From the NYT:
Cosmic Census Finds Billions of Planets That Could Be Like Earth
By DENNIS OVERBYE
MOUNTAIN VIEW, Calif. — Somewhere in all of this, there must be a planet where the volcanoes spout chocolate.
Astronomers reported Monday that there could be as many as 40 billion habitable Earth-size planets in the galaxy, based on a new analysis of data from NASA’s Kepler spacecraft.
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.
Mr. Petigura’s analysis represents a major step toward the main goal of the Kepler mission, which was to measure what fraction of sun-like stars in the galaxy have Earth-size planets. Sometimes called eta-Earth, it is an important factor in the so-called Drake equation used to estimate the number of intelligent civilizations in the universe. Mr. Petigura’s paper, published Monday in the journal Proceedings of the National Academy of Science, puts another smiley face on a cosmos that has gotten increasingly friendly and fecund-looking over the last 20 years.
“It seems that the universe produces plentiful real estate for life that somehow resembles life on Earth,” Mr. Petigura said.
I did a high school science project on the Drake equation in 1975 and came up with the same general result: There ought to be lots of intelligent aliens out there!
Over the last two decades, astronomers have logged more than 1,000 planets around other stars, so-called exoplanets, and Kepler, in its four years of life before being derailed by a mechanical pointing malfunction last May, has compiled a list of some 3,500 more candidates. The new result could steer plans in the next few years and decades to find a twin of the Earth — Earth 2.0, in the argot — that is close enough to here to study.
The nearest such planet might be only 12 light-years away. “Such a star would be visible to the naked eye,” Mr. Petigura said.
His result builds on a report earlier this year by David Charbonneau and Courtney Dressing of the Harvard-Smithsonian Center for Astrophysics, who found that about 15 percent of the smaller and more numerous stars known as red dwarfs have Earth-like planets in their habitable zones. Using slightly less conservative assumptions, Ravi Kopparapu from Pennsylvania State University found that half of all red dwarfs have such planets. Astronomers estimate that there are at least 200 billion stars of all types in the Milky Way galaxy, room for the imagination, and — who knows — perhaps for a few microbes or more complicated creatures to roam.
Geoffrey Marcy of the University of California, Berkeley, who supervised Mr. Petigura’s research and was a co-author of the paper along with Andrew Howard of the University of Hawaii, said: “This is the most important work I’ve ever been involved with. This is it. Are there inhabitable Earths out there?”
“I’m feeling a little tingly,” he said.
At a news conference Friday discussing the results, astronomers erupted in praise of the Kepler mission and its team. Natalie Batalha, a Kepler leader from the NASA Ames Research Center, described the project and its members as “the best of humanity rising to the occasion.”
According to Mr. Petigura’s new calculation, the fraction of stars with Earth-like planets is 22 percent, plus or minus 8 percent, depending on exactly how you define the habitable zone.
There are several caveats. Although these planets are Earth-size, nobody knows what their masses are and thus whether they are rocky like the Earth, or balls of ice or gas, let alone whether anything can, or does — or ever will — live on them.
There is reason to believe, from recent observations of other worlds, however, that at least some Earth-size planets, if not all of them, are indeed rocky. Last week, two groups of astronomers announced that an Earth-size planet named Kepler 78b that orbits its sun in 8.5 hours has the same density as the Earth, though it is too hot to support life.
“Nature,” as Mr. Petigura put it, “knows how to make rocky Earth-size planets.”
As far as we can tell, we're the only intelligent life in the galaxy.
So let's not screw it up.
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90 comments:
The reason that more intelligent aliens don't visit us is that the last time one came they nailed him to a cross.
Too late.
How could we be the only ones? I feel like if I ponder this long enough, I'm going to start believing in God.
still enough credible UFO encounters to seriously doubt the idea that humans are the only living organisms in the galaxy who comprehend electromagnetism, without even getting into technical discussions of drake equation variables, discussions which i've posted about before on here.
might post more about those drake equation variables if i feel like it. for instance the assumption that if there were other civilizations out there, we'd have intercepted electromagnetic communication from them by now just by random chance. that's not true.
we have encountered their craft already however. just as we have sent craft to other planets, so have they to ours.
We're screwing it up, scro. We're screwing it up...
We haven't seriously looked for aliens though. What SETI does is not significant at all. It's like trying to listen in on the aliens' cell phone conversations or something.
And despite the existence of those billions of earth-like planets, we've been able to discover, after all our best efforts, only one White-Hispanic.
Simple life is probably quite common. But to get anything like us, it looks like you need
(a) Standing surface water, but only partial coverage - total water coverage, which is probably the default means NO WEATHERING, which means a very nutrient-poor ocean. It also obviously means no land-based life forms.
(b) a big moon, for tides etc
(c) Plate tectonics?
There are some very odd features of the Earth-Moon system that are not seen with the other planets of our solar system. They may well be freakishly rare, the result of a very unusual early collision that worked out just right for us and has not happened elsewhere in the contactable universe.
In Lindsay Anderson's "If . . ." (1968), one of the characters muses, "In an infinite universe, it's a mathematical certainty that there is another planet where they speak English."
There aren't any other intelligent worlds out there, and I doubt its even possible to reach any of these rocky worlds and terraform them.
We should focus on punching a hole into space time and reaching the Pythagorean dimensions.
We're going to need a pretty big wall to keep out all those aliens.
Would it be a plus or a minus if they had higher IQ's than us?
Enrico Fermi.... another great ethnic-Hebrew!!
Simon in London, I'm with you.
