Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

SETI@Home Adds New Search Method

Soulskill posted more than 6 years ago | from the look-for-interstellar-torrents dept.

Space 191

Adam Korbitz writes to point out that SETI@Home has added a new algorithm for use in evaluating signals from outer space. It's called "Astropulse," and they've made the scientific details available. Quoting: "The original SETI@home is narrowband, meaning that it is listening for a particular radio frequency. That's like listening to an orchestra playing, and trying to hear when anyone plays the note "A sharp." Astropulse listens for short-time pulses. In the orchestra analogy, it's like listening for a quick drum beat, or a series of drumbeats. Since no one knows what extraterrestrial communications will 'sound like,' it seems like a good idea to search for several types of signals. In scientific terms, Astropulse is a sky survey that searches for microsecond transient radio pulses."

cancel ×

191 comments

Sorry! There are no comments related to the filter you selected.

Surprising (5, Insightful)

FeatureBug (158235) | more than 6 years ago | (#24359305)

I find it slightly surprising it has taken the SETI project how many years to start checking broadband as well as narrowband signals. All those years spending a fortune in resources but only checking narrowband seems rather a waste of time. I would have been checking all sorts of broadband signal types from the very beginning.

Re:Surprising (-1, Troll)

Anonymous Coward | more than 6 years ago | (#24359375)

It's about time. Maybe now they can find a nigger at night. With the previous iteration, said nigger had to smile before detection could occur.

Re:Surprising (-1, Troll)

Hurricane78 (562437) | more than 6 years ago | (#24359553)

Troll: Check
Racist: Check
Funny: Check!

One should add: If you have nothing to say, and you're an ass, at least be funny. :D

Re:Surprising (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#24359985)

Caucasians: smug, annoying, lying, douchebags, girlfriends taken by blacks.
Blacks: cause 90% of crime, loud, bellicose, never make it to university
Latinos: reproduce like cockroaches, flea-bitten, smell like onions.
Asians: wallbiting, overachieving, small-dicked, can't drive-for-shit.
Arabs: shady, lying, bloated-ego, closet homosexual, suicide bombers.
Indians: stinky, stinky, stinky.

Re:Surprising (4, Funny)

Ilgaz (86384) | more than 6 years ago | (#24359943)

Broadband wasn't common in 1999. Now they figure aliens must have upgraded too. ;)

Re:Surprising (1, Informative)

FeatureBug (158235) | more than 6 years ago | (#24360027)

Not that kind of broadband - see the other meaning of broadband in telecommunications and signal processing [wikipedia.org]

Re:Surprising (0)

Ilgaz (86384) | more than 6 years ago | (#24360049)

I know! ;)

Re:Surprising (1)

FeatureBug (158235) | more than 6 years ago | (#24360221)

Cool. Just checking:)

Re:Surprising (2)

davester666 (731373) | more than 6 years ago | (#24360141)

Whoosh!

Re:Surprising (1)

FeatureBug (158235) | more than 6 years ago | (#24360299)

Sorry it seemed totally unfunny to me, so I assumed it couldn't be meant even as a bad joke. Give me Douglas Adams for funny, please.

Re:Surprising (3, Interesting)

smaddox (928261) | more than 6 years ago | (#24360205)

They chose 1420 megahertz for a good reason:

There is, however, a pronounced minimum in the radio-noise spectrum. Lying at the minimum or near it are several natural frequencies that should be discernible by all scientifically advanced societies. They are the resonant frequencies emitted by the more abundant molecules and free radicals m interstellar space. Perhaps the most obvious of these resonances is the frequency of 1,420 megahertz (millions of cycles per second). That frequency is emitted when the spinning electron in an atom of hydrogen spontaneously flips over so that its direction of spin is opposite to that of the proton comprising the nucleus of the hydrogen atom. The frequency of the spin-flip transition of hydrogen at 1,420 megahertz was first suggested as a channel for interstellar communication in 1959 by Philip Morrison and Giuseppe Cocconi. Such a channel may be too noisy for communication precisely because hydrogen, the most abundant interstellar gas, absorbs and emits radiation at that frequency. The number of other plausible and available communication channels is not large, so that determining the right one should not be too difficult.

Source:http://www.ufoevidence.org/documents/doc252.htm

More recently scientists have considered neutrino signals to be much more likely for alien communications since they can be sent across the universe with minimal signal degradation. The problem is that they are very hard to sense, and even harder to generate as a controllable signal.

Yes but (4, Insightful)

negRo_slim (636783) | more than 6 years ago | (#24359309)

Haven't we already covered this? The cost in electricity for them to use my "unused" resources is not worth it for SETI which offers and most likely will never offer any tangible benefit to our society.

