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Looking For Aliens In All the Wrong Places
LtFiend writes "Evidently, some astronomers believe that SETI is searching the skies for the wrong type of signal. This new telescope built by Harvard will search for laser light and can detect pulses " as short as a billionth of a second." Looks like we'll need a new version of SETI at home so we can help with
this one."
Now certainly I may be way low -- it HAS been 65 million years from the last major planetary event that caused a mass extinction, but even if you start pushing the timeframe of humans up to 100,000 or a million years, you are still talking about blinks of an eye relative to the estimated age of the universe. But again, the key thing is that one takes the assumption that races might die out -- if you assume otherwise, then yes, as the age of the universe increases, the chance for finding life should increase also.
"Pinky, you've left the lens cap of your mind on again." - P&TB
"I can see my house from here!" - ST:
I'm not saying SETI should be shut down -- because there is the possiblity we'll get something and all these arguements are moot. But it's more just looking at the big picture and realizing that we might just be shooting pot shots into space.
"Pinky, you've left the lens cap of your mind on again." - P&TB
"I can see my house from here!" - ST:
It wouldn't bend around them, radio waves would pass through them. Radio waves tend to be too low of an energy to be picked up by atoms to induce electrion jumps, so they'll pass through objects with no problem (that's why you can get radio and attenna TV inside a house) .. although with a planetary-sized body there will be some distortion. Light waves, on the other hand, are easily picked up by most metallic substances, and therefore will be absorbed.
"Pinky, you've left the lens cap of your mind on again." - P&TB
"I can see my house from here!" - ST:
And the next step up from galaxies is "galactic cluster", where again it's suggested there's some central object which several galaxies tend to gather about, but certainly not as strong that keeps planets in orbit or stars in orbit.
"Pinky, you've left the lens cap of your mind on again." - P&TB
"I can see my house from here!" - ST:
I think the only thing we can safely say about extraterrestial life is that if we are going to find any with sufficient technological progress within the 'lifetime' of humankind, it will have to be from a very small cluster of stars near us, which might have been formed near the same time after the big bang, such that planets capable of supporting life would have all started the evolution timer at the same point. But again, that rate of evolution is so different that the chances of us seeing one another would be very very high.
What I think we should focus on more (and it would be hard to say if we will be able to) is to look for the evidence of early life (single celled protozoa), or evidence of a race gone dorment, on other planets in the nearby cluster. Finding such would at least tell us that the development of life was not a chance happenstance on Earth.
"Pinky, you've left the lens cap of your mind on again." - P&TB
"I can see my house from here!" - ST:
Anyone remember a comic book from the late '80's called "Stray Toasters"? It was about a demon that took a vacation from Hell in New York, and started messing with some really deranged people, lawyers, etc. "Toasters" were demons. (well, it's what they do, right? stick ya with a pitchfork, and hold you over the flames. . . )
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
In human years:
5,000,000 BC
An alien race has evolved intelligence, develops technology and decides to attemtp to contact other intelligent beings using broadcast radio signals.
4,000,000 BC
Another alien race contacts the first race.
2,000,000 BC
These two races have build a huge trade confederation, and have discovered several other races. Humanity is not beyond their frontier, but has not been physically detected. At this point, humans are still spearing wooly mammoths. Several other pre-technological races have been discovered and were nurtured until maturity, when they could join the confederation.
1,000,000 BC
Huge interstallar war wipes out most civilization.
100 BC
On one planet where civilization survives, a new, conservative, isolationist government comes into power. They cease all contact with alien planets, they cease broadcasting.
1900 AD
Humanity has developed into an intelligent, industrialized society on the verge of technological advancement.
2000 AD
Humanity has been listening to the heavens and broadcasting signals, in hopes of contacting an alien race.
2100 AD
A violent civil war on Earth resulted from a combination of depletion of natural resources, destruction of the environment, and massive copy-protection schemes. Humanity is nuked back to the stone age. Both consumers AND business loses. Global warming melts the ice caps, and floods the continents killing all surviors.
2501 AD
A violent civil war on the alien planet unseats the traditionally conservative isolationist government. The new regime soon resumes broadcasting and listening for signals.
