Quantum computing explained in 10 minutes
-
0:01 - 0:02Let's play a game.
-
0:03 - 0:06Imagine that you are in Las Vegas,
-
0:06 - 0:07in a casino,
-
0:07 - 0:11and you decide to play a game
on one of the casino's computers, -
0:11 - 0:14just like you might play
solitaire or chess. -
0:15 - 0:18The computer can make moves
in the game, just like a human player. -
0:18 - 0:20This is a coin game.
-
0:21 - 0:24It starts with a coin showing heads,
-
0:24 - 0:26and the computer will play first.
-
0:26 - 0:28It can choose to flip the coin or not,
-
0:29 - 0:30but you don't get to see the outcome.
-
0:31 - 0:32Next, it's your turn.
-
0:33 - 0:36You can also choose
to flip the coin or not, -
0:36 - 0:39and your move will not be revealed
to your opponent, the computer. -
0:40 - 0:44Finally, the computer plays again,
and can flip the coin or not, -
0:44 - 0:46and after these three rounds,
-
0:46 - 0:48the coin is revealed,
-
0:48 - 0:51and if it is heads, the computer wins,
-
0:51 - 0:53if it's tails, you win.
-
0:54 - 0:56So it's a pretty simple game,
-
0:56 - 0:59and if everybody plays honestly,
and the coin is fair, -
0:59 - 1:03then you have a 50 percent chance
of winning this game. -
1:03 - 1:05And to confirm that,
-
1:05 - 1:09I asked my students to play
this game on our computers, -
1:09 - 1:11and after many, many tries,
-
1:11 - 1:15their winning rate ended up
being 50 percent, or close to 50 percent, -
1:15 - 1:16as expected.
-
1:16 - 1:18Sounds like a boring game, right?
-
1:18 - 1:22But what if you could play this game
on a quantum computer? -
1:23 - 1:26Now, Las Vegas casinos
do not have quantum computers, -
1:26 - 1:28as far as I know,
-
1:28 - 1:31but IBM has built
a working quantum computer. -
1:31 - 1:32Here it is.
-
1:33 - 1:34But what is a quantum computer?
-
1:35 - 1:37Well, quantum physics describes
-
1:37 - 1:41the behavior of atoms
and fundamental particles, -
1:41 - 1:44like electrons and photons.
-
1:44 - 1:45So a quantum computer operates
-
1:45 - 1:48by controlling the behavior
of these particles, -
1:48 - 1:52but in a way that is completely different
from our regular computers. -
1:52 - 1:56So a quantum computer
is not just a more powerful version -
1:56 - 1:58of our current computers,
-
1:58 - 2:02just like a light bulb
is not a more powerful candle. -
2:02 - 2:06You cannot build a light bulb
by building better and better candles. -
2:07 - 2:09A light bulb is a different technology,
-
2:09 - 2:12based on deeper scientific understanding.
-
2:12 - 2:16Similarly, a quantum computer
is a new kind of device, -
2:16 - 2:18based on the science of quantum physics,
-
2:18 - 2:22and just like a light bulb
transformed society, -
2:22 - 2:24quantum computers
have the potential to impact -
2:24 - 2:26so many aspects of our lives,
-
2:26 - 2:30including our security needs,
our health care and even the internet. -
2:31 - 2:35So companies all around the world
are working to build these devices, -
2:35 - 2:37and to see what
the excitement is all about, -
2:38 - 2:40let's play our game on a quantum computer.
-
2:41 - 2:46So I can log into IBM's
quantum computer from right here, -
2:46 - 2:48which means I can play the game remotely,
-
2:48 - 2:49and so can you.
-
2:50 - 2:56To make this happen, you may remember
getting an email ahead of time, from TED, -
2:56 - 2:59asking you whether you would choose
to flip the coin or not, -
2:59 - 3:01if you played the game.
-
3:01 - 3:06Well, actually, we asked you to choose
between a circle or a square. -
3:06 - 3:10You didn't know it, but your choice
of circle meant "flip the coin," -
3:10 - 3:12and your choice of square
was "don't flip." -
3:13 - 3:16We received 372 responses.
-
3:16 - 3:17Thank you.
-
3:17 - 3:21That means we can play 372 games
against the quantum computer -
3:21 - 3:23using your choices.
