Astronomers Estimate Milky Way May Have 100 Billion Alien Worlds 294
astroengine writes "Last year, using the exoplanets discovered by the Kepler space telescope as a guide, astronomers took a statistical stab at estimating the number of exoplanets that exist in our galaxy. They came up with at least 50 billion alien worlds. Today, astronomers from the Space Telescope Science Institute (STScI) in Baltimore, Md., and the PLANET (Probing Lensing Anomalies NETwork) collaboration have taken their own stab at the 'galactic exo-planetary estimate' and think there are at least 100 billion worlds knocking around the Milky Way."
Sweet (Score:5, Funny)
No tentacle monsters though, they will take all our womens!
Re:Sweet (Score:5, Funny)
No tentacle monsters though, they will take all our womens!
Only the Japanese ones.
Re:Sweet (Score:4, Funny)
No tentacle monsters though, they will take all our womens!
Only the Japanese ones.
I experience an alien world ever time I return from vacation, sushi or no.
Re:Sweet (Score:5, Funny)
Re:Sweet (Score:5, Funny)
You just want death by snu snu
Do you blame him? Without a partner, he's just having snu.
Re:Sweet (Score:5, Funny)
Unfortunately, the probability of you finding one of those just went from 1:50 billion to 1:100 billion.
Re:Sweet (Score:5, Informative)
Unfortunately, the probability of you finding one of those just went from 1:50 billion to 1:100 billion.
That is assuming that a planet with Amazonian Women, hot green chicks, and Galactic Girls Gone Wild is unique. If it is the sort of planet that comes up once in every ten billion, his chances of finding such a planet just doubled.
Re:Sweet (Score:4, Informative)
To be pedantic, the chances actually didn't change at all.
Re:Sweet (Score:4, Interesting)
I know you're joking, but you're not going to find any alien species that look anything like human. There are no Romulans, Klingons, nor especially Betazoids. You're probably unlikely to find anything that more than remotely resembles any species from Earth -- look how diverse life here is. We may find intelligent life and not even realise it's alive, let alone intelligent.
Required reading: Isaac Asimov's What is This Thing Called Love? [wikipedia.org] (originally titled Playboy and the Slime God). I've read a lot of Asimov stories, and I don't think the good doctor (a biochemist) had a single alien that looked human-like, and the story I mentioned gives a clue why.
Terry Bison's They're Made Out Of Meat (online at Baen Books) is another good one.
And a thank you to slashdot for waking the muse [slashdot.org] with this topic!
redundant (Score:3, Insightful)
aren't all worlds, not our own, alien?
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aren't all worlds, not our own, alien?
Yes, that's why we call them alien worlds....
Re:redundant (Score:5, Insightful)
I think he's trying to say that its not necessary to say alien worlds, just say worlds. He does kinda have a point, saying alien worlds makes it sound like we're not one of the 100 billion, which we are.
Re:redundant (Score:5, Funny)
We are the 0.0000001%...
Re:redundant (Score:5, Funny)
I think he's trying to say that its not necessary to say alien worlds, just say worlds.
If you just say worlds you have to say a billion and one. That's two extra words.
Re:redundant (Score:5, Funny)
aren't all worlds, not our own, alien?
Yea, so 100,000,000,001 is total.
This Universe Sucks (Score:5, Funny)
Why couldn't I be born to a universe with a less restrictive set of physical laws?!
Re:This Universe Sucks (Score:5, Funny)
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God is a man, you insensitive clod!
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the 1%-ers don't have to follows those laws. you should have been born with money, that's all.
Re:This Universe Sucks (Score:4, Funny)
Those who figure out how to avoid the physical laws are the 0.0001%-ers that don't need money.
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Follow the white rabbit.
100 billion likely way too low (Score:5, Interesting)
As for examining Kepler Objects of Interest (KOIs) more closely it seems there is little point to single them out. So what if we know they have planets -- everywhere you could point a radio dish there are planets. I am a big supporter of SETI and this is all good news for SETI, but it doesn't do anything to narrow the search.
