QUANTUM MECHANICS Bad news for time travellers

摘要

It is a tricky problem that Marty McFly has to solve in the first film of the Back to the Future trilogy. Sent back 30 years, on board a time machine built by the slightly mad scientist Doc Brown (pictured), he accidentally interrupts the first meeting of his future parents, then has to pull all kinds of strings to make their love affair happen — and thereby secure his own existence