computer to notice if some external force
started to much around with its innards, and to do something about it.
So if the world around us is an advanced computer, it knows about us
and chooses for some reason to allow our activities to continue.
Either we are part of this computation, or it works around us.

How much physics do you know Steve? I'm not sure you realize how very
much we do know about all that information streaming around us. We
know which systems are exchanging bits with each other, and how fast,
and where this arrangement changes, etc. We also know a lot about
designing computers, carefully arranging the routes and speeds of bit
exchanges. And these two really look nothing alike! We can see
nature's circuit diagram, even if we don't know what the bits
"encode". In particular, we can see the "short" communications
channels, where we have no strong reason to expect noise-like bits.

To me, the idea that this circuit diagram is actually an
optimum design for an advanced computer seems completely crazy.

Robin D. Hanson