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Looking For Aliens In All the Wrong Places

Hemos posted more than 13 years ago | from the look-pnub-in-too-many-places dept.

Space 189

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."

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The situation is not that confrontational (1)

Anonymous Coward | more than 13 years ago | (#490555)

The media tends to like controversy because it sells better. None of the SETI researchers has claimed that "SETI is searching the skies for the wrong type of signal". Horowitz, who is building this all-sky optical search, has been doing microwave SETI for decades. He is the genius behind the META and BETA searches. Just because people are now exploring the optical regime does not make microwaves a less likely place to find an alien signal. All it means is that the researchers are trying something new. Why try something new? Because our technology has advanced to a point where they can. Also because the researchers get bored with old ways and want to try something different. It can get pretty monotonous doing the same kind of thing year after year with no positive results.

Re:Extraterrestial Life and the Cosmic Time Scale (2)

Masem (1171) | more than 13 years ago | (#490557)

I'd based 20,000 years on the assumption that there are things like planet-scale distasters that a race cannot avoid - meteors from space, killer radiation from local stars going nova - in addition to the fact that based on even primitive life on earth, there would always appear to be a "only the strong survive" drive to survival, and whether that means that two warring tribes of the same race wipe each other out with sticks or nuclear weapons, it still suggests that there will always a possibility for self-destruction of one's race.

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.

Re:Extraterrestial Life and the Cosmic Time Scale (2)

Masem (1171) | more than 13 years ago | (#490558)

With the only senses that we can trust: sight and touch. We have to GO and find these things, and that means space exploration. In the 2nd Millenium and the beginning of the 3rd, this is certainly not a big priority, but maybe by the year 2500, we'll have the technology that will allow a reasonable way to explore nearby star systems and look for signs of life, whether active or not.

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.

Extraterrestial Life and the Cosmic Time Scale (4)

Masem (1171) | more than 13 years ago | (#490561)

I rewatched 'Contact' this weekend, and it gets me to thinking on what chance we have as the human race (as in, over the next several millenia) will have in encountering a non-extinct, developed alien race. Humankind has only been around on the order of 10,000 years, and we'll probably have at least that coming in the future, but 20,000 years on the cosmic scale is a blink of the eye. Assuming that other races have similar 'lifespans', it may be easy enough to miss them because we started too late or too early. For example, we know that there's a narrow band where liquid water could exist on a planet based on our sun; what if earth's orbit was a few thousand kilometers closer: would life have developed a bit faster, and maybe humankind would have rose out 100,000 years earlier? Or mnay it would have been slower and we wouldn't be talking about this for yet another 100,000 years. And that's just earth we're talking about -- in any other solar system you'd have to worry about the same facts.

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.

Re:I have to disagree with the article (1)

JetJaguar (1539) | more than 13 years ago | (#490564)

Yeah, there will be some beam divergence, and, as another poster pointed out, if you have a large distance, the beam size can be pretty big. But in astronomical terms, I don't think the beam could get that big before extinction would would completely absorb the beam, or reduce the signal strength to such a level that it's pretty near impossible to work with.

Alternatively, if you were to go down into the IR, you'd at least have a better chance of the signal getting through (less extinction in the IR), but you still have the problem with the beam size being pretty tight, as well as the need to be looking at the right place at the right milisecond.

I have to disagree with the article (3)

JetJaguar (1539) | more than 13 years ago | (#490567)

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.

Re:Extraterrestial Life and the Cosmic Time Scale (1)

evand (2571) | more than 13 years ago | (#490568)

Humankind has only been around on the order of 10,000 years

This is a common culture-centric idea, albeit a false one.

Homo erectus is currently thought to have arisen about 1.8 million years ago, and existed until about 400,000 years ago. Homo sapiens neanderthalensis, though possibly not a direct ancestor of "modern man," is very similar to our species and probably lived from about 300,000 years ago to about 30,000 years ago. You and I, homo sapiens sapiens, which I assume to be your "humankind," are thought to have appeared about 120,000 years ago.

Every Geek's Dream (1)

Mr. Frilly (6570) | more than 13 years ago | (#490571)

Kudos to Andrew Howard (my former roomate)! You know you've hit it big when your thesis work is getting written up on slashdot.

Then again, he's making the rest of us researchers look like a bunch of slack-jawed yokels.....

