Hawking Predicts Discovery of Alien Life: But Asks, Will It be Carbon Based?

On the 50th anniversary of NASA, Stephen Hawking, Newton's heir as the Lucasian Professor of Mathematics at the University of Cambridge, answered the question, “Are we alone?”

His answer was short and simple; probably not!

Hawking presented three options. One, being that there is no life out there, and two – somewhat pessimistically, but subsequently, a little too realistic – being that when intelligent life gets smart enough to send signals in to space, it is also busying itself with making nuclear bombs.

Hawking, known not only for his sharp mind, but his sharp sense of humor, prefers option number three. "Primitive life is very common and intelligent life is fairly rare," he quickly added: "Some would say it has yet to occur on earth."

Alien abductions, in Hawking’s view, are nothing more than claims made by “weirdos,” but we should be careful if we ever happen upon an alien. Because alien life may not have DNA like ours, Hawking warns "Watch out if you would meet an alien. You could be infected with a disease with which you have no resistance."

Other prominent astrobiologists have warned that we humans may be blinded by our familiarity with carbon and Earth-like conditions. In other words, what we’re looking for may not even lie in our version of a “sweet spot”. After all, even here on Earth, one species “sweet spot” is another’s species worst nightmare. In any case, it is not beyond the realm of feasibility that our first encounter with extraterrestrial life will not be a solely carbon-based occasion.

Alternative biochemists speculate that there are several atoms and solvents that could potentially spawn life. Because carbon has worked for the conditions on Earth, we speculate that the same must be true throughout the universe. In reality, there are many elements that could potentially do the trick. Even counter-intuitive elements such as arsenic may be capable of supporting life under the right conditions. Even on Earth some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines. Several other small life forms use arsenic to generate energy and facilitate growth. Chlorine and sulfur are also possible elemental replacements for carbon. Sulfur is capably of forming long-chain molecules like carbon. Some terrestrial bacteria have already been discovered to survive on sulfur rather than oxygen, by reducing sulfur to hydrogen sulfide.

Nitrogen and phosphorus could also potentially form biochemical molecules. Phosphorus is similar to carbon in that it can form long chain molecules on its own, which would conceivably allow for formation of complex macromolecules. When combined with nitrogen, it can create quite a wide range of molecules, including rings.

So what about water? Isn’t at least water essential to life? Not necessarily. Ammonia, for example, has many of the same properties as water. An ammonia or ammonia-water mixture stays liquid at much colder temperatures than plain water. Such biochemistries may exist outside the conventional water-based "habitability zone". One example of such a location would be right here in our own solar system on Saturn's largest moon Titan.

Hydrogen fluoride methanol, hydrogen sulfide, hydrogen chloride, and formamide have all been suggested as suitable solvents that could theoretically support alternative biochemistry. All of these “water replacements” have pros and cons when considered in our terrestrial environment. What needs to be considered is that with a radically different environment, comes radically different reactions. Water and carbon might be the very last things capable of supporting life in some extreme planetary conditions.

Posted by Josh Hill with Rebecca Sato.

Please DIGG this post.

Related Galaxy posts:

MIT Asks: How Would Extraterrestrial Astronomers Study Earth?
"The Great Silence" -A Galaxy Insight
Harvard-Smithsonian Scientists Zero In On Key Sign of Habitable Worlds
Cruising the Goldilocks Zone -The Search for Super Earths
Dead Zones in the Search for Extraterrestrial Life
GAIA -Mapping the Family Tree of the Milky Way
The "Hubble Effect" -A Galaxy Insight
James Cameron & Arthur C Clarke on 2001 A Space Odyssey
New Technologies & the Search for ET  -A Galaxy Insight
Lonely Hearts of the Cosmos Revisited
Eyes on the Cosmos -European Space Agency's Hawk 1 & Hubble's Successor
New Phoenix Mission Technology to Search for Life
Non-Carbon Lifeforms -Why We May Overlook
The Milky Way Enigma -How Galactic Forces May Control Life on Earth
Astro-Engineering Artifacts as Evidence of Extraterrestrial  Life
The Biological Universe -A New Copernican Revolution 
Jupiter's Europa & the Search for Extraterrestrial Life
Earth's Twin Habitable?

Link: http://www.physorg.com/news128057557.html

Comments

[dmarx]

I have to agree with the esteemed Mister Hawking. It is most certainly arguable as to whether thare is intelligent life here on Earth. Yeah, sure we're the dominant species, but we keep trying to kill each other.

[Fred Mulligan]

Is this a joke? Did I miss something here, because I read this exact article/post/story/whatever over a month ago. It is word for word identical--at least the beginning.

OK, so NASA's 50th was in late October, but why the hell are you re-posting articles with no new information?

[Alex Cassell]

They are good for that here, along with poor grammar and plagiarism (since they rarely link to the source).

[JamesDean]

Wow, cool stuff dude.

www.anonweb.eu.tc

[msavoy]

You had innumerable images to post along this article in depicting the existence of alien life and you chose what is IMHO one of the best.

[SOLIDUS]

The thing we have to fear most with the discovery of intelligent life is the introduction of another religion. The novelty of otherworldly visitors would soon wear off once they force us to drink their KOOL AID.

