Dead and alive cat, electrons passing through a wall, photons united forever whatever their individual destiny… Quantum physics is full of very real situations and, however, inconceivable for the human mind. Even for Einstein’s!
This article is from the magazine Les Indispensables de Sciences et Avenir n°210 of July/September 2022.
Welcome to a world where you can be here and anywhere else, a zoo where an animal can be alive and dead at the same time, a universe where “teleportation” is commonly practiced, this reality is that of quantum physics, that describes light and matter on a scale inaccessible to our eyes.
His concepts are so strange that the American physicist Richard Feynman said about it in 1964, during a very serious conference, in front of the hilarious room: “I think it’s safe to say that no one understands her.” It was a year before he received a Nobel for his contribution… to quantum physics. “We understand it very well scientificallyclarifies Julien Bobroff, professor of physics at the University of Paris-Saclay. On the other hand, it completely escapes our intuition.
How do you know what’s going on inside the box?
Imagine, for example, a cat, locked in a well-insulated box containing a vial of lethal gas and an atom of radon, whose nucleus is radioactive. If the radon decays, the particle it emits breaks the bulb, killing the animal. How do you know what’s going on inside the box? Our classical view of the world leads us to think that the cat is alive or dead, depending on whether or not the radon has decayed. But if we consider this experience through the prism of quantum physics, our brain is in a ball: any quantum object can be in one state or the other, but also in both at the same time.
In other words, a “quantum cat” can be alive, dead, or alive and dead at the same time! Only at the moment of observation will we know its destiny. But beware: quantum physics also tells us that observing a state disturbs or destroys it! Similarly, it prohibits creating a perfect copy: impossible to clone a report. in revenge[…]