The wave function is a probability amplitude.(adsbygoogle = window.adsbygoogle || []).push({});

So far so good.

This means that it doesn't give us the probability directly and it can be a complex number.

Taking the square modulus of it, gives rise to interference. That's very good.

But why the square, why not the fourth power or any even function, like cosh(|phi|)?

Simplicity is the winner, but why?

Michel

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# Why |phi|² ?

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