Will we ever be able to teleport? - Sajan Saini
-
0:08 - 0:10Is teleportation possible?
-
0:10 - 0:13Could a baseball transform into
something like a radio wave, -
0:13 - 0:15travel through buildings,
-
0:15 - 0:16bounce around corners,
-
0:16 - 0:19and change back into a baseball?
-
0:19 - 0:25Oddly enough, thanks to quantum mechanics,
the answer might actually be yes. -
0:25 - 0:27Sort of.
-
0:27 - 0:28Here's the trick.
-
0:28 - 0:30The baseball itself couldn't
be sent by radio, -
0:30 - 0:34but all the information about it could.
-
0:34 - 0:36In quantum physics, atoms and electrons
-
0:36 - 0:40are interpreted as a collection
of distinct properties, -
0:40 - 0:41for example, position,
-
0:41 - 0:42momentum,
-
0:42 - 0:44and intrinsic spin.
-
0:44 - 0:47The values of these properties
configure the particle, -
0:47 - 0:51giving it a quantum state identity.
-
0:51 - 0:53If two electrons have
the same quantum state, -
0:53 - 0:55they're identical.
-
0:55 - 0:59In a literal sense, our baseball
is defined by a collective quantum state -
0:59 - 1:02resulting from its many atoms.
-
1:02 - 1:06If this quantum state information
could be read in Boston -
1:06 - 1:07and sent around the world,
-
1:07 - 1:11atoms for the same chemical elements
could have this information -
1:11 - 1:13imprinted on them in Bangalore
-
1:13 - 1:16and be carefully directed to assemble,
-
1:16 - 1:19becoming the exact same baseball.
-
1:19 - 1:20There's a wrinkle though.
-
1:20 - 1:23Quantum states aren't so easy to measure.
-
1:23 - 1:26The uncertainty principle
in quantum physics -
1:26 - 1:29implies the position and momentum
of a particle -
1:29 - 1:32can't be measured at the same time.
-
1:32 - 1:35The simplest way to measure
the exact position of an electron -
1:35 - 1:39requires scattering a particle of light,
a photon, from it, -
1:39 - 1:42and collecting the light in a microscope.
-
1:42 - 1:47But that scattering changes the momentum
of the electron in an unpredictable way. -
1:47 - 1:50We lose all previous information
about momentum. -
1:50 - 1:54In a sense,
quantum information is fragile. -
1:54 - 1:56Measuring the information changes it.
-
1:56 - 1:58So how can we transmit something
-
1:58 - 2:02we're not permitted to fully read
without destroying it? -
2:02 - 2:07The answer can be found in the strange
phenomena of quantum entanglement. -
2:07 - 2:11Entanglement is an old mystery
from the early days of quantum physics -
2:11 - 2:13and it's still not entirely understood.
-
2:13 - 2:17Entangling the spin of two electrons
results in an influence -
2:17 - 2:20that transcends distance.
-
2:20 - 2:22Measuring the spin of the first electron
-
2:22 - 2:25determines what spin will
measure for the second, -
2:25 - 2:29whether the two particles are a mile
or a light year apart. -
2:29 - 2:33Somehow, information
about the first electron's quantum state, -
2:33 - 2:35called a qubit of data,
-
2:35 - 2:41influences its partner without
transmission across the intervening space. -
2:41 - 2:44Einstein and his colleagues called
this strange communcation -
2:44 - 2:47spooky action at a distance.
-
2:47 - 2:50While it does seem that entanglement
between two particles -
2:50 - 2:55helps transfer a qubit instantaneously
across the space between them, -
2:55 - 2:56there's a catch.
-
2:56 - 3:01This interaction must begin locally.
-
3:01 - 3:04The two electrons must be entangled
in close proximity -
3:04 - 3:08before one of them is transported
to a new site. -
3:08 - 3:12By itself, quantum entanglement
isn't teleportation. -
3:12 - 3:13To complete the teleport,
-
3:13 - 3:19we need a digital message to help
interpret the qubit at the receiving end. -
3:19 - 3:23Two bits of data created by measuring
the first particle. -
3:23 - 3:26These digital bits must be transmitted
by a classical channel -
3:26 - 3:32that's limited by the speed of light,
radio, microwaves, or perhaps fiberoptics. -
3:32 - 3:35When we measure a particle
for this digital message, -
3:35 - 3:37we destroy its quantum information,
-
3:37 - 3:40which means the baseball must disappear
from Boston -
3:40 - 3:43for it to teleport to Bangalore.
-
3:43 - 3:45Thanks to the uncertainty principle,
-
3:45 - 3:48teleportation transfers the information
about the baseball -
3:48 - 3:52between the two cities
and never duplicates it. -
3:52 - 3:56So in principle, we could teleport
objects, even people, -
3:56 - 4:00but at present, it seems unlikely
we can measure the quantum states -
4:00 - 4:04of the trillion trillion or more atoms
in large objects -
4:04 - 4:07and then recreate them elsewhere.
-
4:07 - 4:11The complexity of this task
and the energy needed is astronomical. -
4:11 - 4:15For now, we can reliably teleport
single electrons and atoms, -
4:15 - 4:18which may lead to super-secured
data encryption -
4:18 - 4:22for future quantum computers.
-
4:22 - 4:26The philosophical implications
of quantum teleportation are subtle. -
4:26 - 4:30A teleported object doesn't exactly
transport across space -
4:30 - 4:31like tangible matter,
-
4:31 - 4:36nor does it exactly transmit across space,
like intangible information. -
4:36 - 4:39It seems to do a little of both.
-
4:39 - 4:41Quantum physics gives us
a strange new vision -
4:41 - 4:46for all the matter in our universe
as collections of fragile information. -
4:46 - 4:52And quantum teleportation reveals
new ways to influence this fragility. -
4:52 - 4:54And remember, never say never.
-
4:54 - 4:56In a little over a century,
-
4:56 - 4:59mankind has advanced from an uncertain
new understanding -
4:59 - 5:02of the behavior of electrons
at the atomic scale -
5:02 - 5:06to reliably teleporting them
across a room. -
5:06 - 5:09What new technical mastery
of such phenomena -
5:09 - 5:13might we have in 1,000,
or even 10,000 years? -
5:13 - 5:16Only time and space will tell.
- Title:
- Will we ever be able to teleport? - Sajan Saini
- Description:
-
View full lesson: https://ed.ted.com/lessons/will-we-ever-be-able-to-teleport-sajan-saini
Is teleportation possible? Could a baseball transform into something like a radio wave, travel through buildings, bounce around corners, and change back into a baseball? Oddly enough, thanks to quantum mechanics, the answer might actually be yes... sort of! Sajan Saini explains.
Lesson by Sajan Saini, animation by Karrot Animation.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 05:38
Jessica Ruby approved English subtitles for Will we ever be able to teleport? - Sajan Saini | ||
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Jessica Ruby edited English subtitles for Will we ever be able to teleport? - Sajan Saini | ||
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