132
PHYSICS OF THE IMPOSSIBLE
Institute in Mountain View, California, to centralize SETI research and
initiate Project Phoenix to study one thousand nearby sunlike stars in
the 1,200- to 3,000-megahertz range. Dr. Jill Tarter (the model for the
scientist played by Jodie Foster in the movie Contact) was named director. (The equipment used in the project was so sensitive that it could
pick up the emissions from an airport radar system 200 light-years
away.)
Since 1995 the SETI Institute has scanned more than one thousand
stars at a cost of $5 million per year. But there have been no tangible
results. Nevertheless, Seth Shostak, senior astronomer at SETI, optimistically believes that the 350-antenna Allen Telescope Array now being built 250 miles northeast of San Francisco "will trip across a signal
by the year 2025."
A more novel approach is the SETI@home project, initiated by astronomers at the University of California at Berkeley in 1999. They hit
upon the idea of enlisting millions of PC owners whose computers sit
idle most of the time. Those who participate download a software
package that will help to decode some of the radio signals received by
a radio telescope while the participant's screen saver is activated, so
there is no inconvenience to the PC user. So far the project has signed
up 5 million users in more than two hundred countries, consuming
over a billion dollars of electricity, all at little cost. It is the most ambitious collective computer project ever undertaken in history and could
serve as a model for other projects that need vast computer resources
to carry out computations. So far no signal from an intelligent source
has been found by SETI@home.
After decades of hard work, the glaring lack of any progress in
SETI research has forced its proponents to ask hard questions. One obvious defect might be the exclusive use of radio signals at certain frequency bands. Some have suggested that alien life might use laser
signals instead of radio signals. Lasers have several advantages over
radio, because a laser's short wavelength means that you can pack
more signals into one wave than you can with radio. But because laser
light is highly directional and also contains just one frequency, it is exceptionally hard to tune into precisely the right laser frequency.
PHYSICS OF THE IMPOSSIBLE
Institute in Mountain View, California, to centralize SETI research and
initiate Project Phoenix to study one thousand nearby sunlike stars in
the 1,200- to 3,000-megahertz range. Dr. Jill Tarter (the model for the
scientist played by Jodie Foster in the movie Contact) was named director. (The equipment used in the project was so sensitive that it could
pick up the emissions from an airport radar system 200 light-years
away.)
Since 1995 the SETI Institute has scanned more than one thousand
stars at a cost of $5 million per year. But there have been no tangible
results. Nevertheless, Seth Shostak, senior astronomer at SETI, optimistically believes that the 350-antenna Allen Telescope Array now being built 250 miles northeast of San Francisco "will trip across a signal
by the year 2025."
A more novel approach is the SETI@home project, initiated by astronomers at the University of California at Berkeley in 1999. They hit
upon the idea of enlisting millions of PC owners whose computers sit
idle most of the time. Those who participate download a software
package that will help to decode some of the radio signals received by
a radio telescope while the participant's screen saver is activated, so
there is no inconvenience to the PC user. So far the project has signed
up 5 million users in more than two hundred countries, consuming
over a billion dollars of electricity, all at little cost. It is the most ambitious collective computer project ever undertaken in history and could
serve as a model for other projects that need vast computer resources
to carry out computations. So far no signal from an intelligent source
has been found by SETI@home.
After decades of hard work, the glaring lack of any progress in
SETI research has forced its proponents to ask hard questions. One obvious defect might be the exclusive use of radio signals at certain frequency bands. Some have suggested that alien life might use laser
signals instead of radio signals. Lasers have several advantages over
radio, because a laser's short wavelength means that you can pack
more signals into one wave than you can with radio. But because laser
light is highly directional and also contains just one frequency, it is exceptionally hard to tune into precisely the right laser frequency.