Is there intelligent life in the universe? 5 questions with astrobiologist Caleb Scharf

December 9, 2014 by Jessica Guenzel, Columbia University
Credit: NASA/A. Fujii

Nicolaus Copernicus, the 16th century Polish astronomer and mathematician, wasn't the first to suggest that the Earth wasn't the center of the universe—the idea originated with the ancient Greeks—but he was the first to prove it with a mathematical theorem. By doing so he upended the notion that Earth is unique, giving rise to the idea that there might be life on other planets.

Astrobiologist Caleb Scharf tackles this complex topic in his newest book, The Copernicus Complex. "I've wondered if we're alone in the universe since I was a child, and everyone I've ever known has thought about it at some point," said the British-born astronomer and physicist, who is director of the Columbia Astrobiology Center.

His research focuses on the study of exoplanets and exomoons, and moons outside our own solar system. The center he founded in 2005 includes Columbia faculty from the departments of astronomy, microbiology, climate science, geophysics and astrophysics, and has partnerships with NASA Goddard Institute for Space Studies and the American Museum of Natural History. Its aim is to investigate phenomena related to the origin of life on Earth and on other planets.

The Sunday Times of London just named Scharf's book as its Science Book of the Year. His previous book, Gravity's Engines, about black holes, was listed by New Scientist magazine as one of the 10 books to read in 2012. He is also the author of a popular blog on Scientific American's website called Life, Unbounded.

What do you mean by the "Copernicus Complex?"

It's a phrase that's trying to capture our struggle with one of the biggest questions that we can ask as a species: Are we alone in the universe? Copernican thinking led to the idea that life on Earth, and the Earth itself, aren't special. It's an idea known as cosmic mediocrity, and if that's true, then there has to be lots of other life out there. That was mainstream thinking for a long time.

What have scientists learned that has changed this view?

In the last 20 years we've discovered that planets are pretty much everywhere, which opens up a whole new vista of possibilities. But we've also learned that certain specific conditions must be necessary for life to exist. The question is, what are those conditions, and what are the implications for life's cosmic abundance? In the book I try to reconcile the evidence that suggests planetary life might be common versus the evidence supporting the idea that life on Earth is special and unique. Life equally complex could exist on different planets, but it may have turned out very differently.

Where do you stand on the idea of life on other planets?

There are people out there who really believe in UFOs and humanoid species wandering around in Nevada—if only! I'd put my money on most aliens being microbes, but I think there's complex life too. When we talk about the possibility of technologically intelligent life out there, we're imposing our prejudices on the unknown. Our type of intelligence has only happened once in four billion years on Earth, as far as we know. What if life can be extraordinarily diverse? We could miss a lot simply because it doesn't look familiar. Do I believe there is ? I'd say yes—we're probably already staring at the right places, but to know for sure we need better data.

How have your research interests changed since you started your career?

I did research on the Big Bang and cosmology for many years. But the discovery of other planetary systems and our expanding knowledge of terrestrial biology helped convince me to switch my research focus. Looking for life in the universe is not easy. It will require a great deal of luck in the next few years. We're looking for life markers in the chemical imbalances of small planets around other stars—that's very difficult. It worries me, and I pace up and down a lot and bite my nails! But it is also exciting, and it pushes our scientific ingenuity to the limits.

Do you think there is something special about Earth and its inhabitants?

At the very end of my book I propose that there is something special about us. We observe, we take notes, but we also have the option to change the equation. We can physically reach beyond our origins. In principle our spacecraft can explore interstellar space, and maybe we can, too. As far as we know, no other species here or elsewhere has had that option—certainly no one's shown up yet. We can actually extend the reach of our species, change the balance of in the cosmos.

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6 comments

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Benni
1.8 / 5 (5) Dec 09, 2014
"Do you think there is something special about Earth and its inhabitants?"

"At the very end of my book I propose that there is something special about us. We observe, we take notes, but we also have the option to change the equation. We can physically reach beyond our origins. In principle our spacecraft can explore interstellar space, and maybe we can, too. As far as we know, no other species here or elsewhere has had that option—certainly no one's shown up yet. We can actually extend the reach of our species, change the balance of life in the cosmos."

OK Jessica, quoting you directly above. How is it possible for our species to: "In principle our spacecraft can explore interstellar space"?

The challenge to build a craft the size of a spaceshuttle that will withstand kinetic energy collisions with interstellar dust while traveling at a mere 100K mph is overwhelming. A craft in a onetime head on collision with a period sized dust particle will become a useless hulk.

Uncle Ira
4.5 / 5 (6) Dec 09, 2014
"At the very end of my book I propose that there is something special about us. We observe, we take notes, but we also have the option to change the equation. We can physically reach beyond our origins. In principle our spacecraft can explore interstellar space, and maybe we can, too. As far as we know, no other species here or elsewhere has had that option—certainly no one's shown up yet. We can actually extend the reach of our species, change the balance of life in the cosmos."

OK Jessica, quoting you directly above. How is it possible for our species to: "In principle our spacecraft can explore interstellar space"?


Okayeei Bennie-Skippy, actually it is the Caleb-Astrobiology-Skippy you are quoting. He's the one who wrote the book they are talking about.

What? You just skim the article without seeing what's what, come up with great comment and look up to see who wrote the article. Couyon you.
dumpsta101
4 / 5 (2) Dec 09, 2014
I think we would be very naïve and egotistical to believe that there is no other life in the ENTIRE universe. hell there could be basic life in the oceans of Europa in our own solar system! I am not saying they have come to our planets in UFOs but I am also not not saying that :D
Mimath224
4 / 5 (1) Dec 09, 2014
http://www.space....d=558742
The article suggests this solution for the Fermi paradox but the conditions (no heavy elements) seem to be less likely in our own galaxy than in others. But one must then ask the question of how many galaxies have conditions that would prevent mass extinction by grb?
MandoZink
4.5 / 5 (4) Dec 10, 2014
Given what we see in the observable universe(Hubble distance), low estimates say there at least 100 billion trillion stars in the universe. If you low-ball a guess that only 1 out of 100 million star system might evolve something, that leaves you about one quadrillion star systems with possible life.

So no. I suppose it's just us and nobody else.
Mike_Massen
5 / 5 (1) Dec 26, 2014
@Benni, here's a simple challenge re your claim

You've so often blurted claim re others NOT able to solve Differential Equation (DE), implying U easily can :-)
Strange Y U provoke & as thermodynamics politely advised U its not as easy as U imagine..!

So Benni, here's a simple challenge for U & Water_Prophet who claimed to graduated as a Physical Chemist (PC) :-)

1. Total Solar Insolation (TSI) has more short wave (SW) energy than long wave (LW) radiance
https://en.wikipe...m_en.svg

2. Earth converts SW to LW (SW emission is negligible)
3. LW to space interfered with by absorption/re-radiation of GHG (esp CO2)
http://www.chem.a.../sim/gh/

Here we go Benni, ire your claim on DEs, offer an estimate of LW radiation resistivity due to CO2 & for Water_Prophet suggest Y it's so much more than the thermal energy contributed by burning fossil fuels ~230,000L petrol/sec (0.1% of TSI) ?

Or google scholar ;-)

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