Science Made Cool

Aliens!

No, SETI hasn't found any yet. 

I've already talked about why and how to search for alien life.  Now to speculate about what non-terrestrial life would be like.  This is somewhat topical because in a week there's a National Geographic channel program showing off their ideas of what alien life might be like. 

There are two main schools of thought about alien life. 

The first is the "as we know it" school.  Life is defined as something kinda like what's around us on Earth -- based on strings of nucleotides, made of proteins, and using water as a solvent.  This is the default school for most serious scientific programs to look for life beyond Earth.  When we send probes to Mars, they're looking for liquid water, carbon compounds, and signs of biochemical activity.  It may be unimaginative, but it does have some advantages. 

As-we-know-it life is also easy to look for.  Since we know the range of environments where it can thrive, it narrows the focus of any search immensely.  No point in searching Mercury or Venus because there's no liquid water and never has been.  No point in looking on Pluto.  Before the 1980s we would have said there's no point in looking among Jupiter's moons, but then some bright boys at JPL noticed that Europa might have a subsurface ocean, which meant that a formerly obscure moon became number 3 with a bullet on the list of Places to Search For Life (Earth holds the number 1 spot permanently, Mars is still hanging on to number 2 by its red-caked fingernails).  On the interstellar scale looking for life as-we-know-it means a relatively small class of stars (main-sequence F, G, and K stars, mostly). 

Moreover, we know for sure that as-we-know-it life is possible.  After all, we're here, right?  All other forms of life are conjectural.  If you're spending billions on a space probe, conjecture is a very dodgy thing.  Sure, there might be plenty of ways life can exist, but it's hard to build a probe capable of searching for all of them.  And if you have to pick one kind, why not the one you're certain is possible?

The big problem with the as-we-know-it school of thought is that so far it has produced only one hit:  Earth itself.  We haven't found any unambiguous traces of life elsewhere in the Solar System, and we haven't identified potential lifebearing worlds in any other star systems.  So maybe we shouldn't be looking for life as we know it after all.

The second school of thought might be called the "anything goes" view of alien life.  Life is any self-organizing, self-perpetuating process which can evolve greater complexity.  DNA-and-protein-in-water is just one in a whole universe of possibilities.  Anything which can act as a method of information storage and self-replication can be the basis for a kind life.

This means you can have life based on magnetic field loops on the surface of stars.  Or chains of fluorosilicone molecules in seas of liquid sulfur.  Or complex hydrocarbons in methane.  Or metallic hydrogen at the core of a gas giant.  Or superfluid helium on an icy world like Pluto.  Or ionized dust grains in an insterstellar nebula. 

And these are just the ones scientists have imagined.  Science fiction writers have come up with even more exotic possible life forms, including Douglas Adams's "superintelligent shade of the color blue."

The chief problem with all these not-as-we-know-it forms of life is that it might be very hard for humans to even recognize them as living systems. When can you say something is really alive, as opposed to being just a complex chemical reaction in the local environment?

This isn't an easy question.  My house's septic tank needed replacing a couple of years ago because of a kind of "rot" breaking down the concrete it was made of.  Basically, a complicated chemical reaction involving the waste products from the water-softening system tended to attack the concrete.  It acted for all the world like some kind of "life" digesting the concrete, like microorganisms breaking down a carcass.  Was the concrete rot alive? 

You could say it was just a chemical reaction, and once deprived of its source chemicals it would stop.  Of course, we depend on chemical reactions to live, and if deprived of, say, oxygen, we'd stop, too.  Are we alive?

Complexity seems to be the key.  Stop a living system's chemical reactions and you can't start them again.  Living things die.  And living things are born:  you can't make them just by tossing together the right ingredients.  Living things expend energy to maintain and increase their complexity.

In the Solar System this means we might miss entire ecosystems simply because they don't look alive to us.  Some scientists have started looking for suspicious chemical imbalances (like Earth's oxygen atmosphere).  Any situation which would normally be temporary, but is somehow being maintained, is at least a suggestion of life.