2,000,000 AD
Alien archeologists find evidence of a past civilization on a small planet, which was located just a few light years away from one of the main trade arteries of the old confederation. The surface is covered with ice, beneath the crust lie ruined cities, and craters, evidence of a massive nuclear conflict. Scientists are still unable to decode the contents of data disks recovered from one of the sites; almost as if the data were purposely scrambled. No big loss, since it was a copy of Titanic on DVD.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
While such a thing may be technically possible, these guys seem to be glossing over some very big problems.
1. Optical communication across interstellar distances is going to suffer from severe extinction (signal absorption by intervening dust). Even if you can generate a laser pulse brighter than the sun, interstellar extinction is a big problem to overcome.
2. A laser beam is very tightly confined, and would have to be aimed very precisely in order to "hit" it's target. The probabability that the Earth would just happen to cross one of these "lines of communication" is incredibly small.
So it seems to me that while optical commmunications could work in principal, radio is going to be much easier to work with, since you don't have to worry about extinction or pointing problems as much.
Shop Smart, Shop S-mart!
>My assumption is that the intelligent species out there aren't advertising their presence.
Interesting assumption. Too bad the only example we can test it against in the universe (ie, humans) violates it.
Violates it? Barely. How far are our radio emissions distinguishable from background noise? I thought it was only a few dozen light years. And IIRC, according to the recent Scientific American article on SETI a couple months back, although we could send directed communications for thousands of light years with an Arecibo, our current searches wouldn't detect an 20th century level civilization at any distance.
We make no attempt to hide our presence. It's pretty conceivable to me that other species could make the same "mistake".
Unless it really is a mistake. It could be that a sizable minority of species in the galaxy is both malevolent (in the sense that they would destroy weaker, expanding technological civilizations in order to avoid future threats to their own existance), yet hiding their presence (perhaps because they fear a more powerful, yet similarly hiding civilization). In such a scenario, any emerging technical civilization which did not adopt a hiding strategy would be toast before it was finished colonizing it's own solar system.
There's a cute Fermi's Paradox discussion on sci.space policy about all this, if anyone's curious. It's mostly died down, but you can check Deja.
Error: That's NRAO, Green Bank West Virginia.
(picky, picky I know, but we of WV descent are sensitive to being lumped in with them rebels over in Richmond).
try { do() || do_not(); } catch (JediException err) { yoda(err); }
The signal would be designed to technological
level of receiving race they desired.
Could be a relatively simple signal if they want
to reach a lot of races or very sophiscated if
they wanted a high tech level.
Humans would notice patterns in light signals
thousands of years ago; radio only 75 years ago;
and some known physics not yet.
Me, I'd just laugh about it. Welcome to the wonderful world of science, where you can't just flip the card over and look at the answer. Time and effort spent looking is rarely really wasted, even if it eventually turns out there was nothing to find. Pulsed laser beams is just another thing to try. Maybe we should be scanning through gravity waves, too. Who knows? Maybe any lifeform that has any real sense uses controlled quantized subspace variations to communicate over interstellar distances, and they figure no-one else is intelligent enough to talk to yet.
Are we likely to detect alien races using optical technology? For one thing most lasers are fired down itty bitty pieces of cable, not out to space, and for another, I can hardly imagine being able to detect an alien laser pen at a distance of over 4 light years.
One argument for the unsuccessful detection of radio using aliens has been that this technoly has such a short lifespan in comparison to that of a civilisation e.g. we started using radio about 100 years ago, and we're likely to stop within 30 or so years due to optical technology supplanting it.
The question is what is the likely lifespan of laser technology in the lifespan of a civilisation? How long will it be till we discover something other than coherent light to transmit messages etc ?
Donte Alistair Anderson Roberts - hi son!
Karma: Chameleon
Simply because laser radiation is detected, doesn't necessarily mean that an intelligent entity sent it. This article from the Goddard Space Flight Center describes natural laser radiation from the atmosphere of Mars (basically a sun-pumped CO2 laser). Similar findings have been observed in comets.
- Demosthenes
I always thought it was strange that they never looked at Orion, when it was so obvious... hang on... there's someone at the door...
My assumption is that the intelligent species out there aren't advertising their presence. Anyone worth contacting is probably dangerous.
--
Sheesh, evil *and* a jerk. -- Jade
RF searches are most likely to find someone who went through the same logic as us and have broadcast the same type of signal which we're looking for. Detecting leakage is less likely -- look at our broadcasting antenna farms, sending megawatts along horizontal planes to cover the Earth's surface; the Earth's surface is rotating, creating rotating beams which would flicker weakly across receivers every 12/24 Earth hours (plus 3 minutes).
