Energy and Human Ambitions on a Finite Planet, 2021a

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4 Space Exploration vs. Colonization
This textbook assesses the challenges <strong>and</strong> limitations imposed upon
us by living on a finite planet having finite resources. If harboring
expectations that we will break out into a space-faring existence as a
way to mitigate our earthly challenges, then it becomes harder for us
to respond earnestly to information about where things are headed on
Earth. This chapter is placed where it is to “close the exit” so that the
content in the rest of the book might become more relevant <strong>and</strong> worth
the investment to learn. Some of the sections in this chapter offer more
of an author’s perspective than might be typical for a textbook. Some
may disagree with the case that is made, but consider that the burden of
proof for a way of life unfathomably beyond our current means should
perhaps fall to the enthusiasts. 1
4.1 Scale of Space .......... 54
4.2 The Wrong Narrative ..... 58
4.3 A Host of Difficulties ..... 60
4.4 Exploration’s Role ....... 61
4.5 Upshot: Earth First ...... 64
4.6 Problems ............. 64
1: To quote Carl Sagan, extraordinary claims
require extraordinary evidence.
4.1 Scale of Space
In the span of two hours, we can sit through a movie <strong>and</strong> “participate” in
interstellar travel without getting tired. Let’s step out of the entertainment
(fiction) industry <strong>and</strong> come to terms with the physical scale of the real
space environment.
Describing an analogous scale model of the solar system, galaxy, <strong>and</strong>
universe—as we will do momentarily—is a fraught exercise, because
in order to arrive at physical scales for which we have solid intuition
(driving distance in a day?) we end up with inconceivably small (invisible)
specks representing familiar objects like the earth. By the time we make
Earth the size of something we can hold <strong>and</strong> admire, the scales become
too big for easy comprehension. Figures 4.1 <strong>and</strong> 4.2 demonstrate how
awkward or impossible correctly-scaled graphics are in a textbook.
The convention is to capitalize Earth when
it is used as a proper name, <strong>and</strong> refer to
the earth when it is an object. Similar rules
apply to Moon <strong>and</strong> Sun.
Photo credit: NASA/Bill Anders from Apollo 8 [22].
© 2021 T. W. Murphy, Jr.; Creative Commons Attribution-NonCommercial 4.0 International Lic.;
Freely available at: https://escholarship.org/uc/energy_ambitions.