-
3:23 - 3:25And it's a pretty fast game to play,
-
3:25 - 3:27so I can show you the results right here.
-
3:28 - 3:31Unfortunately, you didn't do very well.
-
3:31 - 3:33(Laughter)
-
3:33 - 3:36The quantum computer won
almost every game. -
3:36 - 3:40It lost a few only because
of operational errors in the computer. -
3:40 - 3:42(Laughter)
-
3:42 - 3:45So how did it achieve
this amazing winning streak? -
3:46 - 3:49It seems like magic or cheating,
-
3:49 - 3:51but actually, it's just
quantum physics in action. -
3:52 - 3:53Here's how it works.
-
3:53 - 3:59A regular computer simulates
heads or tails of a coin as a bit, -
3:59 - 4:01a zero or a one,
-
4:01 - 4:04or a current flipping on and off
inside your computer chip. -
4:04 - 4:07A quantum computer
is completely different. -
4:07 - 4:12A quantum bit has a more fluid,
nonbinary identity. -
4:13 - 4:18It can exist in a superposition,
or a combination of zero and one, -
4:18 - 4:23with some probability of being zero
and some probability of being one. -
4:24 - 4:26In other words,
its identity is on a spectrum. -
4:27 - 4:31For example, it could have
a 70 percent chance of being zero -
4:31 - 4:33and a 30 percent chance of being one
-
4:33 - 4:37or 80-20 or 60-40.
-
4:37 - 4:40The possibilities are endless.
-
4:40 - 4:41The key idea here
-
4:41 - 4:45is that we have to give up
on precise values of zero and one -
4:45 - 4:47and allow for some uncertainty.
-
4:48 - 4:49So during the game,
-
4:49 - 4:54the quantum computer creates
this fluid combination of heads and tails, -
4:54 - 4:55zero and one,
-
4:55 - 4:58so that no matter what the player does,
-
4:58 - 4:59flip or no flip,
-
4:59 - 5:01the superposition remains intact.
-
5:02 - 5:05It's kind of like stirring
a mixture of two fluids. -
5:06 - 5:10Whether or not you stir,
the fluids remain in a mixture, -
5:10 - 5:13but in its final move,
-
5:13 - 5:17the quantum computer
can unmix the zero and one, -
5:17 - 5:20perfectly recovering heads
so that you lose every time. -
5:20 - 5:22(Laughter)
-
5:22 - 5:26If you think this is all a bit weird,
you are absolutely right. -
5:27 - 5:31Regular coins do not exist
in combinations of heads and tails. -
5:31 - 5:35We do not experience
this fluid quantum reality -
5:35 - 5:37in our everyday lives.
-
5:37 - 5:40So if you are confused by quantum,
-
5:40 - 5:41don't worry, you're getting it.
-
5:41 - 5:45(Laughter)
-
5:45 - 5:49But even though we don't experience
quantum strangeness, -
5:49 - 5:52we can see its very real
effects in action. -
5:52 - 5:54You've seen the data for yourself.
-
5:55 - 5:56The quantum computer won
-
5:56 - 6:01because it harnessed
superposition and uncertainty, -
6:01 - 6:03and these quantum properties are powerful,
-
6:03 - 6:05not just to win coin games,
-
6:06 - 6:09but also to build
future quantum technologies. -
6:09 - 6:13So let me give you three examples
of potential applications -
6:13 - 6:14that could change our lives.
-
6:15 - 6:20First of all, quantum uncertainty
could be used to create private keys -
6:20 - 6:24for encrypting messages
sent from one location to another -
6:24 - 6:29so that hackers could not
secretly copy the key perfectly, -
6:29 - 6:31because of quantum uncertainty.
-
6:32 - 6:36They would have to break
the laws of quantum physics -
6:36 - 6:37to hack the key.
-
6:38 - 6:42So this kind of unbreakable encryption
is already being tested by banks -
6:42 - 6:44and other institutions worldwide.
