A groundbreaking quantum experiment recently confirmed the reality of "spooky action-at-a-distance" — the bizarre phenomenon that Einstein hated — in which linked particles seemingly communicate faster than the speed of light.
And all it took was 12 teams of physicists in 10 countries, more than 100,000 volunteer gamers and over 97 million data units — all of which were randomly generated by hand.
The volunteers operated from locations around the world, playing an online video game on Nov. 30, 2016, that produced millions of bits, or "binary digits" — the smallest unit of computer data.
Physicists then used those random bits in so-called Bell tests, designed to show that entangled particles, or particles whose states are mysteriously linked, can somehow transfer information faster than light can travel, and that these particles seem to "choose" their states at the moment they are measured.
Their findings, recently reported in a new study, contradicted Einstein's description of a state known as "local realism," study co-author Morgan Mitchell, a professor of quantum optics at the Institute of Photonic Sciences in Barcelona, Spain, told Live Science in an email.
"We showed that Einstein’s world-view of local realism, in which things have properties whether or not you observe them, and no influence travels faster than light, cannot be true — at least one of those things must be false," Mitchell said.
This introduces the likelihood of two mind-bending scenarios: Either our observations of the world actually change it, or particles are communicating with each other in some manner that we can't see or influence.
"Or possibly both," Mitchell added.
Einstein's worldview — Is it true?
Since the 1970s, physicists have tested the plausibility of local realism by using experiments called Bell tests, first proposed in the 1960s by Irish physicist John Bell.
To conduct these Bell tests, physicists compare randomly chosen measurements, such as the polarization of two entangled particles, like photons, that exist in different locations. If one photon is polarized in one direction (say, up), the other will be going sideways only a certain percentage of the time.
If the number of times that the particle measurements mirror each other goes above that threshold — regardless of what the particles are or the order in which the measurements are selected — that suggests the separated particles "choose" their state only at the moment they are measured. And it implies that the particles can instantly communicate with each other — the so-called spooky action at a distance that bothered Einstein so much.
These synched responses thereby contradict the notion of genuinely independent existence, a view that forms the foundation of the principle of local realism upon which the rules of classical mechanics are based. But, time after time, tests have shown that entangled particles do demonstrate correlated states that exceed the threshold; that the world is, indeed, spooky; and that Einstein was wrong.
Volunteers in 190 countries played a game that provided researchers with more than 97,000 random bits,
which the scientists applied to measurements for entangled particles.
Credit: ICFO
However, Bell tests require that the choice of what to measure should be truly random. And that's hard to show, since unseen factors can influence researchers' selections, and even computers' random data generation isn't truly random. This creates a flaw in Bell tests known as the freedom-of-choice loophole — the possibility that "hidden variables" could influence the settings used in the experiments, the scientists reported. If the measurements aren't truly random, the Bell tests can't definitively rule out local realism.
For the new study, the researchers wanted to gather an enormous amount of human-produced data, to be certain they were incorporating true randomness in their calculations. That data enabled them to conduct a broader test of local reality than had ever been done before, and at the same time, it allowed them to close the persistent loophole, the researchers claimed.
"Local realism is a question we can't fully answer with a machine," Morgan said in a statement. "It seems we ourselves must be part of the experiment, to keep the universe honest."
Random number generators
Their effort, dubbed the Big Bell Test, engaged players — or "Bellsters" — in an online tapping game called Big Bell Quest. Players quickly and repeatedly tapped two buttons on a screen, with respective values of one and zero. Their choices streamed to laboratories on five continents, where the participants' random choices were used to select measurement settings for comparing entangled particles, the researchers reported.
During the Big Bell Test initiative on Nov. 30, 2016, over 100,000 people used an online game to generate data for a global physics experiment.
Credit: ICFO
Each of the laboratories performed different experiments, using different particles — single atoms, groups of atoms, photons and superconducting devices — and their results showed "strong disagreement with local realism" in a variety of tests, according to the study, which was published online today (May 9) in the journal Nature.
The experiments also demonstrated an intriguing similarity between humans and quantum particles, related to randomness and free will. If the Bell tests' human-influenced measurements were truly random — not influenced by the entangled particles themselves — then the behaviors of both humans and particles were random, Mitchell explained.
"If we are free, so are they," he said.
Original article on Live Science.
