"Yes, There Have Been Aliens"

[Jim Leff]

From last week's NY Times by University of Rochester astobiologist Adam Frank (who recently co-authored this paper ):

the odds that we are not the first technological civilization are actually high. Specifically, unless the probability for evolving a civilization on a habitable-zone planet is less than one in 10 billion trillion, then we are not the first. To give some context for that figure: In previous discussions of the Drake equation, a probability for civilizations to form of one in 10 billion per planet was considered highly pessimistic. According to our finding, even if you grant that level of pessimism, a trillion civilizations still would have appeared over the course of cosmic history.

Even aside from NY Times' shameful click-bait headline, I'm trying to decide whether his argument is fallacious or banal. I believe it boils down to something like this: Given the staggering number of planets, any low-probability outcome - e.g. intelligent life - must be manifold. And that's pretty dull-headed.

It only pretends to address the REAL question: whether intelligent life exists beyond Earth. If it exists anywhere else, then it's uninteresting to suppose it'd be manifold, given the immense sample size. The question is whether it's unique. By assuming it's not, the argument becomes circular.

Dumbest of all is his coy declination to suggest that other civilizations exist right NOW. By his very same logic, if there've been trillions, it'd be vanishingly unlikely that a bunch don't exist now, too.

Or am I viewing this all wrong?

[Ann]

From last week's NY Times by University of Rochester astobiologist Adam Frank (who recently co-authored this paper ):

the odds that we are not the first technological civilization are actually high. Specifically, unless the probability for evolving a civilization on a habitable-zone planet is less than one in 10 billion trillion, then we are not the first. To give some context for that figure: In previous discussions of the Drake equation, a probability for civilizations to form of one in 10 billion per planet was considered highly pessimistic. According to our finding, even if you grant that level of pessimism, a trillion civilizations still would have appeared over the course of cosmic history.

Even aside from NY Times' shameful click-bait headline, I'm trying to decide whether his argument is fallacious or banal. I believe it boils down to something like this: Given the staggering number of planets, any low-probability outcome - e.g. intelligent life - must be manifold. And that's pretty dull-headed.

Yes, I'm unimpressed. Certainly, there might be many technological civilizations in the Milky Way. Or there might be only a few, or there might be none apart from ourselves. But how do we find out? That sort of speculation proves nothing.

It only pretends to address the REAL question: whether intelligent life exists beyond Earth. If it exists anywhere else, then it's uninteresting to suppose it'd be manifold, given the immense sample size.

Immense sample size is right. Let's assume there are a hundred billion planets in the Milky Way that are inside their suns' habitable zones. Let's say that out of those one hundred billion planets, there are ten that host technological civilizations. How do we go about finding them?

The question is whether it's unique.

I suppose you're asking if our own technological civilization is the only technological civilization in the Milky Way. It might be, it might not.

By assuming it's not, the argument becomes circular.

Yes... our own technological civilization can't be the only technological civilization in the Milky Way, therefore it isn't the only technological civilization in the Milky Way. Circular argument, indeed.

Feeding this kind of circular argument to the general public might send more tax dollars into NASA's budget. That would be a good thing, of course. For myself, I hope for more hard science and less groundless speculation.

Dumbest of all is his coy declination to suggest that other civilizations exist right NOW. By his very same logic, if there've been trillions, it'd be vanishingly unlikely that a bunch don't exist now, too.

Or am I viewing this all wrong?

Is there even a NOW on any exoplanet that is equivalent to our own present time? If there is a technological civilization on a planet a thousand light-years away, can we really say that that civilization exists there right NOW? What do we mean by NOW? Unless there is a wormhole right next door that we can just dive down into and emerge at that other planet in literally no time, I don't see how we can talk about other planets as existing in the same time frame as ourselves and having technological civilizations at the same time as we ourselves exist. If we can't make contact with them in thousands of years, when we ourselves may have changed irrevocably (or become extinct), how can we say that they exist in our own present time?

Ann

[Chris Peterson]

Even aside from NY Times' shameful click-bait headline, I'm trying to decide whether his argument is fallacious or banal. I believe it boils down to something like this: Given the staggering number of planets, any low-probability outcome - e.g. intelligent life - must be manifold. And that's pretty dull-headed.

Works for me. In its limited way. That is, I think it is very reasonably to assume that there have been a very large number of intelligent life forms in the Universe, and a smaller but still very large number of technological ones. But so what? The interesting question really is whether they have any longevity, and whether there's any significant possibility of our engaging in conversation, or even detecting them. There are too many unknowns in the Drake equation to answer that right now (but my gut says that technological civilizations are transient, and therefore few are around at any one time... and likely to be so far apart that they can have no contact).

[Jim Leff]

I think it is very reasonable to assume that there have been a very large number of intelligent life forms in the Universe

You're usually precise in your word choice, Chris. It's "reasonable" to assume that if there are a few instances in an enormous field, there may be a lot. In fact, that's so reasonable that it's dullish to say so (much less with fanfare). But there's nothing reasonable about assuming that a unique (to our experience) case ever recurs. There's no basis whatsoever for such inference, so it's a matter of faith, not reason.

