# Can an electron be at rest?

1. Feb 3, 2005

### repugno

Can an electron be at rest?

2. Feb 3, 2005

### vincentchan

yes, according the uncertainty principle, $$\Delta x \Delta p \geq h/4 \pi$$, when you completely have no idea where the electron is... it could be at rest......(it's like playing HIDE AND SEEK when you were young)

3. Feb 3, 2005

### repugno

Ahhh, so that is what is meant when the de broglie wavelenght is infinite? h/0

4. Feb 3, 2005

### vincentchan

yes, $p = hk/2\pi = h/ \lambda$
if the uncertainty of momentum is zero, sure the wavelength will go to infinity. That's also mean you have completely no idea where the electron is.....