The moon's tidal effect on not just the ionic oceans, but our magnetized iron core creates subtle eddy currents. The layers of conductive molten core cutting across the magnetic lines of flux of adjacent layers of core create a current flow that make the Earth a rotating alternator, planets may need this type of background electrical activity to foster life. This may be the potential field within which organic processes proceed. Lightening may be the spark that gets things going but the entire planet sings with electromagnetic activity. The Earth is not just an inert lump of rock.
It's very hard to detect transmissions from light years away. They're mostly buried in noise through the distance. You can barely get a multi-pixel image of even the nearest stars. Compare a star's electro-magnetic output to the alien equivalent of Mexican border blasters. Trillions of times larger, and they're just a dot.
The real reason to suspect we're alone, or doomed: Eventually, tech advances should allow artificial wombs and robots to be able to carry life an arbitrary number of light years into space, populating the whole habitable galaxy [1], including a record of how it happened. That clearly hasn't occurred. We're probably alone, or soon to be destroyed, ice-9 style.
[1] I believe the galaxy's escape velocity is beyond any possibility.
Are you sure the Drake Equation wasn't thought up by a high-school science class in the first place? It's not just a wild-ass guess; it's like several wild-ass guesses multiplied together.
Michael Crichton ripped the Drake Equation in his famous Caltech lecture, Aliens Cause Global Warming.
"Intelligent" and "Scientific" are quite distinct. There may be lots of intelligent life that never did and never will develop a science-based civilization. In fact looking at the long history of China - a land full of very intelligent beings - suggests that scientific cultures are rare.
An excellent on this topic is "What If The Moon Didn't Exist". There is much, much more to having an "Earth-like planet" than just having an Earth-sized planet where liquid water can exist.
You can't have a genuinely Earth-like planet orbiting a red dwarf, the planet will be tidally locked causing all sorts of bad things to happen.
You can't have an Earth-like planet anywhere in the galaxy, they can only exist in the galaxies "Goldilocks zone" .. not too far out, not too far in, not in the globular clusters. They have to be more or less where we are.
You can't have an Earth-like planet without plate tectonics. How common is this? Earth is the only planet we know of which has it, and plate tectonics plays a crucial role in regulating the atmosphere. Without plate tectonics you end up with a Venus or a frozen snowball.
A lot of the solar systems we've found are not stable - they feature planets which are spiraling into their sun. Such a system might have an Earth-sized planet in the habitable zone today, but it won't be there 500 millions years from now (which is e short time in evolutionary terms.
And you can't have an Earth-like planet without a Moon-like moon. Ours was formed over four billion years ago when another planet collided with the young Earth.
"Are you sure the Drake Equation wasn't thought up by a high-school science class in the first place?"
That was my impression as a 16-year-old: "Now, this is what I call science!"
Anonymous said...
Enrico Fermi.... another great ethnic-Hebrew!!
Full Italian Catholic ancestry, the rare non-Jew among top 20th century physicists.
Wife was Jewish and the reason he got out of Europe.
As far as we can tell, we're the only intelligent life in the galaxy.
So let's not screw it up.
Have you read any blog post message boards or YouTube comment sections?
of course we are the center of the world. It takes, according to your average physicist, a long time for gravity and matter and their noble hangers on to go through the process of making stars that explode and that seed the universe with heavier elements. If that time is a few billion years, then any creature sitting anywhere in the first living province in that billions and billions year zone is inevitably at a very long-awaited center. Sure if we sit around for a few more billion years we might move out of that center but here we are ... It would be unreasonable to expect the previous empty billions of years to have come up again and again with unmistakably conscious and intelligent life. Someone has got to be first and the first are by definition at the center. Aristotle, Aquinas, and Dearieme (see comment above) were and are right, and Dawkins, Derbyshire (who is right about so many other things but who has admitted, I think, to not understanding the deceptively big numbers of astronomy), and Darwinolaters everywhere are either mysteriously too smart to understand this logic or just plain wrong. imho
Malcolm Gladwell and Greatness
Can everyone achieve greatness?
http://www.glennbeck.com/video#page=1
The energence of the Eukaryote is believed to have been such a singularly rare event that it happened only once in our galaxy, here on Earth!
The most plausible explanation for the emergence of the Eukaryote is the Hydrogen Hypothesis of endosymbiosis as postulated by William Martin and Miklos Muller.
The good news is that all of that real estate is ours once we get a functional method of FTL.
Michael Hart argued back in 1974 that replicating life can only come about as a result of astounding coincidence. From memory:
The Miller-Urey experiment (1953) showed how you can get monomers (e.g. amino acids & I think nucleotides), but no-one knows of any natural process other than blind chance that will get you from monomers to polymers (proteins, DNA).
On a blind chance basis, with reasonable assumptions about frequency of habitable planets, life develops average once per 10-to-the-power-20-something galaxies.
So it's not probable there is any other planet with living things on it in the observable universe.
OTOH if the actual universe is infinite, which seems quite likely, there are an infinity of such planets out there. We could never see them, though.
And that could of course all be wrong.
The conditions for getting from life to intelligent life, and from there to hi-tech civilizations, are utterly unknown.
The key variable, which isn't captured in the Drake equation, is the difficulty of traveling from one star system to another.
If this turns out to be fairly quick and easy, then the expected history of a typical galaxy will be much like that of Earth -- the first intelligent species to arise colonizes the whole thing, and forecloses the possibility of any competitor ever arising. There can only be one!
OTOH, if interstellar travel is not possible at all, then each star is a totally isolated system, and the number of intelligent species in a galaxy will in fact be determined by something like the Drake equation. (That number could still be very small of course, if one coefficients in the Drake equation turns out to be infinitesimal. There is no reason this couldn't happen).
we have encountered their craft already
Jody, please expand on this.
total water coverage, which is probably the default means NO WEATHERING, which means a very nutrient-poor ocean.
