Will we ever be able to teleport? - Sajan Saini

翻译人员: Lipeng Chen 校对人员: 芷蘅 张

Is teleportation possible?

无线传输会成为可能吗？

Could a baseball transform into something like a radio wave,

一个棒球是否有可能转变成一道电波，

travel through buildings,

穿过高楼，

bounce around corners,

弹过转角，

and change back into a baseball?

再变回原样吗？

Oddly enough, thanks to quantum mechanics, the answer might actually be yes.

可能有些奇怪，多亏了量子力学， 答案可能确实是“是”。

Sort of.

可能吧。

Here's the trick.

秘密在此。

The baseball itself couldn't be sent by radio,

棒球本身不能被电波传输，

but all the information about it could.

但是它的所有信息可以。

In quantum physics, atoms and electrons

在量子物理中，原子和电子

are interpreted as a collection of distinct properties,

被解释成一族特性的集合，

for example, position,

譬如，位置，

momentum,

and intrinsic spin.

动量，

以及特征自旋。

The values of these properties configure the particle,

这些特性的值确定了一个粒子，

giving it a quantum state identity.

给了它量子态特征。

If two electrons have the same quantum state,

如果两个电子有相同的量子态，

they're identical.

那么它们就是相同的。

In a literal sense, our baseball is defined by a collective quantum state

字面意义上，棒球可以由形成它的原子的

resulting from its many atoms.

一系列量子态所确定。

If this quantum state information could be read in Boston

如果可以再波士顿读取这量子态信息，

and sent around the world,

并且将它发往全世界，

atoms for the same chemical elements could have this information

那么在班加罗尔，拥有相同化学元素的原子

imprinted on them in Bangalore

可以接收，刻入这些信息，

and be carefully directed to assemble,

被小心的组装，

becoming the exact same baseball.

变成一模一样的棒球。

There's a wrinkle though.

但这有一个问题。

Quantum states aren't so easy to measure.

量子态不容易测量。

The uncertainty principle in quantum physics

量子物理中的测不准原理

implies the position and momentum of a particle

说明不能同时测量

can't be measured at the same time.

一个粒子的位置和动量。

The simplest way to measure the exact position of an electron

测量电子准确位置的最简单方法

requires scattering a particle of light, a photon, from it,

需要散布光的粒子，即光子，

and collecting the light in a microscope.

并在显微镜下收集光子。

But that scattering changes the momentum of the electron in an unpredictable way.

但是这种散布以一种 不可预测方式改变了电子的动量。

We lose all previous information about momentum.

我们失去了之前关于动量的全部信息。

In a sense, quantum information is fragile.

某种意义上来说， 量子信息是脆弱的。

Measuring the information changes it.

测量这种信息会改变它。

So how can we transmit something

所以我们如何传输那些

we're not permitted to fully read without destroying it?

不能完全被我们读取的东西而不毁坏它呢？

The answer can be found in the strange phenomena of quantum entanglement.

可以在量子缠结的奇怪现象中找到答案。

Entanglement is an old mystery from the early days of quantum physics

自量子物理形成以来，量子缠结就是古老的谜题，

and it's still not entirely understood.

而且仍没有完全解释。

Entangling the spin of two electrons results in an influence

缠结两个电子的自旋可以形成

that transcends distance.

超过距离的影响。

Measuring the spin of the first electron

测量第一个电子的自旋

determines what spin will measure for the second,

决定第二个电子会测出什么样的自旋，

whether the two particles are a mile or a light year apart.

不论这两个粒子是距离一英里还是一光年。

Somehow, information about the first electron's quantum state,

然而，第一个电子的量子态信息，

called a qubit of data,

即一个量子位的数据，

influences its partner without transmission across the intervening space.

可以不通过中介传递影响另一个电子。

Einstein and his colleagues called this strange communcation

爱因斯坦和他的同事称这种奇怪的通信为

spooky action at a distance.

鬼魅似的远距作用。

While it does seem that entanglement between two particles

尽管似乎两粒子之间的缠结

helps transfer a qubit instantaneously across the space between them,

会于空间中在它们之间 立刻传输一个量子位，

there's a catch.

但这中间有个问题。

This interaction must begin locally.

这种交互必须在很近的发生。

The two electrons must be entangled in close proximity

两个电子必须很近的进行缠结，

before one of them is transported to a new site.

然后其中一个才可以移到新的地方。

By itself, quantum entanglement isn't teleportation.

本身来看，量子缠结不是无线传输。

To complete the teleport,

为了完成无线传输，

we need a digital message to help interpret the qubit at the receiving end.

我们需要数字信息来 帮助在接收端解读量子位。

Two bits of data created by measuring the first particle.

测量第一个粒子产生了两比特数据。

These digital bits must be transmitted by a classical channel

这些数字比特必须通过传统渠道运输，

that's limited by the speed of light, radio, microwaves, or perhaps fiberoptics.

受制于光速，电波，微波，还可能有光纤。

When we measure a particle for this digital message,

当我们为获得数字信息测量了一粒子，

we destroy its quantum information,

我们便破坏了它的量子信息，

which means the baseball must disappear from Boston

这意味着棒球必须在波士顿消失，

for it to teleport to Bangalore.

才能被无线传输到班加罗尔。

Thanks to the uncertainty principle,

多亏了测不准原理，

teleportation transfers the information about the baseball

在两城市间可以无线传输棒球的信息，

between the two cities and never duplicates it.

而且还不会重复它。

So in principle, we could teleport objects, even people,

所以理论上说，我们可以无线传输物体， 甚至人类，

but at present, it seems unlikely we can measure the quantum states

但是目前未知，我们还不太可能 测量大型物体里面

of the trillion trillion or more atoms in large objects

千千万万的原子的量子态，

and then recreate them elsewhere.

并且在别处复制它们。

The complexity of this task and the energy needed is astronomical.

这项任务的复杂程度和 所需能量是天文级的。

For now, we can reliably teleport single electrons and atoms,

现在，我们可以有保障的 无线传输单个电子和原子，

which may lead to super-secured data encryption

这会形成将来量子计算机的

for future quantum computers.

超级安全数据加密。

The philosophical implications of quantum teleportation are subtle.

量子传输的哲学内涵是微妙的。

A teleported object doesn't exactly transport across space

无线传输的物体不像有形物体一样

like tangible matter,

在空间中传输，

nor does it exactly transmit across space, like intangible information.

也不像无形信息一样在空间中传输。

It seems to do a little of both.

它看上去两者皆有。

Quantum physics gives us a strange new vision

量子物理给我们提供了一个 奇怪的全新视角，

for all the matter in our universe as collections of fragile information.

即我们的宇宙中所有的物质 都是脆弱信息的集合。

And quantum teleportation reveals new ways to influence this fragility.

而量子无线传输展示了新的方法 来影响这种脆弱性。

And remember, never say never.

记住，永远不要说永不。

In a little over a century,

通过一个多世纪，

mankind has advanced from an uncertain new understanding

人类已经由在原子层面上

of the behavior of electrons at the atomic scale

对于电子行为不太确定的认识，

to reliably teleporting them across a room.

发展到可以在房间里可靠的无线传输它们。

What new technical mastery of such phenomena

在1000年，甚至10000年里，

might we have in 1,000, or even 10,000 years?

我们会见证对这种现象什么样的技术运用？

Only time and space will tell.

只有时间和空间会揭开答案。