Nova (1974) s14e05 Episode Script
Is Anybody Out There?
1 You ever wonder what goes on when the theaters close? When no one's watching? I think that's when the space visitors show up.
So they're shy in the day.
That's why you don't see them Unless you know how to communicate.
Hey, I mean, you got to admit it's likely there's all kinds of beings all over the solar system, don't you? We can't be the only things going.
That must mean they're all over the galaxy.
Tomlin: For thousands of years people have been looking at the skies wondering what might be out there.
It's moving! Tomlin: Hundreds of science fiction films have depicted what happens when there's a failure to communicate.
During the 1950s at the height of the cold war on this world many classic science fiction films suggested the aliens were implacably hostile and the sooner they were gone, the better.
By the 1970s, contact, not conflict became the theme of successful science fiction films.
The characters in these films try to communicate in pure tones A language they think might be universal.
Movies like close encounters of the third kind and e.
T.
, the extraterrestrial reflect and shape our changing concepts of the universe and just might help determine if we make contact with real e.
T.
S.
Hello, I'm Lily tomlin.
Recently, I was on Broadway, dy who receives extra-terrestrial messages through her umbrella hat.
I like to think of her as someone who lets her imagination overpower the reality that surrounds her.
But this program is about the real thing How we might actually contact alien civilizations.
Two A.
M.
, September 24, 1985.
In a physics lab at Harvard university earth's most sophisticated detector in the search for life in space in the tradition of hackers everywhere professor Paul horowitz and his student Brian Matthews burn the midnight oil.
To ensure something happens when the system is switched on five days later.
Horowitz: This will be 20.
4 kilohertz off of D.
C.
Say when.
Um Not yet.
Set Go.
Is that running? Oh, crud.
I don't know Okay Tomlin: This may seem like a shoe-string effort And it is But previous efforts have been less specialized using receivers not custom-made for the search.
What sits here is only half the system.
It now says We got a nice signal.
I'm making a chirp and you're looking for it.
Tomlin: Soon, it will be linked to a large radio antenna and the search to detect a signal from an alien civilization will begin.
Scientists have known about radio since the start of the 20th century but have Cade ers provided tools powerful enough for "SETI" The search for extraterrestrial intelligence.
Matthews: It's detected as a synthesized chirp and it tells you exciting messages.
Tomlin: Five days later, September 29 astronomers gather at a radio telescope near Boston.
For the ceremonial switching on of the detector horo up and inside, was still making last-minute fixes.
He calls the system "meta" Mega- or million-channel extraterrestrial assay.
Some of the scientists most interested in SETI came to the ceremony including astro-physicist Philip morrison who first proposed, some 25 years ago the basic methods meta uses.
The member-supported funds the operation of meta with the help of a donation from movie director Steven Spielberg.
An even more powerful detector is now under design.
These SETI experiments may fail to make contact with real e.
T.
S but scientists want to go beyond fantasy and communicate with another civilization.
I'm very happy to be involved in this project.
It benefitted so much from science fiction I just thought is was time to get involved in some science reality.
I just hope there is more up there than just reruns of the Jackie gleason show.
Tomlin: Among the scientists who have helped SETI grow is planetary society president Carl sagan.
May it find something! There is some chance that we will get a signal from some spectacularly distant spectacularly exotic civilization and everything on earth will, as a consequence, change.
That is possible.
Tomlin: If other civilizations where are they? Why aren't they here? After all, we humans are space travelers.
Wouldn't any civilization advanced enough to send a message come to earth in person like Spielberg's e.
T.
? In reality, space visitors would have to come a very long way for we on earth seem to have no close neighbors.
The viking spacecraft touched down on Mars and found no clear signs of life.
Other spacecraft have found no evidence of advanced beings on any other planet in our solar system.
The voyager ii spacecraft is the fastest vehicle ever built but it still took nine years to reach the planet uranus just over halfway to the edge of the solar system.
To find another advanced civilization we must look to the stars.
But voyager would take 100,000 years to r tars.
Barney Oliver, head of NASA's planned SETI project: Oliver: When you compare the costs of interstellar travel with ation they, like us, would choose interstellar communication.
It's far cheaper.
Tomlin: So if we have to expect s what's the best method of communication? That depends on who you're trying to talk with.
In the 19th century scientists still believed our solar system was teeming with life.
They assumed that other beings would be studying earth.
In 1833, a German mathematician, Carl gauss suggested planting in Siberia a huge triangle of wheat bordered by dark-green pine trees.
Alas, gauss' project was never funded.
Nor was the idea of Johann Von littrow, of Vienna who suggested digging geometrical shapes in the Sahara.
He wanted to fill the trenches with kerosene and to set them ablaze to make a glowing beacon on the night side of earth.
In fact, these bizarre schemes might well have worked if aliens had existed on Mars or Venus.
But methods of communication that work over inter-planetary distances have no chance at all between the stars.
Distances between the stars are so enormous that astronomers measure them by the velocity of light.
E ar Six trillion miles.
Our galaxy, the milky way is 100,000 light-years across.
The galaxy contains an enormous number of stars and a vast potential for other civilizations.
Skeptics say that advanced civilizations would surely have made themselves visible but we have seen no evidence of life "out there.
" So, justify h? In 1960, frank Drake made the first radio search for civilizations in space.
Drake's experiment for over 25 years, Drake has kept on looking.
What does he think we might learn? The most important information would be just the simple that will tell us that civilizations like ours can thrive for long periods of time and overcome the threat of nuclear war preserve their environment maintain high technology and a high quality of life and all of that is very important to know.
Tomlin: Drake called his pioneering search "ozma" after a Princess in the fictional land of oz.
He said SETI also deals with faraway lands.
But maybe SETI itself is just as fanciful as the land of oz.
Drake argues that what we already know plus what we have good reason to believe justifies the search.
He came up with a way to organize our knowledge and our ignorance.
Scientists call this "the Drake equation.
" The Drake equation presents seven conditions astronomers think necessary for the existence of a civilization which could send a message to us.
If you make an estimate for each term and multiply them all together you end up with an informed guess about how many advanced civilizations are out there.
The larger that number, the easier to establish contact.
The first term in the equation is the number of stars in the milky way.
This is the only term we know with a fair degree of accuracy.
By observing other galaxies as well as our own we estimate that the milky way contains about second, how many planets might orbit these billions of stars? We don't have clear evidence of any planets outside the solar system but with much improved technology the hunt is on.
In 1985, rich terrile of NASA's jet propulsion laboratory of a faint disk of material surrounding the young star beta pictoris about 50 light-years from earth.
This may be humanity's first glimpse of another solar system.
The disk of material may be about to form planets.
Some scientists argue that, like our sun the majority of stars have planets.
The third term in the Drake equation asks how many planets, or their large moons would provide an environment suitable for life? In our own solar system, we have found no evidence of life on the airless, waterless moon.
Nor in the swirling clouds of Jupiter nor beneath the majestic rings of saturn.
Some scientists believe Mars was once more habitable.
They point to its polar caps of ice and to riverbeds that channeled water a billion years ago.
They look at Jupiter's large moon, europa and wonder about possible life beneath its frozen crust.
They yearn to Pierce the clouds that shroud saturn's moon titan where conditions may resemble earth's at the time when life arose.
