In 2015 the universe was officially proven to be weird. After many decades of research, a series of experiments showed that distant, entangled objects can seemingly interact with each other through what Albert Einstein famously dismissed as “Spooky action at a distance”.
A new experiment by an international team led by Heriot-Watt researcher Dr Alessandro Fedrizzi has now found that the universe is even weirder than that: entangled objects do not cause each other to behave the way they do.
Distinguishing cause from effect comes naturally to us. PhD student Martin Ringbauer from the University of Queensland explains, “Picture yourself in a room where someone is flicking a light switch. Intuition and experience lets you establish a simple causal model: the switch causes the lights to turn on and off. In this case, correlation implies causation.”
“If we could entangle two lights, you would see them turn on and off at random, regardless of how far apart they are, with no obvious switch and in perfect lockstep. Einstein’s preferred explanation of this mysterious effect was that there must be a hidden light switch which acts as a common cause for our entangled lights.”