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About 4 billion
November 4, 2013 12:59 PM   Subscribe


 
A few days ago I came across this webpage from January, which suggests that the answer might be “tens of billions.”

Also at that site, some Milky Way photos. (No, not left-over Halloween candy.)
posted by LeLiLo at 1:14 PM on November 4, 2013 [2 favorites]


That gives pretty good odds for intelligent, technological life somewhere in the galaxy. Life seems pretty likely to develop where it can (the Earth had life start basically as soon as it possibly could, which suggests it is very likely to occur) and intelligent life seems like a natural progression in evolution (many evolutionary branches are 'pre-intelligent' and could conceivably move in a fully intelligent direction given time and suitable pressures). So, the main constraint is time - it seems unlikely that intelligent, technological life survives very long in geological or astrophysical time.

Still, assuming a planetary lifetime of 10 billion years, a 1/4 chance of developing intelligent life, a technological lifetime of 1000 years, and a civilized lifetime of 10,000 years, that gives you a thousand civilizations and a hundred technological civilizations in the galaxy, right now.
posted by Mitrovarr at 1:21 PM on November 4, 2013 [7 favorites]


All of which are more than 10,000 light-years away from us, so we'll never know about them, nor they us. For all the numbers, it's still exceedingly likely that we are alone in the universe, for all practical purposes.
posted by Curious Artificer at 1:27 PM on November 4, 2013 [6 favorites]


There's a reasonable chance we could detect civilizations through the use of large, space-based interferometers, which could do spectral analysis of exoplanet atmospheres. At the very least, we should be able to detect life on exoplanets this way.
posted by Mitrovarr at 1:31 PM on November 4, 2013


At the very least, we should be able to detect life on exoplanets this way.

Yeah, plus imagine a theoretical civilization that started 15,000 years before us. And we start picking up whatever their equivalent of 'I Love Lucy' is. What a mindblower.

Then we start getting their PBS. We get a glimpse into how they construct science. We get a second data point. Our collective minds are widened.

Then they show up on our planet saying that we really should contribute to the pledge drive.
posted by lumpenprole at 1:42 PM on November 4, 2013 [35 favorites]


This is perhaps a lesser form of carbon chauvinism, but while I do not doubt many of them have life on them, I wonder how many have intelligent life. We are lucky to have Jupiter out there sucking up comets, Saturn to stabilize Jupiter's orbit and most importantly our Moon to slow down the Earth's day and stabilize our rotation. Without that, I do not know if complex, multicellular could have evolved and stuck around long enough to have a complex enough ecosystem (even an underwater one) that could produce intelligent life.

Or at least, I would put money that the majority of intelligent life is aquatic. More squids, less apes. Maybe Lovecraft was right about that.
posted by Hactar at 1:50 PM on November 4, 2013 [6 favorites]


All of which are more than 10,000 light-years away from us, so we'll never know about them, nor they us

In my heart, I dream - nay, I know - that someday we will shmush quantum tunneling and higgs bosons and folded space-time together in some obtuse but magical way that allows us to not only communicate with alien civilizations, but meet them, develop a common cultural framework, establish economic ties, mess with their heads, demolish their trust in everything good about the Universe, and make them sincerely regret the day those lying blobs of pink goo draped on white sticks warped into their biosphere.
posted by CynicalKnight at 1:52 PM on November 4, 2013 [9 favorites]




"The universe is a pretty big place. If it's just us, seems like an awful waste of space." -- Sagan.
posted by DigDoug at 2:00 PM on November 4, 2013 [3 favorites]


I find it pretty fascinating that in my life time the conventional wisdom has turned 180 degrees, from only crackpots believing in ET's to only crackpots *not* believing in ET's.
posted by Keith Talent at 2:01 PM on November 4, 2013 [4 favorites]


The crackpots are the ones who believe ETs built the pyramids, vandalize farms in the Midwest, and "borrow" people for invasive medical examinations.
posted by Foosnark at 2:03 PM on November 4, 2013 [2 favorites]


I resent that!
posted by mazola at 2:07 PM on November 4, 2013


All of which are more than 10,000 light-years away from us, so we'll never know about them, nor they us. For all the numbers, it's still exceedingly likely that we are alone in the universe, for all practical purposes.