Re:Yes but (5, Insightful)

vertinox (846076) | more than 6 years ago | (#24359415)

The cost in electricity for them to use my "unused" resources is not worth it for SETI which offers and most likely will never offer any tangible benefit to our society.

True, but who are you to say what others due with their free CPU cycles?

Personally, I like protein folding, but if other people want to look for alien life with their cycles then its their computer.

Re:Yes but (1)

arth1 (260657) | more than 6 years ago | (#24359557)

True, but who are you to say what others due with their free CPU cycles?

"Do", not "due". And I got the right to say the first time we had brownouts in my area, and other people's energy wasting affected me. Not only do you waste an extra 40-100W per computer, but during summer, your ACs work harder too, cooling down that extra heat energy.

Re:Yes but (2, Insightful)

strelitsa (724743) | more than 6 years ago | (#24359591)

When you start paying your neighbor's electric bills, then you will receive a bit more credibility when you attempt to tell them how much or how little electricity they get to use. Let me be the first to solemnly assure you that your brownouts aren't being caused by the kid next door running SETI@Home or downloading Britney Spears pr0n.

Re:Yes but (1, Insightful)

arth1 (260657) | more than 6 years ago | (#24359993)

Let me be the first to solemnly assure you that your brownouts aren't being caused by the kid next door running SETI@Home or downloading Britney Spears pr0n.

No, it's being caused by tens of thousands of kids of all ages running SETI@Home, having ACs set to sub-70 temperatures, running dryers with hot air exhaust, and otherwise wasting energy.

When you start paying your neighbor's electric bills, then you will receive a bit more credibility when you attempt to tell them how much or how little electricity they get to use.

Yes, they pay for the energy they use, but all of us pay when there are brownouts -- they hit those of us who conserve energy as much as the wasters who pick up the slack that we create. Which is why I got a right to bitch. If they only created brownouts for themselves, and not me too, I would have kept my mouth shut.

Re:Yes but (1, Insightful)

Lazy Jones (8403) | more than 6 years ago | (#24359635)

T>True, but who are you to say what others due with their free CPU cycles?

CPU cycles aren't free these days (with good power management), they cost electricity and producing electricty usually leads to CO2 emissions and thus contributes to global warming.

Your pointless SETI computations are heating up my planet, so I can bloody well complain about it.

Now, finding a large prime number on the other hand, might earn me an entry in the Guinness Book of World Records...

Re:Yes but (1, Funny)

Joebert (946227) | more than 6 years ago | (#24359723)

Well this is my universe & I say the Earth needs to warm up so I can keep my pet dinosaurs there again.

Re:Yes but (0)

Anonymous Coward | more than 6 years ago | (#24359781)

Well this is my universe &

Actually you're wrong. This is our universe and not your's. Let's try to think little bit more in term we and little less me.

Re:Yes but (0, Flamebait)

Joebert (946227) | more than 6 years ago | (#24359805)

Actually you're wrong. This is our universe and not your's. Let's try to think little bit more in term we and little less me.

Go fuck yourself.
I'm tired of being taken advantage of in that whole "we" game.

Re:Yes but (1)

Anonymous Coward | more than 6 years ago | (#24360189)

... and get off my lawn!

Re:Yes but (3, Interesting)

Sanguis Mortuum (581999) | more than 6 years ago | (#24359857)

I wonder what the carbon footprint of Seti@Home is...electricity doesn't just grow on trees you know...

Re:Yes but (0, Troll)

Macrat (638047) | more than 6 years ago | (#24359913)

True, but who are you to say what others due with their free CPU cycles?

True, but it would be nice if other spent those cycles on something worthwhile like Folding@home.

Re:Yes but (4, Insightful)

FlyingSquidStudios (1031284) | more than 6 years ago | (#24359475)

The proven existence of intelligent extraterrestrial life will have a profound effect on a lot of people's core religious beliefs. That alone will have a major effect on society and it might just turn a few people away from their outdated superstitious beliefs. I consider that a tangible benefit.

Re:Yes but (0, Troll)

strelitsa (724743) | more than 6 years ago | (#24359535)

Finding ET would only strengthen my "outdated superstitious beliefs".

In my Father's house are many mansions: if it were not so, I would have told you. I go to prepare a place for you. John 14:2

Re:Yes but (-1, Troll)

Anonymous Coward | more than 6 years ago | (#24359581)

Christians who are slaves should give their masters full respect so that the name of God and his teaching will not be shamed. If your master is a Christian, that is no excuse for being disrespectful. You should work all the harder because you are helping another believer by your efforts. Teach these truths, Timothy, and encourage everyone to obey them. (1 Timothy 6:1-2 NLT)

In other words, the Bible is bullshit.

Re:Yes but (1)

AndGodSed (968378) | more than 6 years ago | (#24359633)

How do you pull bullshit from that?

