Thursday, November 16, 2006

Where Are They?

In 1961 Dr. Frank Drake came up with the Drake Equation, which is supposed to be a tool to help us figure out how many intelligent civilizations exist in our galaxy. Ben Bova has called the Drake Equation “numerology,” which sounds right to me. There is simply too much unknown about our galaxy, planet formation, the evolution of life and intelligent life and other factors for the numbers to mean anything.

Whereas the Drake faction thinks intelligent life is common in the galaxy, the Rare Earth Hypothesis argues the opposite, that Earth and its intelligent life (that’s you) are freakishly rare. I think the Rare Earth people make some excellent points, but hashing all that out is beyond the scope of this post.

I want to state up front that none of the following opinions is scientific. This post is the idle speculation of someone who has read too much science fiction.

My guess is that life is probably common, but intelligent life is probably not. I base this on one fact that we do know: in the four billion years that life has existed on Earth, intelligence has evolved exactly once, genus homo. Were it not for genus homo our planet might continue to spin for another two or three billion years until the dying sun turned red and expanded and incinerated Earth without there ever having been a concept thought on the planet.

(I wrote this idea on a science fiction message board once and was immediately attacked by the new age types because I dared to suggest humans are more intelligent than other mammals such as cats. “How do you know they’re not intelligent?! Maybe they’re just different.” Any beast that I can make run in circles with a laser pointer is not intelligent.)

But rare or highly improbable is not impossible, and our galaxy is a big place. With our current state of knowledge, it is impossible to estimate with any certainty how many stars there are in the Milky Way, but some estimates put the number in the low trillions. Even if that is wildly wrong and there are only, say, 400 billion stars, that’s a lot of stars. So many that I think it likely there are other intelligent life forms out there. Remember, we’re not talking about thousands of stars, tens of thousands, hundreds of thousands, millions, tens of millions, hundreds of millions, billions or tens of billions; we’re talking hundreds of billions and possibly trillions. Thinking about space is like thinking about the federal budget – the numbers are so large that it is hard to wrap your mind around them and make them real. And we’re just focusing on our galaxy here; I don’t even want to think about the rest of the universe.

If there were one technological civilization for every 100 billion stars, then there could be 10-20 civilizations like us in the galaxy. If the ratio is more like one civilization to every 10 billion stars, then the number could be 100-200. Whatever. It’s impossible to know, but the more stars there are, the greater the chance of life and intelligent life evolving.

Even if there are only a handful of technological civilizations in the galaxy, if one were of an explorative nature like humans, and if it had the capacity for interstellar travel and if it began moving out to the stars long enough ago, then it could have come to Earth by now. I know, that’s a lot of ifs, but play along.

That brings us to the Fermi Paradox: where are they?

My answer comes down to economics. Let’s look at how hard it would be for humans to travel to other stars.

The distance between stars is vast. It’s one of those things it is hard to make real in your mind. The nearest star to our sun, Proxima Centauri, is 4.3 light years away. Light travels almost 6 trillion miles in a year, so the nearest star is around 25 trillion miles away.

Traveling at one-tenth the speed of light, .1c, it would take us 40 years to get to Proxima Centauri, not including time for acceleration and deceleration. .1c is 10,000 times faster than man managed to travel in the 20th century!

Given our current state of technology, the only realistic way to move humans to another star is by using a slow generation ship. Shipping metal into space to build a generation ship is far too costly. One possible solution is to convert a metal-rich asteroid into a spaceship. Isaac Asimov called such a ship a “spome,” short for space home. Once the spome was launched, generations of humans would be born, live and die within the traveling world before it reached another star.

(To digress for a moment, can you imagine being the third or fourth generation born in such a traveling world? They would watch movies of Earth and know that they would never swim in an ocean, climb a mountain, feel the sun on their back, ride an inner tube down the Sacramento River or see Paris or New York or any of the glorious cities of Earth. Even if they managed to turn their spome around, they would die before it got back to Earth. Instead they’re stuck inside a rock. You think they might be a little pissed off? Preventing societal breakdown and general madness would be a major concern for the spomites.)