Which makes a lot of people really really sad because we are fast running out of home-planet species to be incredibly shitty to. I'm surprised Bayer and Monsanto haven't funded a few interstellar missions just so they can find some fresh and interesting faces to inject chemicals into.
posted by turbid dahlia at 2:09 PM on November 4, 2013 [2 favorites]


We are lucky to have Jupiter out there sucking up comets, Saturn to stabilize Jupiter's orbit and most importantly our Moon to slow down the Earth's day and stabilize our rotation.

It's hard to say much about what's truly necessary from a sample size of one, though. It's likely that if any of those things were different, things just would have turned out slightly differently. No doubt there's some alien astronomer looking at our solar system and saying there's no way it could support intelligent life without a shielding nebula, or with such a large asteroid belt, or without two dwarf suns, or without being in the always-bright galactic core.
posted by echo target at 2:10 PM on November 4, 2013 [6 favorites]


Then we start getting their PBS. We get a glimpse into how they construct science. We get a second data point. Our collective minds are widened.

And then we start picking up their old Doctor Who reruns, and we realize that they're almost exactly the same as our old Doctor Who reruns. Our collective minds are blown.
posted by RonButNotStupid at 2:16 PM on November 4, 2013 [2 favorites]


Any planet with life that's advanced enough to develop radio telecommunication would appear to us as a garbled mess of competing radio noise at any frequency, much like our emissions would appear to anyone monitoring us.
The exception might be the directed, high energy "We're here!" transmissions we send out now and then, but I can pretty much guarantee nobody out there is demodulating I Love Lucy.
posted by rocket88 at 2:23 PM on November 4, 2013


I find it pretty fascinating that in my life time the conventional wisdom has turned 180 degrees, from only crackpots believing in ET's to only crackpots *not* believing in ET's.
I honestly don't remember a time that only crackpots believed in ETs. Only crackpots believed in UFOs, but that's a different matter entirely. The fact that the universe is absurdly huge and likely to contain a great number of things is not new.
posted by Flunkie at 2:30 PM on November 4, 2013 [2 favorites]


From the NYT report:
One of every five sun-like stars in the galaxy has a planet the size of Earth circling it in the Goldilocks zone — not too hot, not too cold — where surface temperatures should be compatible with liquid water, according to a herculean three-year calculation based on data from the Kepler spacecraft by Erik Petigura, a graduate student at the University of California, Berkeley.

You know your thesis project paid off big time when it features in the New York Times. But when you get this:

Geoffrey Marcy of the University of California, Berkeley, who supervised Mr. Petigura’s research [...] said: "This is the most important work I’ve ever been involved with. This is it."

Bravo!

Now would be a really bad time to find a bug in your code, eh?
posted by RedOrGreen at 2:30 PM on November 4, 2013 [4 favorites]




(By the way, the PNAS paper is open access, as far as I can see.)
posted by RedOrGreen at 2:33 PM on November 4, 2013 [1 favorite]


We just need to get to work on an Alcubierre Drive and get the hell out there for a look-see for ourselves.
posted by stavrosthewonderchicken at 2:43 PM on November 4, 2013 [3 favorites]


How many Earth-like planets are there in the Milky Way anyway?

For sufficiently precise values of "Earth-like", one.
posted by George_Spiggott at 2:49 PM on November 4, 2013 [2 favorites]


Doesn't Alcubierre drive require some kind of antigravity to work? The math checks out, I gather, but it relies on technology doing things that we're not even beginning to understand how to approach, if they're even possible.
posted by echo target at 3:04 PM on November 4, 2013


Just show me the world where they never stopped making Breaking Bad.
posted by Stonestock Relentless at 3:32 PM on November 4, 2013 [2 favorites]


He important thing is, have you signed up for a live organ transplant?
posted by five fresh fish at 3:42 PM on November 4, 2013 [1 favorite]


Standard orbit, Mr. Haughey
posted by thelonius at 4:03 PM on November 4, 2013 [1 favorite]


The crackpots are the ones who believe ETs built the pyramids, vandalize farms in the Midwest, and "borrow" people for invasive medical examinations.

You think aliens have something better to do than anal probing? (Kids In The Hall sketch, don't worry)
posted by RobotVoodooPower at 4:28 PM on November 4, 2013 [2 favorites]


An Alcubierre drive requires exotic materials that have the property of negative energy density. No real material has this property; it has been conjectured that Casimir forces could do this, but that hasn't been shown and you'd need something like 10^64 kg of negative mass, which is a bit out of reach (the Galaxy weighs only 10^42 kg or so). Furthermore, even if you start the warp bubble with your massive amounts of negative energy, you can't stop it, because you can't get in front of the bubble to disrupt the warp configuration. Next, we might expect that the Hawking radiation off of the spacetime horizon that the bubble generates might kill everyone inside the bubble and have such a high energy density that it disrupts the bubble itself. Finally, any actual Alcubierre drive is a weapon of interstellar destruction, so be careful who you put in charge of it.

