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February 4, 2000


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The Rediff Interview/ Dr Paul Shuch

'What do you say to a bacterium?'

Now let's assume that looking at the earth again and you see all these radio signals coming your way and they rotate in this 24-hour period and then, all of the sudden, the signals all disappear. But because you are not easily discouraged you keep looking and six months later they are back again. And six months later they disappear again. From this, you conclude the earth is revolving around the sun once every year.

Now let's say that you are an astrophysicist on this distant planet and you know the basic laws of celestial mechanics. I am using an example of what we consider primitive technology on earth because it was discovered here hundreds of years ago... Kepler and Newton and so...

If you know Keplarian mechanics and Newtonian mechanics (let us say you are a sixteenth century intellect), you notice that from the visible appearance of our star, which you can see from your telescope... You figure out the approximate mass and the approximate size and the approximate temperature of our sun.

Now if you that the planet orbiting round the sun has a specific orbital period you can calculate very quickly how far our planet is from its sun and by knowing the spectrum of our sun you can figure out what the surface temperature of our planet must be and, from that, [that] this planet has liquid water.

All this you discover just from radio signals. We hope to discover the same sort of things just from intercepted radio signals.

But to know that the signals are really coming from the stars what else do we see? We look at the frequency of reception over time and we see that, for a true distant signal, for a true astrophysical signal or artificial signal from an intelligence, that signal changes over time at a very predictable rate. That change in frequency is caused by a phenomenon that we call the Doppler shift. And by looking at the Doppler signature of a signal we can say, this is coming from the earth, this is coming from the stars, this is coming from a low-earth orbit satellite or this is coming from radio waves reflected off the moon or any sort of debris. We can tell all this from the Doppler shift. So, that is one of the lines of evidence that we see.

Then we look for spatial coherence. Does the signal move through the pattern of our antenna in a way that is consistent with our hypothesis. We know that the antenna has a particular geometry of reception and that geometry of reception translates into the time it should take a signal to transit our view. So we look at that.

Next, we look for frequency coherence. Natural sources such as star noise tend to be very spectrally broad. They occupy a wide range of frequencies...

What exactly is star noise?

Star noise sounds just like a hiss. If you listen with your ear to a radio receiver it sounds just like ( makes a whooshing sound) sounds just like background noise. You can see it on your television set. Tune to a non-used channel and you will see white and black little sparklies on the screen. This is star noise if your antennas are pointing in the sky. That's what star noise looks like and sounds like. But it covers a wide range of frequencies. Intelligent communication tends to cover a narrow range of frequencies. So if something is broad it is probably natural. If it is narrow spectrally it is possibly artificial.

At a higher level of analysis, let us assume that a signal has passed all these tests. It has spatial coherency, temporal coherence, frequency coherence... They exhibit a periodicity and have the right Doppler shift. These are very convincing lines of evidence. But if we are intending to intercept signals from an intelligent species, it would be very helpful if the signals would be received on a frequency which in itself indicates some special knowledge on the part of the transmitting civilisation.

If, for example, I want to signal my neighbours across the cosmos I know that the most abundant element in space is hydrogen. I know that hydrogen atoms radiate a radio signal at a known frequency.

The atoms themselves spit out photons of energy periodically at 1420.40575 Mhz and this is not a known piece of knowledge. I have this knowledge because I possess the knowledge of radio astronomy.

Any civilisation that has radio astronomy possesses this piece of information. If I have to announce to another species, 'I am intelligent'. If I want to say I understand radio astronomy one of the waves I can communicate is by transmitting on the hydrogen line. Now I have said I have knowledge and here is the proof that I have some knowledge.

What is the hydrogen line?

1420.40575 Mhz. We know this to high accuracy and other civilisations we assume would also know that too accurately. There are many other what we call the magic frequencies because they imply some knowledge of the physical universe. Any civilisation that transmits on one of these magic frequency, we must assume that there is some intelligence behind it or at least some knowledge of the universe.

At the next highest level -- and this is a dream, perhaps not realistic... But it would be very nice if they would transmit to us information content, send us messages. Maybe we would be incredibly lucky and the signals would contain the Encyclopedia Galactica. If that happens it is the highest proof that it is an artificially generated signal. But out of those various characteristics we look for whatever combinations that might exist.

If you spot a signal that is of extra terrestrial origin and it seems to fulfil most of the characteristics you have described do you think it will have a message in it or would it just be a unknown pattern on the receiver?

