archive: FW: Optical SETI Article from The London Times

FW: Optical SETI Article from The London Times

Larry Klaes ( )
Fri, 4 Sep 1998 10:04:38 -0400

From: Dr. Stuart A. Kingsley
Sent: Thursday, September 03, 1998 6:54 PM
Subject: Fwd: Optical SETI Article


Can you get me a copy of this London Times bank holiday article on OSETI?

>Date: Thu, 3 Sep 1998 10:18:41 -0400 (EDT)
>From: "Joseph V. LeSesne III" <>
>Subject: Optical SETI Article
>I guess they hadn't heard of you. Do you know anything about this project?
>Source: The Times [of London]
>Monday August 31 1998
>Features: Mind And Matter
>Scientists have a new way of contacting
>extraterrestrials, says Nicholas Booth
>The light way to track an alien
>If ET is trying to contact us, he won't be phoning - he will use
>the powerful flashlights that are lasers to draw our attention.
>Like lighthouses on the unexplored seas of space, these unique
>flashes of laser light, which astronomers can detect with simple
>equipment, will soon tell us whether any stars are harbouring
>advanced civilizations.
>That is the startling claim of the American inventor of the
>laser, Charles Townes, who has long urged his colleagues to look
>for such tell-tale signs of alien intelligence. All scientific
>searches to date have involved listening for radio signals from
>alien civilizations; now a team from the University of
>California at Berkeley will use a simple, antiquated telescope
>to try to spot the laser flashes.
>At 83, Professor Townes, a Nobel prizewinner, is delighted to be
>vindicated. "I proposed this idea in the Sixties," he says. "Now
>a group of astronomers will start to make a search this autumn.
>I am very pleased."
>This attempt is the start of a new era of astronomy. The method
>is, according to the astronomer in charge, "embarrassingly
>simple". Embarrassing because it could have been undertaken at
>any time in the past four decades, but Professor Townes's notion
>of looking, rather than listening, was largely ignored.
>"If there are aliens sending us messages by laser, we will see
>them," says Dan Werthimer, the director of Berkeley's Search for
>Extraterrestrial Intelligence (SETI) programme.
>Unlike the aliens in movies, who frequently speak English, the
>real ones would probably not use Morse code. "They would send
>very short, powerful pulses of laser light that would be
>unmistakable. It doesn't require that much energy to do," Dr.
>Werthimer says.
>Later this autumn, he and his colleagues will use a 30in
>telescope - modest by professional standards - at Mount
>Leuschner, about 20 miles east of Berkeley, to look for laser
>flashes. Light captured by the telescope will be split into two
>and fall on to photo-multiplier tubes, which will amplify the
>signal. If both see unusual flashes at specific wavelengths
>-lasting perhaps a few billionths of a second, with a power
>output greater than that of the stars they are looking at - they
>will have hit the jackpot.
>Seeing signals in the two separate halves of the beam means that
>they could not be artifacts of the detection process.
>Lasers are the only way that bursts of light could be
>sufficiently concentrated. As with the powerful search beams of
>a lighthouse, they could be directed to specific stars such as
>our Sun. Lasers work by exciting gas atoms and forcing them to
>give up their energy in the form of an intense flash of light.

>"We could easily send a message into space to other
>civilizations," Professor Townes says. His Berkeley colleagues
>agree. According to Dr. Werthimer, you could attach a simple
>laser to an optical telescope and direct it to nearby stars and
>send messages. "You could do that with a laser that transmits
>one megawatt," Dr. Werthimer says. "That's about the same power
>as a television station."
>But that is far into the future. For the moment, the Berkeley
>team is starting its own modest search; improbably, this optical
>work will cost just $20,000 (#11,400) a year, a sign of the
>times for SETI research. Searching for aliens has been
>criticized by some as a kind of wishful thinking, a subject
>without a science. And American legislators certainly agree:
>NASA's ambitious program of SETI research using radio telescopes
>was canceled in 1993.
>However, with private funding from supporters such as the
>science fiction author Arthur C. Clarke and the film director
>Steven Spielberg, SETI struggles on.
>Others have said that finding evidence for alien civilization
>will be impossible. A similar thing was said to Professor Townes
>during the late 1940s after he proposed the forerunner of the
>laser, the maser (which produces microwave radiation rather than
>light). As a researcher at Bell Labs in New Jersey, he was a
>world expert on microwave spectroscopy, the probing of gases
>using radio waves. He realized that by using molecules to
>amplify signals, he could generate a powerful source of
>radiation. After he discussed the method in a scientific journal
>50 years ago, "more than one Nobel laureate said it would never
>work. It was viewed as a crazy, cute idea and there wasn't much
>to it."
>Early one spring morning in 1951, while sitting on a park bench
>in Washington, Professor Townes had what he calls "divine
>inspiration" of how to make a maser work and its possible
>applications. "I recognized that it could be a sensitive
>amplifier or atomic clock," he says.
>Throughout the 1950s, the wavelengths used to probe gases were
>made progressively shorter - so much so that he could get down
>to optical wavelengths. Together with his brother-in-law, Arthur
>Schawlow, he developed the laser. Accordingly, Townes won the
>Nobel Prize in 1964 (along with two Russians who had
>independently come across the same principle). Lasers can now be
>found everywhere, from supermarkets to home CD players to
>"It comes home to me when I hear of friends who have had their
>sight restored," Professor Townes says. "To me, it was clear
>that the most important uses would come from connecting up
>optics and electronics."
>Proof positive comes from the telescope now being used by Dr.
>Werthimer's team (it is normally used to train Berkeley
>undergraduates). In 1959 - the same year in which a workable
>maser was developed - two radio astronomers declared that
>detecting radio signals would be the only way to find aliens. As
>a result, the scientific community tended to dismiss any other
>wavelengths that could be used to send messages.

>By the mid-1960s, Professor Townes had moved to Berkeley and was
>working at the Space Science lab. By then, his idea was
>bolstered by the discovery of naturally existing masers in
>space. There are vast clouds of gas between the stars which can
>act as masers. Their constituent molecules are naturally excited
>to such an extent that they amplify microwaves across the vast
>firmament of the heavens.
>Any sufficiently advanced alien civilization would be well aware
>of that and could emulate the process. Professor Townes points
>out that these clouds have been emitting intense radiation in
>all directions, but it was only recently that humanity has
>acknowledged their existence.
>"If we'd have found them earlier, then we could have developed
>the laser sooner," Professor Townes says. "We didn't look. Other
>civilizations might have taken their cue from natural masers in
>This autumn, the Berkeley group will systematically look at
>2,500 nearby stars. The criterion is fairly simple: they will be
>Sun-like stars, around which planets like ours - and
>corresponding civilizations - could have evolved.
>All involved agree that the search is a long shot, with truly
>astronomical odds against it.
>But the final word goes to Professor Townes, who insists that,
>as with the invention of the laser, the discovery of life in
>space is simply a matter of looking hard enough.
>"We don't know what we will find, so we must keep looking."

Dr. Stuart A. Kingsley, SMIEEE, MIEE, CEng.,
Director, The Columbus Optical SETI Observatory