• Finally I got to carbon, and as you all know, in the case of carbon the reaction works out beautifully. One goes through six reactions, and at the end one comes back to carbon. In the process one has made four hydrogen atoms into one of helium. The theory, of course, was not made on the railway train from Washington to Ithaca ... It didn't take very long, it took about six weeks, but not even the Trans-Siberian railroad [has] taken that long for its journey.