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Number of ET Civilizations In Our Galaxy Is 37,964
KentuckyFC writes "The famous Drake equation calculates the number of advanced civilizations in our galaxy right now. But the result is hugely sensitive to the assumptions you make about factors such as the number of habitable planets that orbit a host star, how many of these actually develop life and what fraction of these go on to become intelligent etc. Disagreements about these figures leads to estimates for the number of advanced civilizations ranging from 10^-5 to 10^6. Now an astronomer in Scotland has worked out how to make the calculations more precise so that different theories about the origin of planets, life and civilizations can be compared. His calculations say that the rare-life hypothesis predicts only 361 advanced civilizations in the Milky Way now. However, the so-called tortoise and hare hypothesis predicts 31,573 and the theory of panspermia says that there ought to be 37,964 extraterrestrial civilizations more advanced than our own in the Milky Way."
...of spurious precision.
1.
And it is as valid as this astronomer's estimation.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
We just don't have a clue.
The number of things we don't have a clue about is staggering.
Counting the number of earth like planets is just plain silly. If life can only start in space and then find a planet, earth might be totally unsuitable for the first start. It also presumes life can only exist under earth like conditions yet we KNOW that even life on earth varies widely. If some species can survive on the bottom of the ocean outside the influence of the sun, is it impossible to imagine a lifeform that exist in space itself?
No, I am sorry but until we can actually go and look our estimates of the number of civilizations is between 1 and 1+.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
But we have no definition of advanced.
Look, just because an alien civilization has been around longer than we have, doesn't necessarily mean they will be more advanced than we are.
Maybe they could have been around one million years before us, but are stuck somewhere between Mesopotamia and Rome.
I'm god, but it's a bit of a drag really...
But that one is terrestrial.
Heck, it may even be the intelligent one!
First, absence of evidence is absence of evidence. Not what you want to be. Do not make this kind of semantic tricks it's worth is a dime a dozen.
Second, Fermi Paradox says that we are alone in galaxy because our belivings are wrong, or we are NOT alone in the galaxy but our observations are not as good as it should be to detect E.T. in some way.
What is the problem with more activity as long as you can get away? It's not like stars crashes into each other every millionth year or so is it?
Wouldn't the extra radiation if any increase the number of mutations (if they worked as life on earth) and thereby increase their development speed? Same with shorter generations I guess.
Because a species of intelligent dolphins would surely be detectable from their radio transmissions.
No. That entire line of thought is based upon the incorrect assumption that WE are the model for all other species.
We're almost unique on Earth. Where we share DNA with every other animal. Why expect that from creatures who evolved on a different world?
Not to mention the incredibly SHORT time we've been looking over an incredibly SMALL portion of the galaxy.
Your entire argument is based upon another species developing the exact same technology that we have ... and using it in a fashion we can detect ... far enough in the past ... but not too far in the past ... so that we can detect it ... using the technology we have ... during the time we have been trying to detect it.
Yeah, like that "proves" anything.
You have no theory, as it stands it is only a hypothesis.
Free Martian Whores!
I am a polar bear. Don't bother to ask me how I managed to get on Slashdot and post this, you would never believe it.
However, I have been doing some estimations of my own. I have always wanted to figure out how many polar bears there are in the world. In my neighborhood here in the arctic, there aren't too many polar bears. About 350. I estimate that we roam over 20 square kilometers. Now, based on some observations I made from the bottom of a well, I figure the earth is around 500 million square kilometers. I haven't actually been outside of my corner of this world, but I imagine everything must be like it is here, and life must be exactly like it is here. I have no evidence to the contrary.
So, I figure there must be 25 million times 350 polar bears or 8.75 Billion of them.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
But, the diameter of the milky way is about 100,000 light years - so, if we assume that pre-Galileo civilization was oblivious to ET, we as a species are only aware of civilization signs within 400 light years or so.