最大的测试仍然表明爱因斯坦错误'远程幽灵行动'
作者Mindy Weisberger，高级作家| 2018年5月9日美国东部时间下午4点53分
最近开创性的量子实验证实了“鬼距离行动”这一爱因斯坦所憎恨的怪异现象 - 在这种现象中，相关的粒子似乎比光速更快地交流。
所花费的全部是10个国家的12个物理学家小组，超过10万名志愿游戏玩家和超过9700万个数据单元 - 所有这些都是手工随机生成的。
这些志愿者在2016年11月30日在世界各地开展了一项在线视频游戏，它产生了数百万比特或“二进制数字” - 这是计算机数据的最小单位。
然后物理学家在所谓的贝尔测试中使用这些随机比特，旨在表明纠缠的粒子或状态是神秘连接的粒子可以某种方式以比光传播更快的速度传递信息，并且这些粒子似乎在“选择”它们的状态他们被测量的那一刻。 [什么是量子力学？]
他们最近在一项新研究中报告的研究结果与爱因斯坦关于称为“本地现实主义”的描述相矛盾，该研究的合着者西班牙巴塞罗那光子科学研究所的量子光学教授Morgan Mitchell告诉Live Science一封电邮。
“我们展示了爱因斯坦关于局部现实主义的世界观，即无论你是否观察到物体都具有属性，并且没有任何影响比光速传播的速度更快，这不可能是真实的，至少其中一种情况必须是错误的，”米切尔说。
这引入了两种情绪折射情景的可能性：我们对世界的观察实际上改变了它，或者粒子以某种我们无法看到或影响的方式彼此沟通。
“或者可能两个，”米切尔补充说。
爱因斯坦的世界观 - 这是真的吗？
自20世纪70年代以来，物理学家通过使用称为贝尔测试的实验来测试地方现实主义的合理性，贝尔测试在20世纪60年代首次由爱尔兰物理学家约翰·贝尔提出。
自20世纪60年代首次由爱尔兰物理学家约翰·贝尔提出
为了进行这些Bell测试，物理学家比较随机选择的测量值，例如存在于不同位置的两个纠缠粒子（如光子）的极化。如果一个光子在一个方向上极化（比如说上），另一个光子只会在一定的时间内横向移动。
如果粒子测量相互镜像的次数高于阈值 - 无论粒子是什么或者测量的选择顺序如何 - 这表明分离的粒子仅在测量时才“选择”它们的状态。这意味着这些粒子可以立即与彼此进行交流 - 这就是所谓的幽灵般的行动，在一段距离之上，这让爱因斯坦非常困扰。
因此，这些同步的反应与真正独立存在的概念相矛盾，这种观点构成了古典力学规则所基于的地方现实主义原则的基础。但是，一次又一次，测试表明，纠缠的粒子确实表现出超过阈值的相关状态;这个世界确实是非常恐怖的;爱因斯坦错了。
但是，贝尔测试要求选择什么来衡量应该是真正的随机。这很难表明，因为看不到的因素会影响研究人员的选择，甚至电脑的随机数据生成也不是真正的随机数。科学家们报告称，这给贝尔测试带来了一个缺陷，称为自由选择漏洞 - “隐藏变量”可能会影响实验中使用的设置。如果测量结果不是真正随机的，贝尔测试不能确定地排除当地的现实主义。
对于这项新研究，研究人员想要收集大量的人为数据，以确定他们在计算中加入了真随机性。研究人员称，这些数据使他们能够进行比以往任何时候都更为广泛的对当地实际情况的测试，同时，这些数据使他们能够弥合持续的漏洞。
摩根在一份声明中说：“地方现实主义是我们无法用机器完全回答的问题。 “看来我们自己必须成为实验的一部分，才能保持宇宙的诚实。”
随机数发生器
他们的努力，被称为大钟测试，在一个名为Big Bell Quest的在线攻击游戏中聘请玩家 - 或“Bellsters”。 玩家快速并重复地点击屏幕上的两个按钮，其值分别为1和0。 研究人员报告说，他们的选择流入了五大洲的实验室，参与者的随机选择被用来选择比较纠缠颗粒的测量设置。
根据研究报告，每个实验室在不同的测试中进行了不同的实验，使用不同的粒子 - 单原子，原子团，光子和超导设备 - 并且他们的结果显示在各种测试中“与地方现实主义的强烈不一致” 今日（5月9日）在“自然”杂志上发表。
实验还表明人类和量子粒子之间有趣的相似之处，与随机性和自由意志有关。 如果贝尔测试的人为影响测量是真正随机的 - 不受纠缠粒子本身的影响 - 那么人类和粒子的行为是随机的，米切尔解释说。
“如果我们自由，他们也是，”他说。
关于Live Science的原创文章。
发表于 2018-5-11 12:39
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