Posted on 10/25/2001 9:13:53 AM PDT by RightWhale
Is there obvious proof that we could be alone in the Galaxy? Enrico Fermi thought so -- and he was a pretty smart guy. Might he have been right?
It's been a hundred years since Fermi, an icon of physics, was born (and nearly a half-century since he died). He's best remembered for building a working atomic reactor in a squash court. But in 1950, Fermi made a seemingly innocuous lunchtime remark that has caught and held the attention of every SETI researcher since. (How many luncheon quips have you made with similar consequence?)
The remark came while Fermi was discussing with his mealtime mates the possibility that many sophisticated societies populate the Galaxy. They thought it reasonable to assume that we have a lot of cosmic company. But somewhere between one sentence and the next, Fermi's supple brain realized that if this was true, it implied something profound. If there are really a lot of alien societies, then some of them might have spread out.
Fermi realized that any civilization with a modest amount of rocket technology and an immodest amount of imperial incentive could rapidly colonize the entire Galaxy. Within ten million years, every star system could be brought under the wing of empire. Ten million years may sound long, but in fact it's quite short compared with the age of the Galaxy, which is roughly ten thousand million years. Colonization of the Milky Way should be a quick exercise.
So what Fermi immediately realized was that the aliens have had more than enough time to pepper the Galaxy with their presence. But looking around, he didn't see any clear indication that they're out and about. This prompted Fermi to ask what was (to him) an obvious question: "where is everybody?"
This sounds a bit silly at first. The fact that aliens don't seem to be walking our planet apparently implies that there are no extraterrestrials anywhere among the vast tracts of the Galaxy. Many researchers consider this to be a radical conclusion to draw from such a simple observation. Surely there is a straightforward explanation for what has become known as the Fermi Paradox. There must be some way to account for our apparent loneliness in a galaxy that we assume is filled with other clever beings.
A lot of folks have given this thought. The first thing they note is that the Fermi Paradox is a remarkably strong argument. You can quibble about the speed of alien spacecraft, and whether they can move at 1 percent of the speed of light or 10 percent of the speed of light. It doesn't matter. You can argue about how long it would take for a new star colony to spawn colonies of its own. It still doesn't matter. Any halfway reasonable assumption about how fast colonization could take place still ends up with time scales that are profoundly shorter than the age of the Galaxy. It's like having a heated discussion about whether Spanish ships of the 16th century could heave along at two knots or twenty. Either way they could speedily colonize the Americas.
Consequently, scientists in and out of the SETI community have conjured up other arguments to deal with the conflict between the idea that aliens should be everywhere and our failure (so far) to find them. In the 1980s, dozens of papers were published to address the Fermi Paradox. They considered technical and sociological arguments for why the aliens weren't hanging out nearby. Some even insisted that there was no paradox at all: the reason we don't see evidence of extraterrestrials is because there aren't any.
In our next column, we'll delve into some of the more ingenious musings of those who have tried to understand whether, apart from science fiction, galactic empires could really exist, and what implications this may have for SETI.
On another thought, wouldn't it be incredible if they had already reached earth from the far reaches of our Galaxy but the alien space craft, which held thousands was only the size of a grain of sand. And we just didn't see the little devils.
Sorry if I'm leaping ahead, skipping a vital step in the elucidation of star explorer principles. It's difficult to know if the class is stuck on a principle of economics, of politics, or of philosophy.
20 years is the normal lifetime for an engineering project or an investment. A career might span 40 years, but the productive portion might be only 20 years. A house loan might be for a term of 20 years, maybe 30.
The first generation works their entire life to climb out of the pit. Twenty years later the second generation finds all doors open, all spoons silver. Another 20 years and the third generation skips class to attend Save the Whale rallies.
Of course your observation is correct. The first generation will not see the conclusion of their endeavor. What of the voyage when the Nth generation finally sets their orbital anchor in a new star system? Will it necessarily be Lord of the Flies from then on?
I think it's wonderful that so many good NEW theories are coming out.
It proves we're not done thinkin' yet, eh?
I hardly impugned your education. I did (and still do) question your knowledge of chemistry particularly on the subject of reaction dynamics. As for appealing to nameless literature, take your pick of any solid text on organic reaction dynamics. There is no need for you to get defensive particularly when this is not your field of specialty.
