Time - Man of the Year/Time_Man_of_the_Year_Compact_Publishing_3YX-Disc-1_Compact_Publishing_1993.iso/moy/101592/10159927.000

Text File | 1993-04-08 | 12KB | 237 lines

                                                                                SPECIAL ISSUE: MILLENNIUM -- BEYOND THE YEAR 2000 

THE NEXT 1,000 YEARS, Page 78

Is Anybody Out There?


After a "False Dawn" in the 20th century, the new Space Age
could bring everything from Mars colonies to galactic voyages

BY DENNIS OVERBYE


    Giant space stations in the sky, underground cities on the
moon, galactic empires that have forgotten the earth,
interstellar war with telepathic ants, voyages to go boldly
where no man has gone before. Such were the predictions about
the glories of the space age. No wonder the failure of events to
live up to the predetermined history bequeathed by science
fiction has disappointed the baby boomers.

    But that future may still be realizable, believe many
scientists in and out of NASA who meet now and then to try to
imagine the technology that could bring the space age to life.
In their eyes, those first moon landings represented a false
dawn of space exploration, just as the early Viking voyages to
America were ahead of their time. Only when technology makes
space flight cheap enough, as one astronomer put it, "to hock
your socks and go," will the real space age begin. What will
that age produce?

    For starters, rockets will go the way of the dinosaurs.
Future spacefarers will look back on the notion of sending
people (or anything precious) aloft on huge, lumbering towers of
flame and smoke as primitive, brutal and notoriously unreliable.
Before the next millennium is very far along, humans will get
their lift from space planes that take off and land like
conventional jets but are powered by "scramjets" that, once
aloft, will enable them to swoop into orbit or go halfway
around the world in two hours. Cargo will be shot into orbit by
electromagnetic rail guns that ramp up the sides of mountains,
or will be flung upward by looping orbital tethers, sort of
like David's slingshot.

    Probes and people would sally forth into the deeper
universe, propelled by thin sails filled by the feeble but
inexorable pressure of sunlight or traveling on ion drives that
get their boost by shooting high-energy electrified particles
out of the rear of the vehicle. Other possible vehicles for
space travel may be propelled by a series of tiny thermonuclear
explosions using pellets of fuel mined on the moon, or by mass
drivers employing electromagnetic fields to expel bucketloads of
dirt from the back.

    Once the transportation is ready, Mars will be a popular
destination. According to scenarios worked out by a group of
scientists who call themselves the Mars Underground, the first
voyagers would be preceded by ferries carrying equipment for
setting up a permanent base. Early visitors would face a
hostile environment: a thin atmosphere of mostly carbon
dioxide, temperatures that fluctuate from -10 degrees F to -190
degrees F and hurricane winds. People would live chiefly
underground, grow vegetables in greenhouses, wear space suits
and explore the countryside in dirigibles.

    After a few decades of familiarization and exploration had
established that there was no indigenous Martian life, humans
might be ready to undertake the ultimate real
estate-development project: the greening of Mars. The first
step, according to one recent study, would be to warm the planet
by releasing large amounts of chlorofluorocarbons into the
atmosphere. These gases would act like a greenhouse, trapping
the sun's heat. As the planet warmed, the polar caps would begin
to melt, releasing water vapor and carbon dioxide into the
Martian air, thickening it and increasing the greenhouse effect.
Eventually the permafrost, where most of Mars' water is locked
up, would melt, and rivers and lakes -- if not oceans -- would
flow across the Red Planet again.

    The next task would be to oxygenate Mars' atmosphere and
introduce life. The "gardeners" on Mars could import anaerobic
organisms -- for example, the blue-green algae that flourished
on earth billions of years ago. Other genetically engineered
organisms would follow until one day, probably millenniums from
now, the new Martians could breathe freely under clear skies.

    Most of the work of investigating and colonizing the solar
system (and perhaps beyond) would be done by robot probes
smaller and smarter than those of today. Advances in computer
technology and genetic engineering, predicts physicist Freeman
Dyson of the Institute for Advanced Study in Princeton, New
Jersey, will enable scientists to squeeze the capabilities of a
Voyager spacecraft, say, into a 2-lb. package that is half
machine, half organism. This he dubs the astrochicken. Launched
as an "egg," the astro chicken would sprout solar-panel wings
that would double as radio antennae during flight. Arriving at
its destination, the craft would nibble on the ice in planetary
rings and shoot around like a bombardier beetle exploring moons.

    Robot probes no bigger than bacteria will eventually be
possible. According to K. Eric Drexler, author of Engines of
Creation, they will use nanotechnology to assemble devices atom
by atom or molecule by molecule. His colleagues have already
made motors smaller in diameter than a human hair. Drexler
believes a bundle of nanorobots, weighing practically nothing,
would be the perfect interstellar emissaries. Having arrived at a
planet or asteroid around some distant star, perhaps in a solar
sailship pushed to high speeds by a powerful laser beam from
earth, they would go to work, antlike, building radio
transmitters and other gear to report home for new
instructions. They could also reproduce themselves and their
ships in order to send off a new set of explorer robots.

