<i>"All of statistics and much of science depends on probability — an astonishing achievement, considering no one’s really sure what it is."</i><p>Hum, I've often pondered what probability actually means for quantum mechanics—that is in respect of its actual underlying mechanics. The more I think about it the more I agree with Sir Roger Penrose: <a href="https://www.youtube.com/watch?v=sGm505TFMbU" rel="nofollow">https://www.youtube.com/watch?v=sGm505TFMbU</a> (40:36 - 46:36. One should however view the whole video for proper context.)<p>This story on probability just further firms up my view.