Quantum mechanics and the macroscopic world?

Question

Can (do) properties of quantum mechanics (such as uncertainty principle, pauli's exclusion principle, and Feynman's sum-over-histories) apply to the macroscopic world (such as behaviors of humans, variations in personalities/consciousness, etc.)?

I understand that quantum mechanics is the science of the atomic world, however, wouldn't the macroscopic world likewise be affected by these principles, for we ourselves are made out of atoms behaving in such a manner?

Thanx

Answer 1

You will find that as the size of the system increases, the results of quantum-mechanical calculations will average out to the common Newtonian results.

For example, a human technically has a wavelength, but the wavelength is so absurdly small that you will never see a human getting diffracted by a diffraction grating.

As another example, while an electron may have a high probability of tunneling through a small barrier, the chances of a human tunneling through a wall are statistically insignificant.

On the other hand, quantum mechanical effects are visible on the macroscopic scale if you carefully design the right experiment (such as the double-slit diffraction experiment). Usually, though, you won't see the effects.

Answer 2

Not in your example. The dice can be adequately explained by classical mechanics. But many quantum mechanical effects result in emergent phenomena that have macroscopic effects. Quantum mechanics drives physical chemistry which dictates the nature of everything around us. Just about all electronics technologies from the transistor onwards are very dependent on understanding QM.

Answer 3

No, not in the way you're thinking. And particularly, not human behavior, personality, or consciousness. It's difficult to find quantum phenomena that we can observe. You can't precisely measure both position and momentum of subatomic particles. But it doesn't matter because it doesn't affect your life.