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It will narrow our search by telling us the properties of some of these planets. For instance, it would be nice to know where all the earth-like planets around sun-like stars are. That would certainly narrow the search, wouldn't it?
Re:100 billion likely way too low (Score:5, Funny)
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With 200-400 Billion suns to survey and most having Planets and probably 10-50% have some planets in its equivalent of the Goldie-Locks zone, then you are far bet
Re:100 billion likely way too low (Score:5, Funny)
To make a car analogy, for the Slashdot crowd; It is like a bunch of hot chicks driving cool cars, you know they exist, but you will never touch them. Just try to keep your basement tidy, since that is where you have to live. If a '61 'vette drives thru the storm doors, you might get lucky.
Re:100 billion likely way too low (Score:5, Funny)
Re:100 billion likely way too low (Score:4, Interesting)
It's acknowledged in the article that this is only for 'worlds' about 5x as big as earth and higher.
The real number, counting everything that would count as a planet in our solar system, may be 5-10X as high.
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Re:100 billion likely way too low (Score:5, Informative)
The problem is that unless said aliens are pulling the strings on a galactic core super massive black hole and manipulating the plasma jet to serve as a "fucking huge" high gain antenna, the attenuation of the rf signal by interaction with cosmic dust will turn even a real whopper of a broadcast into white noise before it reaches us.
Basically, they would have to be broadcasting a massively powerful signal capable of killing off lifeforms from the raw energy in the wave before we could detect it at our distance.
Re:100 billion likely way too low (Score:5, Informative)
The problem is that unless said aliens are pulling the strings on a galactic core super massive black hole and manipulating the plasma jet to serve as a "fucking huge" high gain antenna
They could always just build a big antenna with some power and decent cooling. And we could do the same. No need to sterilize a galactic core any more than it already has been. Cosmic dust is not that effective an attenuator or we wouldn't be able to see objects billions of light years away.
Re:100 billion likely way too low (Score:4, Interesting)
Lets listen to Andromeda which is 2.5 million light years away or about 24x10^21 meters away. Lets assume that that the intelligent life in Andromeda only transmit to the closest galaxy, us. Lets also assume we have a perfect quantum efficiency detector at the 1.420GHz "water hole" and that we have zero noise and hence only a photon per second can be considered enough data to rule out anything but ETs. Finally we assume that we have built a 100m radius antenna to capture these photons.
Ignoring diffraction and the relative orientation of the milky way to Andromeda, we assume they only need the energy to stream that many photons through the milky way disk. The diameter of the milky way is about 100,000 lty so the area is 703x10^39 m^2. We want one photon per second per 100m radius antenna or per 31x10^3. The total number of photons per sec is 22.7x10^36. Each photon has energy E=hv or 937x10^-27J and the total power required is *only* 21x10^12W.
Obviously there are other losses and diffraction, but the real limit is the noise floor at 1.420GHz. I have no idea what that is, but once we consider shot noise etc we start to see that we need a bit more power than 21TW. However this is not an impossible power level, and is not "life sterilizing" really. But then again its only 2.5 million light years away. In terms of galactic distance, that is just over the fence. Also the guys over at Andromeda have to really want to let others know they are around. Which with the distance involved seems less likely than local civilizations.
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neither radio nor light signals would not be detectable at such distances, not even at the distance of Andromeda which is the nearest spiral galaxy
Re:100 billion likely way too low (Score:4, Interesting)
Here is a very fine example of an supernova in another galaxy that is visible from earth, but modulating this to carry information would be somewhat challenging.
http://upload.wikimedia.org/wikipedia/commons/thumb/a/a2/SN1994D.jpg/600px-SN1994D.jpg [wikimedia.org]
That is one beautiful pic though.
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Well, it turns out that our own radio and TV signals don't actually get out into our own galaxy as much as we once thought. They make it barely beyond the influence of our sun and then fade.
So aliens next system over are not actually watching our old TV shows.
Another galaxy would be much farther away and even less likely to hear any signals. Space is big. Really big.
