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- Xref: sparky sci.space:18947 talk.politics.space:1681
- Path: sparky!uunet!olivea!charnel!rat!usc!rpi!batcomputer!cornell!rochester!dietz
- From: dietz@cs.rochester.edu (Paul Dietz)
- Newsgroups: sci.space,talk.politics.space
- Subject: Re: Justification for the Space Program
- Message-ID: <1993Jan7.205156.13655@cs.rochester.edu>
- Date: 7 Jan 93 20:51:56 GMT
- References: <C0163t.Mq4@news.cso.uiuc.edu> <1992Dec29.181813.11510@unocal.com> <jfelder-070193115431@latvia.lerc.nasa.gov>
- Distribution: usa, world
- Organization: University of Rochester
- Lines: 99
-
- In article <jfelder-070193115431@latvia.lerc.nasa.gov> jfelder@lerc.nasa.gov (James L. Felder) writes:
-
- >O.K., I just started following this group today, and already I see one of
- >my favorite topics up for vorciferous debate, so I'll just wade in here. I
- ...
- >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.
-
-
-
- There are a number of problems with this argument...
-
- "We live on a planet with finite resources"
-
- Finite does not mean limited. First, the amount present may be so
- large as to be effectively unlimited. Fertile nuclear materials
- (U-238 and Th-232) fall into this class. Second, aside from
- nuclear uses, elements are not consumed in use, they merely become
- less concentrated. The free energy required to extract materials
- goes as the log of the dilution (higher in practice, but practice
- changes).
-
- "Resources are being used up faster than they are being replaced"
-
- That a resource is limited and not renewable matters only if its
- is very hard to replace with some substitute. Fossil fuels are
- an example -- there is no reason why we should not be able
- to survive indefinitely without them, if some other source of
- energy is available.
-
- [paraphrased] "Growth is necessary to avoid social calamity"
-
- Then we are in big trouble, since growth in resource use cannot
- continue forever. For example, if energy use grows 1%/year,
- then in 10,000 years we are consuming the entire power output
- of the observable universe.
-
- In the short term, however, there is no reason why resource use
- on earth cannot be increased. There is no reason why we could
- not supply several times the current population with several times
- the current US per capita energy consumption indefinitely.
-
- "No inexhaustible energy source on earth"
-
- At least two are already in the engineering stages (solar and fission
- breeder).
-
- "Too Expensive!" you may say. Well, now, yes, but manufacturing
- productivity increases about 3%/year. It gets cheaper to make things.
- Moreover, if we had to make a lot of solar collectors or nuclear
- reactors, economies of scale would drive costs down still further.
- And it's a lot easier to start down a learning curve when you can
- build smallish things on the ground rather than enormous things in space.
- Realize that the current world output of PV modules would take
- more than a century to make enough to cover one 10 GW powersat.
- Space colonization schemes are implicitly assuming big productivity
- increases.
-
- "If we don't go now, resources will be too expensive"
-
- This "window of opportunity" argument falls apart under close
- examination. Resource prices have typically fallen over time, even as
- richer deposits have been exhausted. Moreover, a space program uses
- relatively little in the way of natural resources. What it does use a
- lot of is labor, talent and knowledge.
-
- Look at the price of a shuttle orbiter. It costs more than its own
- weight in gold. The cost of the elements and energy that do go into
- its manufacture is a piddling small fraction of its total cost. The
- same is true of an airliner. The raw aluminum in a 747, for example,
- would cost perhaps a quarter of a million dollars.
-
- Increased raw material prices would only make a space program *more*
- feasible, by increasing the potential profit.
-
- Paul F. Dietz
- dietz@cs.rochester.edu
-