Shohini Ghose – TED Talk TRANSCRIPT
Let’s play a game.
Imagine that you are in Las Vegas, in a casino, and you decide to play a game on one of the casino’s computers, just like you might play solitaire or chess.
The computer can make moves in the game, just like a human player. This is a coin game. It starts with a coin showing heads, and the computer will play first. It can choose to flip the coin or not, but you don’t get to see the outcome.
Next, it’s your turn. You can also choose to flip the coin or not, and your move will not be revealed to your opponent, the computer.
Finally, the computer plays again, and can flip the coin or not, and after these three rounds, the coin is revealed, and if it is heads, the computer wins, if it’s tails, you win. So it’s a pretty simple game, and if everybody plays honestly, and the coin is fair, then you have a 50% chance of winning this game.
And to confirm that, I asked my students to play this game on our computers, and after many, many tries, their winning rate ended up being 50%, or close to 50%, as expected. Sounds like a boring game, right?
But what if you could play this game on a quantum computer?
Now, Las Vegas casinos do not have quantum computers, as far as I know, but IBM has built a working quantum computer. Here it is.
But what is a quantum computer?
Well, quantum physics describes the behavior of atoms and fundamental particles, like electrons and photons. So a quantum computer operates by controlling the behavior of these particles, but in a way that is completely different from our regular computers.