ALCUBIERRE
DRIVE
No discussion of interstellar travel would be
complete without making reference to a
warp drive. This hypothetical device, again
astapleofStar Trek,getsaroundaproblem
with physics, namely that nothing can
travel faster than the speed of light.
Einstein’s Special Theory of Relativity
showed that the speed of light was a cosmic
speed limit. Even though light speed is
roughly 300,000km/s, that’s still slow
compared to interstellar distances. The
neareststartoEarthotherthantheSun,
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light takes 4.3 years to cover that distance.
Unlesswecanbreakthelightbarrier,itwill
always take longer than this to get there.
This is where the warp drive comes in.
It has its basis in Einstein’s next theory,
theGeneral Theory of Relativity, which
expanded the earlier version to include a
description of gravity. Einstein found that
themostnaturalwaytoexplaintheaction
ofgravitywastoimaginespaceasbeing
likearubbersheet.Hecalledthisthe
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objects, such as stars or planets, were
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warped it and created gravity.
In1 99 4, physicist Miguel Alcubierre
Moya published a paper showing that
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continuum so that it would be capable of
propellingastarshipfasterthanthespeed
of light. No physics would be violated
becauseGeneral Relativity only excludes
things travelling through space, not space
itselfmoving.Thetroubleisthattomake
the ‘warp bubble’, as Alcubierre called it,VJG URCEGVKOGEQPVKPWWO YQWNFJCXGVQ
be warped in a way that no known
naturalobjectorenergycando.
Partly in response to Alcubierre’s work,
NASA launched the Breakthrough
PropulsionPhysicsProgram in 1 99 6, to
investigate whether this or any other way
to break the light barrier seemed
plausible. But after six years and a total
investment of $1.2m, the programme was
disbanded. The conclusion was that no
propulsion breakthrough was imminent.
Unfortunately, travelling to the stars as
easilyaswecrosscontinentsissomething
that is highly unlikely to be achieved in
ourlifetimes,andmaybecompletely
impossible.Thatstilldoesn’tstopus
dreaming about the possibilities, of
course. And perhaps one day, someone
willseethewaytomakeourdreams
come true. Never say never...354SPACEILLUSTRATIONS: MAGIC TORCHThe Alcubierre drive pushes the
space-time continuum into a ‘hill’ behind
the spacecraft, creating a kind of anti-
gravity that pushes the ship alongTurning the warp drive off allows
the space-time continuum to return
to its normal flat state, depositing the
ship at a new location2The space-time
continuum is like a
rubber sheet. It is
infinitely malleable,
capable of expanding or
contracting with the
energy deposited in it1The spaceship surfs the space
time continuum; the only trouble is,
noknownenergysourcecould
produce the ‘hill’ in the first placeThe spacecraft’s
drive makes the space-
time continuum
in front of the ship
warp downwards,
creating an attractive
force similar to gravity