Over interstellar distances, this isn't so much a problem.  While there are plans to search for potential lifebearing worlds in nearby star systems using large optical interferometers, most of the search for life beyond the Solar System must be aimed at technological civilizations.  We're listening for other people who can make radio transmitters.  This ignores planets teeming with as-we-know-it life and worlds populated by bizarre not-as-we-know-it forms equally.

As a completely subjective matter, I come down on the side of the not-as-we-know-it school.  I expect that when we do find life beyond Earth -- and I do expect it -- we will discover that it is, in the words of J.B.S. Haldane, "not only queerer than we imagine, but queerer than we can imagine."

The Improved Crystal Ball

The National Weather Service is now providing climate estimates up to a year in advance.  Either they're very confident or this is all some very complicated meteorological prank which will have them snickering for weeks.  Anyway, go here to check out your climate for the next twelve months.

Groping In The Dark

The search for life beyond Earth takes many forms.  We send out probes to the planets of the Solar System, looking for traces of life.  We use telescopes to study nearby stars, looking for planets which might be good candidates to have native life.  And we listen for radio signals from other technological civilizations.

For a lot of people, this seems like the height of pointlessness.  Who cares if there are single-celled organisms in the icy soil of Mars, or algae in the oceans of Europa, or little green men on a planet of Tau Ceti?  Finding out won't put food on anyone's table here on Earth.

This view may be narrow-minded, but it isn't wrong.  But humans do things for reasons other than personal gain.  As I've mentioned before, fear and conviction are as important as greed.  So let's look at the motivations for looking for life beyond Earth, and how they fit into that tripartite scheme.

CONVICTION
    People often do things not for any perceived practical reason but for reasons of moral conviction -- because they believe it's the right thing to do.
    So far, this one has been the biggie for SETI and space exploration both.  Our destiny, higher purpose, human adventure is just beginning, yadda yadda.  I've mentioned that contact with other intelligence would validate the whole existence of the human species.
    Unfortunately, this kind of argument just doesn't cut much ice with a lot of people.  Sure, we should look for other life in the Universe.  We should also help the sick, feed the hungry, and fight against oppression.  None of them are exactly in short supply -- the Universe can get in line, way at the back.
    If you rely on conviction, then unfortunately it becomes a matter of opinion, and I doubt that even a large minority of people will ever consider searching for life beyond Earth to be as important as concerns closer to home.  We need other reasons.

GREED
    If discovering life beyond Earth had obvious practical benefits, then NASA and the various SETI projects wouldn't be necessary -- you'd have private space exploration companies and for-profit radiotelescope operations.
    What possible payoffs are there?
    Finding life in the Solar System would be a tremendous boost to the study of genetics and biotechnology in general.  I should think any biotech company would go ape over the prospect of studying totally alien genetic codes and proteins.  But Glaxo and Johnson & Johnson aren't sending sample-return missions to Europa because of the incredible expense involved.  Sure, the potential payoff is big, but the cost and risk are even bigger.  So greed won't launch any space probes.
    Making contact with an alien civilization by radio would be an equally huge boost to the study of, well, just about everything.  Even if (by some fantastic coincidence) the aliens are no more advanced than we are, you'd still get valuable insights and discoveries just by comparing how they do things to our own methods.
    And SETI isn't very expensive.  Radiotelescopes are just big dish antennas, and any telecom company owns a few of those.  Add some cheap computers and some open-source software, and you've got a SETI program.  All you need are investors willing to fund a project for a decade or more with low probability of success but absolutely fantastic potential payoff.  High risk, high gain.  There are people willing to risk money on things like that.  Instead of going the nonprofit route, why aren't any SETI enthusiasts forming corporations and looking for investors?

FEAR
    Well, if the potential benefits of finding life beyond Earth don't grab you, what about the risks?
    To which the natural reply is, what risks?  We've gotten by for about 10,000 years with no contact with extraterrestrial life and nothing bad has happened.
    It's true.  There isn't much danger in not looking for life in the Universe.  As long as nobody else is looking, that is.  But if, say, the Chinese got first crack at organisms from Europa, or the French were covertly listening to transmissions from a distant civilization, there would be consequences for other nations on Earth.
    So any country which wants to remain competitive technologically had better remain a "player" in space exploration and SETI projects -- just to make sure nobody else gets some goodies and won't share.
    This argument hearkens back to the old Cold War worries about losing the "high ground" of space to a rival power.  Space advocates back then fanned the flames of US-Soviet rivalry in space for their own ends.  Maybe it wasn't strictly ethical, but it got humans to the Moon.
    Serious space and SETI advocates should start getting politicians worried about the Radiotelescope Race.  Imagine how quickly all the nearby stars could get surveyed if governments thought of it as a vital national priority instead of a crackpot scientific boondoggle.

