Dear Physics Forum,(adsbygoogle = window.adsbygoogle || []).push({});

I think I am confused in applying the correspondence principle in QM, using the particle in a box and de Broglie wavelength calculations for massive (macroscopic) objects.

Why is the calculated energy of a massive object so small in the particle in a box

E = h^{2}/8mL^{2}

but when the de Broglie wavelength of a massive object is calculated,

λ = h/p

it is very small, meaning its frequency and so energy are high?

And if the energy level spacing is always n^{2}, why is it said that the spacing becomes continuous, not discrete, for massive objects?

Thanks for your help, Mark

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Is the de Broglie wavelenght incongruent with particle in a box calculation?

**Physics Forums | Science Articles, Homework Help, Discussion**