Loening

bending light (1)

prok (8502) | more than 13 years ago | (#490572)

Also, won't most stellar bodies block laser light, whereas Radio signals will tend to 'bend' around them?
What? Radio waves and light and just different parts of the spectrum. Both are subject to the influence of gravity.

Re:My Grade 12 Thesis Paper Was On This Very Topic (2)

ch-chuck (9622) | more than 13 years ago | (#490573)

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).

Optical Aliens (2)

maroberts (15852) | more than 13 years ago | (#490581)

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 ?

Heh (1)

Rainy (17894) | more than 13 years ago | (#490583)

When I saw the title 'looking for aliens in wrong places' I almost expected the article to say 'after spending millions and millions of dollars to search the sky for aliens, first alien was actually found behind the sofa pillows.' And then I thought 'But how would it get there?'

Who to contact? (3)

Black Parrot (19622) | more than 13 years ago | (#490586)

My assumption is that the intelligent species out there aren't advertising their presence. Anyone worth contacting is probably dangerous.

--

Look to ourselves for answers first. (1)

NeTG0D (21707) | more than 13 years ago | (#490587)

The one thing that truely strikes me as odd about both the previous search for radio signals and now the search for laser bursts is while "guessing" at what an intelligent and advanced species might use to communicate we ignore the technology on our own world.

Right now we have people researching how to use quantum technology for both instantaneous communication as well as encryption. This technology is hard to evesdrop on in the first place, and if you do you can destroy the message due to the basic laws of quantum physics.

If we "primative" humans are researching this why wouldn't another race elsewhere in the universe be using something similar, or more likely more advanced?

Re:Wrong method??? (1)

Smallest (26153) | more than 13 years ago | (#490590)

Well, why don't we just look for little green men on mars

No way. We want the giant green women!!!

-c

Re:great... (1)

SEWilco (27983) | more than 13 years ago | (#490591)

You can bet that of people who hear of this project, those who are the equivalent of CB burpers will be waving laser pointers at the Moon and random satellites. If we had megawatt lasers easily available, by now someone would have etched "Hi Mom" across the Moon.

Re:Its a good thing I never joined the project (2)

SEWilco (27983) | more than 13 years ago | (#490592)

Well, it's no more a waste than using CPU time to animate an aquarium screensaver.

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.

Look in.... (1)

macdaddy (38372) | more than 13 years ago | (#490594)

Canada. Canadians are a cross between an Arkansas inbreed and a promiscuous Whitehoue intern while taking a mix of Viagra and estrogen shots.

--

no change for SETI@Home (2)

DzugZug (52149) | more than 13 years ago | (#490599)

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
...

A nasty little email virus ?!? ... just wait (1)

lildogie (54998) | more than 13 years ago | (#490600)

I still think we're crazie script kiddies
if we think it's a good idea to connect our
global internet to a radio telescope,
hoping some alien message finds its way in.

If we're lucky, they'll put up a little popup
window to tell us we're owned...

Re:Bury the lead! (1)

Cy Guy (56083) | more than 13 years ago | (#490601)

(Mod the parent of this post up)

Exactly!

Why bother communicating with the aliens on other planets when we haven't talked to the ones that are already on our planet.

Presumably if they have the technology needed for interstellar travel, they also are well aware of the proper protocols for interstellar comunications. Presumably the method of communication they use exceeds the speed of light (or it at least exceeds c as we perceive it) So using any method based on light or other EM spectrum will likely be fruitless.

Re:Not Wrong (1)

Cy Guy (56083) | more than 13 years ago | (#490602)

My question is how are they different. If a culture can send coherent EM transissions in the visible light range, then why wouldn't then send them in a variety of frequencies including the radio frequencies that SETI is already listening for.

I mean there is no REAL difference between "radio" and "light" is there? They're both EM particle/waves aren't they? (If I'm wrong please correct me, I've never taken a physics class in my life).

Is the sun blocking our search? (1)

CiXeL (56313) | more than 13 years ago | (#490603)

I've considered this possibility for a very long time though my idea was that the sun was possibly drowning out all signal that we could potentially capture. I mean really how difficult would it be for some naturally occuring process to interfere with radio broadcasts? I'm sure this has been thought of before but why has it never been brought up?

