🚀 go-pugleaf

In article <jfelder-070193115431@latvia.lerc.nasa.gov> jfelder@lerc.nasa.gov (James L. Felder) writes:
>
>Premise 1.  We live on a finite planet with finite resources.
>
>Premise 2.  Our technological society is highly dependent on resources that
>are being used up faster than they can be replaced.
>
>Premise 3.  Economists seem to insist that we must continue to grow to
>increase our standard of living, and the public and politicians seemed to
>have bought into this premise.  For proof one only has to look at the last
>election to see cries that we are "loosing the American Dream" because we
>are not better off than our parents held up as worthy compaign issues.  The
>strong implication is that an ever increasing, I would hazard
>materialistic, standard of living is something we must all strive for.
>
>Premise 4.  We will not stumble across some unlimited sources of energy
>(fusion) or materials (say a way to mine the earths core) here on earth.
>
>Conclusions.  Energy and materials will become increasingly hard to obtain,
>and that eventually the net energy and material production will decline
>below what is required to maintain some existing standard of living.Unless
>we find a way to circumvent the limited resources of our planet, we as a
>technologically advanced society will cease to exist.  People will continue
>to exist, but society will not be as we know it.  I do not know the time
>frame, nor care to hazard a guess, but the end seems to me to be
>unavoidable.  
>
I find this a very concise summary of the "limits to growth" argument.
I am also a strong believer in the need to expand to space -- but I find
this argument very unconvincing in this (the usual) form.

To rebut:

I will grant Premises 1, and 3.

Premise 2 I *almost* agree with -- but there is a slippery loophole which
I believe invalidates it.  "rate" and "resource" are very slippery words.
Your "rate" of using resources can be diminshed by improving technology.
What defines a "resource" is also changed by improving technology.  100
years ago, coal and iron were critical strategic resources, while petroleum
was of marginal value, and aluminum and uranium ores were essentially
valueless.  Needless to say, the situation has changed radically.
Postulating a (hypothetical) super increase in aluminum extraction
techniques, common clay (for aluminum) can become a valuable resource.

Given this, what of Premise 4?

We may not stumble across "unlimited" sources of materials, but, in the
discussion above, I show why this is not necessary.  Assuming (a key
assumption) that technology continues to advance at the unbelievable rate
of the last 200 years, you can start thinking about basing an economy
on recycled trash and dirt! 1/2 :-)

The energy argument is the most persuasive.  It seems that using less
"simple" materials takes more energy.  This requires an advancing EARTHBOUND
civilzation to increase the technology for energy production from EARTHBOUND
resources FASTER than a SPACEFARING civilization would have to.  A
spacefaring civilization can choose to use "simpler" materials on other
planets to do those manufacturing operations which require acess to those
materials.  If we use this argument, we need to argue that it is "cheaper"
IN ENERGY TERMS to do this than to do it on Earth.

For example: we want to mine asteroids for cheap iron.  So, we fly out and
do it.  This burns rocket fuel (or uranium for fission rockets or deuterium
for fusion rockets, etc.) which came from Earth.  This has energy content.
We could have used that energy to extract iron from less efficient ores or
to replace them with aluminum...etc.  So, while it is POSSIBLE that the
spacefaring civilization can survive with a slower rate of technological
advance, it is not OBVIOUS.  In either case, the rate of energy technology
must continuously improve.

Now we come to the critical point in Premise 4, which I would state as "the
rate of technological growth cannot be adequate unless we go to space".  For
that, I see no evidence.  Focused R&D efforts do produce spinoffs, and these
do accelerate technology if they "push the envelope" -- I believe.  However,
it seems clear that the technological advances of, say, the Manhattan
project were probably at least as great, if not greater than, the Apollow
program.  Just as a case in point, IC's, which are often credited to the
space program, depend heavily on ion implantation, which is a clear spinoff
of the Oak Ridge facility in the Manhattan project.  Etc, Etc.

So, I just don't see it.  "Limits to growth" in the material sense is not
a convincing argument for the space program.  PSYCHOLOGICAL "limits to
growth" may be much more convincing.  

Now, IF we decide (for other reasons) to BUILD a spacefaring civilization,
then it will (in retrospect) appear to have been a great idea!  Because,
just like the Manhattan project and the Apollo program, the technology would
spin off, and it would look great, in hindsight.  However, if we decided to
spend what it takes to BUILD a self-directed AI, or BUILD a genetically
engineered mammal, etc., it would probably ALSO look great, in hindsight.

Disclaimer:  All opinions expressed are my own, and do not reflect the 
     position of Intel, Portland State University, or Zippy the Pinhead.  
============================================================================
Jeff Greason                  "You lock the door ... And throw away the key.
  <greason@ptdcs2.intel.com>   There's someone in my head, but it's not me."
  <jeffg@eecs.ee.pdx.edu>				-- Pink Floyd