Albert Einstein (Photo: Wikimedia Commons/Oren Jack Turner) - Credit: Albert Einstein (Photo: Wikimedia Commons/Oren Jack Turner)
Thursday, 22 October 2015 - 10:02
Delft research supports "spooky" quantum theory denounced by Einstein
An experiment done by TU Delft supports the quantum theory that the observation of an object instantaneously has an affect on another object, even if it is very far away. In 1935 Einstein refused to accept the latter part of the theory - the distance - calling it a "spooky influence at a distance". A team of scientists from the Netherlands, Spain and the United Kingdom, led by TU Delft professor Ronald Hanson, now managed to show that Einstein had it wrong. The scientists' experiment showed that electrons in two diamonds, separated 1.3 kilometers from each other, may actually have an invisible and instantaneous connection. According to them, the experiment shows that - how counter intuitive it may be - the "ghostly influence" does actually exist. The findings of their experiment was published in Nature on Wednesday, TU Delft reports on the University's website. "Quantum mechanics states tat a particle, such as an electron, can find itself in two different states at the same time. It may even be in two different places at the same time, as long as it is not observed. This phenomenon is called 'superposition'. It goes completely against our intuition", Hanson explained. His research group worked with "spin", a tiny magnetic effect of an electron, that can point up or down, or both at the same time. "It gets really interesting when we 'intertwine' the two, so that they form a whole together. Then they are both up and down simultaneously, but once we observe one and find it 'up', we determine that the other is 'down'. That effect is instantaneous, even if the other electron would be in a rocket on the other side of the galaxy." Hanson continued. IN 1935 scientists Einstein, Podolsky and Rosen wrote a famous article, the EPR-paper, that stated that quantum mechanics admittedly had proven merits, but because of the strange prediction of intertwining, it could not be a complete theory. Their conclusion was that there were still undiscovered particle properties, or "hidden variables", and if those variables were found, the "ghostly influence at a distance" would no longer be necessary. In 1964 scientist John Stewart Bell devised an experiment that could prove that Einstein's "spooky influence" existed. This "Bell Test" performs measurements on two sides of an intertwined pair and excludes all possible hidden variables. In the following for decades, many scientists performed Bell Tests, but every one of them contained significant loopholes. So Einstein's conclusion could not completely be ruled out. Hanson's team of scientists has managed to close all the loopholes for the first time in history. They placed two diamonds, each with a trapped electron, 1.3 kilometers apart on either side of the TU Delft campus, intertwined them and carried out a Bell Test. "We have two laboratories, one in the physics building and one in the Reactor Institute Delft at the other side of the campus. The large distance between the assemblies ensures that neither the detector nor the electrons themselves could exchange information with each other during the experiment. This exchange can never go faster than the speed of light and the distance between the labs is simply too big to bridge in the time we need to measure the electrons", PhD student Bas Hensen explained in the publication. "This rules closes the location-loophole. We also exclude the detection-loophole, because we detect all intertwined pairs in our experiment. It is the first Bell Test free of loopholes, and still we see that the invisible and instantaneous connection of intertwining is real: the ghostly influences are real."