Building a spome and launching it would be an enormous, costly task that I believe would take generations of effort. The cost of building a small world would easily run into trillions of dollars. How do we pay for it? Three possibilities:


1. Government spending
2. Capital investment
3. Charity

We can rule out government spending. Setting aside the fact that governments are notoriously inefficient and would turn the project into a bureaucratic nightmare, what politician will vote to spend trillions of tax dollars on something that will not benefit his constituents in their lifetime?

Capital investment is out because the time horizons are too long to make a profit from interstellar space travel. The most we can hope for from corporations is that they might sponsor the effort in part for advertising purposes. A company might put its name on the project the way they do to sports stadiums. Imagine the AT&T Spome.

That leaves charity. Interstellar travel would depend on a society of committed visionaries collecting contributions and investing them over generations, probably centuries, to raise the funds.

This raises another problem. When a substantial pool of money exists, politicians want to steal it. Jesse Jackson and other socialists want to tap into America’s pension funds for their redistribution schemes. Can you imagine how they would lust for a fortune of hundreds of billions or trillions that the visionaries created after a century or so of effort? Interstellar travel would depend on a capitalist country that protected private property with absolute vigilance. Such a civilization would have to last for centuries. Given the current degeneration of America and the world into the cesspool of socialism… well, it’s a longshot.

Building and launching one spome would be such a phenomenal achievement that it might very well stand as the technological highpoint and climax of Western Civilization.

So that’s my solution to the Fermi Paradox. Where are the aliens? They’re at home watching TV. When their visionaries knock on the door, they say, “I gave at the office,” then resume watching “Alien Idol.”

UPDATE: Welcome Centauri Dreams readers! CD is a fascinating blog that I read daily.

15 comments:

EdMcGon said...

First things first. We need a telescope more powerful than the Hubble. We need to see what is out there before we go anywhere. While we have made great strides, there is still more to do.

Once we decide where we want to go, we need the technology to get there reasonably fast. Sub-light speed will not work. Also, as you have pointed out, the economic cost is staggering.

The best theoretical idea I have heard is space-folding (i.e. building a wormhole).

Myrhaf said...

I believe that Einstein got it right and that the speed of light is the speed limit in the universe. FTL is fantasy. Interstellar travel is enormously difficult and costly.

EdMcGon said...

I agree that mass cannot exceed the speed of light.

The trick in getting to these places will involve the manipulation of space somehow.

In one method, a ship will not actually be in motion per se, but rather moving space around it.

The other alternative is to punch a hole in the fabric of space, connect your hole to another hole at the place you are going, and simply move thru the two holes.

Myrhaf said...

Unfortunately, there is no evidence that such ideas are anything but fantasies. Any idea that comes from super strings, is based on bad physics. A lot of 20th century physics is based on the idea that if it is mathematically coherent, then it does not have to be supported by the facts of reality. This leads to physicists spinning weird ideas that are impossible, such as multiple universes and wormholes.

Anonymous said...

Hi myrhaf

Wormholes are derived from General Relativity and are only peripherally related to string theory. They're a natural consequence of the equations, though as yet unobserved. But there's no evidence that any naturally occurring wormhole will be a space-time tunnel shorter than the regular distance to its other end either. Fun for SF but short on factual content - as yet.

Adam

Myrhaf said...

Thanks, Adam. I thought it was a super string theory. I'm not a physicist, but I enjoy reading science books written for the general reader.

FWIW, I also agree with Eric Lerner and Fred Hoyle that the Big Bang never happened.

haig51@gmail.com said...

