Tube English 2

When trains are running late, and platforms are crowded (as they were today thanks to the stupid walk-out by drivers on the Circle and District lines), station announcers like to tell us to "Use all available doors". If I was an elementary particle or photon, capable of simultaneously passing through multiple locations (or in some versions of quantum mechanics, theoretically capable of being anywhere in the universe until the collapse of the probability wave function brought about by interaction with another particle or photon), then yes I could indeed aspire to using all available doors. But I am composed of billions upon billions of elementary particles, the probability that I occupy just one position in space-time is overwhelmingly huge and consequently I can use only one door at a time. And so can everyone else. So being told to do something impossible does make the announcers appear to inhabit some parallel universe of their own.