I believe based upon the limitations of our present earth technology we are unlikely yet to receive information content. We will first merely detect the fact that this is artificial. If a detection of that sort is made and even if there is no information content and if that detection is corroborated by other observers...

This is important... One observation is never sufficient. You must have multiple observations.

Given that this occurs I believe, personally, that funding will materialise for developing the next generation of instruments for the next task which is to have greater sensitivity and the ability to seek out information content. First, we need existence proof. Without existence proof we cannot hope to think about information. Once we have existence proof then I am sure that earth will clamour to develop the technology to seek the next level of sophistication.

SETI's endeavour is to find that one pattern which will indicate intelligent life exists in outer space. But what happens once you find a conclusive pattern?

There are four steps initially that are taken when a signal is received. And in very general terms, the first step is, if you are a radio astronomer and you have a signal that is a candidate... First you must run a diagnostic on your equipment to make sure it is not lying to you.

What kind of diagnostic?

Use some sort of laboratory test equipment to verify that your antenna and receiver are working properly that they are really doing what you think they are doing. All of our members... All SETI League members who are building radio telescopes also build as part of the process such test equipment by their system. But you can't be having the test equipment running continuously. Then you can't be able to watch the stars.

So, you have it standing by, waiting so that when you get a detection run a quick, rapid check of your equipment to see if it is functioning properly because equipment can fool you sometimes. If you determine there is no equipment malfunction, the second step is the one that is the province of the psychologist.

As a human being I judge what is flawed. So, I must run a diagnostic on myself to judge that I am not fooling myself. Assuming that I have some way of questioning my judgement and logic and I satisfy myself that, yes, this is really what I am seeing... I am not imagining this.

Then the third step is the process is to invoke collaboration. Seek out another observer who can independently confirm your observations. Here is where strength and numbers is important.

When the SETI League reaches full strength at our dream of 5,000 radio telescopes world-wide it will then be trivially easy to have many independent confirmations of any observation. Right now, we have only 85 observers. That is still enough that we have some opportunity for confirmation or non-confirmation, as the case might be.

If no else is able to see what I am seeing then I must be very suspicious of my results. If other people can also see the same thing, then ruling out the possibility of mass delusion, we have the possibility that we are indeed receiving something valid.

Step four in the protocols is, 'Tell everybody!' Tell you and all the other journalists. Because this message belongs to all humankind and it would be irresponsible science for us not to share our findings with the waiting world. The discovery if made does not belong to one individual or one organisation or one university or government on earth. It belongs to all humankind.

What happens next?

If we are quite certain that we have something valid and it's been corroborated by our colleagues then you go to work. You write your story and knowing what I know about human attention span it will be page one news for about a week. Then it will be on the inside pages of a newspaper for about a month.

And then it'll disappear from the press because people will go back to their mundane lives and then the scientists start the real work. Which is analysing what we have found. And, Personally, I'll go on a lecture tour!

Would we then think about some kind of dialog by transmitting out signals?

The problem is that radio telescopes are time machines. If there is a star thousand light years away sending signals -- and that is very likely, I believe-- those signals arriving here today have travelled a thousand years to get here. I could answer them. In a thousand years I will get my response and in another thousand years I could get some more information. It is a very slow dialogue. I do not see much prospect for dialogue. I think what we have to do is on the lines of electronic archaeology. We dig through what we receive and try to extract as much meaning from it as possible.

So if SETI just finds an affirmative answer to the question, 'Are we alone', would that mean the end of it all?

It is suggested that once we have existence proof of other civilisations people will stop being interested in what's out there. I don't think so.

After all, after Charles Lindbergh flew across the Atlantic ocean, we all know that the aviation industry stopped completely. No one else was interested in flying ever again. Right?

No. Of course not. That Lindbergh was only the beginning. Lindbergh could not anticipate what would follow after his trip from New York to Paris. We all know that after Lindbergh made his trip and proved the possibilities, whole new industries were born. This will happen with SETI. Once the detection is made I cannot anticipate what those new industries will be. But that detection, that knowledge, will change our planet and our way of life in ways that we now cannot begin to anticipate.

What are the challenges before SETI today?

SETI has gone through cycles, in which it has gained and then lost funding from various sources. To do a good search is not inexpensive. The equipment costs, the manpower costs, the time that must be committed, the resources that must be committed, are non-trivial. In the US there was briefly a government-funded SETI program of grand proportions conducted by NASA, funded by Congress to the tune of about twelve-and-a-half million dollars per year. They had a plan to do a thorough search involving two components -- a sky survey and a targeted survey for a period of 10 years.

