But the uncertainty principle isn't physics its mathematics, it spills over

into physics and engineering because of the form QM and EM take.

It is in fact a property of the Fourier transform, that when these things are

appropriately defined and scaled that:

.

This is most easily seen with the Gaussian density, which with appropriate

scaling of the two domains and juggling with the constants involved is

its own FT, then

can be taken as the "standard deviation" in the

-domain,

and

the same in the

domain.

RonL