Re:100 billion likely way too low (Score:5, Insightful)
Re:100 billion likely way too low (Score:5, Informative)
No, the Voyager probes transmit at 23 Watts, which is basically nothing. The entire power system on the craft can generate about 250 Watts, which is used for all the systems. The fact that Nasa can track an object transmitting half the power of a lightbulb 11 billion km away to very fine precision is absolutely the most amazing thing they ever did in the space program IMHO.
http://science.howstuffworks.com/question431.htm [howstuffworks.com]
Re:Like Pluto? (Score:5, Funny)
Disney sued them for copyright infringement. That's why they had to stop calling Pluto a planet.
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Re:Like Pluto? (Score:5, Informative)
Re:100 billion likely way too low (Score:4, Insightful)
I like your point, but I think you're missing out on something.
Radio isn't just used to tell stories. It's used to communicate. Nobody is telling stories in the cockpit of an aircraft, for instance. It's just communicating messages. Information back and forth.
There are lots of examples where this is true. And to extend your analogy with other species, there are plenty of other species that communicate on our own planet (even microbes! [ted.com]). It just so happens that the complexity of that communication seems to scale to a degree with the complexity of the organism. And it also so happens that we're the only species thus far that's developed the reasoning level and had the ability to develop tools to extend communication like radio.
Further, any other species that wishes to communicate over great distances on another world, regardless of whether or not they are culturally story tellers or not, will likely face similar problems to us, in terms of the physical limitations of passing messages across space within the universe (whether that space is a light year or a mile).
It stands to reason that similar solutions (radiation) will be sought. You could argue that they'd use different bands. Perhaps. We use the bands we use because they work best in our environment. For instance, most of our environment is opaque on the visual and IR bands, so that doesn't work. That's why we don't use those bands for much. Radio, on the other hand is easy to generate, can give you good range, is not very bad for you (like x-ray or gamma), and much of the world is transparent to it, so you don't need to worry about line of sight so much.
Now that said, we have no idea what they would transmit. Sound? Visuals? Digital representations of something? What are the odds that another intelligent civilization uses sound to communicate in the first place? I have no idea. If not sound, what? If a civilization is transmitting say, smell, or some abstraction of a sense we do not posses, how would we interpret this if we detected it? If we realized that it was intelligent, how would we decode it?
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It stands to reason that any sentient and even mildly industrious intelligence is going to stumble on it and put it to use. Yes, we only have a few data points for tool use,
Alien life would be quite different from Star Trek (Score:3, Interesting)
Alien life in the universe that we could encounter, depending on the climactic conditions, gravity and atmosphere would be very different from humans to say the least. They would not be all humanoid races that speak english and can walk and act just like humans, they might be boneless creatures like an octopus or evolved dolphins that pilot ships full of water, or something that we have not even encountered yet. Dolphins show amazing intelligence so it is easy to imagine, that if they evolved over the course of millions of years on a remote planet and developed mathematics and science, they could invent space flight. Star Trek had humanoid aliens as standard, but the science fiction of Larry Niven envisaged quite different creatures such as the puppeteers.
Not to forget the even stranger aliens in the book Sundiver [wikimedia.org] by David Brin. Discovery channel one time showed a Jupiter sized Earth like planet that had small creatures crawling along its surface that had to eat continually in order to have enough energy to move in the massive gravity. I am not sure if it is possible for such a large planet to form, most large planets that have been discovered are gas giants. But any alien planet we visited could have alien bacteria that we would not have a immunity to and it could be very dangerous if we brought it back to Earth. So any future space exploration would still require caution.
Re:Alien life would be quite different from Star T (Score:5, Interesting)
Alien life in the universe that we could encounter, depending on the climactic conditions, gravity and atmosphere would be very different from humans to say the least. They would not be all humanoid races that speak english and can walk and act just like humans, they might be boneless creatures like an octopus or evolved dolphins that pilot ships full of water, or [...].
Ships full of water - multiply the difficulties to escape the gravity well by about 1000.
Imagine developing metallurgy and special ceramics (I reckon these would be needed for at least propulsion) in/under water...
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Ships full of water - multiply the difficulties to escape the gravity well by about 1000.
Imagine developing metallurgy and special ceramics (I reckon these would be needed for at least propulsion) in/under water...