In a solar system with some 20 worlds one hit and three near-misses implies that many planets may be habitable by some forms of life.
The fourth question is, on how many of these suitable worlds in a now famous experiment Stanley Miller and his colleagues took answ toward n.
They tried to create a dynamic model of the earth as it was four billion years ago.
The flask represented conditions on earth before life appeared.
They mixed in simple chemical compounds or the sun's energy.
The simple molecules broke apart and then formed more complex compounds.
Four billion years ago these compounds would have rained into earth's seas where they could have formed even more complex molecules such as glycine, one of the amino acids The basic building blocks of life on earth.
Scientists have also found amino acids in meteorites.
These amino acids apparently formed in an environment even more hostile than that of the primitive earth.
From simple organic molecules to a living, reproducing organism, like us is a huge step.
But the most basic building blocks of life appear to be common throughout the universe.
The fifth term in the Drake equation asks how many worlds nurture not just life, but intelligence? We know that on earth simple forms of life have gradually evolved to become intelligent life.
The survival value of intelligence may be so high that intelligence arises wherever life emerges but for now, we just don't know.
The sixth term is the fraction of planets with intelligent life on which emerges a technologically advanced civilization Arbitrarily, one that can use radio.
On earth, we're batting one for one but on other worlds the most advanced forms of intelligent life might be rather like whales or dolphins.
Even if there's a lot of them out there we can't hope to communicate.
Does advanced technology carry with it the seed truction? The seventh question The average lifetime of a technological civilization Cannot easily be answered until we succeed in SETI.
If many civilizations flower briefly and then disappear only a few can be sending messages and SETI will be difficult, if not impossible.
If you ask scientists for estimates for each of the terms you'd find a wide variety of opinions even on factors we think we know.
How many stars are there in the milky way? There are 200 billion stars in our galaxy.
About 20billion stars.
Everybody agrees about 100 billion stars.
I think probably about 400 billion.
A few hundred billion.
Tomlin: How many planets are there per star? About ten planets in each planetary system.
About ten planets per star.
About eight.
One star in ten might have planets.
Several per star.
Tomlin: How many planets per star are suitable for life? One or two planets.
One.
One.
One.
One per system.
Tomlin: Let's get more speculative.
On how many of these worlds does life actually begin? Just the most optimistic s.
It's pretty close to every suitable planet.
It's basically a sheer guess.
Maybe one in ten to the eighth just because eight's my lucky number.
Tomlin: One planet in 100 million? What's the chance of life becoming intelligent? Systems of living things given a few billion years will produce intelligence.
Again, I choose one in ten to the eighth.
Tomlin: On how many worlds would intelligent beings develop the technology to communicate? Wherever intelligence develops it is likely that technology also will develop and the ability to communicate across space.
After intellence forms perhaps a one percent chance of radio communication.
Tomlin: Now, gentlemen what are your guesses for the shortest and longest average lifetime of a technologically advanced civilization? I think if a civilization crosses a technological threshold then that time could be measured in millions of years.
If a civilization doesn't attain that threshold it could 50 or 100 years.
I think it will be billions of years.
Basically, the full lifetime of the star.
I can't imagine that an advanced civilization tomlin: What's the bottom line? Optimistically, frank Drake says there could be at least 10,000 technologically advanced civilizations in the milky way alone.
The larger the number of civilizations the nearer to us our closest neighbor might be.
But Ben zuckerman's pessimism says that no other civilizations exist in the milky way and possibly not in other galaxies.
How useful is the Drake equation? Nobody takes these numbers to be tremendously serious.
Nothing depends on there being a million civilizations as opposed to a billion or a thousand.
The only question is are there many, a few, or none? And as long as there is a plausible argument for many we ought to keep looking.
If there's an argument for a few even if there's an argument that nobody is out there Bearing in mind that we can be wrong We ought to keep looking.
.
It calibrates our place in the universe.
So, it is worthwhile looking for other civilizations I would say, no matter what.
Tomlin: Since these pessimistic and optimistic estimates are simply the results of multiple speculations experimenters such as Paul horowitz aren't willing to stop there.
Horowitz: People have argued about the probabilities that there's life elsewhere in the universe.
It's easy to come up with arguments that make it semi-probable or highly improbable but they're nothing but arguments.
If you want to answer this question to d ent.
Tomlin: Modern equipment is essential but SETI involves more than electronics.
Making contact means considering the technology of whoever might be on the other end.
First, where and when to look? Ernestine's message service.
You stay in touch 'cause we care so much.
Mr.
green? Your rich uncle, Mr.
pursewarden, did phone.
He will call to say how he's coming to town.
You must stand by as you will not be able to reach him once he's gone.
( Telephone ringing ) E.
M.
T.
Oh, miss pinkney A conference call with Mr.
right and Mr.
bright.
Do you have their numbers? Do I have their numbers? If I did, would I be here? ( Telephone ringing ) E.
M.
T.
Oh, Mr.
pursewarden! Yes, sir, I am two ringy-dingys.
Three ringy-dingys.
There's no answer.
I told him to stand by, sir.
Very well and what a pleasure talking with you! E.
M.
T.
Yes, Mr.
Jones.
The 6:00 P.
M.
meeting is now at seven for six.
There's nothing really hard to understand about that, Mr.
Jones if you'd just concentrate.
E.
M.
T.
Yes, Mr.
green, Mr.
pursewarden called.
Just where were you? Really? When I say "stand by," i mean by the telephone.
What did he say He's coming to town next month and if you don't meet him, you're out of the will.
He didn't say how he's coming.
I don't know if he'll call back.
There is no need to yell at me.
Yes, I suppose it is a little intelligence test.
Just figure out where to meet him and stay there.
? Mr.
green, if you're going to shout I'm going to give your plug a yank.
Very well, sir, I understand.
No calls until you figure it out.
Tomlin: In SETI, we're in even worse shape than Mr.
green.
We don't know if there is a rich uncle or where he wants to meet.
Can we figure out how a message might be sent? Consider a great canyon as the chasm of space between the stars.
You're on a camping trip and think someone else is out there.
You want to get in touch but how? Suppose, on the other side of the canyon that "someone" also wants to communicate.
Just by looking, there's no sign of anybody.
One thing's certain about communication Some methods work better than others.
Suppose you realize that a Star Trek is impractical.
In your frustration you come up with an alternate strategy.
Sending a message by unmanned probe might seem preferable.
We humans have put slightly more sophisticated messages aboard the pioneer spacecraft.
Still, there's the question of how much energy you can deliver.
And space is awfully big in comparison to an interstellar probe.
Maybe sending small particles of matter isn't the best idea.
Suppose you send messages by waves Hello! Tomlin: Sound waves, for instance.
You might discover that different frequencies have different characteristics.
As every schoolchild knows at a distance a low frequency shout attracts your attention less than a whistle.
But the most piercing whistle won't be heard even a few miles away.
Well, life must go on.
You need warmth and light.
A camper, like a civilization, may do things for his own purposes that could be visible across the cosmic canyon.
You might not even realize you stumbled on a means of communication.
Across the canyon, the flames might be seen but thought to be a brush fire.
There's no sign of intelligence but it might give you an idea.