[mookstar]

I hope there's life out there and we can find it. It's a bit boring if we're the only ones. I agree with SH that the alien abduction craze is nonsense.

[LTman86]

Here's a thought. We all think that lifeforms out there are either more advanced, same level, or less advanced than us. But the ultimate thought is that they are out there. I'd like to propose this kernel that I'm sure you know but to put it up again. What if we are the very first species or planet to evolve life? If we are the first, it might take a couple million years before we see life on other worlds. So quite possibly, using a Stargate SG-! reference, we could be the Ancients in this case. The first and most advanced species in the universe and will encounter other life forms waay way down in the future.

[Free Xbox 360 Games]

Great article. Thanks for the information.

[Thijs Hakkenberg]

Yes, but water is more probable because of the fact that Hydrogen is the most abundant element and oxygen is also fairly common...

[Johhn]

nice

http://www.youtube.com/watch?v=763vmCrRBDg

[Mike]

Yes, old news considering what Hawking is talking about is the Drake equation from 1960. Carl Sagan stole it first!

[Alfonso]

Homer Simpsons' sweet spot? Beer XD

[Galaxy]

Hawking is Right :)

[ntopics]

I'm convinced that there is enough evidence
we have be visited by advanced life.
How can the videos and news broadcasts of Alien
sightings be explained as non Alien over more
than 20 years?

thanks from tony

[An American Idiot]

This is news? Hawkings is a genius? This is the biggest no-brainer in the history of the universe. Whether you are a creationist or an evolutionist life beyond Earth must exist. Only a small God would create trillions of stars and even more planets and only populate one. Similarly, if life can evolve and the chances are as slim as one in a trillion there will be many inhabited worlds out there. Duh. It does not take a genius to arrive at this. Further more as many others have commented, if Hawkings said this he is certainly not the first.

[john]

the only theory that makes sense can be found at
www.truth-revelations.com

i found it to be the best one ever,explaining atoms, planets, sun,s galaxy,s and blackholes and so logically that it is near to unbelievable they never thought of it in this way before. this writer is a nobel winner in my eyes.

[Wanda]

To the person that said:

"Yes, but water is more probable because of the fact that Hydrogen is the most abundant element and oxygen is also fairly common..."

ON EARTH...this article is discussing possible conditions for life outside of earth, where hydrogen, oxygen, and carbon might not be found. I seems you're missing that point.

[Wanda]

**It seems

[Weirdo Zero]

"Alien abductions, in Hawking’s view, are nothing more than claims made by “weirdos...” "

http://science.howstuffworks.com/ufo-government10.htm

Right Stephen, all weirdos. No government, high ranking military, or scientists EVER claim this sort of thing.

[MICHAEL J. SCHMITZ]

BETWEEN 7-11-08 AND 9-11-08 MY GLOBAL SEARCH TEAMS WERE ABLE TO RETRACE THEIR SEARCH FLIGHTS, BY DOING THIS BY MY DIRECTION, WE'VE BEEN STOPPING THE GLACIERS FROM MELTING OFF AND ON FOR 28 DAYS. MY THEORY IS BY THE PAINTINGS ON CAVES THROUGHOUT THE WORLD FOR CENTURIES ALIENS HAVE BEEN HERE WITH THEIR TECHNOLOGY. THEY'VE BEEN BUILDING UP GLACIERS JUST FOR THIS PURPOSE. MY BELIEF IS THEY HAVE BEEN ON AND IN EARTH FOR 400 YEARS CAUSING GLOBAL WARMING SINCE THE 70'S SINCE THEIR KIDNAPPINGS HAVE PROVEN THAT WERE TO SAVAGE TO LIVE PEACEFULLY NEXT DOOR TO HIGHTECH ALIENS. PREPARATION FOR THIS IS SIMPLE= http://www.socyberty.com/Activism/First-Step-for-the-Solution-to-Global-Warming.103109 TRY MY EXPERIMENT YOU SEE WHAT I MEAN. THIS LOWERS ALL THE OCEANS TO COLLECT ALL THE ICE MELTED ON EARTH. THIS HAS TO BE DONE ON ALL COASTLINE TO WORK. ALL BECAUSE OF THE ALIENS THAT WANT OUR PLANET AND UNIVERSE. 3 MAJOR SOLUTION TO DELETE GLOBAL WARMING= 3/ OF 3 IS IN FULL OPERATION. HAVE A NICE DAY. MIKE

[sam]

Have you noticed how wierdos and freaks ALWAYS WRITE IN CAPS?

[T]

Uh, if/when we do recieve a visitor it wouldn't be a life form. Think of our own rovers, or better yet, like the robot chick from Wall-E. So no disease or environment fears regardless what the aliens body makeup is.

[annonymous]

I wonder if there is another planet out there that is about just as far along as us, thinking the exact same thing. What if when we go searching with the new more high-tech space telescope I heard about (they're bringing down the old Hubble space telescope), they will be doing the same thing. We will find them, and they will find us. I hope at least one of us, us being the two different planets, is intelligent enough to either try to make peace, or just leave them alone.

[Joe]

"Have you noticed how wierdos and freaks ALWAYS WRITE IN CAPS?" Posted by: sam

Have you noticed how wierdos and freaks named Sam always complain about people who write in CAPS?