Modern Physics

Schroedinger’s cat

Schroedinger’s Cat is a fascinating thought experiment, proposed by Erwin Schroedinger, that reinforces the statistical nature of quantum mechanics and the Uncertainty Principle.

Schroedinger’s cat or Schroedinger’s paradox is an imaginary experiment proposed by Erwin Rudolf Josef Alexander Schroedinger, a brilliant Austrian physicist, with the aim of showing how the Uncertainty Principle works in the quantum world.

The experiment consists of putting a cat inside a box and closing it inside. Next to the cat, inside the box, is placed a vial containing a poisonous gas, a radioactive element emitting alpha particles and a device composed of a hammer and a radiation detector. If the detector registers the presence of at least one alpha particle, the hammer is triggered and breaks the vial, releasing the poisonous gas and, consequently, killing the cat. But let’s assume that the radioactive source can release alpha particles within a certain time interval, and that it may not release these particles in that time either. There is a 50% chance that the element will release the particle and a 50% chance that it will not. If he doesn’t release the particle, the cat doesn’t die, that is, the result will be “live cat”. But if the poison is released, the result of the experiment will be “moto cat”. So we can say that we have 50% live cat and 50% dead cat. But if we don’t open the box to look inside, we can’t be sure whether or not the cat is alive. The only way to be sure is if we open the box. But that’s where the weirdest thing comes in! For quantum mechanics, the cat can bealive and dead ! He can be in both states! How?!

By quantum formalism, matter also has a wave nature, and can be represented by a wave function. The dead cat is represented by a wave function, and the live cat is represented by another wave function. The fact that the cat was both alive and dead indicates that there was a superposition of these two wave functions that indicated the two possible states. You may be thinking: Why don’t we just open the box and look?!

The answer to this question comes from Heinsenberg’s Uncertainty Principle, which states that it is not possible to make a measurement without interfering with the results of that measurement itself. That is, if we open the box to look at the state of the cat inside, we will be interfering with the system and altering its results. In fact, this is a fundamental difference between quantum mechanics and classical mechanics. In the classic one, we could open the box and check what had happened to the kitten. In quantum this is not possible!