Re:Yes but (0)

Anonymous Coward | more than 6 years ago | (#24359779)

Gee let me think, slavery, an immoral and evil practice, being endorsed and instructed by Christianity? No clearly there's nothing wrong with the New Testament teaching evil. My mistake.

Re:Yes but (1)

AndGodSed (968378) | more than 6 years ago | (#24360239)

Ah, and here I thought you were up for intelligent discussion.

Maybe I am incorrect, if you are ready for a frank discussion on this, head over

to the GodGab forum. [godgab.org]

No it is not a Christian Forum, atheists hang out there as well as Buddhists and the occasional Muslim.

And yes I am interested in your thoughts (sans attempts at flaming), but /. is not the place for such discussion.

Re:Yes but (0)

Anonymous Coward | more than 6 years ago | (#24360327)

There is nothing to discuss. Slavery is immoral. The Bible teaches it. That's all I need to know to prove to me that it's not divinely inspired by a benevolent creator.

There might be a god but to think that it had itself nailed to a wooden plank so it could forgive me for a choice I didn't make is absurd. Christianity is absurd.

Have a nice day. I have no more time to waste arguing with a brick wall.

Re:Yes but (1)

Macrat (638047) | more than 6 years ago | (#24359957)

How do you pull bullshit from that?

Generations upon generations of practice.

Re:Yes but (0)

Anonymous Coward | more than 6 years ago | (#24359815)

Having to adjust your interpretation of scripture to fit observed reality strengthens your belief in it?

Re:Yes but (3, Insightful)

Stan Vassilev (939229) | more than 6 years ago | (#24359537)

The proven existence of intelligent extraterrestrial life will have a profound effect on a lot of people's core religious beliefs. That alone will have a major effect on society and it might just turn a few people away from their outdated superstitious beliefs. I consider that a tangible benefit.

Sure, finding alien life will have a lot of impact. The thing is SETI won't do that, at least as far as basic physics and math is concerned.

But of course, it may end up replacing out outdated superstitious beliefs, and replacing them with more modern superstitious beliefs, such as trying to catch alien radio on our satelites. The parallels between doing this, and an old-school prayer to God are quite ironic.

Re:Yes but (4, Insightful)

Memroid (898199) | more than 6 years ago | (#24359539)

Yes, but just think of how many more crazy religions it would spawn...

Re:Yes but (0, Troll)

Joebert (946227) | more than 6 years ago | (#24359755)

The proven existence of intelligent extraterrestrial life will have a profound effect on a lot of people's core religious beliefs. That alone will have a major effect on society and it might just turn a few people away from their outdated superstitious beliefs. I consider that a tangible benefit.

You're right.
Instead of having masses of God-fearing civilized people, we'll have masses of people whos' only fear is not achieving their goals or fulfilling their lustfull desires before they die.

Erm... (0)

Slur (61510) | more than 6 years ago | (#24359837)

As a moral Atheist, I take particular offense to this. Believing in a personified God figure who watches and judges may be really useful for the sort of people who need it, but some of us happen to feel a natural impulse to do good, which I feel is instilled in our nature.

The key is to see people as your brothers, sisters, children, parents... everyone part of your family, and to learn to love them despite differences.

You don't have to feel imposed upon by a Daddy God to be a good person, and in fact I would argue that a person who requires Daddy God to keep them in line is probably not very in touch with themselves.

You may have noticed that most species are wholly moral, they don't live hedonistic lives, and they love and care for their young and other members of their social group without need of intellection about imaginary Daddies. This should convince you that there is something innate in all animals, including Humans, that makes it possible - perhaps even imperative - to be moral beings.

Re:Erm... (-1, Flamebait)

Joebert (946227) | more than 6 years ago | (#24359969)

As a moral Atheist, I take particular offense to this.

As me, I don't fucking care & refuse to show any respect, or even read anything you've said after it.

If you want to make a point, do so without trying to guilt-trip me into agreeing with you.
Otherwise, go fuck yourself.

Re:Erm... (2, Insightful)

FlyingSquidStudios (1031284) | more than 6 years ago | (#24360101)

I don't fucking care & refuse to show any respect, or even read anything you've said after it.

This is why we need people to be more rational.

Re:Erm... (0, Troll)

Joebert (946227) | more than 6 years ago | (#24360285)

What's your point, what are you trying to say ?

Re:Erm... (3, Insightful)

MagdJTK (1275470) | more than 6 years ago | (#24360113)

His point was that people can be good without being religious. And of course people can be nasty and religious at the same time.

...go fuck yourself.

Your posts have done a lot to back up his claim.

Re:Erm... (0)

Joebert (946227) | more than 6 years ago | (#24360261)

Who said I'm religious ?
I'm just an asshole.

