## Uncertainty Question

$\Delta p \Delta x\geq \frac{h}{4\pi }$

DHavo_1E
Posts: 118
Joined: Sat Aug 17, 2019 12:17 am

### Uncertainty Question

Hello,

Can someone explain why uncertainty is negligible in bigger masses, and more important with smaller masses?

Julie_Reyes1B
Posts: 105
Joined: Sat Jul 20, 2019 12:16 am

### Re: Uncertainty Question

Hi!
The reason why the uncertainty principle is only significant with smaller objects is similar to why the de Broglie equation only yields noticeable results for smaller objects. Both equations involve a particle’s wavelike properties, which really only applies to subatomic particles. Dr. Lavelle’s lecture on Friday had a really great example which showed that a car would not have a noticeable wavelength/wavelike properties. Similarly, the uncertainty principle is built upon the principles of particle-wave duality, which we can’t apply to larger objects.
Hope this helps!

Petrina Kan 2I
Posts: 102
Joined: Fri Aug 30, 2019 12:17 am

### Re: Uncertainty Question

In Dr. Lavelle's lecture today (Monday), he showed a great example of a baseball being hit by photons and continuing on its pathway and then compared it to an electron going through the same thing. Since the mass of the baseball is so large, it has little to no uncertainty and effect in its velocity and pathway when hit by a photon, which is why the uncertainty is negligible. However, since an electron has such a small mass its path is affected when it interacts with the photon, which causes the uncertainty in its mass and pathway. Hope this helps!

Anokhi Patel 2B
Posts: 76
Joined: Fri Aug 09, 2019 12:17 am

### Re: Uncertainty Question

In the example in lecture, the answer 3.4 x 10-10 m.s-1 was an unrealistic number for the uncertainty, since it was larger than the speed of light. How do we know when the velocity is an unrealistic number, will a probable speed always have to be lesser than 3.0 x 10-8?

Thank you.