    Could humans follow their robots to the stars? Because
people and their life-support systems are so massive, it would
take gargantuan amounts of energy and time to get anywhere. By
one estimate, a round trip to a nearby star at one-tenth the
speed of light would take 500 times the energy the U.S.
produces in a year. Many scientists argue that no society would
ever find the trip worth it, unless perhaps the sun were
threatened with imminent destruction -- an event not due for 5
billion years.

    Nonetheless, within 500 years humans may be ready to pack
their belongings into starships -- as the early Polynesians did
into canoes -- and set off in search of new worlds. With a
possible 1 trillion people spread out over the solar system by
then, a trip into the galaxy beyond will not seem so daunting,
contend Eric Jones, a physicist at the Los Alamos (New Mexico)
National Laboratory, and his collaborator Ben Finney, an
anthropologist and expert on migration at the University of
Hawaii. In their scenario, robots will have transformed the
planet Mercury into a giant solar-power station, beaming energy
to the rest of the solar system in the form of microwaves, and
the moon will be a mining and construction center.

    A starship could be accelerated to interstellar-travel
speeds by having one of those powerful microwave lasers on
Mercury push against a vast, thin sail constructed perhaps of
diamond fibers. At its destination, the starship would then
hunt out an asteroid, upon which microrobots would descend and
begin mining and constructing a colony. Perhaps in a few hundred
or a few thousand years, the inhabitants of this new world would
be ready to send a migratory ship even farther. In this way,
Jones and Finney argue, humans could colonize the galaxy in a
few million years.

    But it might not be necessary to send people's bodies. The
answer, says Konstantin Feoktistov, a former Soviet cosmonaut,
could be the human fax. Feoktistov has pointed out that it
might be possible someday soon to "download" the entire contents
of a human brain into a computer, the way a file on a PC can be
transferred onto a floppy disk, and broadcast it to a robot in a
remote star system. After a few days or years of exposure to
this strange world, the surrogate brain would "fax" its new
information back to earth and its original owner. Feoktistov
suggests that human faxing would be even easier if we could
contact some extraterrestrials and have them build receiving
stations for us.

    What about those extraterrestrials? In that regard, the
future is already here: a new search for extraterrestrial
intelligence (SETI to astronomical aficionados) is about to
start. On Columbus Day, radio antennas in California and Puerto
Rico are scheduled to begin a survey of the heavens, monitoring 8
million radio channels simultaneously for signs of life. By the
end of the decade, if they get lucky, NASA's radio astronomers
may discover the signal that ends mankind's loneliness. SETI
theorists hypothesize that even advanced civilizations might
find interstellar travel an expensive and time-consuming way,
at best, to meet the neighbors, and would instead set up radio
beacons to call out to one another -- a cosmic ham radio club.

    The detection of an extraterrestrial signal would be one of
the greatest events of this or any other millennium. Direct
contact with aliens, who would probably be vastly more powerful
than we ourselves, could have a demoralizing and destructive
effect on human culture, much as white men destroyed Native
American life. It might also pose a challenge to the world's
religions.

    Fortunately, perhaps, the odds against physical contact
are, well, astronomical. Even if another civilization were in
our own corner of the galaxy, it could be several hundred or a
thousand light-years away. With signals propagating at the
speed of light, the distances involved suggest that all
communications would essentially be monologues. Frank Drake, a
California radio astronomer and SETI pioneer, once said that the
most likely signalers would be races of immortals because they
could afford to wait almost forever for the return message.

    Others speculate that humanity will tap into a galactic
radio network, a cosmic encyclopedia in which the cultures and
histories of civilizations -- some of them by now dead -- would
be preserved and broadcast eternally. The development of radio
astronomy technology would constitute the entrance fee for this
cosmic lonely-hearts club. Since we have reached that level of
technology only in the past 50 years, humans would almost by
definition be the most junior members of an association of
cultures thousands or even millions of years older.

    Moreover, the human race would probably not even understand
any signals from outer space. SETI people liken the task of
decoding and understanding such signals to biblical scholarship
or the deciphering of ancient hieroglyphics. The obstacles have
led Philip Morrison, a Massachusetts Institute of Technology
physicist who helped invent SETI, to call the task "the
archeology of the future." How would humanity respond to signals
from other beings? The writer and physician Lewis Thomas once
proposed that we should send the music of Bach, acknowledging
that it would be bragging but holding that we had a right to put
our best foot forward.

    And what if, after a millennium of listening and looking,
there is only silence -- what if we still seem alone? If
interstellar migration is as easy and inevitable as Finney and
Jones have outlined, and if the galaxy, 10 billion years old, is
populated by other advanced races, critics of SETI argue, E.T.s
should have come calling by now. There is no scientific evidence
that they have, and the lack of it has led some scientists to
argue that there is no life out there at all. One answer to the
dilemma, popular in SETI circles but not very flattering, is
called the zoo hypothesis: extraterrestrial ethics would bar
other creatures from interfering with quaint, developing
species. Somewhere out beyond the orbit of Pluto there may be
a sign bearing the astronomical equivalent of DON'T FEED THE
BEARS