But these ideas are all theoretical, so if you happen to have any negative energy matter, please let me borrow it and I will let you know how it turns out.
posted by physicsmatt at 4:29 PM on November 4, 2013 [3 favorites]


Kim Boekbinder- The Drake Equation.
posted by The Whelk at 5:52 PM on November 4, 2013


the Alcubierre drive

is that the dolphin safe one or am i thinking of the yellowfin drive
posted by George_Spiggott at 6:12 PM on November 4, 2013 [2 favorites]


A short story, They're Made out of Meat, by Terry Bisson. Previously on metafilter.
"They use the radio waves to talk, but the signals don't come from them. The signals come from machines."

"So who made the machines? That's who we want to contact."
posted by jjj606 at 6:48 PM on November 4, 2013 [2 favorites]


"The universe is a pretty big place. If it's just us, seems like an awful waste of space." -- Sagan.

It only seems like an awful waste of space to certain humans. Sagan has been dead for sometime and the universe and its vast expanse of space neither noticed nor cared.

Mind you, I believe there is intelligent life out there. But I don't know a lot about the actual chemical process that caused life to arise on Earth, so I'm taking it all on faith about what scientists say on the matter.
posted by Brandon Blatcher at 7:20 PM on November 4, 2013


"The aliens will contact us when they can make money by doing so." - David Byrne
posted by neuron at 7:50 PM on November 4, 2013




Then they show up on our planet saying that we really should contribute to the pledge drive.
posted by lumpenprole at 2:42 PM on November 4 [+] [!]


Yeah, but I bet the DVD they're offering for joining at the $125 level is really cool.
posted by Barry B. Palindromer at 8:06 PM on November 4, 2013


It only seems like an awful waste of space to certain humans. Sagan has been dead for sometime and the universe and its vast expanse of space neither noticed nor cared.

Right. The universe doesn't care about any of us. But I think you're being a dick about it.
posted by crossoverman at 8:14 PM on November 4, 2013


At times like this, I can only think of these words of wisdom from Mr. T-Bone Burnett:

We come from a blue planet light-years away
Where everything multiplies at an amazing rate
We're out here in the universe buying real estate
Hope we haven't gotten here too late

[chorus:]
We're humans from earth
We're humans from earth
You have nothing at all to fear
I think we're gonna like it here

We're looking for a planet with atmosphere
Where the air is fresh and the water clear
With lots of sun like you have here
Three or four hundred days a year

[chorus]

Bought Manhatten for a string of beads
Brought along some gadgets for you to see
Heres a crazy little thing we call TV
Do you have electricity?

[chorus]

I know we may seem pretty strange to you
But we got know-how and a golden rule
We're here to see manifest destiny through
Ain't nothing we can't get used to

We're humans from earth
We're humans from earth
posted by Relay at 9:52 PM on November 4, 2013


The limiting parameter on Contact seems more and more to be temporal, which doesn't bode well for time-travel technology. Maybe we are stuck in some temporal/spatial backwater by bad luck?

Who knows. We are babies. If we are going to make Contact we'll have to do it ourselves, because they probably would have shown up by now if they were watching. But who knows, we are babies.
posted by Camofrog at 10:43 PM on November 4, 2013


No doubt there's some alien astronomer looking at our solar system and saying there's no way it could support intelligent life without a shielding nebula, or with such a large asteroid belt, or without two dwarf suns, or without being in the always-bright galactic core.

That seems a bit obsessive. Why would an alien astronomer spend so much time proving over and over that our solar system, in particular, is unable to support intelligent life?

It was the one question he would never answer, and it was guaranteed to provoke a lecture:

"First of all: call it by its name. The system is named Sol. Names are important."

"But you made up the name --"

"Second of all: I am not trying to prove that it cannot support intelligent life. I am trying to prove that it can support intelligent life. I am simply failing, again and again."

"But why your 'Sol' system in particular? Why not move on to another system when we know this one can't possibly have life?"