Suppose you build a fire but modulate or manipulate the puffs of smoke.
You're sending a clearly artificial signal that travels at the speed of light and es.
But if the laws of Murphy hold true throughout the cosmos then even your best idea may fail.
One civilization may be asleep when the other is sending.
But suppose you were given a method of communication common to both sides of the canyon.
Suppose it was fast, cheap and efficient.
Call it "radio.
" It might seem that your troubles were over once you've learned to turn on and tune in.
But in fact, your work is just beginning.
Hello.
Uh.
Channel one, too obvious.
Channel two.
Hello? Tomlin: Even with just two channels on a walkie-talkie it takes time to figure out when to speak or listen.
Hello.
Tomlin: Successful communication requires mutual agreement on how to communicate.
In SETI, an unspoken agreement must somehow occur without a meeting.
For all these difficulties most SETI scientists think radio is the way to go.
You can see why if you look at how well signals of different frequencies channel one.
Hello.
Tomlin: Light and radio are both parts of the electromagnetic spectrum.
Light's frequency differs from other kinds of electromagnetic radiation.
Light, itself, comes in many different frequencies which we call colors.
Red has the lowest frequency blue a higher one.
All the colors of light span only a tiny part of the electromagnetic spectrum.
At infrared frequencies Below those of visible light on the spectrum the black, but warm campfire glows brightly.
So do the sun the trees and people.
At lower frequencies we observe the scene in radio waves.
The sun is a weak source of radio.
But the milky way, on the left is a strong one.
Artificial sources of radio like our camper's walkie-talkie stand out because the earth has few natural radio sources.
The same principles apply in the heavens.
In visible light, the sun outshines the earth.
That's one reason we haven't been able to detect planets around other stars with even the largest optical telescopes.
It's like trying to see a firefly perched on the rim of a searchlight.
In infrared even earth's dark side glows.
The milky way forms a bright band.
But it's radio that gives earth its unique signature as the home of intelligent life.
At certain times and frequencies the earth outshines all other sources within the solar system.
These radio waves also make earth stand out to d ons.
You ever wonder what goes down when the theaters close? When no one's watching? This program is an interstellar message.
Thirty-three minutes after this broadcast began our opening sequence has traveled 370 million miles and has nearly reached the orbit of Jupiter.
Some of the radio waves that carry TV broadcasts leak into space and expand at the speed of light.
Three hours from now, this program will overtake voyager two billion miles from earth.
Voyager has been traveling for nine years.
If in our imagination, we could travel much faster than light we could overtake our radio and TV broadcasts.
Four and a half light-years from earth we might find news of a royal wedding passing the sun's closest neighbors Alpha centauri a and b.
Any planets around the star, altair 17 light-years from earth are now receiving our news from the late 1960s.
Houston, delta landing, over.
Roger, 1201.
That's one small step for man one giant leap for mankind.
If they had sensitive enough detectors they could watch as we became a space-faring civilization.
Any beings on planets around fomalhaut 23 light-years from earth might see evidence of humanities' nobler aspirations.
Where they will not be judged by the color of their skin I have a dream.
Planets near arcturus or pollox each about 36 light-years from earth might pluck from the cosmic background shows from the early years of television.
Jackie gleason.
The honeymooners.
Aliens might not share ousense of humor and might find programs hard to decipher but there's still much to be learned.
As the earth turns TV, military radar and microwave signals appear and disappear over the horizon.
As a guide to what we may learn about another civilization by eavesdropping on its unintended signals - astronomer Woody Sullivan has studied - what our radio transmissions reveal about earth.
Sullivan: We found you could get the earth's spin rate the earth's size.
You could map where the earth's television stations are located.
You could get the size of the earth's orbit.
You could get the temperature of the earth from basic physical principles.
Think about the difficulty of trying to purposely send a bit of information such as the temperature of the earth.
- Tomlin: What about a message beamed toward us? - we may discover a clue to its contents in t single mess age we have sent into space.
Puerto Rico's arecibo raditelescope is the earth's largest collector of radio waves.
Frank Drake used the arecibo dish to beam a signal toward a distant star cluster.
The signal was a stream of on-off pulses shown here as zeros and ones.
9 pulses repeated an alien civilization might ss unless it realized that 1,679 is the product of two primes, 23 and 73 numbers that are divisible only by themselves, and one.
If the language of mathematics is universal they might hit on the mathematical device of arranging the ones and zeros into columns and rows.
If they darkened the ones, they'd see a picture A crude representation of the beings that sent the message.
A map of our solar system with earth singled out a diagram of the arecibo dish and the all-important DNA molecule.
The arecibo message was beamed toward a star cluster in the constellation Hercules, 25,000 light-years away.
50,000 years from 1974 and about the year 51,974 humanity could receive a reply.
At a symposium, celebrating meta's switching-on Carl sagan and others discussed whether we should send messages or listen.
They argued a reply takes a little too long.
If you're sending you have to wait for travel time At least ten to 20 years.
Those experiments are intrinsically less interesting.
And that's a very optimistic number, ten or 20 years.
Even the most optimistic estimates of the distances to the nearest civilizations generally, are hundreds of light-years away.
So if you said, "hello" it would be 2511 that the message would get back.
Tomlin: What might a message say? What would we like to know? Like perhaps a cure to some of our own human ills like cancer or pollution or the gradual loss of our resources and stuff like that.
I think with all the scare that science fiction puts into the public's minds of these monsters that want to take over our planet I think a friendly message would make everything worthwhile.
And I hope they can teach us how to handle our technology and teach us about how to prevent the environment from being ruined.
Tomlin: Most SETI scientists have a different perspective.
What I would like to know is an answer to a very simple question.
Are we alone, as conscious beings in this 400 billion-star galaxy? It seems pretty implausible.
Tomlin: Phil morrison thinks the signal but the public would feel differently.
It'll be a sensation when it's confirmed.
And then it will turn out to be false then finally confirmed and that would be a sensation.
It'll occupy the front pages of the newspapers for a week.
It'll occupy the inside pages for another month.
And that will be the end of it.
But interested people will grow up everywhere.
They'll build other receivers.
All countries will have them and they'll pool the signals and where it's coming from and a thousand authors will arise to say what they look like and who they are all of which will be false.
And gradually, the truth will come out.
The come and say, "what do they look like?" If radio f choice and listening our best strategy does this make contact easy? Is it enough to turn on our radio detectors and wait? Well, not exactly.
A gracious hello, et&t.
Ernestine tomlin, atop the transmitter.
Let's see what's on the "radi-o," daddy-o.
Oh, yikes, yikes.
There's that crazy radio beacon again.
Aggressive bunch of jokers in that galaxy.
Too bad no one listens to that frequency, fools.
They broadcast one minute, every thousand years.
Just how long did they live? Try 1420 megahertz and keep doing it.
Those nudnicks think they're so great with their zeta-waves.
What a shame no one else has discovered them yet.
If they'd think archaic they'd get an audience.
Oh, there's that catchy tune.
Da, da, da, da, da, da, da.
da, da, da, da, da, da, da.
Oh, I do love that fat guy.
And that Norton.
Must be a real fun planet down there.
Too bad it's so far away.
These life-forms are fascinating.
But of course, none so much as I.