We are most likely to hear dead ETIs. Anyone broadcasting will attract the script kiddies of the Milky Way -- assorted easy-to-create hardware with assorted purposes which is attracted to modulated signals. Any civilization with all its eggs still on its home planet won't survive any space-based intruders.
Spiced Milk Tea? I don't get it...
--
"It's tough to be bilingual when you get hit in the head."
1. Optical communication across interstellar distances is going to suffer from severe extinction (signal absorption by intervening dust). Even if you can generate a laser pulse brighter than the sun, interstellar extinction is a big problem to overcome.
Yes, extinction is going to be a consideration. But it's not all that hard to overcome. Look at it this way: If your laser pulse is 100x brigher than your sun on this side of the dust cloud, it's going to be 100x on the other side, too, even if both the sun's light and the star are both reduced by a factor of ten or whatever. They scale together. Anywhere you can see our sun from, and more, you could see our lasers. In fact, if you use a laser on the redder side of things, say even in IR, you're going to have much smaller extinction for your laser than for the star's light, and you'll win out even more in the long run.
Furthermore, radio signals suffer phase shifts and delays due to the intersteller medium. This tends to spread out a signal, originally sent at a narrow wavelength range, into a broader and fainter signal. You don't have this problem with IR or optical lasers, so that's a win for them.
2. A laser beam is very tightly confined, and would have to be aimed very precisely in order to "hit" it's target. The probabability that the Earth would just happen to cross one of these "lines of communication" is incredibly small.
Wah, major error! Time to go brush up on your optics some more. A laser beam does spread out as it travels, in exactly the same way and at exactly the same rate as radio waves do. Diffraction-limited optics is the same for all frequencies:
S = lambda/D*R
That is, the beam size is proportional to the wavelength, divided by the size of your transmitting telescope, times the distance the beam has traveled. For larger lambda (i.e. radio) you need to use a larger telescope to get as focused a beam - but we do that already, that's why radio telescopes are so much larger than optical ones. Besides which, you neglect the fact that it's *trivially* easy to send as wide a beam we want, just by de-focusing the telescope a little or using a smaller telescope. It's sending narrow beams that's hard! Wide is easy.
The long and the short of it is this: By the time ANY signal, radio, optical, or whatever, has traveled the many lightyears to some other star, the beam will have spread out to be *much* larger than the target solar system. This is true because all forms of light spread out the same way as they travel, and because it's trivial to send as wide a beam as we want just by de-focusing things a bit.
I don't see how this effects seti@home. The "pulsing light detector" sounds pretty strait forward. If you see a flashing light, you found something now go analize it. With radio there is all kinds of noise so you need a lot of computer power to look for something which you want to study in greater detail, hence seti@home. With this telescope, as soon as you see anything, it is worth studying in greater detail. Think of the logs...
1:00:00 AM - no signal
1:00:01 AM - no signal
1:00:02 AM - no signal
...
For my grade 12 english thesis paper, I wrote said paper on this very subject. Feel free to read it: Get Probed.
------------
CitizenC
This is the Harvard group's page.
Heh - maybe the Russians ran across a group of Western European tourist's kids & their Aibos out for a walk :)
you arent actually "looking around in the wrong places".. decoding of radio-signals has found quasars, and some other anomalies in space.. not *everything* has to be about BEM's does it?
Maeryk
Feminine Protection? What is that? A chartreuse flame thrower?
IMO man will never discover alien intelligence in the heavens because he doesn't really want to fidn it. If he did, he wouldn't dismiss the examples right here on earth.
It took 10 years of fighting to get much of the scientific community admit thatour higher ape relatives (chimps, gorillas, and such) possess all the fundemental intellectual capability of about a 5 year old human child. The fight over ape-signing being communication was the focal point of the debate and at the same time the defining exampel of this humanocentric bias.
Even more amazing, wild porpises have shown all the same basic behaviro patterns as humans (including social touchign and recreational sex, as an aside.) There have alsoi beene xperiments with porpises that **stringly** suggest they have their own fairly sophisticated language.
