What is the quantum tunneling?

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Occasionally I have commented on this blog the number of totally anti-intuitive things that happen when we talk about the behavior of sub atomic particles or, what is the same, quantum mechanics.

In addition to the more well-known properties of state superposition and entanglement, another of the strange phenomena of quantum behavior is the so-called "quantum tunneling".

Very briefly we can say that the quantum tunneling is a phenomenon by which a sub atomic particle crosses a barrier that, following the rules of classical mechanics, it could not cross due to not having enough energy.

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As you all know, according to quantum mechanics, all particles can behave interchangeably as waves or as particles, this wave being the probability that a particle is at a certain point.

Among all those probabilities there is one that the particle is on the other side of the barrier and that would be, very roughly, the so-called quantum tunneling.

Following this principle, if you hit a wall the necessary number of times there is a very slight probability that you will go to the other side, but it will make your face look like a pepperoni pizza.

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At this point in the post you will be wondering, and what do I care about all this mess?, because if it were not for the quantum tunneling the Sun could not give us heat because the fusion would not occur.

You will all have experimented with magnets and you will have verified that the currents of the same sign repel each other, taking into account that the charge of the protons is positive, the sun would not have enough energy to produce that fusion if it were not for the Quantum tunneling.

Another very interesting application of quantum tunneling has been the construction of Scanning tunneling microscope, which allow us to observe sub-atomic particles.

More information:
https://en.wikipedia.org/wiki/Quantum_tunnelling

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