There must be all sorts of minerals at the bottom of the ocean. Why wouldn't some of those dissolve into the water near the bottom?
Steve says, "As far as we can tell, we're the only intelligent life in the galaxy."
By saying this he implies that, as far as we can tell:
God does not exist, and/or
God is not intelligent, and/or
God is not alive, and/or
God is not present in the galaxy.
I'll dispute any of those assertions. In comparison to God, humans are not only very close to having zero intelligence, they are also very close to nonlife.
Knowing the vastness of the universe, and knowing that the rules of nature are the same everywhere in the universe - isn’t it just impossible to believe that we live on the only life producing planet anywhere?
And surly we are not the newest kids on the universe’s block - YET - there are no patterned signals on any frequency that we can find.
Hmm! We must need to know a lot more then we currently do.
Not only are "we" the center of the universe, the Earth is also in a special place in the universe. At least that is the obvious conclusion once you stop believing in invisible and undetectable non-entities like dark matter and dark energy.
There is far more evidence for the existence of invisible beings like angels and demons that many people experience every day than there is for the dark material no one can see or detect needed by theory for the Earth to not be in a special place in the middle of it all.
Anon 7:23:
Well, it's clearly possible to get to nearby stars, it's just slow. But SF writers in the last century have come up with a bunch of plausible ways to make this work--suspended animation, very long-lived humans, robots transporting artificial wombs and frozen fertilized embryos, generation ships. And if there is a lot of advanced life, some of it is going to be long-lived enough to handle those trips without any of those tricks. There isn't some obvious reason why a technology-inventing sentient species *couldn't* have the lifespan of a redwood tree, which would make an interstellar trip a lot more practical.
So "where is everyone" is an interesting question. The lack of visible signs of aliens given the huge number of earthlike planets out there should make us suspect that other terms in the equation are smaller--life or complex life or technology is less likely to arrive, or technological civilizations are more likely to kill themselves off.
Consider the following scenario:
We have an intelligent, tool-and-language using social species, of the sort most likely to potentially develop interstellar communication or travel. In addition to biological, Darwinian evolution, we also have memetic propagation.
Thus, every so often, a meme cluster emerges in one group or another which is highly attractive on an emotional level, and competitive and contageous on a purely memetic level, but sufficiently divergent from reality as to have negative impact on the Darwinian fitness of the host group. The spread of such a cluster is thus limited when the host group is out-competed by rival groups.
Now, consider when a particularly bright and cooperative group, with sufficient accumulated capital and division of labor to support science, start the industrial revolution. They then escape the Malthusian trap, dominate their rivals, and begin Moore's law style exponential technological growth, with corresponding economic growth. They extract most of the easily-accessable mineral and energy resources, the "low-hanging fruit", but use them to create the tools and systems to profitable access more remote resources. They thus accumulate large amounts of industrial, intellectual, and social capital.
Then they develop radio, which is of course a necessary step for interstellar communication. However, the more immediate use is communication with one another. Thus, mass communication and the ever more rapid sharing of ideas, which fuels the continued acceleration of technology.
Now, however, consider what happens when one of the previously mentioned meme clusters emerges within this superpower. Thanks to mass communications and the intellectual leadership of the dominant group, it will spread rapidly. But, the continued progress of technology, the consumption of the accumulated capital, and the lack of any significant rivals can all offset, at least for some time, the detrimental effects of the mind virus; thus, the group persists long enough for the meme cluster to propagate so widely through the species, with such detrimental, dysgenic effects on intelligence, social capital, and physical capacity, that when the inevitable failure comes, it destroys the aforementioned tools and systems needed to extract the remaining resouces; so that when the mental virus burns itself out by finally killing off its hosts, the survivors lack the resources needed to rebuild a industrial society, or even maintain what remnants they have, and slip back permanently into a pre-industrial (deindustrial?) society, until a climate shift, newly-evolved virus or microbe, asteroid impact, nearby supernova, or some other disaster renders them extinct.
What if this scenario is the course of every species with interstellar potential? It certainly appears to be the inevitable path for humanity.
Jeff W:
Or you could also think that God's existence isn't really being discussed at all. The question is about other species that, like humans, developed technology. It's like if someone in Europe speculated about whether there were people of some unknown type out there somewhere across the ocean. God exists (or doesn't) regardless of the answer to that question.
Geez unless Aliens regularly survey the galaxy looking for planets that might develop life, or intelligent life, or whatever an utterly alien intelligence might be interested in...
Well why would they have been paying attention to us? It's pretty big out there, and there are lots of interesting places to pay attention to.
I mean what? Does anyone think that Aliens had to have left something like that Sentinel thing the Fantastic Four found on that island? Or 2001?
Another thing is that we idea what an Alien intelligence, multiple Alien intelligences might find interesting.
For reasons I'll get to in a second, if I were reading the paper while taking a dump and came across an item that saying we found undisputable radio signals of an intelligent ... something a couple of hundred lightyears away, I'd say "Cool," and go on to the Suddoku.
Also I might add that we only have about 100 years of electromagnetic radiation emitting into space. They have to know we are here before they engage Hyperdrive and send in the Berserkers. Right now the only place we would be known is a 100 lightyear bubble centered on earth (okay earth has been moving the whole time; getting a headache thinking about that shape; still it will be pretty much a sphere).
Anonymous wrote:
"The key variable, which isn't captured in the Drake equation, is the difficulty of traveling from one star system to another."
