Today, an old inquiry into life on other planets.
The University of Houston's College of Engineering
presents this series about the machines that make
our civilization run, and the people whose
ingenuity created them.
Long ago a Jehovah's Witness
came by selling the Watchtower. When my wife
found she could get it in German, she signed up so
she could practice reading German. When the
Watchtower arrived, the lead article asked,
Gibt es Leben im Weltraum? -- Is there Other
Life in the Universe?
Jehovah's Witnesses believe the Genesis creation
was unique, and there's no other life in the
universe. Modern scientists divide on the question.
Carl Sagan believed he could find alien life. But
the question is much older. It took shape in the
17th century as modern cosmology formed out of
conflicting theories of the heavens.
Christiaan Huygens was an early believer in
alien life. Born in 1629, Huygens worked in math,
optics, astronomy. He built the first practical
pendulum clock. He spent
time in France before the French Catholic Church
turned conservative in 1684. Then, since he was a
devout Protestant, he had to leave France for good.
Late in life, Huygens finished his
Cosmotheoros, a book of careful conjectures
about life on other worlds. By then, he'd talked
with Newton about Newton's new theories. Huygens
loved the new calculus, but he was skeptical of
Newton's gravitational theory.
Huygens argued that God's wisdom and providence is
clearest in the creation of life, and Earth holds
no privileged position in the heavens. Since the
same natural laws operate everywhere, life must be
universal, and it cannot differ much from life on
But as he looks at the solar system, the weakness
of his case becomes evident. Anything resembling a
human would be squashed like a bug by Saturn's
gravity. (Without accepting Newton's gravitational
laws he couldn't see that.) Also missing was the
late-19th-century molecular theory of gases. On
earth, gas molecules move much slower than the
escape velocity. That's why we keep our atmosphere.
The moon with, its much lower escape velocity,
loses its atmosphere. Mars is in between, and its
atmosphere is very thin.
Worse yet, Huygens had no knowledge of oxygen and
its role in sustaining life. He had no way of
knowing that other gases surround other planets.
For many reasons, unknown to Huygens, the planets
offer vastly different environments to any life
they might harbor.
Huygens also argued that cultures will be similar.
Take music: Our scales are dictated by laws of
physics. All music must have
elements in common . (That really is
true on planet Earth.)
But as we search for extra-terrestrial life, it
retreats from us. It's now clear that if there is
other life in the solar system, it's minimal. Our
listening posts have heard no signals from outer
space yet. Still, the universe is vast and full of
surprises. Huygens might yet be vindicated.
Meanwhile, that argumentative question in the
Watchtower, Gibt es Leben im
Weltraum?, remains as open as it was when
Huygens wrote about it, three hundred years ago.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
Huygens, C., Cosmotheoros, Sive de Terris
Coelestibus, Earumque Ornatu, Conjecturae. The
Hague: 1698 (Oeuvres XXI). (Huygens's work appears in
many later versions and in various languages. I am
grateful to Toni Blackwell, UH Library, for drawing
my attention to one of these sources.)
Bos, H. J. M., Huygens, Christiaan. The
Dictionary of Scientific Biography, New York:
Charles Scribner's Sons, 1973.
I find it interesting to note Huygens's remark
about the origins of the planets. He doesn't
believe that either science or religion will be
served by chasing this question. He says,
I shall be very well contented ... if I can but
[know] how things are now, never troubling myself
about their beginning ... knowing that to be out of
reach of human knowledge or even conjecture.
For more on Huygens, see:
The Engines of Our Ingenuity is
Copyright © 1988-1998 by John H.
From the 1832 Edinburgh
Huygens's Pendulum Clock
Episode | Search Episodes |