Who said the ship needs to be full of water. given many of the oceanic creatures on earth only the breathing apparatus needs to meet the creatures environmental requirements. Isn't it entirely possible to create a space suite for an aquatic organism in the same way we have pressure suits for humans?
Your second point is much more interesting. I the best guesses I can come up with are either do it on land using machines (in the same way we use submersibles to work under the sea) or have an entirely differe
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I think the issue is how does this water creature develop fire and metal smelting in the first place (you know bronze and iron age level) - once they have technology working around it is easy, the tricky bit would be developing that technology in the first place.
Re:Alien life would be quite different from Star T (Score:4, Interesting)
I think the issue is how does this water creature develop fire and metal smelting in the first place (you know bronze and iron age level) - once they have technology working around it is easy, the tricky bit would be developing that technology in the first place.
You can create fire underwater, it's a different chemical process to on land.
Besides, you dont need fire for smelting, you simply need heat and there are plenty of active underwater volcano's on earth as well as other heat sources.
Needless to say, an aquatic civilisation would develop things in radically different ways to the way we have.
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Ships full of water - multiply the difficulties to escape the gravity well by about 1000.
Who said the ship needs to be full of water.
The GP post did - straight copy/paste citation: ... they might be boneless creatures like an octopus or evolved dolphins that pilot ships full of water, or something that we have not even encountered yet
given many of the oceanic creatures on earth only the breathing apparatus needs to meet the creatures environmental requirements.
I really doubt it (the only part of it). E.g. reverse the situation and imagine yourself travelling for years in a complete suit that wouldn't allow you to clean you skin.
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Plus the difficulty of developing technology if you don't have hands
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Re:Alien life would be quite different from Star T (Score:5, Insightful)
Alien life in the universe that we could encounter, depending on the climactic conditions, gravity and atmosphere would be very different from humans to say the least.
Not proven until we meet one.
They would not be all humanoid races that speak english....
Star Trek did not portray this.
Dolphins show amazing intelligence so it is easy to imagine..
No, it is not easy to imagine. Dolphins lack the dexterity to build a space ship. We may find out that any given species rarely (if ever) reach space unless they meet certain other criteria like opposable thumbs and originate from a planet where it's easy to start a fire. We don't know what all is involved in inspiring a species to leave the planet, just that it likely requires a complex series of events.
It's easy to jump to the conclusion that every planet that sports life will create a random space faring civilization species. However, to put things into a more realistic perspective, consider that this planet has created over a hundred million species of life and only one has intentionally gone into orbit.
Star Trek had humanoid aliens as standard...
No, they did not. The 'humanoid' races were explained by one species that seeded our area of the galaxy with similar genetic material. Elsewhere in the series, the Federation was accused of really only allowing humanoids to join.
We just don't know.
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Basically, a guy dies, leaving clues to a big mystery. Piccard, as well as a Klingon crew and Cardassian crew are all in competition to independently solve this mystery, hoping for gold or secret mega-weapons.
They all solve the mystery at once and meet at the same place where the secret is finally activated: It is a hologram of a proto-humanoid, describing(in English) how their race seed
Re:Alien life would be quite different from Star T (Score:5, Informative)
You do realize that only the humans in Star Trek spoke English, right? Everyone used universal translators to reduce communications problems. They just didn't portray it the way some other sci-fi has; for instance, in the movie Dune, in the first scene, when the Guild Navigator meets with the Emperor, his helpers speak first using a mechanical device that translates their language, and you can hear both. Star Trek just eliminates that for budget reasons and to avoid distracting viewers.
Besides, 300+ years in the future it's quite possible we won't be speaking English at all, or it might be very different from what we speak now. With any sci-fi that's in English and set in the future, you might as well assume that all the dialog has been translated into modern English for the benefit of the reader. I believe the Dune series (set 10,000 years in the future) even explicitly says they use a different language, or several in fact, but the characters' dialog is still in modern English so that the author didn't have to invent a new language like Tolkein's Sindarin.
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You do realize that only the humans in Star Trek spoke English, right?
Well... humans and really nerdy Klingons.
