It's a un-baa-lievable fact that a sheep, rooster and a duck were the first passengers in a hot air balloon in 1782. What a quacker of an idea!

There is a limit to how big you can build an aircraft. Once it gets to a certain size its mass prevents it staying airborne whatever shape you make it.

Adam and the team tested the mathematics of flying by trying to build an aircraft entirely of paper which is capable of lifting Adam's weight.

Big planes
At the time of making the programme, the largest passenger plane is the Boeing 747, which can carry up to 524 people. A new passenger plane called the Airbus A380 was set to beat this record in 2005. [You can read more about this behemoth with BBC Southern Counties' guide to the A380]

With greater numbers of people flying, bigger planes are needed to reduce air congestion. The biggest cargo plane is the Russian Antonov with a wing span of 88 metres and capable of carrying 80 cars.