He would never answer. He simply continued to publish papers -- one reason after another to doubt that the object of his obsession could sustain life. "For Want of a Nebula: An account for the lack of life in the Sol system." "Dante's Noose: The inhibitory effects of a large asteroid belt." "Half Life: How life may have evolved in a Sol-like system with two dwarf suns." And so on.

His colleagues pitied him, perhaps, but respected the peculiar genius -- halfway to madness -- that allowed him to stare at the same distant star for a thousand nights and hope to see something new. As a joke, or a courtesy, they began to point instruments at the Sol system before turning them over to him at the end of a shift; new members of the department soon learned the coordinates of the system by heart. As he grew older, he would no longer even check. He may, toward the end, have forgotten that telescopes were even capable of pointing toward another part of the sky.

In his final interview, a reporter asked yet again the question he had always refused to answer: why spend your life studying this one barren system?

Just then a young astronomer burst into the hospice room, out of breath, clutching a handful of papers. The reporter sat up straighter. Could this be a real story after all? A spark returned to the old astronomer's eye, and he strained to push himself up in his bed.

"Well, what is it? What have you found?"

"Our new radio telescope -- the most powerful we've ever had -- we pointed it at the Sol system as a -- as a test --"

The young astronomer's eyes flicked involuntarily to the reporter, who thought: as a joke.

"-- and we found radio waves! A lot of radio waves. It's a garbled mess, but we're seeing something way out of proportion to the other systems we've looked at."

The old astronomer sagged, but dutifully took the papers and looked them over. The reporter saw her big story slip away with the spark in his eyes.

"No ... no. It's more precise, of course, but this is the same radiation I described in a paper, oh, 35 years ago now. Radiation of this strength is quite incompatible with the chemical bonds necessary to the development of life."

The reporter watched the young astronomer flip through several possible responses, decide that none were worth the trouble, apologize for the interruption and turn to go. The old astronomer said, "wait! You asked me why I spent all those years studying the Sol system."

The reporter nodded, checked her tape recorder. It might not be a new discovery, but it was something.

"When I was very young, I realized that we were alone. We surveyed a billion stars, and found nothing. Nothing but rocks and gas and dust. A universe of physics and chemistry. Calling ourselves 'astrobiologists' was a cruel joke."

The reporter wondered how long the old astronomer had been rehearsing this explanation in his head, reciting it. He was staring intently at the young astronomer.

"We cannot grieve for a billion stars. We don't have the capacity. The tragedy is too large. I picked the Sol system -- I gave it a name -- because I wanted to grieve for it properly. I wanted to write a proper eulogy for an empty universe."

The old astronomer stopped and his face closed off. His rehearsed speech had run out; the interview was over. The young astronomer collected the stack of printouts from the new radio telescope and carried them back to the observatory, lost in thought.
posted by jhc at 5:52 AM on November 5, 2013 [8 favorites]


Lovely, jhc. Very nice indeed.

(But it's a cruel joke to say that calling ourselves 'astrobiologists' was a cruel joke. Any halfway competent astronomer (yes, yes, I know) looking at a spectrum of the Earth would know that something was up, especially compared to spectra for Venus or Mars.

Looking at just the Sol system, without being able to see individual planets - yeah, that's harder.

But radio waves with information content? That's pretty definitive. Usually.)
posted by RedOrGreen at 7:26 AM on November 5, 2013


Usually...
posted by atbash at 8:52 AM on November 5, 2013 [1 favorite]


Thanks, RedOrGreen, and thanks for the links as well. I certainly meant no insult to astrobiologists, only to observe that it must be frustrating to specialize in the study of something for which there are currently no known specimens. It must also be very exciting to keep finding better ways to continue the search -- but that's a different character in a different story.
posted by jhc at 9:12 AM on November 5, 2013 [1 favorite]


Right. The universe doesn't care about any of us. But I think you're being a dick about it.

More like Sagan's statement betrays a human romanticism, based on human limitations, but a very understandable one. It is an awful lot of space for just one habited planet and the idea of that being reality strikes me a ludicrous.

But why? There's mind numbing expanses of space, just in our solar system. That space isn't filled with anything in particular, why should the rest of the universe be in different? We really don't know and that's ok, because we are still babies at this. But let's not pretend otherwise or that we have a clear idea of what's really out there.

That said, I do hope the next 20-30 years include fill in some of these gaps in our knowledge. It would be wonderful if another Kepler or 10, with better instruments, started honing on some the candidates that have been found
posted by Brandon Blatcher at 10:47 AM on November 5, 2013


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