I can't quite believe this is true but apparently, a tunnel has been built from London to New York, so that, using optical devices, you can see from one end to the other. I thought this may be an April fool joke at first, but it's May, so that's unlikely! Interesting website here
Turns out nights must have affected my brain! The Telegraph puts a more likely theory, being that the "tunnel" is actually a broadband connection between London and New York. Sad in a way - all the mystery is now gone!