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I have eyes, and I can tell you that what the show claimed to be starships flying in space and firing phasers were in fact actually models, with late 80s-quality special effects added on top in crappy NTSC resolution.
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My favourite example at the moment is Solaris (the book by Lem, not the new movie I've never seen or the old one I can't remember). In that example humanity has spent a lot of resources over a century trying to understand WTF is some connection between themselves and the alien/s and at that point even the human experts have trouble communicat
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And one planet has been identified (Score:3)
Just a factor of 2? (Score:4, Funny)
Star Control was right! (Score:2)
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Now where are the ruby worlds?
Alpha Centauri is the closest, but we need to trade the locations of at least three rainbow worlds to afford the lander upgrades before I'll even consider landing on those worlds.
Oblig. Arthur C Clarke quote (Score:5, Interesting)
Now this is an interesting number, for by a curious coincidence there are approximately a hundred billion stars in our local universe, the Milky Way. So for every man who has ever lived, in this Universe there shines a star.
But every one of those stars is a sun, often far more brilliant and glorious than the small, nearby star we call the Sun. And many--perhaps most--of those alien suns have planets circling them. So almost certainly there is enough land in the sky to give every member of the human species, back to the first ape-man, his own private, world-sized heaven--or hell.
How many of those potential heavens and hells are now inhabited, and by what manner of creatures, we have no way of guessing; the very nearest is a million times farther away than Mars or Venus, those still remote goals of the next generation. But the barriers of distance are crumbling; one day we shall meet our equals, or our masters, among the stars. "
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So for every man who has ever lived, in this Universe there shines a star.
Not universe.. galaxy..
"alien worlds" count not so interesting (Score:5, Interesting)
In a couple years kepler will have sufficient data so we can estimate the number of rocky worlds in habitable zones, that's what is most interesting to me. Once we find such worlds, we'd need to fund the type of probe that can analyze atmosphere, life as we know it does a very detectable transformation. Then step up our optical SETI efforts in those world's directions (they won't use radio waves, sorry microwave SETI dudes....)
Re:"alien worlds" count not so interesting (Score:4, Informative)
Drake equation++ (Score:2, Funny)
I recently had the misfortune of meeting some extraterrestrial aliens from outer space right here on earth.
I have not much time now, but I'll jot down what I can.
They were very enthusiastic. They explained how wonderful it was to find a planet with the temperature and the water and the magnetic field and the life and the intelligence and the technology and ... advertising(!?) .
They we're an ancient species, homeless since eons. They had been scouring space, looking for intelligent life that could scratch th
Re:Drake equation++ (Score:5, Funny)
Wider implications (Score:2)
That's just the number of possible planets in our galaxy. If you take a rough estimate of galaxies we can see as 500 billion, in other words a galaxy for every star in the Milky Way, and those are just the ones we can see.
Okay, 500 billion galaxies, 100 billion exoplanets per galaxy, which is probably conservative. I'm going to go out on a limb and say there's at least one other earth-like planet out there.
whatever (Score:3, Interesting)
everyone knows they'll ignore us until we have warp capability.
2 weeks to the Moon?
9 months to Mars? lol.
Galactic Explanetary Estimate? (Score:3)
Jeeze.
Why not just call it what it is?
An ass-pull number.
Re:Galactic Explanetary Estimate? (Score:5, Informative)
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I'm going to guess.... (Score:3)
100,000,000,001.
Hope I win!
640 Billion (Score:5, Funny)
Please don't start using Drake's equation (Score:3)
We have some data points on exoplanets... that's great and you can probably start estimating the numbers in the galaxy from that.
Right now someone is trying to come up with a way to estimate life or even intelligent life or even star spanning civilizations. Don't do that until we have actual data... please... Drake's equation has done enough damage.
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The satisfaction of knowing you were correct.
Your prize is... (Score:3)
I put my estimate in at 150 billion. What's the prize if I guess the closest?
Alien invasion!!! Blerg! We come in pieces, shoot to kill! Take me to your ladder!
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I was expecting Lrrr
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I put my estimate in at 150 billion. What's the prize if I guess the closest?