-
6:45 - 6:51Today, we use more than 17 billion
connected devices globally. -
6:52 - 6:55Just imagine the impact quantum encryption
could have in the future. -
6:56 - 7:02Secondly, quantum technologies could also
transform health care and medicine. -
7:02 - 7:08For example, the design and analysis
of molecules for drug development -
7:08 - 7:10is a challenging problem today,
-
7:10 - 7:15and that's because
exactly describing and calculating -
7:15 - 7:19all of the quantum properties
of all the atoms in the molecule -
7:19 - 7:23is a computationally difficult task,
even for our supercomputers. -
7:23 - 7:26But a quantum computer could do better,
-
7:26 - 7:29because it operates using
the same quantum properties -
7:29 - 7:32as the molecule it's trying to simulate.
-
7:32 - 7:36So future large-scale quantum
simulations for drug development -
7:36 - 7:40could perhaps lead to treatments
for diseases like Alzheimer's, -
7:40 - 7:42which affects thousands of lives.
-
7:42 - 7:45And thirdly, my favorite
quantum application -
7:45 - 7:50is teleportation of information
from one location to another -
7:50 - 7:53without physically transmitting
the information. -
7:54 - 7:57Sounds like sci-fi, but it is possible,
-
7:57 - 8:01because these fluid identities
of the quantum particles -
8:01 - 8:04can get entangled across space and time
-
8:04 - 8:08in such a way that when you change
something about one particle, -
8:08 - 8:10it can impact the other,
-
8:10 - 8:12and that creates
a channel for teleportation. -
8:13 - 8:16It's already been demonstrated
in research labs -
8:16 - 8:19and could be part
of a future quantum internet. -
8:19 - 8:23We don't have such a network as yet,
-
8:23 - 8:25but my team is working
on these possibilities, -
8:26 - 8:29by simulating a quantum network
on a quantum computer. -
8:30 - 8:34So we have designed and implemented
some interesting new protocols -
8:34 - 8:40such as teleportation
among different users in the network -
8:40 - 8:42and efficient data transmission
-
8:42 - 8:44and even secure voting.
-
8:45 - 8:47So it's a lot of fun for me,
being a quantum physicist. -
8:47 - 8:49I highly recommend it.
-
8:49 - 8:51(Laughter)
-
8:51 - 8:54We get to be explorers
in a quantum wonderland. -
8:54 - 8:57Who knows what applications
we will discover next. -
8:57 - 9:00We must tread carefully and responsibly
-
9:00 - 9:02as we build our quantum future.
-
9:03 - 9:05And for me, personally,
-
9:05 - 9:10I don't see quantum physics as a tool
just to build quantum computers. -
9:10 - 9:15I see quantum computers as a way
for us to probe the mysteries of nature -
9:15 - 9:19and reveal more about this hidden world
outside of our experiences. -
9:19 - 9:21How amazing that we humans,
-
9:21 - 9:24with our relatively limited
access to the universe, -
9:24 - 9:27can still see far beyond our horizons
-
9:27 - 9:30just using our imagination
and our ingenuity. -
9:30 - 9:33And the universe rewards us
-
9:33 - 9:36by showing us how incredibly
interesting and surprising it is. -
9:37 - 9:41The future is fundamentally uncertain,
-
9:41 - 9:44and to me, that is certainly exciting.
-
9:44 - 9:45Thank you.
-
9:46 - 9:52(Applause)
- Title:
- Quantum computing explained in 10 minutes
- Speaker:
- Shohini Ghose
- Description:
-
A quantum computer isn't just a more powerful version of the computers we use today; it's something else entirely, based on emerging scientific understanding -- and more than a bit of uncertainty. Enter the quantum wonderland with TED Fellow Shohini Ghose and learn how this technology holds the potential to transform medicine, create unbreakable encryption and even teleport information.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 10:04
Brian Greene edited English subtitles for A beginner's guide to quantum computing | ||
Brian Greene approved English subtitles for A beginner's guide to quantum computing | ||
Brian Greene edited English subtitles for A beginner's guide to quantum computing | ||
Krystian Aparta accepted English subtitles for A beginner's guide to quantum computing | ||
Krystian Aparta edited English subtitles for A beginner's guide to quantum computing | ||
Krystian Aparta edited English subtitles for A beginner's guide to quantum computing | ||
Joseph Geni edited English subtitles for A beginner's guide to quantum computing | ||
Joseph Geni edited English subtitles for A beginner's guide to quantum computing |