an alien on the bus would be strange — but it's almost equally strange that
humankind has never encountered aliens. The universe is vast. Can we really be
alone in it? (Cue "X-Files" theme song.)
it: What are the chances that life on Earth is the only life in the impossibly
probably 100 Earth-like planets for every grain of sand in the world, yet we've
never even heard from an extraterrestrial life form. No "Hey" — not
even a "U up?" Why?
the first people to wonder. Enrico Fermi, a Nobel Prize-winning physicist, also
thought it was odd. As he famously put it to his friends in the cafeteria one
day: "Where is everybody?" In 1950, this became formalized as the
Fermi paradox. How can we have not one scrap of evidence aliens exist, when
it's overwhelmingly likely that they do?
assume aliens are just too far away, but Fermi wasn't swayed by that argument.
An alien civilization with a solid space program could make rapid imperial
progress, Fermi argued. He estimated it would take just 10 million years for an
alien civilization to take over our entire galaxy. They've had tons of chances
when you consider that the Milky Way Galaxy has been around for 10 billion
what Fermi won the Nobel for, FYI; that was for his research into radioactivity
and nuclear reactions. Feeling excluded from the universe's social scene was a
explanation of the Fermi paradox is the zoo hypothesis.
admittedly a freaky situation to consider, but here it is: aliens know we
earthlings are here, but they're purposely avoiding contact with us, opting to
study us from afar instead.
hypothesized answer to the Fermi Paradox was proposed by MIT astronomer John A.Ball in 1973. It's named the zoo hypothesis because it suggests that all life
on Earth is just like an animal (or, you know, a few billion animals) at the
zoo — look, but don't touch! Ball suggests that maybe alien civilizations are
advanced enough to know not to influence our primitive society, or not to get
involved with other intelligent lifeforms (the Prime Directive, anybody?).
Ball laid out 10 possible solutions to Fermi's Paradox. The zoo hypothesis
covers just two of them: in one, aliens find us "of some interest"
and study us casually; in the other, aliens find us "interesting" and
pay closer attention. In both scenarios, though, they're actively avoiding us.
In an even
harsher solution, outside the zoo hypothesis, aliens know about us and don't
care. In this scenario, "We pose no threat, and we have nothing they
want," Ball writes. "This is a likely but a very unpopular answer,
for it seems to downgrade mankind's importance, and we do like to feel
popular answer to the Fermi Paradox is that alien life is still very primitive
or has already come and gone. At this point, it's really anyone's guess. So if
you want to assume we're a Very Important Species, at this point, go ahead. Why