Combustion is largely unrelated to the topic at hand, so being a rocket plumber doesn't give one much in the way of usable knowledge, nor does some basic classes in organic chemistry. Therefore, your background is essentially an appeal to improper authority. They don't teach what you need to know for this discussion at that course level or in that field. You see, I do have a chemistry degree with a specific concentration that just happens to be molecular dynamics (and having spent quite a bit of time on various aspects of protein synthesis no less). No need for chest-thumping; I am quite willing and able to step up to the plate to defend my assertions against any specific arguments. However, I'm not teaching a class, so I'm not going write a dissertation here for your benefit either.
Okay folks, move along. Nothing to see here...
3. Appeal to the general literature and claim that the answers to the posed questions are obvious.
4. Arrogantly indicate that you aren't going to teach a class.
Keep it up, chief. You could write the book.
Nothing to see here...
Not from you- that's for sure.
It is a dissertation that hasn't been written and can't be written because the answers to my questions have not been answered by any one or any hundred researchers.
Quit misleading the masses.
Tortoise's original rebuttal of your contention about the pile of carbon was right on the money. You should pay more attention to what he said instead of taking offense at having a gross misconception corrected for you free of charge.
By the way, there are plenty of dissertations and other research papers of the type you need to correct your mistake. You won't find them by sticking to the approved sources of the Creation Research Society however.
There is a variant of the Fermi notion. It does not require an interstellar "empire", no conquering:
Given an advanced technological civilization, say one 10,000 years more advanced than we are, one strategy which will suggest itself is the construction of "Von Neumann robots," which are sent at random to the stars. Say at 5% of light speed. These robots carry the instruction: "Learn all you can about the solar system you enter. Using local materials, build a copy of yourself and download all of your data into it. Then both robots depart for different randomly-selected stars."
This results in an exponential explosion of probes. The pay-off comes when one probe--a descendant of the first ones--wanders home at random and dumps its datastore--consisting of ALL of the data collected by each ancestor.
This is a high-payoff strategy for a very small investment. If it can occur to us it will occur to at least a few of the intelligent ETs. If we are around 10,000 years from now I am certain we will attempt it.
There has been ample time--even at .05 c--for every single star in the galaxy to have been visited at least once. If high-technology civilizations are common, there should be a veritable traffic jam of probes.
We do not observe such a traffic jam; hence there are probably very, very few intelligent and technological civilizations...a conclusion corroborated by Rare Earth-like arguments.
--Boris
Also look at your math. Noting a lack of traffic jam today as proof that we're alone you're still running the assumption that there was someone with that level of technology (10,000 years past our own) pretty much from the beginning of time. Which just doesn't grock with our own knowledge of technical and social progression. Let's say there actually is a civilization in Alpha Cen, one well in advance of our. Not so dramatically far in advance that they were doing this 8,000 years before the birth of Christ but advanced enough that, if they had chosen the model you outlined and that first probe land on earth tomorrow. Well that means they sent that probe in 1401 earth time, 91 years before Columbus "discovered" America.
I put those anchor points in for a reason. They're a reminder on why that is an incredibly pointless way of gathering data. Even if the probe didn't do the spawn and send out randomly, even if it just spent some time here and went back the data would be utterly useless. Let's back track our Alpha Centari even farther. Let's say their probe is getting BACK this year. Meaning it left here in 1401, so it left there no later than 801 (this assumes it spent less than a year observering earth). Would any of that data be remotely useful? Would you have the same nation state in charge? Would they speak the same language?
It's a very cute hypothetical method. But it fail misserably in the practicle application front.
If a technological civilization has persisted for 10,000 years, it is likely to be able to persist for much longer time-scales.
The Sun is a third-generation star; there has been ample time for life--even intelligent life--to arise during this stellar generation or even the previous one. As Carl Sagan pointed out in one of his few moments of lucidity, we are among "the newest" technological civilizations in the Galaxy or even in the universe. We have had radio for less than a century. Everybody else has been "civilized" for hundreds of centuries--if they exist at all.
--Boris
And who know what shape things would take at home during all that. Our civilization is nothing like what was here hundreds of years ago. The only people on earth that were paying any real attention to the stars in 800 AD were the Aztecs and Mayans, they're wiped out. Had they, somehow, developed the technology to send a probe to alpha cen and it were on it's way back who'd get it?
Let's also not forget that any habitible planet would probably have a large variety of environments, one probe wouldn't provide useful data. If you landed a probe in Death Valley you'd have a completely different concept as to what life was like on earth than if you landed one in Napa Valley, and those places are only a few hundred miles apart.