This is something that is always overlooked in science fiction stories, because it doesn't make for a good story.
Why would anyone go to the trouble of sending goods across stellar distances? It's a good bet that if you can cross them, you don't need to.
You pretty much have to postulate a pretty unimaginably cheap (energetically or any other way you want to put it) transportation method to make moving goods across stellar distances make sense.
And let's leave people out of it. I kind of doubt we ever have much of a manned presence in space, Gerard O'Neil notwithstanding. There really isn't anywhere to go. If you want to go to Mars find a high, dry, cold desert. Something like Chile. Mars couldn't dream of having a single day as nice as 15,000 foot elevation in the dead of winter.
And humans are pretty much the high cost weak link of any sort of probe mission you'd send anywhere. In the case of Mars, robots will be wandering the Martian surface a long time before a human foot steps on it. Yeah, I know we've sent some already, but you know what I'm talking about, the real bots, the ones that build things and do in depth work.
The only good reason for space travel is survival in my opinion. Not spreading your seed across the Universe or some improbable Galactic Empire. I mean you could do it, but you are gonna have to have Hyperdrive or something, and some easy way to get out of gravity wells.
As for survival it can be a dangerous universe. There are several internet sites that categorize existential threats to human existence. One for example is a massive Gamma Ray Burst.
This is too long now. I was going to write some stuff about how you can't dismiss transhumanism, but I'll sum up everything with an old Asimov quote:
"INSUFFICIENT DATA FOR MEANINGFUL ANSWER."
"So it's not probable there is any other planet with living things on it in the observable universe."
Suppose the correct version of Drake's equation predicts that there should be one planet at most with intelligent life in the entire universe. In that case, I'm going to take the idea that God exists a lot more seriously. That coincidence would be just too hard to swallow. One good empirical argument for the existence of God is the occurrence of something resembling a miracle. This would be close enough.
"Without plate tectonics you end up with a Venus or a frozen snowball."
Venus has plate tectonics.
Overlooked in these debates is that though the universe is really large, its also really old. With a near infinite time frame, the chances of two instances of intelligent life arising at the same time on different planets, and both being able to venture into space without destroying themselves, is vanishing small.
Also, planets have an limited amount of the materials needed to construct long distance space craft. In the case of humans, it looks like we prefered to use these resources on electronics and suburban sprawl. Something equivalent probably happened on all those other planets.
"Jody, please expand on this"
iran 1976
alaska 1986
belgium 1990
Enrico Fermi.... another great ethnic-Hebrew!!
Full Italian Catholic ancestry, the rare non-Jew among top 20th century physicists
Not technically true, in fact the the 3 primary founders of quantum mechanics were Heisenberg, Schroedinger, and Dirac, all of them Gentiles like Fermi. Additiionally you have Indians like Bose and Raman around the same time who were obviously not Jewish either. Even the Jewish guys who contributed were often mixed Jewish/Gentile like Niels Bohr and Wolfgang Pauli. Since then, you would be right, Jews have dominated theoretical physics particularly in the US and Russia.
The problem with the Drake equation is that it only provides us with meaningful information if we can come up with reasonable guesses for every variable.
As Cail Corishev said, it's several wild-ass guesses. Some of those guesses we may be able to make reasonable estimates of now, but even one variable we have no way to determine is one variable too many for us to get meaningful data from it.
http://www.youtube.com/watch?v=3i11Q0Muqv0
What intelligent life?
The Kepler mission used the transit method to determine extra-solar planets. It's a pretty good method with modern equipment--cheap and fast, only needed a few years of operational time to produce results.
The PopSci media has flavored the Kepler results with a lot of rah-rah interpretation of the data. It's safe to ignore that as largely meaningless. I don't recall if Kepler had any spectrometer equipment on board, or if they captured that kind of data for later study. Even if they did, the picture is not nearly as clear as a popular science journalist might suggest. You can only know so much from the data.
Re: the Drake Equation, I always interpreted that as an expression of probability. The uncertainties compound as you progress through the variables, so it's hardly scientific.
If you read the story with a more critical eye, it says "probability calculations suggests as many as 40 billion planets in the habitable zone of Sun-like stars in the Milky Way galaxy". That's it. That's the entire story. The rest is journalistic lagniappe.
It seems to me that a planet partially covered by water doesn't need a moon to induce tides to have seawater circulate. Coriolis force, due to planetary rotation, would be sufficient to induce ocean currents. In fact, Coriolis force is why our northern hemisphere's warm currents flow northward up the east side of landmasses and cold currents flow southward down the west side of landmasses - and the opposite takes place in our southern hemisphere.
Another factor in the probability of extraterrestrial life is planetary electromagnetic shielding, which earth enjoys owing to the magnetic field generated by dynamic fluid masses of molten iron in its core. Life, as we know it, could not exist on another planet that lacks an intrinsic electromagnetic field-shield generator. Without our planet's electromagnetic field-shield, our sun's enormous discharges of electromagetic energy would have pre-emptively super-fried any molecules that might have developed into the first living single-celled animal.
Could it be that another planet has intelligent life, but SETI can't detect those beings because they were smart enough to have stopped looking for radio wave communication once they'd gotten landline telephones?
But, seriously, as far as intelligent extraterrestrial life goes, I have but one thing to say: "Gort: Klaatu berada nictow."
Where is everybody?
Bankstas creating cyclic deflationary spirals and subsequent wars keep most of them down in the mud.
I think the only ones likely to make it into space will either have evolved an understanding of their own nature which makes the Star Trek "watch and wait" prime directive paradigm very likely or they'll be some kind of genocidal hive-mind type species and if they'd found us first we'd be long extinct.
