6k views

Can Newton's laws be explained by Quantum Physics? [duplicate]

I have only basic knowledge of physics. Could you please explain to me if a "Quantum" laws can theoretically (perhaps in the future?) be used to explain everything in macro levels? I'm having ...
2k views

From Quantum Mechanics to Classical Mechanics [duplicate]

Is it possible, and has it been attempted, to use quantum mechanics to deduce Newtonian, macroscopic level mechanics laws as was the case of statistical mechanics deriving thermodynamic relations?
721 views

Can the laws of classical mechanics be derived from quantum mechanics? [duplicate]

Can classical mechanics be derived from quantum mechanics as the same way thermodynamics derived from statistical mechanics?
295 views

How to prove Newton's second law with quantum mechanics? [duplicate]

Newton's second law claims that $F=ma$. In terms of quantum mechanics, the equality can be written as $\frac{d\langle p \rangle}{dt} = -\langle \nabla V(x) \rangle$. How can I prove this with non-...
227 views

How to go from Quantum World to Classical World? [duplicate]

Possible Duplicate: Is it possible to recover Classical Mechanics from Schrödingerâ€™s equation? Classical Limit of the Feynman Path Integral In the quantum world we don't have specific ...
7k views

Classical limit of quantum mechanics

I have heard that one can recover classical mechanics from quantum mechanics in the limit the $\hbar$ goes to zero. How can this be done? (Ideally, I would love to see something like: as $\hbar$ ...
Let's take the very simple problem of what happens if I drop a 1 kg ball from a height of 1 meter. Classically, $F = mg$ and $g \approx 10 \frac{\mathrm{m}}{\mathrm{s}^2}$, so the ball feels a force ...