Quantum theory ranks pretty high on the list of the least attractive fields of science. Because it deals more in theory than in practice and tends towards abstract complicated terminology, quantum physics isn’t something most people know or care about. However, a recent study into one of the most fundamental claims of quantum physics has created quite a stir even outside the world of science by suggesting that an experiment has proven that certain particles, even if separated by a huge distance, can instantly affect each other’s behavior.
The New York Times reported on Oct 21, that the study is part of an ongoing field of research that is challenging some of the most basic principles of standard physics. In this instance, the principle is what is called “locality” which claims that any object can only be directly changed or influenced by something in its immediate surroundings. Now the idea that some objects might be altered by forces outside of their “locality” has been around for a while, long enough in fact for Einstein to have famously rejected the theory, saying that quantum theory required “spooky action at a distance.” Unfortunately for Einstein’s opponents, their ideas were largely theoretical and the possibility of attaining any kind of proof was far out of reach.
Enter a group of brilliant scientists at Delft University of Technology in the Netherlands, whose study, published Wednesday in the journal Nature, has presented the best evidence yet for quantum mechanics and the fundamental theory that the world is much more like a fabric of subatomic particles in which matter does not actually take shape until it is observed than it is like the solid matter we seem to see. The study was performed by Ronald Hanson, a physicist at the Dutch university’s Kavli Institute of Nanoscience, and his team of researchers from Spain and England.
The international team of researchers dubbed their experiment the “loophole-free Bell test” as a reference to John Stewart Bell who in 1964 proposed an experiment to test “spooky action at a distance.” The goal of the test was to prove one of the major claims of quantum theory. Called “entanglement,” the theory suggests that two particles could be bound up so completely in each other that they could instantly affect the other particle even if the two are placed at separate ends of the universe.
It was the idea of “entanglement” that drew particular ire from Einstein; however, for decades scientists have been trying to prove that it is actually true. So far, the biggest obstacle for all of these tests is loopholes, which are alternate explanations for the results of the test that are not quantum “entanglement.”
“These tests have been done since the late ’70s but always in the way that additional assumptions were needed,” said Dr. Hanson in an interview with the New York Times. “Now we have confirmed that there is spooky action at distance.”
To make their test loophole-free, the researchers entangled two electrons and placed these electrons in separate diamonds, setting them at a distance of 1.3 kilometers, just short of a mile, from each other. Each of the entangled electrons in the diamond possessed a quality called “spin” and the team used pulses of microwave and laser energy to both entangle the electrons and measure their “spin.” The distance of the two diamonds ensured that there could be no communication between the teams in the time it took for the measurements to be made.
While the early results are already incredible, scientists involved in the field of quantum physics are anticipating that this study is laying the groundwork for some truly revolutionary advances. Quantum mechanics has already been more or less responsible for the advent of modern computers and lasers, and further development of technology that uses entanglement might lead to what some researchers call the “quantum internet.”
Today, the Internet faces many major security issues due to super-advanced computers that can process an amazing amount of data and can power through most encryption technology, posing a major threat to world’s electronic commerce. However, a communication network based on quantum entanglement would allow for the instant sharing of encryption keys, and make eavesdropping practically impossible.
The study by the Delft researchers was a major step forward, but an even more ambitious experiment is being designed by David Kaiser a physicist at M.I.T. who believes that his test will seal the case on quantum entanglement. Dr. Kaiser doesn’t believe that the Delft experiment was quite as loophole free as claimed. “The experiment has closed two of the three major loopholes beautifully, but two out of three isn’t three,” he said. It’s unlikely that we’ll have definitive proof for a while though, as Kaiser’s test isn’t slated to begin until 2017 or 2018. In the meantime we’ll just have to live with our regular old non-quantum internet.