So, if there are 40,000 civilizations within a 100,000ly diameter, then there are approximately 2.56 civilizations within a 800ly diameter.
Personally, I feel like Earth represents the .56 of a civilization in that scenario...
If we ask "where are they?", could it not be possible that NO advanced civilisation could make it to interstellar travel, given how difficult it would be to maintain a survivable environment, enough resources for the trip, and so on? After all, we can look in out neighbourhood and conclude that life is not abundant in the vastness of space, so it must need some kind of special environment to develop and grow. No matter what type of environment a civilisation may develop under, it's unlikely to be one easily recreated on a spacecraft.
Oh, now I read the wiki I see this has already been considered. Well, there's no evidence that our TV signals and such would be powerful enough to reach beyond the solar system. All our deep-space communication is done to a very precise point. Same goes for the Arecibo message, and that has many years to travel before it reaches its destination. These other civilisations would have to be millions of years ahead of us for us to hear them now.
Michael Crichton criticised the Drake equation years ago:
http://www.crichton-official.com/speech-alienscauseglobalwarming.html
My personal guess is that there are OVER 9000 civilisations out there.
Squirrel!
Please define exactly what evidence we should be looking for. Until that is done, absence of evidence will NEVER be acceptable as evidence of absence. There is simply way too much that we do not know about the nature of life, it's origins or it's potential manifestations. Bit of pot calling the kettle black there Mr Hand Waver.
"Gold still represents the ultimate form of payment in the world." - Alan Greenspan, 1999
Doesn't that beg the question? I mean it assumes we have the means to actually make that observations. But we don't. We don't see very much of the universe.
Assume there is a space ship that travels through our solar system. It would be pure luck if we would detect it. And there is zero chance we would see a space ship that is not in our solar system. And that whole space ship scenario assumes there is a way to travel faster than light...
What about signals? How could we recognize them? Take a look at SETI@home. Huge amounts of processing time are donated to that project, to try to distinguish noise from signals. Only a small fraction of the stars is covered with only a small time frame. The Milky Way as like 200 billion stars. Observing one percent of them for one second accumulates to 1500 years of data. And we don't know how good the scanning algorithms really are.
And that assumes the aliens are in our range, which means they are probably extinct at the moment we receive their signal.
It is like observing a glass of water with bare eyes. You see nothing that is alive, and then you conclude you are the only living individual on the whole planet.
Lay off the sci fi.
I am very small, utmostly microscopic.
Good article references. I always thought it hilarious but sad the same "great minds" who support random evolution also make arguments against life on other planets. When your theory has to have so many caveats to make it continue to match the observed data, you need to revise your theory. The only theory in accordance with evolution from a single cell/proteins is most planets older than the earth will have life more advanced than the earth. Mars, I'm talking about you!
Does anyone else think it odd ancient cultures have artwork of flying disks and flying men as well as stories about creatures from other worlds? A very interesting calculation would be the probability space aliens would visit earth during our recorded history or during the history of video recording. And then calculate the probability they would land in a way they would be recorded. Even hunters know how to create a blind. That's simple.
Happens when you play Pan's flute too long.
It is entirely plausible that a civilization could be a billion years ahead of us.
Nerd rage is the funniest rage.
That's not an answer. It's a tautology. It amounts to "We are unique because the universe was tailored to produce us", which itself amounts to "We are unique because the universe exists", which itself amounts to "The universe exists". It's not so much an answer as it is the ultimate expression of vanity.
The Fermi paradox and Drake equations are not predictive tools. They are not predictive because we have no estimations of any of the parameters, and no data on which to test them. They cannot tell us anything without data to back them up, and for that to exist we need to find at least one other "civilisation", if not more.
A lot of the speculation among scientists about extra terrestrial life is pretty substandard, leading to frankly appalling constructs like the Anthropic principle being taken as a valid scientific argument. Nonsense statements like "All Life needs Water to survive" betrays an absolute lack of imagination among those supposedly seriously investigating these matters.
