Posted with permission from the author.
Date: Tue, 16 Jan 2001 09:22:43 -0800 (PST)
From: "Robert J. Bradbury" [EMAIL PROTECTED]
To: Larry Klaes [EMAIL PROTECTED]
Subject: Re: Stephen Hawking does not buy into advanced ETI
On Tue, 16 Jan 2001, Larry Klaes wrote:
http://www.cnn.com/2001/ASIANOW/south/01/14/india.stephenhawking.ap/index.html
Hello all. As this article puts Hawking into the Tipler camp, I
thought it would be useful to provide an alternate perspective.
The following is a very condensed explanation for the lack of
obvious ETs that has heretofore been insufficiently explored.
It is the implicit assumption in all discussions of colonization by
humans or machines (von Neumann probes) that I have seen, that there
is some motivation for this. Humans colonize to have access to greater
resources (to gain economic advantage). If that is not the case then
the argument falls apart. If a civilization (and its individuals)
recognize that there is nothing to be gained by this strategy then
they will not exercise it as an option.
That is the case when civilizations have reached the limit of what
can be constructed as "thought machines" at the limits of the laws
of physics (e.g. solar system sized nested Dyson shell supercomputers,
a.k.a. Matrioshka Brains).
If you have one of these, there is virtually no point to constructing
a second one, or a 3rd, 4th, 5th, etc. because the return-on-investement
is minimal (essentially zero). This is because the propagation delays that
exist between such entities relative to their large information storage
and thought capacities make it impossible to do collaborative thinking in
a way that justifies the investment of resources in the construction effort.
Evolution at this point wants to decrease its size scale, not increase
it. I.e. to gain more resources (for "thought") one wants to get
smaller, not larger. "Colonization", so to speak wants to occur
in sub-atomic space, not outer-space. Advanced civilizations would
recognize Feynman's statement, "There is plenty of room at the bottom,"
should be modified to "There is *more* room at the bottom"!
Our need to "explore" and/or "sample" is (seen in the space program)
would be counterbalanced by their massive observation and simulation
capacities which provide a greater return for less investment. You also
don't "explore" things when you can dissassemble them and turn them into
something more useful (its kind of like playing with your food).
But if you turned "everything" into computronium, the universe would
be a pretty boring place with no natural phenomena to observe.
I suspect that the universe is exactly the way we observe because the
optimum "computation" of the phase space of things that can exist is
balanced between "consciously" constructed thought machines (thinking
about whatever they want to think about) and that which results from
the "natural" (chaotic) computation derived from atomic and molecular
interactions based on the fundamental laws of physics. Another way
of thinking about this is that a computer cannot run a *completely*
accurate simulation of a galaxy, faster than the galaxy itself can.
Explanations such as Hawkings, always treat the "aliens" as
collections of individuals like us with our drives and motivations.
Rapid self-driven evolution of civilizations to the limits of physical
laws makes those assumptions fundamentally doubtful. It is also
worth noting from my perspective as a computer scientist and molecular
biologist that his development time line is way too conservative.
I think the moral of the story is that we should always beware the
statements of scientists when they step outside of their field of expertise.
I'll give you another example you can add so it doesn't seem like
I'm picking on Hawking alone.
Frank Drake, a radio astronomer, has a number of interesting
discoveries to his credit. He made early maps of the
rings of ionized gas at the center of our galaxy, commonly
referred to in Russian literature as Drake Rings. He and George
Helou discovered that free electrons in interstellar space
have a Doppler effect on radio signals passing through them
placing a lower limit on the narrowness of the bandwidth of
any interstellar signals. This is known as the Drake-Helou Limit.
He is also the author of the infamous Drake Equation that
attempts to provide a framework for thinking about the parameters
that have an impact on the abundance of communicating civilizations
in the galaxy.
However, he too can find himself in error when stepping
outside of his field of expertise. In his book "Is Anyone
Out There?" with Dava Sobel (Delacorte, 1992), he discusses
the possibility of "immortal extraterrestrials":
"I suspect that immortality may be quite common among extraterrestrials.
By immortality I mean the indefinite preservation, in a living being,
of a growing and continuous set of memories of individual experience.
I think this might come about through the
