Everyone likes a shortcut
and a quick trip somewhere cool, which means that everyone loves a wormhole —
at least in theory. In actuality, these space-time tunnels are probably not the
alleged intergalactic shortcuts we’re looking for — and this isn’t a mind trick
from Obi-Wan, either. But first, let’s talk about what wormholes are and how
they could theoretically allow for faster-than-light travel; it’s always better
to build up all of our hopes before dashing them to pieces, I find.
When physicists started
tinkering with general relativity, they predicted that black holes might exist.
The same physics that predicts black holes also predicts white holes, which are
just what they sound like: the opposite of black holes. The event horizon of a
black hole is a corner of space that is impossible to escape once you’ve
entered it. On the other hand, the event horizon of a white hole is impossible
to enter — but you can escape if you’re already there.
The wormhole comes
in when we learn that all black holes are naturally connected to white holes;
these identically opposite twins are joined at the singularities.
Or so the math says. While we’ve seen black holes a-plenty,
there’s no evidence at all for white holes — nor any evidence for any process
that could form them, or any means for them to stay in existence if they
formed, or even any way they could survive their “symbiotic” connections to
black holes.
There is just no way they could ever form, or be stable enough to
remain once formed. That instability would directly affect any wormholes: they
would never be able to last, and would instead stretch and break almost
immediately.
If you happened to see a
wormhole and went for a ride, you’d be on a one way trip into an event horizon
of a black hole. That sounds cool, but remember: you’d then be stretched
endlessly and pummeled to death by gravity (and even Anthony
Perkins thinks that’s crazy).
However, some still believe
that we can make wormholes work for us, as sort of a next level tube system
going all over the universe rather than just beneath London. To make it work,
you’d need to enter just outside the event horizon so you could get through the
wormhole without getting done in by gravity first. You’d also need a tunnel
strong and stable enough to handle both the gravitational pummeling mentioned
above, and the force of people flying through it at extreme speeds.
What would make that
possible? A tunnel made of negative-mass material. Negative-mass materials have
not been found in the universe anywhere, although physicists in Washington
recently created a fluid with negative-mass. So will they someday create
negative-mass material that you could, say, build a tunnel with? Maybe.
Still, should this really be
a priority—? There are plenty of reasons why traveling this quickly would mean
a lot to humanity: we could explore far reaches of the galaxy, potentially
finding alien life, more habitable planets, and whatever else it has to
offer—probably a lot. However, we don’t need to pin all of our hopes on
wormholes just because we wish to traverse the galaxy.
First of all, even
breakthroughs in physics such as the creation of negative-mass materials are
unlikely to lead to workable wormholes. These fantastical space travel tunnels
would violate numerous laws of physics — many of which are very
well-tested. The odds of defeating each and every one of them seem long,
indeed.
Furthermore, there are a
number of other projects in the works that could help us travel faster in
space. NASA and others have been studying the EmDrive, a radio frequency resonant cavity
thruster that uses microwaves inside a truncated cone to create a thrust at the
narrow end of the cone. If it works, it would mean the ability to create thrust
without a propellant — a huge advancement for long-distance space travel. This
tech is a long way from being viable, however.
Ion propulsion is already being used once rockets are
already in space. NASA’s Dawn mission uses ion propulsion, as do several other
missions from Japan and the ESA. How long it will be before the technology
could be used to help humans travel extremely long distances, however,
remains to be seen.
In short, it seems unlikely
that a solution that would require breaking every law in the physics book will
be the one that gets us there. As fun as wormholes feel from the outside,
they’re probably not worth too much of our focus.