Jeudi 30 mai 2013
According to Hund (1927) quantum mechanics forbids the existence of stable optically
active (chiral) molecules as they violate the invariance under parity of the Hamiltonian.
This paradox has attracted much attention ever since and there is not yet a
universally accepted explanation. I will contend that spontaneous symmetry breaking
provides a qualitative and quantitative explanation.
A second paradox concerning chiral molecules is the predominance of left handed
molecules (amino acids) in living matter. This may remind of the predominance of
matter over antimatter in the universe. I shall briefly discuss of how recent results in
non equilibrium statistical mechanics may offer a clue.