Re:Erm... (1, Interesting)

Gordonjcp (186804) | more than 6 years ago | (#24360021)

You may have noticed that most species are wholly moral, they don't live hedonistic lives, and they love and care for their young and other members of their social group without need of intellection about imaginary Daddies.

How do you know this? I find it interesting that you can describe animals as having morals, and expressing love, but not religious beliefs. How do you know that animals don't believe in God?

Re:Yes but (0)

Anonymous Coward | more than 6 years ago | (#24360043)

Which alternative is worse? Right now its difficult to tell...

Re:Yes but (1)

hansamurai (907719) | more than 6 years ago | (#24359797)

Read the Rama series by Arthur C. Clarke and Gentry Lee, crappy fiction after the first one, but they examine things just like this.

And personally, extra-terrestrial life doesn't contradict my personal Christian beliefs.

Re:Yes but (1)

FlyingSquidStudios (1031284) | more than 6 years ago | (#24360127)

So did Jesus die for the aliens' sins as well or are they all just bound straight for hell?

Re:Yes but (1, Insightful)

Anonymous Coward | more than 6 years ago | (#24359887)

That alone will have a major effect on society and it might just turn a few people away from their outdated superstitious beliefs. I consider that a tangible benefit.

You really underestimate the irrationality of the deeply religious. I mean, one might think our acquired understanding of evolutionary theory, archeology, biology, geology, sociology, chemistry, cosmology, physics, dinosaurs, carbon dating, etc. etc. might have turned more humans away from believing religious nonsense, but no such luck.

It will not be difficult for the irrational to hold yet another conflicting idea simultaneously in their heads: "Aliens! It just goes to prove how much more powerful the Creator is than we ever even suspected! Praised be his name!!!" "Ah yes, the good book refers to the angels in the heavens. Once again, the bible is proven correct," "The so-called-Alien claim is nothing more than Satan's test of our faith," "There is nothing about this in the bible. Therefore the aliens are a hoax perpetrated by atheist scientists." etc.

Just as "life finds a way"... so does humanity's need to find comfort, meaning, and social standing in profoundly shallow thinking.

Re:Yes but (1)

ionix5891 (1228718) | more than 6 years ago | (#24359955)

well lets just hope "they" don't happen to have supplies of oil

Re:Yes but (1)

Amorymeltzer (1213818) | more than 6 years ago | (#24360277)

To paraphrase someone far smarter than me on the results of the Drake Equation, when it comes to proving whether extraterrestrial life exists or not, either answer will be astounding.

Highly Debatable (3, Insightful)

Crazy Taco (1083423) | more than 6 years ago | (#24360361)

The proven existence of intelligent extraterrestrial life will have a profound effect on a lot of people's core religious beliefs. That alone will have a major effect on society and it might just turn a few people away from their outdated superstitious beliefs. I consider that a tangible benefit.

Yes, but is there any alien life? Certainly there's been no evidence of any, though you talk as though it certainly, and inevitably, exists. It sure sounds like you are the one making assumptions and promoting a faith based argument!

And as for this changing anyone's beliefs, that's highly debatable. Christian author CS Lewis wrote a trilogy in the late '40s that imagined intelligent life to be on both Mars and Venus. He was a noted apologist and theologian for the Christian faith, and he had no problem with considering the existence of extraterrestrials. (Note: The starting book of the trilogy was called Out of the Silent Planet).

Re:Yes but (0)

Anonymous Coward | more than 6 years ago | (#24359519)

Haven't we already covered this? The cost in electricity for them to use my "unused" resources is not worth it for SETI which offers and most likely will never offer any tangible benefit to our society.

Isn't it the whole point of SETI@Home to use the normally unused cycles which you are already spending electricity and therefore money on? Years ago, I stopped running SETI@Home because it was too slow to respond to changes in the way I was using my computer, resulting in lag. But aside from that it certainly didn't seem like a waste of money to me, unless you mean that it is cheaper to have a computer in stand-by mode with the CPU not in used as opposed to the CPU running SETI@Home instead of mumbling to itself "doing nothing. doing nothing..." But then, it is cheaper still to just turn the PC off...

Re:Yes but (2, Informative)

Fex303 (557896) | more than 6 years ago | (#24359677)

Isn't it the whole point of SETI@Home to use the normally unused cycles which you are already spending electricity and therefore money on?

The thing is that idle CPU time uses minimal electricity and generates minimal heat. The HLT command [wikipedia.org] means that you're using less energy. This is particularly noticeable in laptops. Run something that uses 100% CPU time (SETI@home/video conversion/etc) and see how long your battery lasts compared to simply having the machine sit at idle (turn off screen saver and power management software).