To admit we aren't alone woudl be to admit we aren't unique. That we are just one of countless natural variations on life, no better or worse then any other. This last bit of humano-centricity, that somehow we are "not animals" is a hard thing for many people to accept, even many "objective" scientists.
...doesn't this make sense? I mean, if they're far in advance of us, or even about par, who is to say that they did use or still use radio waves?
:) ), and how do we know that every life form would use SOUND as communication?
We came up with radio for the transmission of sound (at least, if I am wrong about that, don't kill me
Also, I hate to say it, but I mean, look at our planet and our people. If YOU were out looking to meet someone, and the first person you ran into was a raving loonie, attacking various parts of his/her own body/pod/gelatinous mass and still mired in the belief in some mystical deities... wouldn't you KEEP looking? Personally, I'd be willing to bet that aliens are out there looking at us like we are the little "challenged" kid down the block, and they are coming up with secret code to keep us from finding them out. And sooner or later they'll be like "Oh shit... they saw us... pretend you didn't notice and run back into your backyard, man... I don't want to hang out with MANKIND. They'll break all our toys."
Ceci n'est pas une sig.
'Zeelub, stop pointing your laser-pointer at Earth -- you're making the mammals excited.'
Room for all scans. We have an over-abundance of computing power to process these signals as is evident with sei@home. Why is searching using radio signals wrong? Once the sensors are built, there are millions of people willing to spend their cycles analyzing your data. I believe there is room for both projects, and many more.
Also, won't most stellar bodies block laser light , whereas Radio signals will tend to 'bend' around them?
Yep, I never spell check.
More incorrect spellings can be found he
Harvard University, said: "Using only Earth 2001 technology, we could now generate a beamed laser pulse that appears 5,000 times brighter than our sun, as seen by a distant civilisation in the direction of its slender beam.
What will it say? Make Money Fast? Send back a green flash if you want to be removed from our beam-list?
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
And by the way... we're listening, but are we transmitting? Is our usual EMF noise enough to clue an alien race in?
--
SO YOU'RE GOING TO DIE: The Comic for Dealing with Death
StarWars/SETI - communicate with aliens and blow up ICBMs!
First of all, not to complain or anything, but we still don't know enough about the natural universe to have any clue whether a billionth-of-a-second-long pulse of coherent light is natural or not.
Oh, no! I hope this experiment doesn't tell us more about the natural universe!
I disagree...with a sufficiently long message, and all other things being equal, it is no more or less difficult to determine how to reconstruct a message from a technical standpoint, whether that message is encoded digitally or in analog. ALL formats are completely arbitrary to someone who has no idea what you are trying to communicate. Consider, for example, analog NTSC television signals....there are many channels of data encoded in a "single channel": horizontal, vertical, color, sound, SAP, frame timing data, and captioning. And there are dozens of neighboring stations in the spectrum. And right next door is FM. And right next to that is cellular, CB, etc. Since a given TV signal is spread all over the place, how do you, a priori, determine where to start hacking the signal up? Which subsignals do you associate with each other?
It is a much more difficult problem when you have NO IDEA where to begin.
If we're just meat, then they are toasters.
I always used to call Data on ST:TNG "the toaster," which pissed off my wife. It's my preferred racial slur for intelligent machines.
"Sir, we have intercepted an alien recon pod."
"And?"
"It's full of toasters."
"Toasters?"
"Yes sir, small, chrome-plated machines with simple moving parts and heating elements."
"You're telling me that toasters dropped a rock on New York?"
"That is the lab's unfortunate conclusion, sir."
[by Terry Bisson; originally appearing in OMNI Magazine]
Imagine if you will... the leader of the fifth invader force speaking to
the commander in chief...
"They're made out of meat."
"Meat?"
"Meat. They're made out of meat."
"Meat?"
"There's no doubt about it. We picked several from different parts of
the planet, took them aboard our recon vessels, probed them all the way
through. They're completely meat."
"That's impossible. What about the radio signals? The messages to the
stars."
"They use the radio waves to talk, but the signals don't come from them.
The signals come from machines."
"So who made the machines? That's who we want to contact."
"They made the machines. That's what I'm trying to tell you. Meat made
the machines."
"That's ridiculous. How can meat make a machine? You're asking me to
believe in sentient meat."
"I'm not asking you, I'm telling you. These creatures are the only
sentient race in the sector and they're made out of meat."