My Grade 12 Thesis Paper Was On This Very Topic (3)

citizenc (60589) | more than 13 years ago | (#490604)

For my grade 12 english thesis paper, I wrote said paper on this very subject. Feel free to read it: Get Probed [escape.ca] .

------------
CitizenC

alien life could be anywhere... (1)

andyschm (74188) | more than 13 years ago | (#490606)

SETI should also be using STM microscopy to look for sub-quantum alien worlds on the surface of electrons - its just as likely a location as deep space.

Re:IANAA (1)

bensej (79049) | more than 13 years ago | (#490607)

sound doesn't exactly travel well in near vacuums

The real site for Optical Seti is (4)

chriscappuccio (80696) | more than 13 years ago | (#490608)

www.oseti.org [oseti.org]

This is the Harvard group's page.

Re:advanced technologies (1)

Pulzar (81031) | more than 13 years ago | (#490609)

You are missing the main point, though. The idea is to discover if there is intelligence out there, we'll work on figuring out what they are saying later. SETI is trying to find ANY signal that looks to be artifically created. I'm sure that if we received Alien HDTV signal or the Galactic Quake login prompt, we'd know that it is a sign of intelligence, even if we didn't know how to decode it.

Re:Extraterrestial Life and the Cosmic Time Scale (1)

LordNimon (85072) | more than 13 years ago | (#490611)

Alright, say 100,000 years. Or 500,000 years. It doesn't matter. Anything less than 10,000,000 years is still a blink of the eye as far as the Universe is concerned.

But his point is more subtle: the chance of another civilization out there that is of comparable technological advancement as ours is practically zero. It's far more likely that they are either way more advanced or are a bunch of cavemen. If they are so much more advanced, then chances are they've known about us for a long time now, so they're ignoring us.

"But there could be millions of worlds out there, each with intelligent life." It doesn't matter - there would still be at least one world that is super-advanced compared to us, and already knows about us and all the other intelligent species out there.
--

cosmic rays (1)

Dalroth (85450) | more than 13 years ago | (#490616)

Hey, maybe cosmic rays are some really tightly encoded pulses of information being sent across the universe by other species? Maybe everytime a species figures out how to send out a cosmic ray pulse, they send their response then die out before ever getting a response back, therefore explaining the long periods between cosmic rays! Many species are constantly trying to communicate with each other all the time, they're just dying out before anybody actually can. :)

Um... (1)

Cyno (85911) | more than 13 years ago | (#490617)

No one know what the right signals are to look for since we haven't found anything yet!


Maybe your follow-up article should state how superstring theory isn't using the right equations because they can't be proved, come on edittors, you can be a little more creative than that.

Re:Its a good think I never joined the project (2)

Maeryk (87865) | more than 13 years ago | (#490619)

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

So how do we send a signal back? (1)

jimmcq (88033) | more than 13 years ago | (#490620)

Project leader Professor Paul Horowitz, of 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.
"In other words, interstellar laser communication is altogether practicable.


So we can communicate by shooting a really strong laser at nearby stars?

I can just see it now... "We come in peace!" ZAAAAAP!

Re:I have to disagree with the article (1)

CSG_SurferDude (96615) | more than 13 years ago | (#490623)

Yes, they spread, but when you have light years to do it in, it turns out to be pretty big. AND, there's nothing stopping them from setting up a laser-sat, and program it to zap the nearest 1000 stars every 1/10th of a second, and do so for many years.

The hard part is to watch for a RETURN signal.

Re:OT? You decide. (1)

compwiz3688 (98919) | more than 13 years ago | (#490626)

"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 Simpsons episode comes to mind...
"We'll just cover you with rum and nobody will believe you!"
---

How about on earth? (2)

catseye_95051 (102231) | more than 13 years ago | (#490627)

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.

Now... (3)

Raymond Luxury Yacht (112037) | more than 13 years ago | (#490629)

...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?

We came up with radio for the transmission of sound (at least, if I am wrong about that, don't kill me :) ), and how do we know that every life form would use SOUND as communication?

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."

great... (5)

.c (115916) | more than 13 years ago | (#490632)

'Zeelub, stop pointing your laser-pointer at Earth -- you're making the mammals excited.'

Re:bending light (1)

bluelip (123578) | more than 13 years ago | (#490634)

I was referring to actually being absorbed. If I sent a radio transmission in the direction of the moon, Some of the waves will go around it due to the waves not traveling in a straight line. With a laser, the light might be reflected, but it probably won't continue to move in any direction close to its original path.

Not Wrong (4)

bluelip (123578) | more than 13 years ago | (#490635)

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?

I remember that.... (1)

Therlin (126989) | more than 13 years ago | (#490639)

Funny you mentioned that. I was actually living in Spain that year and I clearly remember the story about the humanoids in Russia story being mentioned on a "News Break!"

They didn't say anything else later in the news that day.

Ouch! (5)

istartedi (132515) | more than 13 years ago | (#490640)

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?

Re:Extraterrestial Life and the Cosmic Time Scale (1)

Wraithlyn (133796) | more than 13 years ago | (#490641)

"but 20,000 years on the cosmic scale is a blink of the eye. Assuming that other races have similar 'lifespans'" ...

But why DO you make this assumption? I rather cling to the idea that so long as we don't blow up the Earth before we start interstellar colonization, humans will be around indefinitely. Of course we could be obliterated in an interstellar war with a xenophobic alien civilization down the line, but I digress.

The fact that so much time has passed (IMO) makes it far MORE likely that we will run into some advanced race who has colonized a substantial fraction of the Galaxy over countless millenia. Who would stop the first race to become advanced enough to attempt this? Nobody, unless another race is reaching the same technological levels at essentially the exact same instant in Galactic history, which is such a low probability it is almost absurd. (Which is one thing in Star Trek and almost all other pop sci-fi that is entirely contrived and hard to swallow, but hey it makes for a good story setting)

You've been watching Contact, I've been reading Asimov.. does it show? ;)

how about Gravity Waves? (2)

kisrael (134664) | more than 13 years ago | (#490643)

I was reading this short story by Niven (I think it was in N-Space, can't remember the title) that suggested maybe aliens would try to communicate using gravity waves... ('course that's assuming there is a possible way of controlling gravity, like the Tufts Gravity Stone [cwru.edu] thinks there is.) The story suggested Gravity's proogation would be less limited than light, radio, or other Electromagnetic principles.

And by the way... we're listening, but are we transmitting? Is our usual EMF noise enough to clue an alien race in?
--

Re:no change for SETI@Home (1)

superdan2k (135614) | more than 13 years ago | (#490644)

Actually, your log isn't going to be that simple. Like radio, light suffers from interference from things like gas clouds, other planetary systems, Vogon Construction Fleets, etc.

Furthermore, there's this thing called "Doppler shift" -- changing of wavelengths based upon the motion of the source in relation to the observer. The observer's motion also has an effect on this.

Furthermore, the difference between signal and noise is one of those things that has a huge grey area. The fact that you'll have coherent light is great...determining whether or not it's a signal is hard.

I'm sure someone's thought of it, but I wonder if anyone has bothered to create a Doppler-shift filter that accounts for Earth's orbit around the sun and axial rotation in relation to the target it's looking at? I suppose that the more crud you can filter out the better, but I'd be willing to bet that the horsepower for this might be a bit high. (Furthermore, without an *exact* fix on the location of the star, there's going to be room for ambiguity.

There's room for a PhD thesis in here.


----------------------------------------
Yo soy El Fontosaurus Grande!

Re:My Grade 12 Thesis Paper Was On This Very Topic (1)

yamla (136560) | more than 13 years ago | (#490645)

There are a couple of problems I saw immediately with your paper. Apart from the very casual writing style, you make a few factual errors. You seem unable to distinguish between galaxies and starsystems. You also don't identify the reasons behind any of the numbers in the Drake Equation. Ns is trivially incorrect. Fp looks suspicious, as does Ne and Fi.

Still, it is an interesting overview.

Lasers (2)

Dethboy (136650) | more than 13 years ago | (#490646)

So if this is so easy - why haven't we (Earth bound beings) built a laser that beams out??

StarWars/SETI - communicate with aliens and blow up ICBMs!

Re:IANAA (1)

Arcanix (140337) | more than 13 years ago | (#490647)

He was obviously talking about building a tunnel of air from their home planet to Earth and then communicating using sound waves.

Re:How much data can FIT in a billionth of a secon (2)

startled (144833) | more than 13 years ago | (#490649)

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!

Eureka! (1)

pmcneill (146350) | more than 13 years ago | (#490650)

"It's almost like they're pointing a flashlight straight at us!"
"That's a star, sir"

HUH? And thats different from Radio how? (1)

Srin Tuar (147269) | more than 13 years ago | (#490651)

The idea is not that they would be trying to communicate with us, but rather we would detect very old traces of aliens communicating with each other.

Faster than light? (1)

ritlane (147638) | more than 13 years ago | (#490652)

Here is something I've always been curious about:

Not too long ago, on /. there was a story about a researcher getting particles to travel faster than the speed of light. The odd thing about this is that if we have some idea that this is possible and we are trying to talk to a civilization with greater intelligence than us, wouldn't they probably use this technology.

I mean really, isn't the speed of light just a little too slow for your average space faring cell phone.

So what does everyone think? Do I remember my stories correctly? Is my physics sound?

What I'm picturing is one day we build a receiver for these faster than light signals, and we suddenly start to pick up all the alien communication signals buzzing around.


---Lane

Hello neighbour! (1)

stain ain (151381) | more than 13 years ago | (#490653)

There's a flat 200 meters from where I live, direct line of sight, it has a window and I see light when it's dark, about 12 the light is turned off, almost everyday.
Thinking about it, I got to the conclussion that there's some kind of intelligent life there (how clever!)
The point is that, I know someone lives there, but I will never be able to communicate with that someone because he/she is not aware of my presence, and we are 200 meters apart, too much.
Just think how impossible is to establish some kind of communication with an alien, living millions of light-years (or is it years-light?) away from us, so talking to an alien is impossible given the universe we live in, the limited speed of light is a big constrain.
Anyway, I have a SETI client installed; the fact that I know I have a neighbour living 200 meters away doesn't change anything, but it certainly would change things if I had the confirmation that there is intelligent life somewhere (oh! wait! there is intelligent life on the earth!).

Dissipation? (1)

TheFrood (163934) | more than 13 years ago | (#490659)

According to basic physics, a beam of light that is emitted from an aperture will widen over distance -- that is, the area of the beam's cross-section increases the further you get from the source of the beam.

Can someone who knows the math tell us something about this? I would think you'd want the beam to cover the entire solar system of the target star, or at least the inner planets, where a technological society would be more likely to live. What size of physical laser are we talking about here?

TheFrood

Re:OT? You decide. (2)

IronChef (164482) | more than 13 years ago | (#490661)

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."

OT? You decide. (5)

IronChef (164482) | more than 13 years ago | (#490662)

[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."

Just hope we're the target (3)

ocelotbob (173602) | more than 13 years ago | (#490665)

Now, correct me if I'm wrong, but isn't the point of laser communication the fact that the signal does not dissipate nearly as much as a regular beam of light? So it goes to argue that we'd never see the signal unless someone was pinging us to see if there was anybody on Ulmach or whatever they call our little stellar system.

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.

Re:Interesting but worthless (1)

Atticka (175794) | more than 13 years ago | (#490666)

your thinking earth terms, what if they have some other method of sending light that we havent discovered yet? or maybe a power source that doesnt make sending beams of light around the galaxy a big deal.

Its probably a good idea to scan the sky for almost any type of un-natural signal.

Atticka

why dont we... (1)

Atticka (175794) | more than 13 years ago | (#490667)

make as much noise as possible, what if other beings are listening for us? Along with listening we should be making some noise our selves, and lots of it. It might spark a response from some civilization to tell us shut the hell up!

Its a good think I never joined the project (1)

SnapperHead (178050) | more than 13 years ago | (#490668)

If I was on something like this for a long time and sudden found out that it was a complete waste, becuase of looking in the wrong place, I would be very pissed. But, as the article says, might be looking in the wrong place. We'll just have to wait and see.
until (succeed) try { again(); }

Then after that... (5)

Fervent (178271) | more than 13 years ago | (#490669)

Present: Radio signals? What alien would use radio signals? They'd have better technology than that, right? Use light.
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 Agree... (1)

jonfromspace (179394) | more than 13 years ago | (#490670)

...This paper (if one can call it that) is just plain silly. I especially liked his use of Scientific terms such as "Super-Fast"

BAH! (4)

jonfromspace (179394) | more than 13 years ago | (#490671)

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!

