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

« Detecting Extraterrestrial Life -The "Man vs. Machine" Space-Exploration Debate | Main | Barcoding the Ocean's Species »

April 23, 2008

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

2001monolithonmoon_2_2 At an event marking the 50th anniversary of NASA on Monday, Stephen Hawking, Newton's heir as the Lucasian Professor of Mathematics at the University of Cambridge, answered the question, “Are we alone?”

His answer is 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.

Diggready 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?



Well duh... I could have told you that.

That's cool and a little scary, but I still want to meet an alien. I pray that I am alive when we find life either intelligent or not out there.

What would the protocol be for if we arrived at an earth like planet and saw it was inhabited by primitive humans such as the Incas? Would we touch down and say hello,or quietly observe or....?

isaac asimov said that 45 years ago

Look at the other side of the coin, maybe the extraterrestrial being out there will discover us and be amazed that we are EARTHLING living on EARTH and the most brillant minds today are HAWKINS and many more. All these word (each one as a word) are very peculiar to pronounce and are raw versions of we would expect from our counter part in the univers. Lets see when we find each an others in this univers.

Indeed Deathnutz, indeed. Your erudite comment exemplifies your ability to elucidate the finer points of potential extraterrestrial life and their elemental construction. Kudos to you. I only wish you would have left us a link to your life's work, so we could all peruse your intellectual breakthroughs.

I watched the interview.
Thats not what he said.
Not that i disagreee with you,
but if you are going to use someone elses fame to endorse your points, then at least quote them accurately.

Almost everyone tends to hold to the archaic view that extraterrestrial life will be just like us, except for " MINOR " diferences like green skin, pointed ears & / or antennae, different colored blood, etc. Any extraterrestrials will very likely be stranger than we can imagine. A species that shares a group consciousness, or beings that resemble stalactites or use tentacles, just for example. They might very well THRIVE on worlds where we couldn't even set foot. Anthropomorphizing " aliens " may have been permissible back in the days of pulp science - fiction, but the probabilty is that we'll be very disappointed if we expect them to be " humanoids " with scales & a few weird protuberances, etc.

But what about Mr Paul McCartney's
Spirits of Ancient Egypt Echoes of Ancient Rome?
If the Pyramids were built by a higher intelligence, whether Earthen of ExtraEarthen, then in order to get from Here to There, or for that Matter Anywhere in the future, what humanoid could do it without an AstroBioLogist@M.D.
so that one could rearrange his matter in order to survive the trip and get home on time?

But if one didn't survive the trip, then the one after 9 oh 9 comes at 1 ten.


And if we never met,
Or until we Meet Again if we have,
May you always be healthy, wealthy and wise.

dePaul Consiglio

Extra - terrestrial life may not even have a high level of technology. Almost all of the scenarios about extra terrestrial life & intelligence have them posessing an almost supernatural level of technology. Some of those folks might be still trying to invent their equivalent of the wheel, for all we know.

interesting post.hope that you would post more interesting topics on your blog. You inspire me in the way you use your blog to share informations to others
Busby SEO Challenge

What if we find out that our Science is simply learning how GOD did it.What if we realized someday that the natural world was the opposite of the spiritual world,would we be disappointed?

The comment regarding death nuts was hilarious

Post a comment

If you have a TypeKey or TypePad account, please Sign In


TrackBack URL for this entry:

Listed below are links to weblogs that reference Stephen Hawking Predicts Discovery of Alien Life: But Will It be Carbon Based?: