After having been acquainted with enantiomerism for nearly six months, I have one standing doubt.
Consider the structure of alanine. Suppose I have a pure mixture of exclusively 'S-alanine'(left in the picture) in a flask.
There are hundreds, if not, thousands of molecular collisions in the flask per second. Why can not a bump to one of the S-alanine change it to R-alanine? This way, the mixture should racemise itself if left standing for some time. But this does not happen. Why? Can someone please explain?