Your using the rules of the OLD economy. The economics of the NEW economy is more appropriate, ie dealing with goods that more closely resemble the production of non-tangible, non-rivalrous goods like data on the internet. A civilization advanced enough to even begin to seriously consider interstellar travel will most assuradly be capable of manipulating matter on very small scales (nanotech) and thus would be able to create self-replicating machines (w/ AI or copies of the aliens' brains (if thats what they use to 'think')).These machines would have similar economics to software or other intellectual property with initial fixed costs but negligable variable costs. Long story short...some things akin to Von Neumann probes exploring the galaxies at exponential rates are most likely; much more probable than the other scenarios.

EdMcGon said...

Unfortunately, there is no evidence that such ideas are anything but fantasies.

I have two things to say:

"Jules Verne" and "nuclear submarines".

Today's fantasy COULD be tomorrow's reality. Have faith, young jedi. ;)

Myrhaf said...

haig51, good point. Robot probes are more likely and less expensive. I focused on moving humans as we know them with technology as we know it.

Ed, thank you, Obi Wan. I hope they don't invent the light saber in my lifetime, because I'd probably activate it while I was looking down the barrel of the handpiece.

DP said...

Myrhaf wrote:

"My guess is that life is probably common, but intelligent life is probably not. I base this on one fact that we do know: in the four billion years that life has existed on Earth, intelligence has evolved exactly once, genus homo."

If you're going to speak on this topic you should make sure you know something about the wealth of biological experiments and discoveries that deal with topics of: 1) the beginning of life, 2) evolutionary history of life on Earth.

In particular I think you are overlooking some crucial facts from the latter. I refer you to, for example, the writings of Ernst Mayr, in particular the fourth question on this website ("What Percentage of Planets on Which Life Has Originated Will Produce Intelligent Life?") :

http://www.planetary.org/explore/topics/search_for_life/seti/mayr.html

DP said...

Sorry for the broken link. Here's one more attempt:

Ernst Mayr

Anonymous said...

Maybe this idea is not original, but anyway: Assuming that we know where to go, would be more feasible to send to those destinations: eggs and sperm, artificial wombs (techology is being developed), (humanoid) robots to protect and educate new borns. When the righ place has been reached, the in-vitro fertilization takes place, the robots rear the new borns, help them restart the civilation.

Anonymous said...

As haig51 said, Von Neumann probes are much more likely than fleshy biological organisms to travel through the galaxy. Your response to haig51 was that you were less interested in whether robots could explore the galaxy and more interested whether humans could...but that is beside the point. Your original post was a speculation on the Fermi paradox, not on human exploration. If the galaxy were saturated with Von Neumann probes and computerized robotic lifeforms that spread in an exponential fashion, then the Fermi paradox is still a perfect valid challenge to the idea of intelligent ETs. Thus, and I have held this position for quite some time specifically *because* of Von Neumann probes, there are very likely no other intelligent civilations in our galaxy.

Keith
http://www.cs.unm.edu/~kwiley

Anonymous said...

As haig51 said, Von Neumann probes are much more likely than fleshy biological organisms to travel through the galaxy. Your response to haig51 was that you were less interested in whether robots could explore the galaxy and more interested whether humans could...but that is beside the point. Your original post was a speculation on the Fermi paradox, not on human exploration. If the galaxy were saturated with Von Neumann probes and computerized robotic lifeforms that spread in an exponential fashion, then the Fermi paradox is still a perfect valid challenge to the idea of intelligent ETs. Thus, and I have held this position for quite some time specifically *because* of Von Neumann probes, there are very likely no other intelligent civilations in our galaxy.

Cheers!

Keith
http://www.cs.unm.edu/~kwiley

Myrhaf said...

Keith, I must admit you are right. My idea does not answer the Fermi Paradox unless building robotic probes itself is so costly that some civilizations never do it.

I don't think the absence of probes means we're necessarily unique. Given the vastness of the galaxy and the energy it takes to travel fast, if the other civilizations are fairly young, it might be that the probes simply have not gotten to us yet.