Practicable? (1)

Nos. (179609) | more than 13 years ago | (#490672)

In other words, interstellar laser communication is altogether practicable.

I don't know about you, but I think any conversation that takes 1000 years to get a reply isn't exactly practicable. The message would only be transmitted at the speed of light, which could take thousands of years to get here, depending how far away they were, then another few thousand for us to reply. I guess it would still be faster than the postal system.

Re:HUH? And thats different from Radio how? (1)

Nos. (179609) | more than 13 years ago | (#490673)

That doesn't seem to likely either, since a laser doesn't dissipate very much, they would have to be talking to someone that resides in the same direction as us.

advanced technologies (2)

Alien54 (180860) | more than 13 years ago | (#490679)

All one has to do is to check out the Dead Media website [slashdot.org] to get a sense of the huge variety of communication media and technologies that are no longer in use just on our planet alone.

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.

Re:Interesting but worthless (1)

jchristl (184275) | more than 13 years ago | (#490680)

which civillization will be so stupid to use light to cummunicate in open space??!!
We don't (and we humans are quite stupid).


Of which you are a good example of (stupid, that is). We humans DO use light as a form of communication. We need light to see, and to help form words on paper, by the act of absorption and reflection...

Re:Then after that... (1)

jchristl (184275) | more than 13 years ago | (#490681)

While I agree with you on most of this, I doubt that in 30 years we would have advanced that far. Moreover I believe that we'd be asking "Why'd we switch from radio to light?", while the aliens will be asking:

Why are they not using Light?
Why are they not using quantum particles?
Why are they not using antimatter?
Why are they not using quark synthesis?
Why are they not using harnessed 'Black-hole' energy?

Re:Just hope we're the target (1)

KjetilK (186133) | more than 13 years ago | (#490683)

Yeah, I was about to post the same thing, this seems weird (so mod the parent up! :-) ).

So, yeah, they might well be using laser beams, but if they were we would hardly see anything.

This seems so obvious I bet it's answered in somebody's FAQ, so if someone cares to dig, I'd like to be corrected.... :-)

Last paragraph of article? (1)

jdunlevy (187745) | more than 13 years ago | (#490684)

The last paragraph of the CNN article [cnn.com] :

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.

Huh? Apropos what?

Slightly flawed assumption (1)

dstone (191334) | more than 13 years ago | (#490685)

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. (Let's put arguments of humans being "intelligent" aside!) We make no attempt to hide our presence. It's pretty conceivable to me that other species could make the same "mistake".

Anyone worth contacting is probably dangerous.

Now that might be true. But let's find the signal first and decide later if we want to contact them. The discovery of other life, dangerous or not, will be fantastic and change our point of view forever. Not to mention, we might learn a tidbit or two from their signal.

Misguided misdirection (1)

ThomK (194273) | more than 13 years ago | (#490688)

San Jose? Don't they have bigger fish to fry right now?
Maybe they should build a telescope to look for power.

Wrong method??? (1)

OtaconX (199675) | more than 13 years ago | (#490689)

Well, why don't we just look for little green men on mars, we'd have a better chance of finding intelligent life there, anyway... And while we're on the subject, we need to search for other intelligent life, because there is none on this planet to speak of.....besides us geeks that is...=)

Re:OT? You decide. (1)

OtaconX (199675) | more than 13 years ago | (#490690)

LOL

That's hysterical.
hmm, but just think about it, if we are just 'meat' to them, what would they be to us?
And who's to say that they aren't just 'meat' to some other race above them...

We'll show them, let's make contact with their superiors and get 'em fired. It works when you get a bug in your quarter pounder, right???

Wait just a minute here... (2)

CraigoFL (201165) | more than 13 years ago | (#490691)

Optical SETI plans to look for messages encoded using a laser... meaning that the message would have to be beamed directly at Earth (even directly at the telescope itself) for it to be seen? Please correct me if I'm wrong, but the laser beam (being unidirectional) would have to be specifically intended for us to before we'd know it was there. At least the radio waves that the original SETI was looking for were omnidirectional (ie: an alien intelligence could have blasted a message to no one in particular and we could have picked it up).

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.

Re:Just hope we're the target (1)

DickBreath (207180) | more than 13 years ago | (#490695)

Wouldn't it be easier to get funding just to listen for signals rather than sending them?