As for the sun thing there's a few fact you're missing out: A - each generation of star is more rich in the irons and carbides that are the building blocks of life as we know it. 1st and 2nd generation stars, were they to make life that life would be so different as to probably be unrecognizable by us. B - as I have pointed out before we're looking around a very large galaxy with a very small penlight. Radio and TV make up around 10% of the bandwidth we KNOW can be used as carrier waves; we even know that they do not cover the BEST part of the bandwidth, just the part we figured out first. Things like SETI don't even scan on TV bandwidth, only radio, so chop about 10% off of that. Our search for intelligent life is focusing on 9% of the bandwidth that COULD be used for communication, we literally could have a pocket of alien civilization right here on the planet, communicating daily with the home office and never find out if they're using any of the 90% of the bandwidth we ignore completely. Of course that ASSUMES they use carrier wave technology for communication, which isn't a good assumption because carrier waves are limited to the speed of light, so communication would be visciously slow.
The simple fact of the matter is that we're not sure about all of the species that inhabit this rock, we're barely looking off the rock at all, our footprint in the galaxy is so miniscule that were their an identical civilization in alpha cen we'd only just have found out about them, change one little thing about the civilization (like change the frequencies they use for mass communication) and we wouldn't know about them at all. There quite simply isn't enough data to speak knowledgably. All we can do is hypothesise. Most of theories that say "they'd be here by now" assume we're the retards of the galaxy, bottom of the heap. Well there's 3 possibilities: we're top of the line, we're middle of the road, we're galatic rejects. If the later one (Sagan's and Fermi's favorite) is true, we just plain might be too dense to notice what's going on (and too pathetic for the aliens to care). If either of the other two are true then the feelers of the various civilizations (those that have gotten to the point of caring what's off their rock) are no where near each other.
You're assuming that only a single probe gets sent. If we were designing a probe program, we'd probably build in some redundancy, on the assumption that a single probe might fail. We'd probably send one out every 10 years or so. At least once a generation. And we wouldn't have to wait until they reached their destination. They could be signalling back to us all the time. At least at regular intervals. So we would have a more-or-less continuous stream of data coming in -- from each probe we send out.
We would know that the data we're receiving about some other world is old by the time we get it. But that data would constantly be updated by the arrival of later probes. So we'd have an idea of what was going on, and the rate at which events were changing. It's always going to be old data, but hardly worthless.
And if we can figure this out, so can they. So where are their probes? It's still the Fermi Paradox, alive and well.
What do you mean, where are they?? There are aliens all around you.
As for where are the probes, look at some of the other stuff I've put. We are scanning very little of the carrier wave spectrum, and we've got a big planet that stuff litterally falls on all the time. With only about 5% of our land mass populated, and land only accounting for 1/3rd of the surfacee, probes could be dropping on us with regularity and we wouldn't know it. I know a lot of UFO detrators like to talk about our magnificent radar dome, but frankly our radar dome ain't worth squat. Remember we lost one of our own A-10s (flown right here out of DM in Tucson) within our national borders for 6 months; then there's the drug runners that make it in with no problem; anybody that thinks that system would let us know about every alien object that could get here is just high.
True, it would be difficult to spot an occasional fly-by probe today; and it would have been impossible if they flew by a few generations ago. Still, those probes should be sending signals. And their homeworld should be emitting detectable signals too. If such signals exist, sooner or later we should be stumbling onto them -- if we're listening. It's a low-cost project that can be continued for generations. Eventually it could be automated. The more our economy grows, the easier it is to do these things. At some point, costwise, it's no more of a problem than having a fire alarm installed. Small loss if we detect nothing. Possibly a huge payoff if we hit paydirt.
In principle, a single probe suffices because of the exponential increase in probes over time. Occasionally, a probe will reach a barren solar system which does not contain sufficient materials to build a copy or copies and refuel. Therefore, prudence dictates sending multiple probes in the first "wave"...perhaps 10, perhaps 100. The end result is the same; at least one probe for every star and possibly many more.
--Boris
One and three are virtually identical. If were top of the line, it's a pretty sorry universe. If we are the best the universe can do--ugh.
Option one ("we're top of the line") means we are effectively alone.
And option three leaves us alone, too..I take it that "galactic rejects" is your phrase for Sagan's claim that we are the youngest technological civilization. If we are rejects--i.e., the new kids on the block--our failure to detect our betters means we are alone.
It is unlikely we are "middle of the road". That would mean that, in the vastness of time, nobody smarter or longer-lived developed. Everybody just arrived on the scene. As Garrison Keilor said of Lake Woebegon, "All the kids are above average."
All of human history is the merest blink of time. Essentially all of the history of complex life on this planet--about 600 million years--is a tiny fraction of the age of the universe.
If life is common and evolution works the way we say it does, our little flicker ought to be drowned out in a gigantic fireworks display. Where are the fireworks?
--Boris
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