"Maybe they're like the Orfolei. You know, a carbon-based intelligence
that goes through a meat stage."
"Nope. They're born meat and they die meat. We studied them for several
of their life spans, which didn't take too long. Do you have any idea
the life span of meat?"
"Spare me. Okay, maybe they're only part meat. You know, like the
Weddilei. A meat head with an electron plasma brain inside."
"Nope. We thought of that, since they do have meat heads like the
Weddilei. But I told you, we probed them. They're meat all the way
through."
"No brain?"
"Oh, there is a brain all right. It's just that the brain is made out of
meat!"
"So... what does the thinking?"
"You're not understanding, are you? The brain does the thinking. The
meat."
"Thinking meat! You're asking me to believe in thinking meat!"
"Yes, thinking meat! Conscious meat! Loving meat. Dreaming meat. The
meat is the whole deal! Are you getting the picture?"
"Omigod. You're serious then. They're made out of meat."
"Finally, Yes. They are indeed made out meat. And they've been trying to
get in touch with us for almost a hundred of their years."
"So what does the meat have in mind?"
"First it wants to talk to us. Then I imagine it wants to explore the
universe, contact other sentients, swap ideas and information. The
usual."
"We're supposed to talk to meat?"
"That's the idea. That's the message they're sending out by radio.
'Hello. Anyone out there? Anyone home?' That sort of thing."
"They actually do talk, then. They use words, ideas, concepts?"
"Oh, yes. Except they do it with meat."
"I thought you just told me they used radio."
"They do, but what do you think is on the radio? Meat sounds. You know
how when you slap or flap meat it makes a noise? They talk by flapping
their meat at each other. They can even sing by squirting air through
their meat."
"Omigod. Singing meat. This is altogether too much. So what do you
advise?"
"Officially or unofficially?"
"Both."
"Officially, we are required to contact, welcome, and log in any and all
sentient races or multibeings in the quadrant, without prejudice, fear,
or favor. Unofficially, I advise that we erase the records and forget
the whole thing."
"I was hoping you would say that."
"It seems harsh, but there is a limit. Do we really want to make contact
with meat?"
"I agree one hundred percent. What's there to say?" `Hello, meat. How's
it going?' But will this work? How many planets are we dealing with
here?"
"Just one. They can travel to other planets in special meat containers,
but they can't live on them. And being meat, they only travel through C
space. Which limits them to the speed of light and makes the possibility
of their ever making contact pretty slim. Infinitesimal, in fact."
"So we just pretend there's no one home in the universe."
"That's it."
"Cruel. But you said it yourself, who wants to meet meat? And the ones
who have been aboard our vessels, the ones you have probed? You're sure
they won't remember?"
"They'll be considered crackpots if they do. We went into their heads
and smoothed out their meat so that we're just a dream to them."
"A dream to meat! How strangely appropriate, that we should be meat's
dream."
"And we can mark this sector unoccupied."
"Good. Agreed, officially and unofficially. Case closed. Any others?
Anyone interesting on that side of the galaxy?"
"Yes, a rather shy but sweet hydrogen core cluster intelligence in a
class nine star in G445 zone. Was in contact two galactic rotations ago,
wants to be friendly again."
"They always come around."
"And why not? Imagine how unbearably, how unutterably cold the universe
would be if one were all alone."
However, it also once again emphasises the we need to take a somewhat more proactive approach and not just receive from systems that are possible targets for life, but also send out. After all someone has to be the initiator of conversation, and who's to say there is life out there, but they too are just listening and not sending.
Marxism is the opiate of dumbasses
10 years later: What alien would use light? Use quantum particles.
10 years after that: What alien would use quantum particles? Use antimatter.
10 years after that: What alien would use antimatter? Use quark synthesis.
Eventually we're just going to find we should have been searching for bacteria on fallen meteorites.
-
-Be a man. Insult me without using an AC.
- I don't care if they globalize against free speech. All my best free thoughts are done in my head.
I think it is obvious that Hemos is an alien and is trying to throw us off the trail...
Sashdotters, I say install SETI@Home on every system you get near, someone write a nasty little email virus that installs the software... lets track those aliens down and EXPOSE HEMOS!
I am become Troll, destroyer of threads
Another element is that some forms of encryptions are designed to make your data look indistinguishable from noise. Granted that in certain situations (such as politics) this is a naturally occuring phenomena. But in any case, this make detection much more difficult.