Some other civilization can go to the trouble to get funding for sending signals to us.

Re:Beware! (2)

DickBreath (207180) | more than 13 years ago | (#490696)

Maybe not signals. Maybe software.

It's a conspiracy to implant software into everyone's computers. You know, the RIAA-at-home client.

Re:Optical Aliens (2)

DickBreath (207180) | more than 13 years ago | (#490697)

As communications technology keeps changing, so will our focus on what we should be trying to detect from another civilization.

Maybe other civilizations would realize that if radio is one of the first technologies developed, that they should merely augment what kind of signals they listen for and transmit. Continue broadcasting and listening for the "primitive" radio signals as that is the least common denominator. Something you expect the other side to have in common. Like PI.

It almost makes me think of them sending a signal so complex or a math problem so hard that we can't decode it or solve it. Wouldn't you rather expect a simple puzzle, recognizable to someone who evolved differently? Similar for the kind of signals they might send.

Since radio signals are the "first" signals out there, leading optical signals by at least dozens of years, they are most likely to be detected first. Shouldn't you keep sending them and listening for them? (Even if you start listening for lasers, etc.?)

Finally one last reason, radio signals are probably the only kind of signals that other civilizations are capable of sending legally. Wouldn't their equivalent of the RIAA/MPAA make more advanced forms of communication illegal?

Re:Practicable? (2)

DickBreath (207180) | more than 13 years ago | (#490698)

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?

Re:Extraterrestial Life and the Cosmic Time Scale (3)

DickBreath (207180) | more than 13 years ago | (#490699)

Interesting thought.

But you raise a huge question. You suggest that we should start looking for something else. But you don't suggest how.

Specifically, using current technology, how would you look for signs of early life or past life? What phenomena would we be trying to detect using what kind of instruments?

Again, I don't think your idea is bad, I just don't see how it can translate into practical action.

Any ideas?


You can kill the revolutionaries, but you can't kill the revolution. Thus leaving a revolution that is carried out by non-revolutionaries. So why have a revolution?

Re:I have to disagree with the article (3)

DickBreath (207180) | more than 13 years ago | (#490700)

Don't laser beams spread apart, just very slowly? Don't lasers have ratings of divergence that are measured in extremely small angles? I'm no expert on this. I just recall seeing HeNe lasers in Edmund Scientific that had a "divergence" or somesuch measured in some thousanths of a radian or something. Many years ago.

Re:How much data can FIT in a billionth of a secon (1)

BlueJay465 (216717) | more than 13 years ago | (#490705)

If we add up all the data that this new optical telescope over the most complex equations and algorithms that scientists can muster, will we get an answer of....42?

Re:I have to disagree with the article (1)

!usr-bin-parrothead! (219104) | more than 13 years ago | (#490706)

Also, for #2, not only would Earth have to cross one of the small lines of communication, the line would have to land on the telescope as it spins around with the Earth, and it has to be on a clear night!
If I didn't get a "C" in my statistics class, I might be able to figure out that probability.
In the meantime, I'm sitting back, drinking a beer, listening to Jimmy Buffett, waiting for aliens to talk to us. (wastin' away again in Margar-alien-ville.)
Parrothead logging out...

Ummm.. (2)

Auckerman (223266) | more than 13 years ago | (#490707)

From the article

"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.

All this time? (1)

will_code_for_beer (224193) | more than 13 years ago | (#490709)

You mean to tell me that we've spent 500,000 years of computing power searching for the wrong signals? geez... I'd rather have my computer search for the ten trillionth digit of PI, at least it would have been doing something.

Re:OT? You decide. (2)

corvi42 (235814) | more than 13 years ago | (#490711)

this is actually a flash cartoon that was on the scifi.com seeing ear theatre - go have a look.

laser is a poor method to scan for contact (3)

corvi42 (235814) | more than 13 years ago | (#490712)

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.

What?! (1)

paranoidsim (239426) | more than 13 years ago | (#490714)

Yeah, with all the experience I've had dealing with aliens....I'd assume they use laser pulses to communicate too.

How much data can FIT in a billionth of a second? (2)

Goldenhawk (242867) | more than 13 years ago | (#490716)

Okay, this is great...