Barry Goldwater on Curtis Lemay and UFOs:
https://www.youtube.com/watch?v=gPFBg1NNUBU
twisted151
"What if this scenario is the course of every species with interstellar potential? It certainly appears to be the inevitable path for humanity."
I think that's what game theory would suggest if it was applied to this - that there's only a few likely outcomes for a social species who develop technology past a certain point and the most likely outcomes are both bad and fatal.
I think there are probably billions of dead civilizations out there or civilizations that ate the ladder on the way up and then collapsed below the level where they could build a new ladder.
we have encountered their craft already however. just as we have sent craft to other planets, so have they to ours.
Good point. There have been a ton of eyewitness events of UFOs by pilots, military personnel and the like. What are the odds that they're all wrong or lying?
"There is far more evidence for the existence of invisible beings like angels and demons that many people experience every day than there is for the dark material no one can see or detect needed by theory for the Earth to not be in a special place in the middle of it all."
People who posit the existence of dark matter to explain observed phenomena are craaaazy. People who believe in angles and demons are just rationally following the evidence where it leads. I see.
"Suppose the correct version of Drake's equation predicts that there should be one planet at most with intelligent life in the entire universe. In that case, I'm going to take the idea that God exists a lot more seriously. That coincidence would be just too hard to swallow. One good empirical argument for the existence of God is the occurrence of something resembling a miracle. This would be close enough."
If that's the tack you want to take I'd remind you there are plenty of other "close enough is good enough" reasons to have a faith in God (or some 'higher power'), many of them much better than "oh my, we're unique, that means there's just gotta be a God!"
What really concerns people is what you might do if you were to start believing in God. Are you going to "spread the gospel"? Are you going to drag people to church and force them to recite prayers? Are you going scan brainwave data in order to detect "sin"? Are you going to ban sex? That sort of stuff is what really irks the non-religious. If religious people weren't such godbotherers far fewer would care about what they believed.
To disclose my religious position, I'm a "Christian atheist." I don't really believe in any of it - not the the way I believe in the equation of gravity, say - but the idea that I'm "saved" is attractive enough to make putting some faith into it worth the effort. And it's a wonderful cultural identity too. I'm looking forward to going to church this Christmas and having a jolly good time. Whether any of it's "true" or not is kinda beside the point.
The same logic that says, "Intelligent life must exist elsewhere in the universe" implies that, if intelligent life does not exist anywhere else in the universe, then it cannot exist on Earth.
The real question here is, "what is the nature of life?"
I did some of my back-of-a-paper-napkin stuff on this once. The most salient fact seemed to be that the time it took life on Earth to go from protein soup to Newton was most of the estimated life span of the universe. And since Earth is an old planet in an old solar system in an old part of the galaxy, the idea that we're (among?) the elder statesmen of the Milky Way seems likely. It would seem that we're more likely to be the ones showing up on other species' doorsteps than the other way around. The time it'll take to spread out across our galaxy at even 5 or 10 percent of the theoretical maximum of light speed is a blink of an eye compared to evolutionary time.
As for the UFO thing; they can cross the galaxy, but they can't do stealth tech? They can't park on Mars and sneak in and live in human form and observe? They can't make replicants to collect the data? Or clouds of nanobots? And they have to keep getting caught over and over and over again? What's taking them so long to collect the data they need?
One thing's for sure, if there are intelligent space-faring civilizations observing us, there aren't many of them. Probably just one. The odds of more than one species being dumb enough to encounter us and leave us alive are too long to be taken seriously.
There are some very odd features of the Earth-Moon system that are not seen with the other planets of our solar system. They may well be freakishly rare, the result of a very unusual early collision that worked out just right for us and has not happened elsewhere in the contactable universe.
Yes. Every time I read a snippet here or there on the subject, it reinforces the idea of how persnickety Earth is (see anon's stuff on the moon, tidal lock, the Goldilocks zone; other anon's comments on Earth's magnetic field; etc.).
It's very hard to detect transmissions from light years away. They're mostly buried in noise through the distance. You can barely get a multi-pixel image of even the nearest stars. Compare a star's electro-magnetic output to the alien equivalent of Mexican border blasters. Trillions of times larger, and they're just a dot.
The idea that we're still here (and not wiped out) is more salient, IMO. If there were many space-faring species in the galaxy, one of them would have wiped us out by now*. And probably all of the others, too. Again, a few hundred thousand years (the time it would take to explore a galaxy at a significant fraction of light speed) isn't much compared to evolutionary time.
*In fact, one of them would have wiped out all the others, as well.
The real reason to suspect we're alone, or doomed: Eventually, tech advances should allow artificial wombs and robots to be able to carry life an arbitrary number of light years into space, populating the whole habitable galaxy [1], including a record of how it happened. That clearly hasn't occurred. We're probably alone, or soon to be destroyed, ice-9 style.
See, this is why I should read the entire post before I respond. You have my thinking exactly.
either mysteriously too smart to understand this logic or just plain wrong. imho
Part of it is enthusiasm for exploration; it's easier to get people excited about exploring a galaxy teeming with intelligent life. Another part is lib anti-humanism; be humble fellow SWPLs, bow before your intergalactic betters.
The good news is that all of that real estate is ours once we get a functional method of FTL.
It's ours once we get a functional method of STL travel.
And if there is a lot of advanced life, some of it is going to be long-lived enough to handle those trips without any of those tricks. There isn't some obvious reason why a technology-inventing sentient species *couldn't* have the lifespan of a redwood tree, which would make an interstellar trip a lot more practical.
How so? Generation ships don't seem to add any new problems.
