Somehow I started reading this paper about a new theory of time travel. Can’t understand much of it but man it’s fun!
Here’s my favourite bit:
‘I received a telephone call one day at the graduate college at Princeton from Professor Wheeler, in which he said, “Feynman, I know why all electrons have the same charge and the same mass.”
“Why?”
“Because, they are all the same electron!”
And, then he explained on the telephone, “Suppose that the world lines which we were ordinarily considering before in time and space – instead of only going up in time were a tremendous knot, and then, when we cut through the knot, by the plane corresponding to a fixed time, we would see many, many world lines and that would represent many electrons, except for one thing. If in one section this is an ordinary electron world line, in the section in which it reversed itself and is coming back from the future we have the wrong sign to the proper time – to the proper four velocities – and that’s equivalent to changing the sign of the charge, and, therefore, that part of a path would act like a positron.”
What the? Mind boggling. I wish I had the right brain for physics sometimes!
” and is a history, guide and tribute to Lego. Did you know that the Lego company was founded in 1916 by a Danish carpenter? At first he made furniture, but in 1932 he switched to children’s toys. The company did really well out of pull-along toys before inventing the Lego brick in 1949. Anyway there is a lot of good stuff in it as well as beautiful full colour photos. And if that wasn’t enough, it comes with a BONUS book “Standing Small” which is a tribute to 30 years of the Lego mini-figure! 