Please wait approximately 150 billion years while our galactic survey is completed. Meanwhile, you'll have to clear off, we're building a highway.
Re:I'll jump in (Score:4, Informative)
It doesn't matter, you lose, by a long shot.
(Which you learn when you read the details and learn that this only applies to worlds about 5x as big as earth. Everything smaller is left out of the estimate, and may result in the final number being as much as 5-10x higher).
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Then you've won the showcase showdown! Vanna, tell him what he's won ...
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Sorry, string bet.
Re:TPIR (Score:4, Insightful)
But with alien slave girls, amazons, and the like, wouldn't it be more aptly named "planet 'boobs'" instead?
Amazons? Then that would be planet "Boob".
Re:I'll jump in (Score:4, Informative)
And I would say that I happen to know for a fact, that there are at least 8.
Re:Fermi Paradox (Score:4, Interesting)
20 years or more ago we could have speculated that planetary systems were rare, thus life had few places to evolve on and that could have been a possible solution to the Fermi Paradox -- finding so many worlds deepens the Fermi Paradox.
Let us hope Fred Saberhagen doesn't have the correct answer to the question with his Berserker series of novels.
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2. Takeaway all the gas giants (a lot) but include the moons (not known).
3. Takeaway the ones without a proper magnetic field (and therefore pummeled with cosmic rays and solar particles).
4. Takeaway the ones that are not protected from asteroids by outer gas giants.
5. Takeaway the ones with environments that are too static for life to evolve beyond micro-organisms
6. Takeaway the ones with basic life fo
Re:Fermi Paradox (Score:4, Informative)
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This is just baseless speculation. I think it is fairly obvious that it probably isn't likely.
First of all, even if ET's were common, the galaxy (let alone the universe) is an enormous place. We're talking like all the matter put together in the galaxy is a couple grains of sand in a stadium. Even if you disregard problems like the speed of light, there is simply no reason to think an ET would have been anywhere near our planet.
Second, even if our solar system was a freaking interstellar highway, we probabl
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Am I the only one wanting to scream 'Fermi Paradox!' at the top of my lungs whenever the probability of extraterrestrial life is discussed?
Seems like a good guess.
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there is no Fermi Paradox yet, we've only learned how to use radio and light waves for comm in the last century and a half (discounting smoke signals and mirrors in the sun). Thus far, we've been searching mostly microwave frequencies for ET signals, but the smart thing for them would be to use light or even higher frequency waves (gain, effective radiated power). It's a bit early in the game to say there are no signs of any ET around us
Re:Fermi Paradox (Score:5, Interesting)
Or even some clever use of entangled particle pairs. (Simply because we haven't figured out how to use them for comm doesn't mean others haven't.)
Personally though, I think seti is looking for the wrong things.
Instead of trying to eavesdrop on the grey aliens ordering space pizza from planet foodcourtia, they should be looking for localized light displacements from known stellar markers, as caused by the huge gravitational eddies that several hypotherical FTL systems would make. Interstellar highways would show up on a sufficiently detailed map of the CBR because of the regular disruptions.
(This assumes something like an albucare (however you spell his name...) warp drive though, which create a wave of negative spacial curvature behind the vessel, and a synthetic gravity well in front.)
Our current CBR maps are pretty coarse, since we are dealing with single measurement devices with very wide frequency emmisions, so a highway search would require interferometry to be fruitful. We need to launch about 50 more COBE sats up.
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Am I the only one wanting to scream 'Fermi Paradox!' at the top of my lungs whenever the probability of extraterrestrial life is discussed?
I suspect there are lots of people signalling "Fermi Paradox' all over with smoke signals, but I use the Internet now, so I never notice.
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It strikes me that the likelihood of other life out there somewhere is probably very, very high. In fact I'd be surprised if the galaxy isn't teeming with simple life. The question is more one of technological life (not 'intelligent', as some think, or even tool users - they have to be progressive tool users getting more advanced with time). It's really hard to make any useful estimates about the chances of technological life developing somewhere, but I think it is clear that it is not inevitable from any g
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You have absolutely no evidence to back up this assertion; your argument, then, fails utterly.