9“9x6” b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanity92. An Astronaut’s Dilemma..................................................
Chapter 2
“Is it alive?”Overview: Where there is self, there is life.
Let us start with a trip to the far side of the universe. Imagine you are an
astronaut and your spacecraft is approaching a solid planet. You are curi-
ous if there is life in this corner of the cosmos. Before departing Earth,
you have seen movies with imaginary extraterrestrial beings that came in
all shapes and forms, most of which were grotesque and frightening. You
probably have read Barlowe’s Guide to Extraterrestrials, lavishly illus-
trated with pictures of 51 species, all products of fantasy, of course.^1 You
have also read the book The Black Cloud, a science fiction novel written
in 1957 by the astrophysicist Fred Hoyle, in which an immense cloud
approaches the solar system from outer space and comes to rest between
the sun and the Earth, threatening eradication of all life by blocking
photosynthesis in plants. The cloud is unpredictable in movement and
turns out to be conscious, expressing surprise in discovering intelligent
life on Earth.^2 While still immersed in fantasy and dazed by confusion,
your spacecraft lands, and you are ushered out into the uncharted land.
There you are immediately greeted by three unidentified objects,
of which you cannot make heads or tails (see Fig. 2.1). With only bare
hands, you have to make a quick judgment as to whether each object
is alive. Some questions instantly come to your mind, such as: Does it
move? Does it respond to stimulus? Does it increase in size? Does it