The boundary between mind and matter could be tested using a new twist on a well-known experiment in quantum physics.
Over the past two decades, a type of experiment known as a Bell test has confirmed the weirdness of quantum mechanics – specifically the “spooky action at a distance” that so bothered Einstein.
Now, a theorist proposes a Bell test experiment using something unprecedented: human consciousness. If such an experiment showed deviations from quantum mechanics, it could provide the first hints that our minds are potentially immaterial.
Spooky action at a distance was Einstein’s phrase for a quantum effect called entanglement. If two particles are entangled, then measuring the state of one particle seems to instantly influence the state of the other, even if they are light years apart.
But any signal passing between them would have to travel faster than the speed of light, breaking the cosmic speed limit. To Einstein, this implied that quantum theory was incomplete, and that there was a deeper theory that could explain the particles’ behaviour without resorting to weird instantaneous influence. Some physicists have been trying to find this deeper theory ever since.
In 1964, physicist John Bell paved the way for testing whether the particles do in fact influence each other. He devised an experiment that involves creating a pair of entangled particles and sending one towards location A and the other to location B. At each point, there is a device that measures, say, the spin of the particle.
The setting on the device – for example, whether to measure the particle’s spin in the +45 or -45 degree direction – is chosen using random number generators, and in such a way that it’s impossible for A to know of B’s setting and vice-versa at the time of the measurement.
The measurements are done for numerous entangled pairs. If quantum physics is correct and there is indeed spooky action at a distance, then the results of these measurements would be correlated to a far greater extent than if Einstein was correct. All such experiments so far have supported quantum physics.
However, some physicists have argued that even the random number generators may not be truly random. They could be governed by some underlying physics that we don’t yet understand, and this so-called “super-determinism” could explain the observed correlations.
Now, Lucien Hardy at the Perimeter Institute in Canada suggests that the measurements at A and B can be controlled by something that could potentially be separate from the material world: the human mind.
“[French philosopher Rene] Descartes put forth this mind-matter duality, [where] the mind is outside of regular physics and intervenes on the physical world,” says Hardy.