Think of space aliens trying to decode all of those encrypted transmissions that we might be seeing from HDTV in a few years. it certainly would not show up in the clear.
Now we try to apply this to projects like SETI. We might have any number of very bright "noise" sources that are actually quantum transmitters for the Server planet of the Western Galactic Gamers Conglomerate (or whatever). and because we haven't paid our subscription fee, we do not get in to play the game.
Needless to say, we would have a long time trying to decode the transmission.This is without even hazarding a guess about what galactic politics is like. We could be in a back water that recently got wiped by some sort of war. We could be in some one's nuetral zone. etc etc etc
the possiblities are endless.
"It is a greater offense to steal men's labor, than their clothes"
Even if they did, laser based communication is likely to be line of sight so any aliens using this technology will be aiming the beams at their detectors. For us to detect the beam either they'd have to miss and hit us accidentally, or we've got to be within the spreading path of the beam behind the target, or we've got to detect it reflected off interstellar dust or something (which would radically reduce it's brightness).
So now we've got plans to look for intelligent life that sent a message directly to us, to a precise location in the cosmos (that wasn't blocked by a star, planet, gas cloud, etc), during a certain period of time, using a given range of the electromagnetic radiation spectrum, and in a format that we could decipher. Ya right. I'm holding my breath for this one.
Maybe not signals. Maybe software.
It's a conspiracy to implant software into everyone's computers. You know, the RIAA-at-home client.
I'll see your senator, and I'll raise you two judges.
Maybe the other side of the conversation doesn't think of 1000 years as such a long time. Sort of like the annoying delay to talk to, say Jupiter from Earth.
Depends on how fast their brains work. Or other factors could influence their perception of time. Maybe depends on what their brains evolved to accomplish.
I don't know. I'm only guessing. But could a being's lifecycle be more like what we would call a "geologic" time scale? Maybe there are reasons that preclude this as a possibility?
I'll see your senator, and I'll raise you two judges.
"They believe a technologically advanced race might be more likely to communicate using pulsed laser beams rather than radio. "
So, are they sayingis that "advanced races" use a high tech version of morse code. This raises a problem. This implies that the signal is in some unknown Base (binary being base 2) and is encoded in some unknown format for transmission, possibly encrypted by default.
So, lets assume for the sake of arguement that we do find pulsating light that shows some form of pattern, there is pretty much no chance we would have any idea what it's saying and we would have no ability to respond. At least with basic radio signals, like TV and Radio, you can easily reverse enginner the signal...assuming thats not encrypted too (I remeber watching a discovery show where the kid who invented the TV was watching RCA's transmissions to see how far along they were, before he went public). Thus we would have a better chance of being able to respond to them, if it's a local (100 Light years) species.
Burn Hollywood Burn
This article is quite silly. Laser light communication would be excellent for communicating to a civilization - but only once you knew where they were. The problem with lasers is that they are highly directional. you need to point them in the direction you want to make a broadcast to and then send you're message. This would entail that any aliens sending out a general "hello and welcome to the club" message, or even just the ambient signals of their civilization, would need to have established the exact position of our planet from very far away.
Think about how many stars are visible to the naked eye - hundreds of thousands. Then think about how many are visible through high powered telescopes - millions. now think of the task of analyzing each star to establish to a high degree of accuracy its particular movement so that you can know exactly where it will be in the thousands of years in the future when your signal will actually arrive at it. And even once you'd done that you'd have to broadcast in such a wide area around the stars position such that the signal could be received by any orbiting planets. That's a computational job on a scale many millions of times greater than simply sending out an all points radio broadcast. and radio waves still travel at the same speed as laser light.
Plus with a laser the beam is so narrow that any dark matter ( think planets, large dust / gas clouds ) which might float by in the time between broadcast and receipt, and happen into its path could block the signal or alter its direction in uncalculable ways.
Overall radio is much more efficient for sending out a general "welcome to the sentience club - wanna play the swap ideas game?" type message.
There are a thousand forms of subversion, but few can equal the convenience and immediacy of a cream pie -Noel Godin
Okay, this is great...
r /e lectromagnetic.html
* Split Infinity Music
First of all, not to complain or anything, but we still don't know enough about the natural universe to have any clue whether a billionth-of-a-second-long pulse of coherent light is natural or not.