While it's not huge on a minute to minute basis, the cost of power adds up over the course of a year. I found this out when I had a roommate that ran distributed computing software. When he moved out, our power bills dropped by about a third. In my opinion, that much money is not worth searching for intelligent life.

Re:Yes but (1)

bazorg (911295) | more than 6 years ago | (#24359809)

well, I play in the lottery. the probability of success is extremely slim but the prize is very high and the cost of the missed attempts does not impact my finances that much.

Re:Yes but (1)

KGIII (973947) | more than 6 years ago | (#24360259)

I am just hoping that the first translated message says, "Hello World!"

we'll never find any signals (5, Interesting)

Anonymous Coward | more than 6 years ago | (#24359319)

As the information in a radio signal approaches the Shannon limit, it becomes indistinguishable from noise to an outside observer. Any sufficiently advanced civilization will have the technology to maximize the information sent in a radio signal. Therefore we will not be able to detect radio signals from other civilizations (except for perhaps a 100-200 year period in their evolution where they use inefficient radio signals)

Why not? (2, Insightful)

FeatureBug (158235) | more than 6 years ago | (#24359361)

Except for a huge assumption you're making: that an advanced civilization wouldn't want to broadcast a distinctive, easily decoded, narrowband signal. Perhaps they might want to do it to announce their existence to the rest of the universe, even though they would have the know-how to sendmuch more efficient broadband signals.

Re:we'll never find any signals (4, Insightful)

Free the Cowards (1280296) | more than 6 years ago | (#24359405)

SETI is not searching for accidental transmissions or leakage. SETI is only searching for deliberate beacons being sent by alien civilizations. SETI's techniques cannot detect random radio chatter and are not intended to.

SETI is doomed (0)

Anonymous Coward | more than 6 years ago | (#24359463)

If the point is to find radio beacons from alien civs looking to be found the odds of that are near zero. Darwin is everywhere. Only the paranoid survive.

Re:SETI is doomed (1)

FlyingSquidStudios (1031284) | more than 6 years ago | (#24359483)

Oh, well that explains the peacock.

Re:SETI is doomed (1)

FlyingSquidStudios (1031284) | more than 6 years ago | (#24359507)

Shit. Sorry. This reply was meant to go to the message below.

Re:SETI is doomed (1)

Joebert (946227) | more than 6 years ago | (#24359695)

Well that explains the peacock.

Re:SETI is doomed (2, Interesting)

Gabesword (964485) | more than 6 years ago | (#24360057)

The Voyager Interstellar Mission would seem to show that at least one civilization is not so paranoid as to be prevented from sending out an invite to a home planet. The golden record inside both Voyagers include directions to Earth.

Re:we'll never find any signals (1)

4D6963 (933028) | more than 6 years ago | (#24359795)

If so we're out of luck. I mean how often do we even deliberately try to send beacons to eventual alien civilizations? We couldn't find ourselves in a giant space mirror the way we're doing it.

Re:we'll never find any signals (1)

Free the Cowards (1280296) | more than 6 years ago | (#24359885)

SETI is not trying to find civilizations like ours. It is trying to find significantly more advanced civilizations which are deliberately trying to contact civilizations like ours.

Re:we'll never find any signals (1)

4D6963 (933028) | more than 6 years ago | (#24360313)

[SETI] is trying to find significantly more advanced civilizations

Great, so what you're saying is SETI is just a bunch of elitist? That's grand, I just can't wait until they make the Earth move to a gated planet community.

Don't get me wrong, that would be great, with all these asteroids impacts we've had these last few eons in our neighbourhood..

Re:we'll never find any signals (1)

gardyloo (512791) | more than 6 years ago | (#24359763)

Could you expand a little on that statement? I have two interpretations:

    * Noisy-channel capacity theorems state that if information is being sent at less than channel capacity, error correcting codes can, in principle, ensure no errors on the part of the receiver, even in the presence of noise (in which case outside observers should have no problems decoding any messages);

    * However, if information is being sent at over channel capacity, errors can grow without bound. If some civilization was communicating near the channel capacity (which they're likely to do to maximize information flow), and we happened to listen in (thus our interstellar channel is different, and probably has lower -- perhaps much lower -- capacity), then we're likely to receive lots of errors.

      Is the latter point what you mean?

Re:we'll never find any signals (1)

khallow (566160) | more than 6 years ago | (#24359775)

As the information in a radio signal approaches the Shannon limit, it becomes indistinguishable from noise to an outside observer.

Doesn't work that way. The Shannon limit restricts how much information you can pass in a noisy channel. SETI is looking for a very restricted question, is there a signal? That's just one bit of information. Listen long enough on the channel and that bit of information will come through, no matter how noisy the channel is.

Re:we'll never find any signals (0)

Anonymous Coward | more than 6 years ago | (#24359903)

And thats why all our modems use 65536-QAM.