Tomlin: Ernestine is grappling in her usual, efficient manner but the many problems that remain for SETI scientists who have chosen radio What kinds of signals to expect, when to listen and where and how many frequencies to monitor.
An ordinary fm radio dial shows frequencies in megahertz or mhz one million vibrations per second for the radio waves carrying the broadcast.
To avoid interference we, on earth, license a sm but the cosmic radio dial is very different.
The region between 90 and 92 megahertz can contain 20 million different channels each capable of carrying a message from another civilization.
With a conventional radio receiver the signal would be lost in the sea of background noise.
The cosmic radio dial must be sliced much finer.
On the cosmic dial, the region from 88 to 108 megahertz contains about 200 million potential channels.
And fm is just a tiny part of the spectrum.
- Belo - for ts.
Nds all the way down to zero frequency.
With ge how can we possibly figure out what frequency an alien N we believe, and that is in the microwave region.
The reason for that is that the noise that would interfere with our transmissions or theirs, is lowest there.
Tomlin: We find the low frequencies, shown at left - are noise in - space.
Es.
In the middle, lies the preferred region.
There are about 100 billion potential channels here.
Are there any other clues to help narrow the search? One basic fact about the universe is that hydrogen is the most abundant atom.
- Hydrogen atoms naturally emit radio waves - at one particular frequency 1420 megahertz.
That the universe might tell us where to look in frequency was first proposed by Philip morrison.
At the symposium on meta he reasoned that intelligent beings could re ment.
Morrison: This in an anti-cryptological game.
A game where the rational transmitter says "i want to make it easy for those distant, primitive folk "to get onto this channel.
"I will not conceal it.
"I'll make it as self-transparent as visible as possible.
" Tomlin: Ency helps to simplify the task of sifting the cosmic haystack.
An alien civilization might broadcast a powerful signal at this magic frequency hoping it could be detected above the background noise.
Drake's ozma search used 1420 megahertz to scan two stars for 400 hours.
His receiver could cover only one channel like a radio tuned only to one station.
A search called ozma ii, made by Ben zuckerman looked at 674 stars also around this magic frequency.
And horowitz in meta is still essentially playing the magic frequency game.
Unlike the ozma searches which looked at individual stars meta is a sky survey.
Meta's antenna sweeps out a beam across the entire sky.
In eight months, meta surveys the entire sky visible from the observatory.
When one survey is complete at a different magic frequency.
But astronomers have come up with more than a dozen magic frequencies.
Because the earth is always moving any signal will drift in frequency over time.
So SETI detectors must be able to scan many channels or groups of frequencies.
Drake's ozma detector had only one channel One ten-thousandth of a megahertz wide.
Horowitz's system scans 8.
4 million channels.
It can do in a second what would have taken ozma five years.
- Horowitz: - This - as an receiver - 8.
4 and where you do one channel after another, sequentially.
This receiver box is like 8.
4 million radios all tuned to successive stations.
Tomlin: Despite this progress meta covers only a small part of the radio spectrum.
But it is perhaps the ultimate magic frequency machine.
From this array the information passes to this controlling computer.
This computer really rides herd over the whole system.
It downloads the instructions to the different processors keeps track of the earth's motion and looks for possible signals of extraterrestrial origin.
When it finds something it does several things.
It archives unusual, rder.
Actually, a friend of mine came and looked at this and said "horowitz, the reporters will say 'show us what happens if a signal comes in.
'" so I said, "we can do that by turning on an oscillator.
It'll say, 'large peak.
'" and he said, "no, no, no.
"Have it say "'notify operator immediately.
Possible signal of extraterrestrial origin.
'" tomlin: No such signal of extraterrestrial origin has yet been detected.
We have hardly begun to search.
We've hardly searched all the various frequencies from which signals might come.
The fact that of extraterrestrial life is not discouraging.
We shouldn't have found it yet.
We have hardly begun.
Tomlin: In the heart of esert NASA researchers are testing prototype equipment specially designed for a far more comprehensive search.
The site is the goldstone tracking station The main downlink for NASA's interplanetary spacecraft e L that's coming from the pioneer which is now outside the solar system.
It's beyond the orbit of Neptune at a distance of about three billion miles.
Its carrier is a one-watt signal and that is about 1/20th of the energy of a candle burning so we're picking up a really small signal.
Tomlin: Finding pioneer's signal is easier than detecting an alien civilization's beacon.
Note this down and have him turn his signal on again.
Tomlin: The signal is weak and drifting in frequency but it's very close.
I have to go 333 147.
Tomlin: This test challenges the computer's ability to recognize an artificial signal in a sea of radio noi s.
This one's 291.
This one is 874.
Really? It's got rong tomlin: NASA has united Barney Oliver with a younger generation of computer programmers.
Let's see what happens, Peter.
Tomlin: Slated to last ten years and to cost $100 million SETI is one of the least risky items in NASA's portfolio.
They hope to be funded by 1988.
I think that's it.
This bright line you see, going, slanting down the screen is the signal from the pioneer 10 spacecraft.
Tomlin: D reli and to search the spectrum's entire favorable region.
By distinguishing different types of signals over a wide range of frequencies they will cover millions of times more possibilities than all previous searches.
NASA will use existing radio telescopes and equip them with new, sophisticated signal processors.
SETI deputy project manager, Mike klein describes NASA's two search strategies.
Klein: One of them is called the sky survey and another is called the target search.
The objective of the sky survey is to search the entire sky.
We have to do it quickly - which means we've sacrificed sensitivity to signals.
- we only detect the strongest of the signals.
Tomlin: NASA's survey will cover a frequency range 20,000 times wider than meta.
To cover the sky quickly it will drive the antennas more rapidly than usual.
So rapidly that researchers are worried the telescope mountings may the complimentary approach is to say let's concentrate on detecting with more sensitivity and on weaker signals.
To do that, we look in a few directions for longer periods of time.
We pre-select a set of stars that are similar to our sun and look in those directions with the ability to detect many more complex signals.
Tomlin: The targetted search will look at diffe equencies NASA hopes to use the world's great radio antennas in their search.
Antennas in the Southern hemisphere are also needed.
Most of the stars in the milky way are best observable from the Southern hemisphere but so far, only a few searches have been made from there.
The realities of contemporary SETI are quite different from the movie fantasies most scientists believe alien visits are unlikely and a dialogue would take too long.
A one-way radio message is the best we can hope for.
It isn't a complete tragedy if we just receive a message and can't talk back.
I've received lots of one-way messages of great significance from every author and thinker now in the human past.
But in SETI, it's our future that might be speaking to us.
Morrison: I think this can best be understood as an exercise in the archaeology of the future.
We're aware of the archaeology of the past.
We find a ruin, take a spade and dig into the ground and if you're lucky you discover something marvelous.
Now we never thought we could examine the same thing in reverse time.
But, in a way, we can.
We know that it's possible that somebody who wants to do it, will bring us in.
It is their past, but our future which we are investigating.
Even though they're made of different chemistry if they have got radio astronomy and the kind of technology we are imagining we have much in common The development of a culture.
So, that's the story.
It's a question of being patient.
You've got the spade.
You know the future is there.
It seems very wrong not to dig.
