It seems like the research world launched a full-throttle
game recently, "what superpower would you choose? "For those who want
invisibility, engineers are developing exotic materials that can bend the light
of an object out of sight. For would-be telepaths, neurobiologists are working
on ways to read one person's brain wave patterns and transmit them to the head
of another.
Perhaps my personal favorite is the most insane fantasy
force of all: teleportation, the ability to arrive without flying. Imagine
being able to dematerialize from your living room and wake up in Venice or the
Amazon rainforest or Saturn's rings (wearing a fitting space suit, of course).
The idea is so seductive that it has been a staple of science fiction since
Star Trek and Doctor Who's early days, but it also seems an affront to common
sense.
Fortunately, common sense does not govern the rules of
quantum physics, as demonstrated by a brief 1993 paper with a mouthful title:
"Teleporting an Unknown Quantum State Through Dual Classical and
Einstein-Podolsky-Rosen Channels." In it, a team led by Charles Bennett
from IBM's T.J. Watson Research Center showed how to link two particles
together in a certain way, and how to keep them linked even at great rates.
That connection, called quantum entanglement, has remarkable
power. It allows someone holding one of the particles to instantly send a chunk
of information — the "unknown quantum state" in the paper's title —
to someone else holding the other particle. Because of this strange quantum
connection, information goes from person to person without physically passing
between them. It's arriving without flying.
Relocating information from one particle to another may not
sound like "Scotty, energize," but two versions of the same process
at a fundamental level. Every atom in Captain Kirk 's body is a set of data
(type of atom, location, energy state, etc.); the captain as a whole is just a
huge collection of these data sets. Teleport all relevant information to a planet's
surface and re-create Kirk exactly as he was on board the ship.
Okay, maybe ... yeah. Teleportation technology has
progressed rapidly since 1993, now being tested in the laboratory. But, as the
Enterprise crew discovered repeatedly, human teleportation is hard to do right
and easy to do wrong. There could be cheaper, easier ways to attain such
superpower.
Login to Quantity Device
Even minimal teleportation may be a revelation. Physicists
build a quantum computer, a similar technology that handles information using
individual atoms or particles instead of transistors. Such a computer might,
for example, outperform conventional processors on certain types of
calculations: breaking codes and solving complex equations.
A quantum computer could contribute to the first completely
practical simulations of quantum phenomena. All biology, chemistry, and
nanotechnology operate at the quantum level. To grasp these systems on their
own terms will be a giant leap.
Teleportation is a crucial enabling technology for quantum computing
because it enables you to retrieve the computer's information without
disrupting the rest of the device. No teleport, no results. Last year, a team
led by physicist Alex Kuzmich, then at the Georgia Institute of Technology,
demonstrated a realistic method of information teleportation by tangling on
demand the atoms and photons of a device. Once you can do that, you can
leverage that quantum connection to beam data from your quantum computer and
get it exactly where you need it.
And once you construct a quantum machine, the possibilities
start. Kuzmich and others see entire "quantum networks" linking
different computers and providing high-speed connectivity between them. If you
think the idea sounds vaguely familiar, you 're right; it's an Internet quantity.
Security is a primary reason to go down this path. Working
with enmeshed particles requires amazing delicacy, but that also makes it
incredibly private. If someone attempts to eavesdrop an enmeshed post, the very
act of unwelcome listening disrupts the entire teleportation method. Therefore,
any message sent over a quantum internet is perfectly secure — or as good as
anything known to mankind. Heartbling bug? There's no problem.
What's about me?
Yeah, yeah, yes. You want to learn about the infinite kind
of teleportation, the kind that beams people from place to place. Two
considerations, one metaphysical and one technical, will threaten your
enthusiasm.
First, removing all the knowledge from the body of Captain
Kirk (or yours) involves understanding each atom's physical state, which would
require complete disintegration. Each time Kirk steps into the transporter, he
suicides and then gets reborn at the other end. Second, the amount of
information needed to recreate him is staggering — about 4.5 x 1042 bits, by
one estimate, recently as part of a highly entertaining graduate physics
project at Leicester University.
Nobody knows how much information to gather and send. And
note how the slightest disturbance breaks quantum enmeshment? Reassembling the
atoms will inevitably scramble knowledge. It's suicide at one end without
rebirth at the other. Kirk could put a red shirt first.
The teleportation situation becomes much less bleak if,
however, you bend the definition somewhat. As many video game players have found,
the human brain has a remarkable capacity to project itself into other objects
or simulated spaces beyond the body. NASA is using Human Exploration
Telerobotics, a project that enables astronauts to "inhabit" robots
in dangerous or inaccessible places.
A robot astronaut also walks outside the International Space
Station. In the near future, you can encounter space exploration through a Mars
rover or mechanical arms poking at a distant asteroid.
If that's too much for you, how about a DNA fax machine? J.
Science guru. Craig Venter suggests that if we find microbial life on Mars, we
can sequence its genome locally, transmit information, and rebuild the organism
on Earth. In theory, Venter says, the cycle could go the other way: it would be
possible to send human DNA along with a suitable incubator to distant planets
and synthesize people at the other end. Then your clone could set up shop on a
world orbiting Alpha Centauri B.
Cloning also doesn't satisfy Teleportation 's complete
superhero dream, I remember. No, what you ideally want is a complete
mind-upload to your distant doppelganger so you can be there. That would that
the teleportation problem from "possibly impossible" to "wildly
complicated," which still leaves the brain's big information content
problem. If, however, you agree that knowledge is the only thing that
determines your mind, the mission seems feasible. You no longer need to
carefully assemble atoms in the right locations; only the evidence do.
Notice a curious common thread through all this. If you find
yourself a pile of atoms, a DNA sequence, a collection of sensory inputs or an
intricate machine device, in all these definitions you are nothing but a data
stack. According to unitary theory, quantum knowledge is never lost. Put them
together, and these two claims lead to a stunning corollary: at the most
fundamental point, physics laws suggest you 're immortal.
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