When I'm sending signals across vast times and distances I've got better things to worry about than getting the theoretical maximum data rate out of my bandwidth.

Re:we'll never find any signals (0)

Anonymous Coward | more than 6 years ago | (#24360009)

The short range of WiFi doesn't keep me from talking all around the world with PSK31.

About Time (1)

AndGodSed (968378) | more than 6 years ago | (#24359323)

Strange that they are only doing that now - haven't they seen Contact?

Re:About Time (1)

4D6963 (933028) | more than 6 years ago | (#24359861)

Strange that they are only doing that now - haven't they seen Contact?

What the hell are you talking about? In Contact the SETI is basically just a bunch of hippies who time-share radiotelescopes and look for signals by listening into headphones. Here we're talking about listening to bands hundreds of megahertz wide. Very different.

I'm Going To Be Royally Pissed (1)

strelitsa (724743) | more than 6 years ago | (#24359365)

If the alien really IS Jodie Foster's father.

Probing... (1)

sponga (739683) | more than 6 years ago | (#24359439)

You now have the option to filter out aliens who might want to probe you.

Actually that is happening... (1)

Slur (61510) | more than 6 years ago | (#24359869)

...In Soviet Russia!

Use light, not radio waves (1)

Toffins (1069136) | more than 6 years ago | (#24359443)

It's very difficult to keep radio waves from spreading out in many directions, thus weakening the signal that can be detected by a distant receiver in any particular direction. Light, on the other hand, being much easier to focus into a tight beam, tends to stay within a narrower cone of space, leaving a stronger signal in the direction of aiming.

If I wanted to send a signal across the universe, I'd use light, not radio waves.

So, why is SETI still limiting itself to searching for signals in the radio spectrum?

Re:Use light, not radio waves (1)

MLCT (1148749) | more than 6 years ago | (#24359543)

They are both part of the same thing, the EM spectrum - and light has a much higher chance of being absorbed by interplanetary "stuff" before it ever reached us (hence why we can use FM radios indoors, but not something in the visible spectrum).

Radio can be directional as well (microwave transmitters) - but all the worry about focussing is not really on the agenda - any alien who puts the effort into "focussing" a beam on us might as well just use some more obvious means of catching our attention - a binary broadband pulse every 60 units of time or something equally unnatural to make us sit up and take notice.

Re:Use light, not radio waves (1, Interesting)

Toffins (1069136) | more than 6 years ago | (#24359651)

Err, in fact we can easily see the light from stars that are billions of light years away, without light absorption by "interplanetary matter" being a big problem. Of course, we can detect other types of EM too at similar distances, including radio, e.g. using radio telescopes. And, of course, all types of EM - light, radio, microwave - is absorbed and scattered to some extent by matter. But my point is, across the whole spectrum, it is light that can be most easily focussed into the tightest of beams with minimal divergence. Lasers are easy to make, easy to use, and can send beams of light of really enormous power with tiny divergence.

Re:Use light, not radio waves (1)

photonic (584757) | more than 6 years ago | (#24359895)

True, but only if you know were you are pointing (they do this with satellites [esa.int] ). If ET does not know where we are, and just randomly points his laser in the sky, the detection chance drops enormously, I guess the two effects cancel each other in the detection probability. Also note that any light you sent will might be lost in the background radiation of the star or the planet (I don't know if this is better or worse with radio).

Re:Use light, not radio waves (1)

Toffins (1069136) | more than 6 years ago | (#24359989)

Why wouldn't ET know exactly where to point a beam? We have science projects searching the universe for solar systems similar to ours with medium-size planets at Earth-sun distances where liquid water could exist. We find a new such solar system every few months, and get a very precise location too.

ET might be running similar projects. Every time ET finds a new candidate solar system, ET just points a laser at it. At such distances, with non-zero divergence of the laser beam, all of the planets in that solar system would be simultaneously lit up without having to wiggle the beam around to try hitting each of the planets one by one.

Tight beams, eh? (1)

Slur (61510) | more than 6 years ago | (#24359901)

The problem with a tight beam is that although you may get further, you only get one narrow beam that's unlikely to be crossed. A radiant energy is far more likely to be detected if it emanates in all directions.

So, combine your tight beam with continuous oscillation in all directions, and then you've got something.

Re:Tight beams, eh? (1)

Toffins (1069136) | more than 6 years ago | (#24360187)

Beam tightness brings targetability and signal strength, brings detectability, beats divergence any day. Most directions in space go thru empty regions. You don't want to waste precious signal strength on empty regions if you can possibly avoid it. And we know exactly where we should target tight beams of light to hit ET with high probability. [slashdot.org]

Re:Use light, not radio waves (1)

Atari400 (1174925) | more than 6 years ago | (#24359953)

Err, in fact we can easily see the light from stars that are billions of light years away, without light absorption by "interplanetary matter" being a big problem.