Well why would they have been paying attention to us?
Because it's in the nature of intelligent life to be worried about the competition.
Also I might add that we only have about 100 years of electromagnetic radiation emitting into space. They have to know we are here before they engage Hyperdrive and send in the Berserkers. Right now the only place we would be known is a 100 lightyear bubble centered on earth (okay earth has been moving the whole time; getting a headache thinking about that shape; still it will be pretty much a sphere).
Given self-replicating robots, it wouldn't be that big of a challenge to survey the whole galaxy.
"The key variable, which isn't captured in the Drake equation, is the difficulty of traveling from one star system to another."
This is something that is always overlooked in science fiction stories, because it doesn't make for a good story.
Why would anyone go to the trouble of sending goods across stellar distances? It's a good bet that if you can cross them, you don't need to.
Colonization.
And let's leave people out of it. I kind of doubt we ever have much of a manned presence in space, Gerard O'Neil notwithstanding. There really isn't anywhere to go. If you want to go to Mars find a high, dry, cold desert. Something like Chile. Mars couldn't dream of having a single day as nice as 15,000 foot elevation in the dead of winter.
Terraforming.
The only good reason for space travel is survival in my opinion. Not spreading your seed across the Universe or some improbable Galactic Empire. I mean you could do it, but you are gonna have to have Hyperdrive or something, and some easy way to get out of gravity wells.
What are you, kidding? That's like saying the only reason to tame North America was survival. Spreading your seed is what organisms do.
Overlooked in these debates is that though the universe is really large, its also really old. With a near infinite time frame, the chances of two instances of intelligent life arising at the same time on different planets, and both being able to venture into space without destroying themselves, is vanishing small.
The universe is actually really young, if you take evolutionary time into account.
Good point. There have been a ton of eyewitness events of UFOs by pilots, military personnel and the like. What are the odds that they're all wrong or lying?
There has been a ton of eyewitness accounts of miracles like pillars of flame, resurrection, self-replicating food, swords in stones, demi-gods with impenetrable skin, etc. What are the odds that they're all wrong or lying?
"Got to love the Drake."
To Anon at 9:26, how about Msgr. Georges Lemaitre?
I know, I know, the Church is anti-science.
"Now, this is what I call science!"
That's the funniest thing I've read on your blog, and you're a pretty funny guy.
"Venus has plate tectonics."
I gather there's some debate over this. It may be that Venus has the kind of plate tectonics Earth would have if Earth was covered by a single continent with no oceans: rift valleys, etc., but no mid-ocean spreading ridges with subduction zones at the continental shelves. For the Drake Equation we need to know whether this kind of plate tectonics perform the same role as Earth-style plate tectonics.
http://www3.imperial.ac.uk/earthscienceandengineering/research/iarc/theplanets/platetectonicsonvenus
"Cail Corishev said...
Are you sure the Drake Equation wasn't thought up by a high-school science class in the first place? It's not just a wild-ass guess; it's like several wild-ass guesses multiplied together."
Yes, the Drake Equation (aside from not even being an equation - it's a formula) is a lot of nothing. It is a name we give to our ignorance.
Iran 1976, etc...
I’m not denying that extra-terrestrial intelligence is out there, but anyone who makes the assumption that it so prevalent as to be a credible contender in explaining any of Jody’s events has done just that: i.e. they have made a very big assumption. I contend that a more appropriate approach would not be so back-ended.
If Jody or anyone else seriously thinks that any of these incidents have anything much to say about ETI, I submit he or she should expend a little more effort on understanding and applying Bayes’ theorem, or at least Occam’s razor. Oh, and while you’re at it, maybe put down the bong.
"Anonymous said...
We haven't seriously looked for aliens though. What SETI does is not significant at all. It's like trying to listen in on the aliens' cell phone conversations or something."
SETI is, in all likelihood, a waste of time. The losses and dispersion incurred by artificial radio-waves travelling over interstellar distances would render them undetectable or unintelligible.
The belief of such people in alien life - the desire for it to be true, really - amounts to a religion. Why a person's life should acquire meaning because of the discovery of the traces of some sentient beings light-years away is beyond me. Might as well just believe in God.
SETI is a religion for those who deem themselves too good for religion.
There is no form of propulsion that would allow the gulf between stars to be bridged within a human life-time. Generational ships or robot ships would be required, and it is not clear that these could even be built. Probably not. That leaves some kind of space-warping or worm-hole travel. That's well beyond our ability to do or really even to imagine how it might be done. The reality is, were probably stuck in this solar-system, and that would likely be true for every other putative alien species as well.
I've pondered the idea that a sufficiently advanced alien race would have mastered the art of actually knowing *everything* that is going on Earth, past, present and future, through the mastery of technology that is simply beyond our imagination, in much the same way that our technology is simply beyond the imagination of a human from 20,000 years ago.
Perhaps through their all seeing, all knowing technology they can anticipate exactly what earthlings are going to do - centuries before we actually do it, and the aliens wisely 'hang-back' for our own good.
Intelligent life on this planet worth preserving?
What with the NYT, 'The Economist', Bryan Caplan, George W. Bush and all the rest?
Mrhinks a radical re-think of hypotheses is in order, Steve.
Bertrand Russell once put it thus (paraphrasing):
"If there truly is intelligent life elsewhere in the vast universe, then that fact is astonishing and earth-shattering.
If there truly isn't intelligent life anywhere else except on planet Earth in the entire, vast universe, and we are truly alone, then that fact is also just as astonishing and earth shattering".
