Are We Alone In the Universe?
ls there life on distant planets? Is an intelligent being watching over us?
November 22, 2004
Is the truth out there—somewhere? Speculation about these big questions made the X-Files a cultural phenomenon. Trying to answer them using real science has made the career of Cuban-born astronomer Guillermo González colorful and controversial.
A research professor of astronomy at Iowa State University, González is a leader in the new and burgeoning field of astrobiology—the “highly interdisciplinary study,” he explains, “of life in the universe: its origin, distribution, and destiny.”
With University of Washington paleontology professor Peter Ward, González formulated the ultimate hitchhiker’s guide to the galaxy: a remarkable theory about where in space intelligent life might exist—in so-called "Galactic Habitable Zones.”
Our solar system, González claims, is part of a Galactic Habitable Zone in the Milky Way galaxy—probably the only zone of its kind.
Galactic Habitable Zones have suns—like ours—composed of just the right kind and amount of metals and positioned in the perfect way to support beings with a brain on nearby planets such as Earth.
“This is a very, very interesting idea,” says Dr. William Borucki, a research scientist in the Planetary Studies Branch of the NASA-Ames Research Center. “I like how González has imagined the consequences of planets existing at different parts of the Galaxy.”
The stuff of life on Earth-like planets is unique, refined, and inherently rare, González says.
Take water. It doesn't behave like most other liquids, yet each of its quirks makes it perfect for the existence of creatures like us.
We also breathe cosmically rare air. Our atmosphere helps protect us from harmful radiation, but it also has just the right-sized window open to the helpful radiation—sunlight and warmth—crucial for our everyday existence.
With Princeton theologian Jay Richards, González refined his ideas in a book Cambridge University paleobiologist Simon Morris says has “magnificent sweep and daring.” In this year's science bestseller, The Privileged Planet: How Our Place in the Cosmos is Designed for Discovery, (2004, Regnery Publishing), González and Richards argue that Galactic Habitable Zones are brilliantly planned communities, begging a controversial and philosophical question: who—or what—did the planning?
For González—a lifelong Christian who converted to Protestantism from Roman Catholicism—the answer may lie in a brilliant Creator with an “intelligent design.”
“While most discussions about intelligent design have been about biology,” González says, “my primary interest is in evidence of design in physics and astrophysics.”
González's designs on the Universe have lately received much attention. Following his seminal 2001 paper in Scientific American —the world's leading journal of scientific endeavor—other papers on intergalactic habitability have appeared, most notably by Charles Lineweaver, an Australian cosmologist who recently fine-tuned Gonzalez's work in another top journal, Science.
By mapping and quantifying González's original claims, Lineweaver and other astronomers want to point cosmic hitchhikers to the precise location of life in our otherwise lonely cosmos.
“The most promising places are regions of the Milky Way’s disk at about the same distance from the galactic center and between the spiral arms,” strings of stars that swirl out from the galaxy’s radiant core, González says.
Distant horizons have long fascinated González, who fled at 3 years old with his Spanish parents from Fidel Castro’s Cuba in 1967. “I spent many hours observing [the stars] from my home in Miami and the Everglades,” he says. “In my teens, I built an observatory in my backyard with my father.”
Reflecting on his Cuban roots, González says that while he has never visited his homeland, he intends to make the voyage once a free and democratic government takes over. He’s also bemused by his own rare Earth status: as a Cuban astronomer.
“I only know of one other professional American astronomer who was born in Cuba,” González says.
There may only be a handful of Cuban-American astronomers on Earth, but what about life-harboring planets in our galaxy?
“If you mean a planet that could support ‘simple’ microbial life, then yes, there are probably quite a few in the Milky Way,” González says.
“If you mean a planet that could support complex animal life, then I would say Earth is the probably the only one.”