Ultimately from a scientific standpoint, the existence of one life supporting planet allows at least the possibility of more existing. But then again, so too does the existence of one Elvis Presley. Until another is discovered, we must say that extraordinary claims require extraordinary evidence, and until that time, speculators can stick to science fiction stories, which are not entirely without benefit to society.
May the Maths Be with you!
Or 4352342. "Calculating" any such number is not in hardly more scientific than throwing dice to figure it out. Sometimes I wish scientists wouldn't have this urge to make the impression of having a clue, when, quite obviously, the don't have a clue. Or, as in this case, provably cannot have a clue.
Now one knows yet how life came into being. Stop making calculations that require knowing that to even get close to meaningful numbers.
The instinct to reproduce and grow in numbers is fundamental to all life. To "hole up" is to accept death as the local star fades--contrary to the most basic life instinct.
Advanced civilizations don't "hole up," they spread.
A slashdotter who didn't build his own computer is like a Jedi who didn't build his own lightsaber.
Maybe not. It is not like Hans Reiser was tried by a jury of people who wrote advanced file systems, or a jury of homicidal maniacs, take your pick.
Correct me if I'm wrong here, but an Earth-like planet couldn't have come about much sooner, since we need so many elements that we can only get from old burned-out stars. There's gotta be a lot of cycles before there's enough material further up the atomic chart to make an interesting planet.
I didn't bother to RTFA, but is this guy talking about 37,964 intelligent species, or 37,964 different civilizations? Because if our little planet is anything to go by, a single species can have multiple civilizations, concurrently. Depending on how you count them, there are up to 245 different civilizations just on earth.
Life isn't Star Trek, there's no reason we should assume a single species has only a single cultural heritage for itself.
God invented whiskey so the Irish would not rule the world.
It's the most trivial equation I've ever seen. It ranks up there with embarassing things like the Hardy-Weinberg equation and the Fick equation.
Maybe exp(pi*sqrt(163))'s equation ought to become famous. The probability of getting to work is the probability of me being alive in the morning times the probability of me getting up times the probability of it being a work day times the probability of me being bothered with going in times the probability of me surviving the journey.
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
Predation seems unlikely given the resources needed for interstellar travel. Either the civilization is sufficiently advanced that they have no need for anything we might have and so are, at worst, ambivalent; or they are not sufficiently advanced enough in which case the cost of predation would outweigh the benefit gained.
Given the size of the galaxy, predation seems even more unlikely. Why prey on another civilization when there are resources to spare available that are almost certainly closer and easier to acquire.
But let's assume a worst-case scenario: A galactic empire consuming everything in its path as it grows. They are coming, certainly. But they will get here when they get here regardless of radio signals. And I still wonder what we could have that they could possibly want at that point.
Because if our little planet is anything to go by, a single species can have multiple civilizations, concurrently.
Based on how alien alien civilizations probably are, I imagine everything from Wall Street to bush men will fall under "human civilization" and the point you're trying to make would look as meaningless as saying you and the guys on the other side of town live in different civilizations.
Live today, because you never know what tomorrow brings
People hate facing up to the fact that we're alone. But it just seems to be the fact of the matter.
Following that logic, if there was another civilization somewhere in the galaxy, they would likewise argue that clearly they are alone in the universe since they have seen no sign of us. It then follows logically that there is obviously no intelligent life in the universe.
As the air to a bird or the sea to a fish, so is contempt to the contemptible -W.B.
an alien invasion force would care about as much about different human civs as you care about which hive an ant you just stepped on belonged to.
___
No power in the 'verse can stop me
Of course all of these wild guesses are based on the kind of linear determinism found in games like Civilization & based on the antiquated and racist ideas of social darwinism from the 19th century.
Who says that "intelligent life" is a survival advantage? How does one say which society is "more advanced?" Based on our industrial western ideals of technology? Bah, if we were really smart we'd all be fat seals basking in the sun and eating fish to our heart's content.