Captioned by the caption ce wgbh educational foundation funding for Nova is proded by: Supplyinhethar products wldwide d prime computer pplying integrated computer solutns the wld nufactg, mercial technical and scientic marketplaces.
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So they're shy in the day.
That's why you don't see them Unless you know how to communicate.
Hey, I mean, you got to admit it's likely there's all kinds of beings all over the solar system, don't you? We can't be the only things going.
That must mean they're all over the galaxy.
Tomlin: For thousands of years people have been looking at the skies wondering what might be out there.
It's moving! Tomlin: Hundreds of science fiction films have depicted what happens when there's a failure to communicate.
During the 1950s at the height of the cold war on this world many classic science fiction films suggested the aliens were implacably hostile and the sooner they were gone, the better.
By the 1970s, contact, not conflict became the theme of successful science fiction films.
The characters in these films try to communicate in pure tones A language they think might be universal.
Movies like close encounters of the third kind and e.
T.
, the extraterrestrial reflect and shape our changing concepts of the universe and just might help determine if we make contact with real e.
T.
S.
Hello, I'm Lily tomlin.
Recently, I was on Broadway, dy who receives extra-terrestrial messages through her umbrella hat.
I like to think of her as someone who lets her imagination overpower the reality that surrounds her.
But this program is about the real thing How we might actually contact alien civilizations.
Two A.
M.
, September 24, 1985.
In a physics lab at Harvard university earth's most sophisticated detector in the search for life in space in the tradition of hackers everywhere professor Paul horowitz and his student Brian Matthews burn the midnight oil.
To ensure something happens when the system is switched on five days later.
Horowitz: This will be 20.
4 kilohertz off of D.
C.
Say when.
Um Not yet.
Set Go.
Is that running? Oh, crud.
I don't know Okay Tomlin: This may seem like a shoe-string effort And it is But previous efforts have been less specialized using receivers not custom-made for the search.
What sits here is only half the system.
It now says We got a nice signal.
I'm making a chirp and you're looking for it.
Tomlin: Soon, it will be linked to a large radio antenna and the search to detect a signal from an alien civilization will begin.
Scientists have known about radio since the start of the 20th century but have Cade ers provided tools powerful enough for "SETI" The search for extraterrestrial intelligence.
Matthews: It's detected as a synthesized chirp and it tells you exciting messages.
Tomlin: Five days later, September 29 astronomers gather at a radio telescope near Boston.
For the ceremonial switching on of the detector horo up and inside, was still making last-minute fixes.
He calls the system "meta" Mega- or million-channel extraterrestrial assay.
Some of the scientists most interested in SETI came to the ceremony including astro-physicist Philip morrison who first proposed, some 25 years ago the basic methods meta uses.
The member-supported funds the operation of meta with the help of a donation from movie director Steven Spielberg.
An even more powerful detector is now under design.
These SETI experiments may fail to make contact with real e.
T.
S but scientists want to go beyond fantasy and communicate with another civilization.
I'm very happy to be involved in this project.
It benefitted so much from science fiction I just thought is was time to get involved in some science reality.
I just hope there is more up there than just reruns of the Jackie gleason show.
Tomlin: Among the scientists who have helped SETI grow is planetary society president Carl sagan.
May it find something! There is some chance that we will get a signal from some spectacularly distant spectacularly exotic civilization and everything on earth will, as a consequence, change.
That is possible.
Tomlin: If other civilizations where are they? Why aren't they here? After all, we humans are space travelers.
Wouldn't any civilization advanced enough to send a message come to earth in person like Spielberg's e.
T.
? In reality, space visitors would have to come a very long way for we on earth seem to have no close neighbors.
The viking spacecraft touched down on Mars and found no clear signs of life.
Other spacecraft have found no evidence of advanced beings on any other planet in our solar system.
The voyager ii spacecraft is the fastest vehicle ever built but it still took nine years to reach the planet uranus just over halfway to the edge of the solar system.
To find another advanced civilization we must look to the stars.
But voyager would take 100,000 years to r tars.
Barney Oliver, head of NASA's planned SETI project: Oliver: When you compare the costs of interstellar travel with ation they, like us, would choose interstellar communication.
It's far cheaper.
Tomlin: So if we have to expect s what's the best method of communication? That depends on who you're trying to talk with.
In the 19th century scientists still believed our solar system was teeming with life.
They assumed that other beings would be studying earth.
In 1833, a German mathematician, Carl gauss suggested planting in Siberia a huge triangle of wheat bordered by dark-green pine trees.
Alas, gauss' project was never funded.
Nor was the idea of Johann Von littrow, of Vienna who suggested digging geometrical shapes in the Sahara.
He wanted to fill the trenches with kerosene and to set them ablaze to make a glowing beacon on the night side of earth.
In fact, these bizarre schemes might well have worked if aliens had existed on Mars or Venus.
But methods of communication that work over inter-planetary distances have no chance at all between the stars.
Distances between the stars are so enormous that astronomers measure them by the velocity of light.
E ar Six trillion miles.
Our galaxy, the milky way is 100,000 light-years across.
The galaxy contains an enormous number of stars and a vast potential for other civilizations.
Skeptics say that advanced civilizations would surely have made themselves visible but we have seen no evidence of life "out there.
" So, justify h? In 1960, frank Drake made the first radio search for civilizations in space.
Drake's experiment for over 25 years, Drake has kept on looking.
What does he think we might learn? The most important information would be just the simple that will tell us that civilizations like ours can thrive for long periods of time and overcome the threat of nuclear war preserve their environment maintain high technology and a high quality of life and all of that is very important to know.
Tomlin: Drake called his pioneering search "ozma" after a Princess in the fictional land of oz.
He said SETI also deals with faraway lands.
But maybe SETI itself is just as fanciful as the land of oz.
Drake argues that what we already know plus what we have good reason to believe justifies the search.
He came up with a way to organize our knowledge and our ignorance.
Scientists call this "the Drake equation.
" The Drake equation presents seven conditions astronomers think necessary for the existence of a civilization which could send a message to us.
If you make an estimate for each term and multiply them all together you end up with an informed guess about how many advanced civilizations are out there.
The larger that number, the easier to establish contact.
The first term in the equation is the number of stars in the milky way.
This is the only term we know with a fair degree of accuracy.
By observing other galaxies as well as our own we estimate that the milky way contains about second, how many planets might orbit these billions of stars? We don't have clear evidence of any planets outside the solar system but with much improved technology the hunt is on.
In 1985, rich terrile of NASA's jet propulsion laboratory of a faint disk of material surrounding the young star beta pictoris about 50 light-years from earth.
This may be humanity's first glimpse of another solar system.
The disk of material may be about to form planets.
Some scientists argue that, like our sun the majority of stars have planets.
The third term in the Drake equation asks how many planets, or their large moons would provide an environment suitable for life? In our own solar system, we have found no evidence of life on the airless, waterless moon.
Nor in the swirling clouds of Jupiter nor beneath the majestic rings of saturn.
Some scientists believe Mars was once more habitable.
They point to its polar caps of ice and to riverbeds that channeled water a billion years ago.
They look at Jupiter's large moon, europa and wonder about possible life beneath its frozen crust.