Fwiw, I don't necessarily doubt your faith....I'm more mildly agnostic. And, yes, I'm familiar with the various lines of conjecture. I find it exciting and interesting and provocative! But speculation is not reason, even if it's well-reasoned.

But if you buy into the assumption which makes his argument circular, I can understand why his argument might work for you!

[Chris Peterson]

I think it is very reasonable to assume that there have been a very large number of intelligent life forms in the Universe

You're usually precise in your word choice, Chris. It's "reasonable" to assume that if there are a few instances in an enormous field, there may be a lot. In fact, that's so reasonable that it's dullish to say so (much less with fanfare). But there's nothing reasonable about assuming that a unique (to our experience) case ever recurs. There's no basis whatsoever for such inference, so it's a matter of faith, not reason.

I disagree. I think it is reasonable because of a number of rational, evidence-based observations. Nothing appears unique about the Earth itself- in a tiny sampling, we've found sufficiently similar planets that we can reasonably expect to find much more similar ones with more samples. There's certainly nothing special about Earth chemistry. And we know that life formed very, very early. That's an argument that life itself is easily formed (and there are some theoretical and lab experiments that support that). It is, of course, difficult to know what leads to a technological species, but there are several highly intelligent species on the Earth, and given the power of evolution, little reason to think that similar paths couldn't occur elsewhere. So I don't consider it a matter of faith in the least.

[Evermore]

Please note they said "technological" civilization and not "intelligent" civilization. There is a great difference, as we on earth are direct witnesses to.

[Chris Peterson]

Please note they said "technological" civilization and not "intelligent" civilization. There is a great difference, as we on earth are direct witnesses to.

Indeed, which is why I was careful to separate the two.

[Jim Leff]

I don't consider it a matter of faith in the least..

Not "in the least"? Really? Is this because you because you find your point airtight, or because you just happen to dislike the word "faith"?

Good point on technological vs intelligent, Evermore (and Chris)!

[Chris Peterson]

I don't consider it a matter of faith in the least..

Not "in the least"? Really? Is this because you because you find your point airtight, or because you just happen to dislike the word "faith"?

Not in the least. Epistemologically speaking, faith is belief in something without requiring evidence. As I pointed out, my suggestion that the inference of intelligent life elsewhere is reasonable is based on specific examples of evidence. Note that I did not take any kind of extreme position like "there must be intelligent life elsewhere", only that there's enough evidence to say that the claim itself is reasonable. No faith required.

[geckzilla]

Someone who has faith that aliens exist would present more like so:
"I believe there are aliens because I just can't imagine a Universe in which we are alone. There is no way anyone can convince me that aliens do not exist."

[Jim Leff]

I don't consider it a matter of faith in the least..

Epistemologically speaking, faith is belief in something without requiring evidence. As I pointed out, my suggestion that the inference of intelligent life elsewhere is reasonable is based on specific examples of evidence.

It is impossible to infer other instances of a uniquely observed thing. You can speculate. You can conjecture. You can flat out guess. But you can't infer. Since there's inherently no evidence, your certainty can only stem from faith.

FWIW, I'm not trying to flame or needle you (and I won't have much further to say).

[Chris Peterson]

Epistemologically speaking, faith is belief in something without requiring evidence. As I pointed out, my suggestion that the inference of intelligent life elsewhere is reasonable is based on specific examples of evidence.

It is impossible to infer other instances of a uniquely observed thing.

I disagree completely.

[Fred the Cat]

The Drake Equation uses a number of fractions very hard to estimate. Other equations come to an estimate using different criteria. We know some reasons why Earth is unique for the types of life which have developed over the millennia. No Earthlings from our future or aliens from a distant past have made their presence known as far as I know. Attempting to compile a set of reasonable parameters necessary to produce any proof that other lifeforms exit or did exist would at best be a good guess.

And if good guesses are the best we can do should astronomy stop until testing hypothesis is a viable option? I have little doubt anyone alive today is willing to wait for that. I know my imagination won't.

What one thing separates humans on Earth or life elsewhere from lower life forms? Hypotheses – Ideas are propagated via imagination and perhaps it is the only method in which intelligent beings are able to communicate? Wouldn't it be fun if it could travel over distance and time if we can't? Nanu-Nanu

[Evermore]

There are tribes on earth who say they arrived here from other planets. There is literature considered factual by hundreds of millions of people which tell of intelligent beings across the universe.

[Chris Peterson]

There are tribes on earth who say they arrived here from other planets. There is literature considered factual by hundreds of millions of people which tell of intelligent beings across the universe.

A great deal of what people believe makes no sense.

[Ann]

We know some reasons why Earth is unique for the types of life which have developed over the millennia.

Great article, that one. Although I didn't entirely get the light smiles. Nanu Nanu? Or this one ?

Oh, and thanks for telling me about the Seager equation! Much better than the Drake equation.

Ann

[Evermore]

There are tribes on earth who say they arrived here from other planets. There is literature considered factual by hundreds of millions of people which tell of intelligent beings across the universe.

A great deal of what people believe makes no sense.

I couldn't agree more, Chris Peterson.