# Quantum uncertainty affecting classical object? [duplicate]

As far as I know, the probability of a quantum object being in a certain position depends on the wave function value for each position. That raises a question: Is this probability strictly greater than 0 for all points? If I place an electron in a box, it can be anywhere on the box, or anywhere on the universe?

For example, there is always a small possibility of finding a value however far from the mean, while that is not the case for a triangular distribution.

Also, slightly related: Is this property maintained when studying classical objects? Is there any possibility, even if unimaginably small, that all of the particles of a cat will simply move somewhere else at the same time, "teleporting" it?

If the value of $|\psi|^2$ is greater than zero there is a probability of detecting the particle. Whether this is the case depends on the potential. For example if the particle is in an infinite potential well then $\psi$ is zero outside the box and there is no probability of detecting the particle outside the box. If the box is not an infinitely deep potential well then there is a probability of detecting the particle outside the box, though this probability rapidly falls to such small values that it is indistinguishable from zero.