They yearn to Pierce the clouds that shroud saturn's moon titan where conditions may resemble earth's at the time when life arose.
In a solar system with some 20 worlds one hit and three near-misses implies that many planets may be habitable by some forms of life.
The fourth question is, on how many of these suitable worlds in a now famous experiment Stanley Miller and his colleagues took answ toward n.
They tried to create a dynamic model of the earth as it was four billion years ago.
The flask represented conditions on earth before life appeared.
They mixed in simple chemical compounds or the sun's energy.
The simple molecules broke apart and then formed more complex compounds.
Four billion years ago these compounds would have rained into earth's seas where they could have formed even more complex molecules such as glycine, one of the amino acids The basic building blocks of life on earth.
Scientists have also found amino acids in meteorites.
These amino acids apparently formed in an environment even more hostile than that of the primitive earth.
From simple organic molecules to a living, reproducing organism, like us is a huge step.
But the most basic building blocks of life appear to be common throughout the universe.
The fifth term in the Drake equation asks how many worlds nurture not just life, but intelligence? We know that on earth simple forms of life have gradually evolved to become intelligent life.
The survival value of intelligence may be so high that intelligence arises wherever life emerges but for now, we just don't know.
The sixth term is the fraction of planets with intelligent life on which emerges a technologically advanced civilization Arbitrarily, one that can use radio.
On earth, we're batting one for one but on other worlds the most advanced forms of intelligent life might be rather like whales or dolphins.
Even if there's a lot of them out there we can't hope to communicate.
Does advanced technology carry with it the seed truction? The seventh question The average lifetime of a technological civilization Cannot easily be answered until we succeed in SETI.
If many civilizations flower briefly and then disappear only a few can be sending messages and SETI will be difficult, if not impossible.
If you ask scientists for estimates for each of the terms you'd find a wide variety of opinions even on factors we think we know.
How many stars are there in the milky way? There are 200 billion stars in our galaxy.
About 20billion stars.
Everybody agrees about 100 billion stars.
I think probably about 400 billion.
A few hundred billion.
Tomlin: How many planets are there per star? About ten planets in each planetary system.
About ten planets per star.
About eight.
One star in ten might have planets.
Several per star.
Tomlin: How many planets per star are suitable for life? One or two planets.
One.
One.
One.
One per system.
Tomlin: Let's get more speculative.
On how many of these worlds does life actually begin? Just the most optimistic s.
It's pretty close to every suitable planet.
It's basically a sheer guess.
Maybe one in ten to the eighth just because eight's my lucky number.
Tomlin: One planet in 100 million? What's the chance of life becoming intelligent? Systems of living things given a few billion years will produce intelligence.
Again, I choose one in ten to the eighth.
Tomlin: On how many worlds would intelligent beings develop the technology to communicate? Wherever intelligence develops it is likely that technology also will develop and the ability to communicate across space.
After intellence forms perhaps a one percent chance of radio communication.
Tomlin: Now, gentlemen what are your guesses for the shortest and longest average lifetime of a technologically advanced civilization? I think if a civilization crosses a technological threshold then that time could be measured in millions of years.
If a civilization doesn't attain that threshold it could 50 or 100 years.
I think it will be billions of years.
Basically, the full lifetime of the star.
I can't imagine that an advanced civilization tomlin: What's the bottom line? Optimistically, frank Drake says there could be at least 10,000 technologically advanced civilizations in the milky way alone.
The larger the number of civilizations the nearer to us our closest neighbor might be.
But Ben zuckerman's pessimism says that no other civilizations exist in the milky way and possibly not in other galaxies.
How useful is the Drake equation? Nobody takes these numbers to be tremendously serious.
Nothing depends on there being a million civilizations as opposed to a billion or a thousand.
The only question is are there many, a few, or none? And as long as there is a plausible argument for many we ought to keep looking.
If there's an argument for a few even if there's an argument that nobody is out there Bearing in mind that we can be wrong We ought to keep looking.
.
It calibrates our place in the universe.
So, it is worthwhile looking for other civilizations I would say, no matter what.
Tomlin: Since these pessimistic and optimistic estimates are simply the results of multiple speculations experimenters such as Paul horowitz aren't willing to stop there.
Horowitz: People have argued about the probabilities that there's life elsewhere in the universe.
It's easy to come up with arguments that make it semi-probable or highly improbable but they're nothing but arguments.
If you want to answer this question to d ent.
Tomlin: Modern equipment is essential but SETI involves more than electronics.
Making contact means considering the technology of whoever might be on the other end.
First, where and when to look? Ernestine's message service.
You stay in touch 'cause we care so much.
Mr.
green? Your rich uncle, Mr.
pursewarden, did phone.
He will call to say how he's coming to town.
You must stand by as you will not be able to reach him once he's gone.
( Telephone ringing ) E.
M.
T.
Oh, miss pinkney A conference call with Mr.
right and Mr.
bright.
Do you have their numbers? Do I have their numbers? If I did, would I be here? ( Telephone ringing ) E.
M.
T.
Oh, Mr.
pursewarden! Yes, sir, I am two ringy-dingys.
Three ringy-dingys.
There's no answer.
I told him to stand by, sir.
Very well and what a pleasure talking with you! E.
M.
T.
Yes, Mr.
Jones.
The 6:00 P.
M.
meeting is now at seven for six.
There's nothing really hard to understand about that, Mr.
Jones if you'd just concentrate.
E.
M.
T.
Yes, Mr.
green, Mr.
pursewarden called.
Just where were you? Really? When I say "stand by," i mean by the telephone.
What did he say He's coming to town next month and if you don't meet him, you're out of the will.
He didn't say how he's coming.
I don't know if he'll call back.
There is no need to yell at me.
Yes, I suppose it is a little intelligence test.
Just figure out where to meet him and stay there.
? Mr.
green, if you're going to shout I'm going to give your plug a yank.
Very well, sir, I understand.
No calls until you figure it out.
Tomlin: In SETI, we're in even worse shape than Mr.
green.
We don't know if there is a rich uncle or where he wants to meet.
Can we figure out how a message might be sent? Consider a great canyon as the chasm of space between the stars.
You're on a camping trip and think someone else is out there.
You want to get in touch but how? Suppose, on the other side of the canyon that "someone" also wants to communicate.
Just by looking, there's no sign of anybody.
One thing's certain about communication Some methods work better than others.
Suppose you realize that a Star Trek is impractical.
In your frustration you come up with an alternate strategy.
Sending a message by unmanned probe might seem preferable.
We humans have put slightly more sophisticated messages aboard the pioneer spacecraft.
Still, there's the question of how much energy you can deliver.
And space is awfully big in comparison to an interstellar probe.
Maybe sending small particles of matter isn't the best idea.
Suppose you send messages by waves Hello! Tomlin: Sound waves, for instance.
You might discover that different frequencies have different characteristics.
As every schoolchild knows at a distance a low frequency shout attracts your attention less than a whistle.
But the most piercing whistle won't be heard even a few miles away.
Well, life must go on.
You need warmth and light.
A camper, like a civilization, may do things for his own purposes that could be visible across the cosmic canyon.
You might not even realize you stumbled on a means of communication.
Across the canyon, the flames might be seen but thought to be a brush fire.
There's no sign of intelligence but it might give you an idea.
