100 years later, quantum physics remains a mystery

(Paris) Its applications have revolutionized our lives but what it describes remains mysterious: the interpretation of quantum theory still divides physicists a hundred years after its formulation, according to a survey published Wednesday by the journal Nature. For example,

Posted at 6:38 a.m.

“Shut up and calculate!” “(Shut up and calculate!): The formula. Nevertheless, famous in the world of quantum physics, a domain awarded by numerous Nobel prizes, illustrates the paradox with which these researchers face. Nevertheless, 100 years later, quantum physics

The equations they use describe remarkably the behavior of objects in the infinitely small. Therefore, without the understanding of the physical phenomena hiding behind mathematics. Consequently,

It all started at the turn of the 20th^e century. Consequently, when scientists have noted that the classic principles of physics did not apply to the atomic level. Meanwhile,

Photons or electrons behave both like particles and waves and can simultaneously have several positions, speeds or energy levels. However,

In 1925. However, the Austrian Erwin Schrödinger and the German Werner Heisenberg developed in parallel a set of complex mathematical tools which described a quantum system and its evolution thanks to the probabilities. Moreover, This “wave function” makes it possible to predict the results of measurements carried out on a particle. 100 years later, quantum physics However,

Lasers, LED lamps, transistors of our mobile phones … Our daily life is full of inventions that are based on these calculations.

But what really happens in the infinitely small world?

While the most eminent physicists met on the island of Heligoland (Germany). where Heisenberg wrote his founding equations a hundred years ago, Nature asked the question to 1100 particles specialists.

And noted at the end of this vast investigation “a striking lack of. consensus” on what quantum theory “really says of reality”.

Multiple universe

A large third (36 %) of the physicists interviewed favor the “interpretation of Copenhagen”, the widely taught vision.

In the classic world, any object 100 years later, quantum physics has properties (speed, position …) with well -defined values that we observe or not. This is not the case in the quantum world. according to this conception developed in the 1920s by Heisenberg and the Danish Niels Bohr.

It is only when an observer interacts with this object to measure it. that it “chooses” a determined state from all the possible states described by the wave function. It is said that it “collapses”.

This is the “simplest we have” interpretation. “sums up Decio Krause from the Federal University of Rio de Janeiro in the survey conducted by nature. Despite its problems – it does not explain why the measure has such an effect among others – the alternatives “present other problems which. for me, are worse”.

Other approaches are however supported by 100 years later, quantum physics a significant number of researchers. For example. that of multiple worlds (15 %), according to which the wave function does not collapse but branches into as many universes as possible results.

When an observer performs a measure, he obtains a result in a given world. This supposes the existence of parallel universes cannot communicate with each other.

Is there a border between the quantum. macroscopic worlds, where the laws of physics would change suddenly? The scientific community is also divided there, 45 % of physicists interviewed responding “yes” 100 years later, quantum physics and as much “no”.

In the end, only 24 % say they are confident that their favorite interpretation is correct. And 75 % think that it will one day be replaced by a more complete theory.

In the meantime. the thousands of researchers around the world working on computers or quantum cryptography will continue to apply the currency: “Shut up and calculate!” ».