At the end of 10 years, they figured they would have either answer to the question or found new technologies by then. The 10-year SETI plan went online on October 12,1992. They turned on the switches, turned on the antennas and started observing. Just one year later, in 1993, the project was cancelled by the Congress. All the funding was terminated. After only one year of the 10-year search.

The reasoning given by our elected officials in the US... Senator Richard Bryne from the state of Nevada gave a nice little speech. He said, "We have been looking for one whole year. We have spent millions of dollars, and not one little green man has stepped forward to say, 'Take me to your leader.'

This, Senator Bryne said, proves they are not there. Well, unfortunately he had the popular will behind him because most Americans -- most laymen -- can think of something better to do with 12 million dollars in a year than look for aliens. Never mind we are only talking about two rupees per American citizen. Each citizen wants his two rupees. So the government support for SETI was terminated.

But isn't there something better to do with the 12 million dollars than look for aliens? What do we gain because of all this spending?

What we gain is technological fallout... spin-offs. In the process of designing better SETI receivers my colleagues and I have also developed technologies that have commercial applications for the telecommunications industry, for the computer industry. As we develop with the objective of doing SETI, as we develop new technologies, our colleagues in the industries find ways to apply these technologies to benefit humankind.

Simple example: the Cold War was a period of tremendous waste of money. We spent it on weaponry. What do we have to show for it? Well, we have for show communication satellites and global television and global Internet. It never would have been possible without the Cold War... And the personal computers. It has completely changed our way of life.

SETI is similar. The money is not wasted. Even if we never hear a whisper from the sky the technologies that we develop for SETI will have practical applications on earth... Maybe in biomedical electronics, maybe in information-processing technology. I can't anticipate. All I can say is that science -- pure science -- has been a wonderful breeding ground for serendipitous discovery.

Since the US government stopped funding the SETI search, the movement has gone private, with a host of private organisations being established. How do these organisations deal with funding problems?

Each in its own way of course. My colleagues at the SETI institute in California have a rather impressive budget not quite as large as the old massive SETI budget. But I think they are spending perhaps something close to seven million dollars a year right now. That money came from trying to turn misfortune into a positive experience. Two prominent industrialists of the United States died about a year apart. Dr Bernard M Oliver who had been the vice president of engineering of Hewlett Packard Corporation and who had been a strong SETI supporter.

And, a year later... David Packard, who was the co-founder of the Hewlett Packard Corporation, coincidentally died about a year later. Both of these gentlemen left their estates to SETI institute for use in the research. They very generously endowed through their personal fortune many millions of dollars to the SETI institute.

This is how Project Phoenix is being financed. When that money is gone we can hope that someone else dies. But I am not going to suggest that!

In fact, SETI has also had generous gifts from living people. A few come to mind. Gordon Moore, founder of Intel Corporation, has donated very generously to SETI. So has the guy who founded Asysmetric Corporation. What's his name? He was also one of the principals in Microsoft at the beginning.

I should remember his name... it escapes me at the moment. But industrialists have supported SETI very generously.

How does SETI League deal with the problem of funds?

The SETI League is a different kind of organisation. We are an amateur participatory grassroots membership supported organisation. We don't receive multi-million bequests. Well, actually received one bequest. It was to the tune of about half a million dollars. It was from an attorney who was one of our founders who died a few years ago. And he left us a very generous bequest.

That's the money we are spending, trying to spend abstemiously at the rate of 100,000 dollars a year. So we will be running out of that money in two years. But it has given us some sustenance in funding. But aside from the occasional inheritance our support comes from the individual contributions of our members around the world -- about 1,200 of which who pay on average 50 US dollars per year in membership dues.

It's not a great deal of money for us. But we don't need a great deal of money because our efforts are all volunteer efforts. We don't have to pay a staff of professional scientists. We have a coterie of amateur scientists with high levels of enthusiasm willing to spend their own time and own resources on building their individual radio telescopes. This helps a great deal.

So if you are a SETI league member who is affluent and wishes to build a radio telescope, your contribution to SETI goes far beyond your 50 dollars to the SETI League, because you are also contributing hundreds or thousands of dollars of your own equipment... Hundreds and thousands of dollars of your own labour. And this is all of great value. We have learned that, through volunteer efforts, a great deal can be accomplished at very low cost.


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