Suppose you build a fire but modulate or manipulate the puffs of smoke.
You're sending a clearly artificial signal that travels at the speed of light and es.
But if the laws of Murphy hold true throughout the cosmos then even your best idea may fail.
One civilization may be asleep when the other is sending.
But suppose you were given a method of communication common to both sides of the canyon.
Suppose it was fast, cheap and efficient.
Call it "radio.
" It might seem that your troubles were over once you've learned to turn on and tune in.
But in fact, your work is just beginning.
Hello.
Uh.
Channel one, too obvious.
Channel two.
Hello? Tomlin: Even with just two channels on a walkie-talkie it takes time to figure out when to speak or listen.
Hello.
Tomlin: Successful communication requires mutual agreement on how to communicate.
In SETI, an unspoken agreement must somehow occur without a meeting.
For all these difficulties most SETI scientists think radio is the way to go.
You can see why if you look at how well signals of different frequencies channel one.
Hello.
Tomlin: Light and radio are both parts of the electromagnetic spectrum.
Light's frequency differs from other kinds of electromagnetic radiation.
Light, itself, comes in many different frequencies which we call colors.
Red has the lowest frequency blue a higher one.
All the colors of light span only a tiny part of the electromagnetic spectrum.
At infrared frequencies Below those of visible light on the spectrum the black, but warm campfire glows brightly.
So do the sun the trees and people.
At lower frequencies we observe the scene in radio waves.
The sun is a weak source of radio.
But the milky way, on the left is a strong one.
Artificial sources of radio like our camper's walkie-talkie stand out because the earth has few natural radio sources.
The same principles apply in the heavens.
In visible light, the sun outshines the earth.
That's one reason we haven't been able to detect planets around other stars with even the largest optical telescopes.
It's like trying to see a firefly perched on the rim of a searchlight.
In infrared even earth's dark side glows.
The milky way forms a bright band.
But it's radio that gives earth its unique signature as the home of intelligent life.
At certain times and frequencies the earth outshines all other sources within the solar system.
These radio waves also make earth stand out to d ons.
You ever wonder what goes down when the theaters close? When no one's watching? This program is an interstellar message.
Thirty-three minutes after this broadcast began our opening sequence has traveled 370 million miles and has nearly reached the orbit of Jupiter.
Some of the radio waves that carry TV broadcasts leak into space and expand at the speed of light.
Three hours from now, this program will overtake voyager two billion miles from earth.
Voyager has been traveling for nine years.
If in our imagination, we could travel much faster than light we could overtake our radio and TV broadcasts.
Four and a half light-years from earth we might find news of a royal wedding passing the sun's closest neighbors Alpha centauri a and b.
Any planets around the star, altair 17 light-years from earth are now receiving our news from the late 1960s.
Houston, delta landing, over.
Roger, 1201.
That's one small step for man one giant leap for mankind.
If they had sensitive enough detectors they could watch as we became a space-faring civilization.
Any beings on planets around fomalhaut 23 light-years from earth might see evidence of humanities' nobler aspirations.
Where they will not be judged by the color of their skin I have a dream.
Planets near arcturus or pollox each about 36 light-years from earth might pluck from the cosmic background shows from the early years of television.
Jackie gleason.
The honeymooners.
Aliens might not share ousense of humor and might find programs hard to decipher but there's still much to be learned.
As the earth turns TV, military radar and microwave signals appear and disappear over the horizon.
As a guide to what we may learn about another civilization by eavesdropping on its unintended signals - astronomer Woody Sullivan has studied - what our radio transmissions reveal about earth.
Sullivan: We found you could get the earth's spin rate the earth's size.
You could map where the earth's television stations are located.
You could get the size of the earth's orbit.
You could get the temperature of the earth from basic physical principles.
Think about the difficulty of trying to purposely send a bit of information such as the temperature of the earth.
- Tomlin: What about a message beamed toward us? - we may discover a clue to its contents in t single mess age we have sent into space.
Puerto Rico's arecibo raditelescope is the earth's largest collector of radio waves.
Frank Drake used the arecibo dish to beam a signal toward a distant star cluster.
The signal was a stream of on-off pulses shown here as zeros and ones.
9 pulses repeated an alien civilization might ss unless it realized that 1,679 is the product of two primes, 23 and 73 numbers that are divisible only by themselves, and one.
If the language of mathematics is universal they might hit on the mathematical device of arranging the ones and zeros into columns and rows.
If they darkened the ones, they'd see a picture A crude representation of the beings that sent the message.
A map of our solar system with earth singled out a diagram of the arecibo dish and the all-important DNA molecule.
The arecibo message was beamed toward a star cluster in the constellation Hercules, 25,000 light-years away.
50,000 years from 1974 and about the year 51,974 humanity could receive a reply.
At a symposium, celebrating meta's switching-on Carl sagan and others discussed whether we should send messages or listen.
They argued a reply takes a little too long.
If you're sending you have to wait for travel time At least ten to 20 years.
Those experiments are intrinsically less interesting.
And that's a very optimistic number, ten or 20 years.
Even the most optimistic estimates of the distances to the nearest civilizations generally, are hundreds of light-years away.
So if you said, "hello" it would be 2511 that the message would get back.
Tomlin: What might a message say? What would we like to know? Like perhaps a cure to some of our own human ills like cancer or pollution or the gradual loss of our resources and stuff like that.
I think with all the scare that science fiction puts into the public's minds of these monsters that want to take over our planet I think a friendly message would make everything worthwhile.
And I hope they can teach us how to handle our technology and teach us about how to prevent the environment from being ruined.
Tomlin: Most SETI scientists have a different perspective.
What I would like to know is an answer to a very simple question.
Are we alone, as conscious beings in this 400 billion-star galaxy? It seems pretty implausible.
Tomlin: Phil morrison thinks the signal but the public would feel differently.
It'll be a sensation when it's confirmed.
And then it will turn out to be false then finally confirmed and that would be a sensation.
It'll occupy the front pages of the newspapers for a week.
It'll occupy the inside pages for another month.
And that will be the end of it.
But interested people will grow up everywhere.
They'll build other receivers.
All countries will have them and they'll pool the signals and where it's coming from and a thousand authors will arise to say what they look like and who they are all of which will be false.
And gradually, the truth will come out.
The come and say, "what do they look like?" If radio f choice and listening our best strategy does this make contact easy? Is it enough to turn on our radio detectors and wait? Well, not exactly.
A gracious hello, et&t.
Ernestine tomlin, atop the transmitter.
Let's see what's on the "radi-o," daddy-o.
Oh, yikes, yikes.
There's that crazy radio beacon again.
Aggressive bunch of jokers in that galaxy.
Too bad no one listens to that frequency, fools.
They broadcast one minute, every thousand years.
Just how long did they live? Try 1420 megahertz and keep doing it.
Those nudnicks think they're so great with their zeta-waves.
What a shame no one else has discovered them yet.
If they'd think archaic they'd get an audience.
Oh, there's that catchy tune.
Da, da, da, da, da, da, da.
da, da, da, da, da, da, da.
Oh, I do love that fat guy.
And that Norton.
Must be a real fun planet down there.
Too bad it's so far away.
These life-forms are fascinating.