After all, "laser" light is a natural phenomenon we have learned how to produce and control at will. It stands to reason it may be naturally produced without any intelligence. If you apply the same "intelligence has just gotta happen sometime" standard used by Carl Sagan, so coherent light oughta happen spontaneously at least somewhere, sometime.
The only reasonable way to PROVE it isn't natural is to detect an intelligent pattern embedded in it.
So here's my question: If you only pick up a signal a few billionths of a second in duration, just how much data can be fit there to prove intelligence?
If you look at the electromagnetic spectrum, and presume they'll be looking for light somewhere near the visible spectrum (which is a bad idea for transmission efficiency anyway), and assume that you have to modulate the "carrier" frequency to transmit some data, I calculate that you could fit at most several tens of thousand of bits in a pulse that short. That sounds like a lot but it may be hard to fit (or in our case FIND) a lot of meaning in that kind of pulse.
A good light primer can be found here:
http://micro.magnet.fsu.edu/primer/lightandcolo
What's wrong with this picture?
* ~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
--Brandon / Split Infinity Music
The strangest part of this entire article is the last paragraph.
In October, 1989, a Russian news agency reported that scientists claimed to have established that a city in the former Soviet Union had been visited briefly by a spaceship crewed by three feet tall humanoids and a robot.
The whole article is about using a telescope and computers to look for aliens on distant worlds, then at the end we learn that they have been hanging out in Russia all this time!
The Harvard group postulates that we are much more likely to be contacted by aliens via laser, or other tight-beam system, as the narrower beam width would require less power (makes more effiecient use of power). This theory is right on the money--if the aliens are deliberately trying to contact us. Much more likely, however, is that we would pick up extraneous signals intended for their own use. For those who have seen Contact, think about how the otherworlders discovered us--they picked up the first signal we radiated into space with any significant power. We weren't trying to contact anybody, just send TV across the ocean; that the signal was radiated into space was merely a consequence of using radio as the method of transmission. Because radio signals tend to scatter, especially on that older technology, the signal was radiated in all directions, including "up." Detecting that accidental emission, the aliens determined that there was life on our planet. It is less like communication (a deliberate two-way discourse), and more like Signals Intelligence (SIGINT). And (don't all raise your hands at once) who knows who the leader in SIGINT is? The NSA! Odds are, the NSA is going to discover the signal before SETI, NASA, or any others. I don't mean to suggest that they will discover life--in my opinion, that is highly unlikely, simply because those aren't the types of signals NSA looks for--it would likely be chalked up as noise, and they would go back to monitoring Chinese satellite traffic. I am only saying that they would likely be the first to receive (detect) the presence of the signal. It would have to be analyzed in the proper context (enter SETI) to be recognized for what it is. The ultimate dream system for SETI would be to use the Areciebo (sp?) dish, the VLA, etc, as well as NSA's resources, use NSA's signal-detection and -processing systems, then use their own analysis tools. Imagine what a powerful combination that could be!
The point here is that we are far more likely to detect an alien civilization by listening for spurious emissions (SIGINT) than by searching for signals deliberatly aimed at us. In order to detect a laser aimed at us, we would have to examine every star capable of supporting life (same as with SIGINT), but they would also have to aim the signal at us deliberately--that is, they would have to have already detected us and decided to try to contact us. Think about that from their point of view--if you worked for SETI or NASA or others, would you be shining lasers into space to try to communicate with other planets that may or may not have life and may or may not be listening and may or may not even understand what they are looking for? I know I wouldn't, and I'm a supporter of SETI. Realistically, listening for broadcast signals is much more likely to yield results than looking for tight-beam communications.
Incidentally, I didn't bring up the NSA to suggest any sort of conspiracy, just to discuss the equipment differences. And, no, I really don't believe the US Government has been hiding aliens at Roswell for the last 40 years. To almost-quote Dave Barry, it isn't that I don't believe that aliens might have crashed at Roswell, I just don't believe that our government could successfully run a cover-up for that long.
"Make it ten--I am only a poor corrupt official."
--Captain Louis Renault (Claude Rains), Casablanca
What I didn't understand, was why in the world did that article contain the bit about Russian scientists claiming evidence of: three foot tall humanoids and a robot???!!! That had almost nothing to do with the article and was from 1989! I wonder what prompted the writer of the article to throw that in?