Those stars are generally supernova, and are putting out a serious amount of energy. As for light absorption by interstellar matter, it is a problem for observing some stars, as we can't see them (at visible wavelengths anyway).

Re:Use light, not radio waves (1)

Toffins (1069136) | more than 6 years ago | (#24360105)

Actually, the stars we see in the sky at night are generally not supernovae. While some stars are indeed obscured by interstellar matter, the light from many millions of others is clearly visible. Most of outer space is empty enough to support truly excellent light transmission. A pulsed laser can easily send many orders of magnitude greater light power than any ordinary star!

Re:Use light, not radio waves (1)

Toffins (1069136) | more than 6 years ago | (#24359909)

Re. what type of signal to send:

I'd think sending something like a tight beam of intensity-modulated monochromatic light would be more obviously unnatural than a periodic binary broadband pulse, which could just be mistaken for a weird sort of pulsar emission. Or intensity modulate it to N different levels giving I(t+k_i) where the k_i are some short period sequence of small integers, and N is a prime number. If we saw a weird beam of light like that, we'd probably assume it had a an intelligent origin.

A terrible analogy (5, Interesting)

no reason to be here (218628) | more than 6 years ago | (#24359467)

As a musician and a recording engineer, I feel I must comment on the analogy used.

For someone with a trained ear picking out an A#, or any particular note, shouldn't be all that difficult, especially if that note is tonic, 3rd, 4th, 5th, or other similar high recognizable interval from the tonic. It would be trivially easy for someone with perfect pitch to pick out a particular note.

I suppose the analogy might hold if we compared the prior SETI searching signals to be like a man who is deaf in his right ear turning his left ear away the orchestra to try and determine if the 2nd piccolo is playing sharp on A#, and now, SETI is that same man, facing forward with a brand new hearing aid, merely trying to pick out staccato notes.

Re:A terrible analogy (1)

Derosian (943622) | more than 6 years ago | (#24359761)

So basically all we need is human-level thinking computers and we might find E.T. life?

Re:A terrible analogy (0)

Anonymous Coward | more than 6 years ago | (#24359893)

I think what they meant is, imagine trying to listen to an orchestra if you're deaf to every note except A#. And that includes all those harmonics that give the note character -- so you couldn't even distinguish which instrument is playing it. So you'll sit in the conference hall, and hear an A#, and then a little later another A3, and then two of them... You can't call that listening to music.

Re:A terrible analogy (1)

4D6963 (933028) | more than 6 years ago | (#24360211)

No it's a good analogy, although worded it a manner that may make its interpretation prone to confusion. "and trying to hear when anyone plays the note "A sharp."" should really be "and trying to hear nothing but "A sharp" notes".

It has nothing to do with identifying the pitch of a note as you seem to have misunderstood, it has to do with not being able to hear anything but one note in an entire piece.

New algorithm... (1)

Adreno (1320303) | more than 6 years ago | (#24359469)

... same results? Given their vast historical success in their endeavors (/sarcasm)... I'd bet on it.

Re:New algorithm... (0)

Anonymous Coward | more than 6 years ago | (#24359733)

New algorithm...same results? Given their vast historical success in their endeavors[,] I'd bet on it.

A recent Nova ScienceNow [pbs.org] program did a featurette on the SETI project (specifically the Allen telescope array [wikipedia.org] ). The analogy they used for current efforts to locate extraterrestrial intelligence is trying to determine if there are fish in the ocean. Space is BIG (yadda yada long way to the chemist yada yada), and current efforts are very narrow, so it's like trying to use a water glass. Dip the glass into the ocean, look at the contents, say "nope, no fish in there", repeat. Just because on the first ten thousand times you don't find a fish in the glass, doesn't mean there aren't fish in the ocean. Now they're dipping the glass in another location - they may find fish there, they may not. (e.g. if they try to fish in a tropical tidal pool they'll have more success than in the open Arctic ocean.)

The payoff for finding aliens is SO big that even though the tasks seams sisyphean the people performing it think it's worth the effort. True, using a bigger net or fishing in more populated waters would likely speed the task, but at this point we know nothing of fish, so we don't know where they live or even what sort of net would hold them.

Although I doubt that they will find anything, I wouldn't be so scathingly dismissive. After all, if you don't look you know you won't find anything.

I got the beat. (1)

thbigr (514105) | more than 6 years ago | (#24359529)

Thump...Thump..Thump..

I wonder if they should look for styles of rythms. Dance, hip-hop, etc.

Re:I got the beat. (1)

PPH (736903) | more than 6 years ago | (#24359585)

This may not work out as planned.