But of course, none so much as I.
Tomlin: Ernestine is grappling in her usual, efficient manner but the many problems that remain for SETI scientists who have chosen radio What kinds of signals to expect, when to listen and where and how many frequencies to monitor.
An ordinary fm radio dial shows frequencies in megahertz or mhz one million vibrations per second for the radio waves carrying the broadcast.
To avoid interference we, on earth, license a sm but the cosmic radio dial is very different.
The region between 90 and 92 megahertz can contain 20 million different channels each capable of carrying a message from another civilization.
With a conventional radio receiver the signal would be lost in the sea of background noise.
The cosmic radio dial must be sliced much finer.
On the cosmic dial, the region from 88 to 108 megahertz contains about 200 million potential channels.
And fm is just a tiny part of the spectrum.
- Belo - for ts.
Nds all the way down to zero frequency.
With ge how can we possibly figure out what frequency an alien N we believe, and that is in the microwave region.
The reason for that is that the noise that would interfere with our transmissions or theirs, is lowest there.
Tomlin: We find the low frequencies, shown at left - are noise in - space.
Es.
In the middle, lies the preferred region.
There are about 100 billion potential channels here.
Are there any other clues to help narrow the search? One basic fact about the universe is that hydrogen is the most abundant atom.
- Hydrogen atoms naturally emit radio waves - at one particular frequency 1420 megahertz.
That the universe might tell us where to look in frequency was first proposed by Philip morrison.
At the symposium on meta he reasoned that intelligent beings could re ment.
Morrison: This in an anti-cryptological game.
A game where the rational transmitter says "i want to make it easy for those distant, primitive folk "to get onto this channel.
"I will not conceal it.
"I'll make it as self-transparent as visible as possible.
" Tomlin: Ency helps to simplify the task of sifting the cosmic haystack.
An alien civilization might broadcast a powerful signal at this magic frequency hoping it could be detected above the background noise.
Drake's ozma search used 1420 megahertz to scan two stars for 400 hours.
His receiver could cover only one channel like a radio tuned only to one station.
A search called ozma ii, made by Ben zuckerman looked at 674 stars also around this magic frequency.
And horowitz in meta is still essentially playing the magic frequency game.
Unlike the ozma searches which looked at individual stars meta is a sky survey.
Meta's antenna sweeps out a beam across the entire sky.
In eight months, meta surveys the entire sky visible from the observatory.
When one survey is complete at a different magic frequency.
But astronomers have come up with more than a dozen magic frequencies.
Because the earth is always moving any signal will drift in frequency over time.
So SETI detectors must be able to scan many channels or groups of frequencies.
Drake's ozma detector had only one channel One ten-thousandth of a megahertz wide.
Horowitz's system scans 8.
4 million channels.
It can do in a second what would have taken ozma five years.
- Horowitz: - This - as an receiver - 8.
4 and where you do one channel after another, sequentially.
This receiver box is like 8.
4 million radios all tuned to successive stations.
Tomlin: Despite this progress meta covers only a small part of the radio spectrum.
But it is perhaps the ultimate magic frequency machine.
From this array the information passes to this controlling computer.
This computer really rides herd over the whole system.
It downloads the instructions to the different processors keeps track of the earth's motion and looks for possible signals of extraterrestrial origin.
When it finds something it does several things.
It archives unusual, rder.
Actually, a friend of mine came and looked at this and said "horowitz, the reporters will say 'show us what happens if a signal comes in.
'" so I said, "we can do that by turning on an oscillator.
It'll say, 'large peak.
'" and he said, "no, no, no.
"Have it say "'notify operator immediately.
Possible signal of extraterrestrial origin.
'" tomlin: No such signal of extraterrestrial origin has yet been detected.
We have hardly begun to search.
We've hardly searched all the various frequencies from which signals might come.
The fact that of extraterrestrial life is not discouraging.
We shouldn't have found it yet.
We have hardly begun.
Tomlin: In the heart of esert NASA researchers are testing prototype equipment specially designed for a far more comprehensive search.
The site is the goldstone tracking station The main downlink for NASA's interplanetary spacecraft e L that's coming from the pioneer which is now outside the solar system.
It's beyond the orbit of Neptune at a distance of about three billion miles.
Its carrier is a one-watt signal and that is about 1/20th of the energy of a candle burning so we're picking up a really small signal.
Tomlin: Finding pioneer's signal is easier than detecting an alien civilization's beacon.
Note this down and have him turn his signal on again.
Tomlin: The signal is weak and drifting in frequency but it's very close.
I have to go 333 147.
Tomlin: This test challenges the computer's ability to recognize an artificial signal in a sea of radio noi s.
This one's 291.
This one is 874.
Really? It's got rong tomlin: NASA has united Barney Oliver with a younger generation of computer programmers.
Let's see what happens, Peter.
Tomlin: Slated to last ten years and to cost $100 million SETI is one of the least risky items in NASA's portfolio.
They hope to be funded by 1988.
I think that's it.
This bright line you see, going, slanting down the screen is the signal from the pioneer 10 spacecraft.
Tomlin: D reli and to search the spectrum's entire favorable region.
By distinguishing different types of signals over a wide range of frequencies they will cover millions of times more possibilities than all previous searches.
NASA will use existing radio telescopes and equip them with new, sophisticated signal processors.
SETI deputy project manager, Mike klein describes NASA's two search strategies.
Klein: One of them is called the sky survey and another is called the target search.
The objective of the sky survey is to search the entire sky.
We have to do it quickly - which means we've sacrificed sensitivity to signals.
- we only detect the strongest of the signals.
Tomlin: NASA's survey will cover a frequency range 20,000 times wider than meta.
To cover the sky quickly it will drive the antennas more rapidly than usual.
So rapidly that researchers are worried the telescope mountings may the complimentary approach is to say let's concentrate on detecting with more sensitivity and on weaker signals.
To do that, we look in a few directions for longer periods of time.
We pre-select a set of stars that are similar to our sun and look in those directions with the ability to detect many more complex signals.
Tomlin: The targetted search will look at diffe equencies NASA hopes to use the world's great radio antennas in their search.
Antennas in the Southern hemisphere are also needed.
Most of the stars in the milky way are best observable from the Southern hemisphere but so far, only a few searches have been made from there.
The realities of contemporary SETI are quite different from the movie fantasies most scientists believe alien visits are unlikely and a dialogue would take too long.
A one-way radio message is the best we can hope for.
It isn't a complete tragedy if we just receive a message and can't talk back.
I've received lots of one-way messages of great significance from every author and thinker now in the human past.
But in SETI, it's our future that might be speaking to us.
Morrison: I think this can best be understood as an exercise in the archaeology of the future.
We're aware of the archaeology of the past.
We find a ruin, take a spade and dig into the ground and if you're lucky you discover something marvelous.
Now we never thought we could examine the same thing in reverse time.
But, in a way, we can.
We know that it's possible that somebody who wants to do it, will bring us in.
It is their past, but our future which we are investigating.
Even though they're made of different chemistry if they have got radio astronomy and the kind of technology we are imagining we have much in common The development of a culture.
So, that's the story.
It's a question of being patient.
You've got the spade.
You know the future is there.
It seems very wrong not to dig.
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