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/lightandcolor /e lectromagnetic.html

What's wrong with this picture?
* ~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
* Split Infinity Music [simusic.com]

Bury the lead! (3)

Cytotoxic (245301) | more than 13 years ago | (#490717)

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!

Re:They're both wrong! (1)

dervish121 (245708) | more than 13 years ago | (#490718)

That's not a troll, you syphalitic retard. If it was, I would've said we'd be making first contact with your scabby little dick.

Hope this helps.

Re:Heh (1)

Big Brass Balls (257794) | more than 13 years ago | (#490720)

You know what I think would really kick ass is if we picked up signals, thinking that they were transmitted by aliens...when in fact, they were just our own signals transmitted by either space junk long decommissioned, or our our signals rebounded back to us by some dead space object.

--

Re:My Grade 12 Thesis Paper Was On This Very Topic (1)

badbrainsg (259879) | more than 13 years ago | (#490722)

I have two words for you: Paul Kurtz. (Books & articles showing the vacuity of claims of UFOs, ETs, etc etc.) I wouldn't demean you for the paper, but I think your teacher needs to be told what a "thesis paper" is.

Re:My Grade 12 Thesis Paper Was On This Very Topic (2)

KupekKupoppo (266229) | more than 13 years ago | (#490727)

I just read your paper, and my grade 12 professor would have murdered you for such poor work.

The lack of cohesion and support for any of your points proves it to be SOLELY random theorizing.

Some of your points may be interesting, but only when left to the reader to fill in ALL the spaces on their own. Your real point is "I don't have a point, but you can make one."

Bad, bad paper.

Now, the paper I wrote on cows being the most superior of all Earth's species, that was terrific. I even got it published!

-k.

Laser for deliberate communication; radio for luck (2)

BarefootClown (267581) | more than 13 years ago | (#490728)

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.

Just the next step... (1)

BLAMM! (301082) | more than 13 years ago | (#490729)

Now the tech details may be off, but isn't searching for laser (visible) light just moving down (up?) the spectrum from radio waves? It's all EMF. I thought the reason we (SETI) were concentrating in the radio portion of the spectrum was because the frequencies were meaningful. That they were related to the natual frequencies of hydrogen and helium. Moving to visible light is just moving to another street in the same neighborhood. Sure its "lasers" we're looking for, but that only means we're concentrating on coherent light. Can't radio waves be sent as coherent beams as well? Visible light can be sent omnidirectional the same as radio.

I guess my point is, that this isn't as big a deal or as big a leap of thought as it is being made out to be. There is a lot of real estate out there to look in. Ok, its cool, but we had to do this eventually.

Naeser's Law:

If they're looking for Lasers... (1)

Xeo2 (301694) | more than 13 years ago | (#490731)

Why isn't earth putting out laser messsages? It's not like they're not looking for us too. In the article, it says that we are able to put out pulses of light to other stars that would appear many times brighter than the sun. So why aren't we?

Re:Is the sun blocking our search? (1)

Xeo2 (301694) | more than 13 years ago | (#490732)

No... to an observer outside the solar system, the radio activity around the sun is hundreds of times higher than it should be. Consider this: If the sun were more powerful than the radio broadcasts, radio transmissions would be dorwned out. They aren't so it isn't.

Interesting article, but what was that at the end? (3)

cavemanf16 (303184) | more than 13 years ago | (#490735)

I think it is good for us to be using both radio and optical telescopes as we can learn things about the cosmos besides just alien life. A previous poster to this discussion noted that some quasars and other anomaly were found thru SETI@home, which supports this theory.

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?

Looking in the right place and the correct spectra (1)

ChildofAndromeda (308041) | more than 13 years ago | (#490739)

I do not think aliens would use a laser to communicate. The laser would have to be fired directly at the target. A civilization that was located 100 light years away from our planet would be firing at a target 12000 miles in diameter from a distance of 586,971,360,000,000 miles. That means the laser would have a window of 2.64953E-05 arcseconds to actually be seen by anyone here. Factor in that we are moving at a great rate around the sun, which is also moving relative to the other stars in the local region and it would be almost impossible to effectively use the laser as a communication beacon. In contrast, radio waves propagate radially from the source. This means that with sufficient amplification they can be heard at any time after they are created. Also, a radio station can be operated for thousands of years on the amount of power that would be required to produce perhaps a dozen laser beams which were sufficient to be noticed at such a distance.
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