9 Supersonic 747s Many of us have travelled faster than sound. There are a number of jet streams in the upper atmosphere, notably on the journey from the US to Europe, where a temperature inversion causes a corridor of air to move as fast as 250mph. If an airliner with an airspeed of 550mph enters a jet stream, the result can be to fly at 800mph, above sound’s 740mph. 10 Flying through time Time zones provide an artificial journey through time – but special relativity means that a flight involves actual time travel. It’s so minimal, though, that crossing the Atlantic weekly for 40 years would only move you 1/1,000th of a second into the future. 11 Terrible tea Don’t blame the cabin attendant if your tea isn’t great. Water should be just under 100°C when it is poured on to tea leaves – but that isn’t possible on a plane. It’s impossible to get water beyond 90°C during flight – so choose coffee. 12 I can’t hear my food Airline food has a reputation for being bland and tasteless. Some of the problem may not be poor catering, though. A plane is a noisy environment and there is evidence that food loses some of its savour when we are exposed to loud noises. 13 Needle in a haystack With modern technology, it seems strange that Malaysian flight MH370 could disappear without a trace – yet, finding a missing aircraft is a needle- in-a-haystack problem.