Some­one asked me the oth­er day why I became a scientist.

Thir­ty years ago, at about the time I began to study sci­ence, I came across a book called “A Mil­lion Ran­dom Dig­its.” Here, in a vol­ume as thick as the Boston tele­phone direc­to­ry, were page after page of num­bers with no appar­ent pat­tern. No mat­ter how long you stud­ied the num­bers, there was no way to pre­dict what dig­it would occur next.