So:  if you want more resources involved in the search for life beyond Earth, here are two strategies which look promising.

1.  Write your Congressman (or your Despotic Overlord) and complain that your country is falling behind in the race to explore space, and that this can have dire economic effects.  Try not to sound crazy.

2.  Find investors for a for-profit SETI project.  (If you don't, you'll have to watch Zygote Games LLC grow fat on alien technology patents.)  Try not to sound unprofitably crazy.



      

Moon Day

Thirty-seven years ago today, humans first set foot on the Moon.  Happy anniversary, Neil Armstrong!

It has been a bit more than thirty-three years since the last human left the Moon.

Today we have a three-person International Space Station orbiting 200 miles up, and that is the sum total of human space exploration since Apollo.  People camping out in aluminum canisters in low orbit.

During  the same period, unmanned probes have visited most of the planets, explored comets, and observed distant stars.  They seem to be doing a much better job than humans have.  Maybe we should just let automatic machinery do everything so we can watch TV and play Grand Theft Auto without being disturbed.

Bitter?  Me? 

Tangled Bank #58

Tangled Bank #58 is up at Salto Sobrius. Click on over and read some excellent science bloggers. 

Let Us Reason Together

In the past couple of weeks there have been some interesting discussions of the Evolution vs. "Intelligent Design" controversy.  In Florida a group of scholars gathered to talk about the implications of the Dover decision.  Over on Carl Zimmer's Web log Randy Olson, the producer of the documentary Flock of Dodos, shares his own ideas.

I find it very encouraging that defenders of science are finally trying to make an effort to understand their opponents and seek some common ground.  As I've noted before, the Creationists have some legitimate concerns.  (Full disclosure:  I am, in fact, an atheist.)

First of all, Christian opponents of evolution fear that a completely mechanistic universe, with no Divine creator, has no moral order to it.  Humans are typically motivated by three impulses:  greed, fear, and morality.  We do things because we will gain something (greed), we do things because we want to avoid consequences (fear), or we do things because we believe they are right -- even if it means risking loss and harm. 

Without a supernatural creator to provide an objective standard of what is good, the only motivators left are greed and fear, and that is no basis for a society.  (Here someone may object that you can have a moral order without God -- no, you can't.  See C.S. Lewis's masterful essay The Abolition of Man for a discussion of why any question of "ought" always turns up God lurking in the background.)

Second, religion supports individuality.  How can this be?  Surely religions are the great enforcers of conformity?  Well, yes and no. 

Consider the two ways humans face mortality.  You either believe that your own identity ("soul") will somehow persist after your body quits, in some form of supernatural afterlife.  (Mary Roach's book Spook looks at some attempts to actually locate and study the soul.)

Or you seek continuity through genetic and "kinship" immortality.  You may die, but your descendants and your tribe will live on.  But in that case, you don't really matter except as part of a tribe.  This is one of the things which makes Fascism so repugnant to anyone in modern liberal society -- the subordination of the individual to the Folk.  But anyone from the ancient Classical world, before the development of the idea of an afterlife -- an Athenian, say -- wouldn't find it disturbing at all.  Of course you subordinate yourself to your polis.  That way your deeds will be remembered long after your ghost descends beyond the Styx and drinks the waters of Lethe.  That was why Socrates killed himself rather than go into exile.

So any religion with the concept of an afterlife includes the seeds of individual conscience.  This is an important idea to modern Christians and secularists alike.  But when Christians look at Darwinian evolution, they see the germ of the horrors of Fascism or totalitarianism.  And they may not be wrong.

Am I saying Evolution leads to Communism?  (Snickers from the audience.)  No.  But I am saying that the concerns of Christians about the implications of evolution are real, and are things which everyone should worry about.  Misreadings of Darwin have had tremendous effects on the world.  Simply dismissing them as irrelevant is the same as a Christian dismissing all the crimes committed in the name of God.