Electromagnetic radiation (i.e., radio signals) follows the inverse square law. That is, the strength of a signal is inversely proportional to the square of the distance. So radio signals quickly drop off to almost nothing as distance from the transmitter increases. In order for us to hear a signal, any aliens out there would have to be nearby and blasting straight at us. That is most unlikely.
True, but if there were 40 billion advanced civilizations broadcasting into the galactic plane it is more than likely we would detect an artificial signal sooner than later. Laser radiation detected as time clustered photons would be a cleaner signal but once again you're only going to be targeted once in a millennia by chance by an alien laser. Maybe the best way to hunt for evidence of extraterrestrials is to send space ships to Jupiter and Saturn and hunt for monoliths captured in the orbital rings: in other words, go on an exoarcheological expedition.
Perhaps as others before me have speculated all life in the universe evolves according to a Darwinian paradigm and thus is governed by innate Darwinian tropes of aggression and competition due to the genetic replication paradigm which after all is the essence of earth bound life. Then its not too far fetched to postulate that all intelligent life will inevitably destroy itself once it reaches a sufficient nuclear level of technology.
kurt9 said...
The energence of the Eukaryote is believed to have been such a singularly rare event that it happened only once in our galaxy, here on Earth!
Not convinced. For one thing there were at least a couple other endosymbiotic associations on earth that did quite well: chloroplasts in plants/algae and plastids in protozoa. There are so many intracellular bacteria
For another, endosymbiosis is not the only option for compartmentalizing reactions: most membrane-bound organelles don't have their own genomes.
And surly we are not the newest kids on the universe’s block - YET - there are no patterned signals on any frequency that we can find.
A signal which is highly compressed or encrypted looks like white noise---i.e. is not obviously patterned. Radio spectrum is scarce; therefore, all traffic will eventually be highly compressed. How long until Earth is not emitting much patterned radio traffic? A century? So, that would be two centuries total of patterned radio traffic from us.
Jonathan said...
Electromagnetic radiation (i.e., radio signals) follows the inverse square law. That is, the strength of a signal is inversely proportional to the square of the distance. So radio signals quickly drop off to almost nothing as distance from the transmitter increases. In order for us to hear a signal, any aliens out there would have to be nearby and blasting straight at us. That is most unlikely.
One: You are saying this in a thread spawned by our ability to detect planets by watching to see how much less light is visible from their stars when the planets transit in front of them. Planets are a lot smaller than stars. A lot.
Two: The SETI guys are then fraudsters, ripping off that famous rube, Paul Allen. Seriously?
if intelligent life does not exist anywhere else in the universe, then it cannot exist on Earth.
That would explain a lot actually.
I know even within our own circle of experience, were it not for coincidences in geography and biology, what group beyond European males were going to pioneer space exploration?
"Venus has plate tectonics."
No, it does not.
"radio signals quickly drop off to almost nothing as distance from the transmitter increases."
It would be trivial for them make a colossal radio station.
"Perhaps through their all seeing, all knowing technology they can anticipate exactly what earthlings are going to do - centuries before we actually do it, and the aliens wisely 'hang-back' for our own good."
Thank you, Paul Krugman.
There has been a ton of eyewitness accounts of miracles like pillars of flame, resurrection, self-replicating food, swords in stones, demi-gods with impenetrable skin, etc. What are the odds that they're all wrong or lying?
You mean there have been eyewitness accounts of things like "pillars of flame, resurrection, self-replicating food, swords in stones, demi-gods with impenetrable skin" by multiple military and airline personnel, air traffic control, corroborated by radar data, etc., in the 20th century?
If a planetary body is *capable* of sustaining life, then the odds that life will arise at some point in time, somewhere on the planet, are probably pretty good. They may not be 100%, but 10E-1 or 10E-2 seems reasonable. Given the potential number of habitable planets, even odds of 10E-3 wouldn't be bad.
A planet's lifespan and surface area are immense, especially compared to the size and lifespan of single-celled organisms. The odds that a handful of molecules (out of quadrillions) will eventually interact in a way which ultimately leads to life may be small, but they aren't that small.
But the odds that intelligent life has arisen, life capable of communicating with us, in a part of the galaxy visible to us, are much smaller. 8.8 billion chances may not be nearly enough.
It's an absolute certainty that there's intelligent life somewhere else in the universe - beings that have reached into space, are capable of communicating with us, and would even like to communicate with us. They just may not be anywhere near us. The Star Wars-esque vision of thousands of habitable planets all within relatively easy reach of one another is unlikely. One life-sustaining planet per galaxy may be the best the universe can do.
If that's the tack you want to take I'd remind you there are plenty of other "close enough is good enough" reasons to have a faith in God (or some 'higher power'), many of them much better than "oh my, we're unique, that means there's just gotta be a God!"
I don't buy the "we're unique = God" line of reasoning. How do we know that if there is a God, that he/she/it didn't create life on many worlds? The real point is that many of the more fundamental Christians are closet geocentrists.
There has been a ton of eyewitness accounts of miracles like pillars of flame, resurrection, self-replicating food, swords in stones, demi-gods with impenetrable skin, etc. What are the odds that they're all wrong or lying?
What are the odds they are the result of Chariots-of-the-gods ancient astronauts rather than actual divine beings?
Oh yeah, then there's the Dyson sphere thing. It makes sense; the end-game of an advanced civilization's exploitation of a star system should be to capture all of its energy, a behavior we should be able to detect if it were widespread, right?
"Not technically true, in fact the the 3 primary founders of quantum mechanics were Heisenberg, Schroedinger, and Dirac, all of them Gentiles like Fermi. Additiionally you have Indians like Bose and Raman around the same time who were obviously not Jewish either. Even the Jewish guys who contributed were often mixed Jewish/Gentile like Niels Bohr and Wolfgang Pauli. Since then, you would be right, Jews have dominated theoretical physics particularly in the US and Russia."
