# Heisenberg Uncertainty Principle - h/(4.Phi) versus h/(2.Phi)

1. Mar 3, 2005

### jvicens

Heisenberg Uncertainty Principle - h/(4.Pi) versus h/(2.Pi)

What's the reason behind the factor 2 in the way some books/papers present Heisenberg Uncertainty Principle?
h/(4.Pi) versus h/(2.Pi)
When in history did this discrepancy arise and who was responsible for that?
Ultimately, which figure should we use when we are solving HUP problems?

Last edited: Mar 4, 2005
2. Mar 3, 2005

### masudr

I think you mean $h/4\pi$ and $h/2\pi$. I would refer you to http://en.wikipedia.org/wiki/Uncertainty_principle which provides an excellent description of the general uncertainty principle and also explains why the two reults are often quoted. The more correct one is $h/4\pi$.

3. Mar 7, 2005

### dextercioby

The correct one is with $$\frac{\hbar}{2}$$ as it can be shown starting with the general uncertainty relations.

Any other constant is incorrect.

Daniel.

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