When I hear that "Thump, thump, thump" noise coming from a rice burner next to me at the stop light, I pretty much give the occupants the thumbs down on intelligence.

What are the chances? (2, Interesting)

photonic (584757) | more than 6 years ago | (#24359637)

The type of data analysis they perform on these radio signals looks pretty similar to what they do with the data from gravitational wave detectors such as LIGO [caltech.edu] , which also look at both periodic sources and short glitches. In that community, they do an estimation of detection rates based on hard science: number and distribution of stars and expected rates of supernovae etc. Detection rate for last years' science run is on the order of 1 per 10 to 100 years, which should increase to hopefully tens per year with the advanced detectors that should come online in several years. Nothing has been detected yet, but this is more or less understood. If the advanced detectors detect nothing, the taxpayer owes an explanation.

I wonder if similar detection rates have been calculated for SETI (e.g., assume ET having a transmitter of 1 MW, at what distance would you still detect anything? And how many life supporting planets are in that range? ) This will depend a lot on the parameters in your Drake's equations, but they should at least give some order of magnitudes. I remember reading some skeptic article several years ago, which claimed that even with optimistic estimates, the chance of detecting anything would be absolutely zero.

Until that time, I rather waste my computer cycles on the LIGO data (Einstein at home [uwm.edu] ) or one of the various medical applications (e.g. Folding at home [stanford.edu] ), which produce scientific results today.

Priorities (1, Redundant)

PerroBestial (1333849) | more than 6 years ago | (#24359647)

Guys and Dolls, aliens are certainly interesting, but I want to remind everybody that there actually exist projects you may donate machine time to, projects whose results might be more immediately useful, such as folding@home (folding.stanford.edu). Cheers, PB

Re:Priorities (1)

Phurge (1112105) | more than 6 years ago | (#24359739)

also see http://www.worldcommunitygrid.org/projects_showcase/viewResearch.do/ [worldcommunitygrid.org]

current topics include:
Nutritious Rice for the World
Help Conquer Cancer
AfricanClimate@Home
Discovering Dengue Drugs - Together
Human Proteome Folding - Phase 2 Project
FightAIDS@Home Project

WHat I wanna know is... (0)

Anonymous Coward | more than 6 years ago | (#24359683)

Do they still gots that 'leet screen saver that looks like it's doing important stuff, so that when the babes come by your cube, you can impress her by saying you are searching for extraterrestrial life, instead of living a pathetic life of sheer misery?

Ironic (3, Insightful)

Randall311 (866824) | more than 6 years ago | (#24359849)

Does anybody else find it ironic that we are looking for intelligent extra-terrestrial communications on the very same frequency that we (an intelligent species) are prohibited from transmitting on? The 1.420 gigahertz frequency was chose (I believe) because of the hydrogen line. It would seem to me that a more effective methodology would be to do a spectrum sweeping search. The odds of any intelligent species transmitting on just one frequency are unlikely enough. Combine that with the fact that we are only listening on one frequency. Now we can compare finding a needle in a haystack as trivial in comparison.

Re:Ironic (1)

4D6963 (933028) | more than 6 years ago | (#24360255)

Pffft, but obvious, the aliens will have thought of the same thing as us, that we should reserve the 1.420 GHz frequency for interplanetary communications and that we would be listening and that they would be the ones listening.

Now excuse me while I go back to listening to some radio frequency I think would be good for two persons to communicate on and wait for someone I never communicated with before to talk to me on this agreed frequency.

Re:Ironic (3, Insightful)

Ransak (548582) | more than 6 years ago | (#24360365)

The concept of SETI is to look for radio signals that have been intentionally directed toward us (ie, not stray signals).

The SETI line of thought is if another civilization is intelligent enough to understand the Hydrogen Line and the Microwave Window and that another civilization - us - would understand that as well and use it for radio astronomy, the frequency of Hydrogen (1420.40575 MHz) would be the most likely place we would be listening since the universe is mostly made up of it from what we can tell so far.

Wow, so much SETI love... (0, Offtopic)

NewbieProgrammerMan (558327) | more than 6 years ago | (#24360001)

If SETI ever detects a real, verified alien signal, as soon as I hear the news, I'm going to drop whatever I'm doing, and rush to see the comments on Slashdot. I can't imagine what the response would be if a project so (apparently) universally hated here actually turned up a positive result.

Not that I run SETI@home, plan to, or expect an actual SETI discovery to happen in my lifetime, if ever. It's just something on my "wouldn't it be funny to watch if..." list.

SETI is not interested in finding alien life (0)

Anonymous Coward | more than 6 years ago | (#24360363)

SETI is a gov't dis-information campaign. http://www.v-j-enterprises.com/sfufovsseti.html [v-j-enterprises.com]
Load More Comments
Slashdot Login

Need an Account?

Forgot your password?