And what a productive 60 years of non-Gentile physics theory we've had. I mean they figured out... and developed... of course with many practical applications in...
Oh, well at least we furnished them nice offices in old stone buildings and they could walk around feeling like they're just the smartestest.
The Derb said: OTOH if the actual universe is infinite, which seems quite likely, there are an infinity of such planets out there. We could never see them, though.
Whoa. So the Derb is rejecting the Big Bang Theory (the cosmological fact, not the TV show) in favor of the long-discredited Steady State Theory?
"10E-1 or 10E-2 seems reasonable. Given the potential number of habitable planets, even odds of 10E-3"
Are these fancy ways of saying one-tenth, one-hundredth, and one-thousandth? Just say that, OK?
"Bill said...
One: You are saying this in a thread spawned by our ability to detect planets by watching to see how much less light is visible from their stars when the planets transit in front of them. Planets are a lot smaller than stars. A lot."
And stars are a lot brighter than RF antennas. An alien race would really want to have to talk to us to broadcast radio waves with a power comparable to what a star puts out.
"Are these fancy ways of saying one-tenth, one-hundredth, and one-thousandth? Just say that, OK?"
It's useful notation for very small numbers because the zeroes can otherwise be very hard to count, but to use E notation for anything larger than a thousandth in casual conversations like these = 10E1% poseur.
What really concerns people is what you might do if you were to start believing in God. Are you going to "spread the gospel"? Are you going to drag people to church and force them to recite prayers? Are you going scan brainwave data in order to detect "sin"? Are you going to ban sex? That sort of stuff is what really irks the non-religious. If religious people weren't such godbotherers far fewer would care about what they believed.
Such people should read Vox Day's The Irrational Atheist, so they can stop fearing such ridiculous strawmen and relax. They're more likely to be killed by some atheist's plan for global utopia than they are to be seriously inconvenienced by any god-botherer.
There has been a ton of eyewitness accounts of miracles like pillars of flame, resurrection, self-replicating food, swords in stones, demi-gods with impenetrable skin, etc. What are the odds that they're all wrong or lying?
You mean there have been eyewitness accounts of things like "pillars of flame, resurrection, self-replicating food, swords in stones, demi-gods with impenetrable skin" by multiple military and airline personnel, air traffic control, corroborated by radar data, etc., in the 20th century?
Did...did you just call the Hebrews liars?
Mr. Anon:
There is no form of propulsion that would allow the gulf between stars to be bridged within a human life-time.
Not yet. But it doesn't mean people aren't thinking about it.
http://www.cannae.com/
"There is no form of propulsion that would allow the gulf between stars to be bridged within a human life-time. " - Theoretical nuclear salt water rocket designs could visit our nearest neighbor in about 120 years, and there are some other forms of propulsion proposed that could do the job even sooner, but that really doesn't matter, if it takes 10 Million years to explore the galaxy, that is only 1/6th the time that has past since the dinosaurs went extinct.
"Oh yeah, then there's the Dyson sphere thing. It makes sense; the end-game of an advanced civilization's exploitation of a star system should be to capture all of its energy, a behavior we should be able to detect if it were widespread, right?" - and easy to aim a relativistic weapon at. If you're looking for some real downer fiction I suggest The Killing Star, or(even worse) Blindsight.
Such people should read Vox Day's The Irrational Atheist, so they can stop fearing such ridiculous strawmen and relax. They're more likely to be killed by some atheist's plan for global utopia than they are to be seriously inconvenienced by any god-botherer.
I fear both.
"It's useful notation for very small numbers because the zeroes can otherwise be very hard to count, but to use E notation for anything larger than a thousandth in casual conversations like these = 10E1% poseur."
It's ironic that I'm being criticized for using scientific notation by people who abbreviate the words "it is." How many keystrokes did that save you?
"Anonymous said...
Mr. Anon:
""There is no form of propulsion that would allow the gulf between stars to be bridged within a human life-time.""
Not yet. But it doesn't mean people aren't thinking about it.
http://www.cannae.com/"
Yes, gullible, dim-witted people are thinking about it. It violates the law of conservation of momentun. The world is full of guys like this - half-educated, not-very-bright undiscovered geniuses who think they are scientific revolutionaries. They aren't.
It's bullshit.
"Anonymous said...
Theoretical nuclear salt water rocket designs could visit our nearest neighbor in about 120 years, and there are some other forms of propulsion proposed that could do the job even sooner,........"
I don't believe that. What specific impulse do they claim for thier concept? What's thier alpha? How much mass do they claim they could move to another star in 120 years? A thimble-full? I've never heard of a nuclear salt-water rocket (a thing, which - by the way - does not exist) that would be capable of anything more than inter-planetary travel.
The Star Wars-esque vision of thousands of habitable planets all within relatively easy reach of one another is unlikely.
To be fair, the reason all those planets are within easy reach of each other is because the galactic civilisation in Star Wars has access to FTL travel that's absurdly fast even by normal sci-fi standards (going from Tatooine on the Outer Rim to Coruscant in the Galactic Core in the space of an afternoon, for example). Of the really well-known visually-based sci-fi franchises, I think only Stargate tops that level of performance.
@ Anonymous 11/4/13, 9:26 PM -
Wolfgang Pauli was three-fourths Jewish by ancestry. The Nazis treated such people the same as they did full Jews. Also, don't neglect the contributions of Born and von Neumann to the mathematical foundations of quantum physics.
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