Experiment rejects a challenge to quantum physics
Physicists have ruled out a mundane explanation for a weird effect known as entanglement, once again confirming the bizarre predictions of quantum physics.
In entanglement, two particles are inextricably linked so that measuring a property of one instantly reveals information about the other, no matter how far apart the two particles are. Many experiments have confirmed this eerie connection.
Few physicists doubt that these strange properties are real, but some skeptics still look for ways to explain the weirdness with normal, nonquantum effects. In response, experimental physicists have been working on ruling out nonquantum explanations — in other words, closing the “loopholes” in quantum theory. A recent experiment described online the week of October 25 in the Proceedings of the National Academy of Sciences is the latest in an effort to close all the proposed loopholes and definitively show that quantum mechanics can’t be brus