Science is an amoral enterprise.  It tells how things are, not how things should be.  This gets it into trouble with all parts of the ideological spectrum.  E.O. Wilson's ideas about sociobiology were simply a description, but that didn't keep him from getting water dumped on him by people who feared his conclusions could be used to support racist ideas.

So what's to be done?  How to reconcile the non-moral nature of science with the need people have for a moral order in the world?  I don't know any one definitive answer, but I do have some suggestions.

-- There are a number of theologians who have grappled with the role of science and religion.  It seems to me that showing the theological support for science (Darwinian evolution in particular) would have a tremendous effect.  Certainly a better effect than calling religious people idiots.

-- Failing that, pointing out that God and Darwin are not mutually exclusive would also help.  It would be useful if one could find, as a companion piece to the "Steve shirt," a shirt listing 500, or 5,000, or 5,000,000 devoutly Christian scientists who accept the truth of evolution as a scientific fact.

-- Finally, and this is almost a pipe dream, perhaps scientists, especially sociobiologists and anthropologists, could work with religious leaders to show how ideas like altruism and self-sacrifice have a sound evolutionary basis, and that our notions of what is right and wrong actually do have their roots in how we evolved.  Science and religion are tremendously powerful forces in human society; what could they accomplish pulling in the same direction?

How To Do It

A while back I noted Winchell Chung's excellent atomic rocket site.  Since it's summer and all, I figure most of you have had plenty of time to get your rockets built by now, so you're probably wondering what to do next.

NASA's Jet Propulsion Laboratory has the answer.  Here are The Basics of Space Flight, including handy quizzes to keep you honest.  The page linked is non-technical (no equations) but if you want the hard stuff follow the links to some number-crunchy goodness.

It's only a week until the 37th anniversary of the first Moon landing.  Meet me at the big party in Mare Tranquilitatus.

Ornithopters!

A team of Canadian aeronautics engineers have created a functioning ornithopter. 

What is an ornithopter?  An airplane which flies like a bird, by flapping its wings.  For centuries before the Wright brothers, inventors trying to build flying machines assumed they would have to work just like birds, and so created dozens of contraptions with flapping wings.  Leonardo da Vinci sketched a few designs. 

Unfortunately, it turned out that flying with flapping wings is incredibly complicated (just like walking on two legs).  When humans finally did build flying machines, they weren't bird-like at all.  They used the wing flaps for control but moved propulsion to an entirely separate system.

Comic book fans may remember that Airboy's plane was a kind of hybrid jet ornithopter.

So congratulations to the Canadians for solving a problem which people have been grappling with for at least five hundred years.  I don't know of any practical applications for an ornithopter, but something may turn up.

Video of the machine is available here.

Thanks to Chad Orzel's 'blog for spotting this story.

The Evolution of Niceness

Over at TerraDaily News there's an interesting discussion of a British study about cooperation.  According to the study they describe, cooperation (as opposed to selfishness) is a successful evolutionary strategy in small groups.  While being selfish is advantageous for a specific individuals, groups with more cooperators do better.  So you wind up with successful groups of cooperators and unsuccessful groups of backstabbers. 

This has two interesting implications.

First, it touches on one of the major difficulties that some people have with the idea of evolution by natural selection:  without a Divine creator the world appears to be without any moral order.  To them, evolution seems to encourage selfishness and amorality.  But this study points up something which they should find reassuring:  our common ideas of morality are the result of our evolutionary history. 

It also has a less reassuring implication.  Evolution favors cooperation within small groups -- the size of a troop of early hominids, say.  In large societies, we need other mechanisms to prevent bad behavior.  Hence the invention of laws, police, judges, and so forth.  Humans seem to have trouble relating to large societies.  You can see this in popular culture:  the yearning for a bar "where everyone knows your name" or the romanticizing of small town life by people who would hate to live in a small town.  We want to be part of a small group because you can trust the others in a small group.  We've evolved that way.  Unfortunately, we can't live in little close-knit groups any more.

A tip of the hat to Transterrestrial Musings for spotting this interesting article.