

Research paper: Interstellar flight is at least 200 years away - llambda
http://arxiv.org/pdf/1101.1066v1.pdf

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Steuard
It's an interesting analysis, but I'm extremely dubious about the degree of
extrapolation going on here. It's hard to imagine that the past 25 years have
been typical in human history, or for that matter that the past 125 years have
been. Is it really safe to make _any_ quantitative assumptions about how
technology and society will support spaceflight 200 years from now?

Those concerns are only magnified by the author's willingness to list a
"nominal readiness date" of the year 5000 for humanity to be able to capture
and use 100% of the entire galaxy's energy output (last line of Table 5). It
would take 20 times that long just for us to _reach_ the other edge of the
galaxy, even assuming light speed travel.

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Ralith
This paper appears to assume that no revolutionary changes in energy
production make it vastly more available. Am I misreading it? With projects
like polywell fusion reactors[1] showing great promise, I'm not sure if the
conclusions drawn on that assumption are very predictive.

[1] <http://en.wikipedia.org/wiki/Polywell>

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rubidium
"calculated based on 27 years of data on historic energy trends, societal
priorities, required mission energy, and the implications of the Incessant
Obsolescence Postulate "

Yes, you're right. He's assuming everything proceeds growing the way it is
now. You gotta start somewhere when predicting the future.

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stfu
The problem is, that things like these create a misguided perception in the
general public. Papers like these should be full of disclaimers that making
predictions about any technology 200 years in the future is at best highly
speculative. Ultimately I would argue the value of a constructed research like
this is very little more than the work of a scifi author who just makes up
some story based on the last 27 years of his life experience. The choice
ultimately comes down to what method one prefers for speculating on what is
going to happen 200 years from now.

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mmphosis
"We are not going to be able to operate our Spaceship Earth successfully nor
for much longer unless we see it as a whole spaceship and our fate as common.
It has to be everybody or nobody."

 _\--Buckminster Fuller_

<http://en.wikipedia.org/wiki/Spaceship_Earth>

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kstenerud
Interestingly, the author dismisses the 0.3c matter-antimatter possibility in
favor of a much more modest 0.03c, and then goes on to list "earlier",
"nominal", and "later" scenarios while ignoring an entire order of magnitude
of velocity.

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DennisP
That's a pretty interesting way to look at it. It also makes sense given that
it'll take longer than that to exploit our own solar system, given that it's
got millions of times the accessible resources of Earth.

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rbanffy
The vertical axis of the graph on page 6 is in log scale - it already accounts
for exponential growth, considering we get there in 600 years, which is, IMHO,
a very reasonable (and I dare to say, optimistic) extrapolation.

Consider you need more than access to raw materials: you need the
manufacturing capacity to harness the power source. Covering the Moon with
100% efficient solar panels wouldn't even put us on 1 at the Kardashev scale.

