Theory of Giant Peach is Wrong

By Gabriella Munoz

How many seagulls do you need to fly James’s giant peach? Here you will find the answer.

It was 1961 and Roald Dahl, the author behind the amazing Charlie and the Chocolate Factory, published a book titled James and the Giant Peach, in which an orphan boy named James Henry Trotter has to cross the Atlantic Ocean to escape from his evil and greedy aunts Sponge and Spiker.

To get to the other side of the world James has to use quite a peculiar aircraft: A peach the size of a small house. In the book the magnificent peach is lifted by 501 seagulls “tethered by the thread of a giant silkworm.” But, is this possible if seagulls are capable of carrying over 2 newtons (a metric unit of force named after Sir Isaac Newton that equals about 0.10 kilograms of force)?

Physics students at Leicester University, in the UK, read Dahl’s book, watched Disney’s 1996 film adaptation, and calculated the weight of the peach. Then, applying Newton’s second law of motion, came to the conclusion that to lift such a peach 4,890,579 N would be needed.

In the book, Dahl—who didn’t get his maths of physics right—missed the mark, as the scientists have demonstrated that to lift James’s giant peach 2,425,907 seagulls would be needed.

The researchers say that James and the Giant Peach poses other science conundrums, including the loading of the silk threads used to suspend the peach. Why don’t you give them a go? Ask you teacher to help you.


Read the paper “James’ Giant Peach Transport across the Atlantic” here and see how these physics students tackled the problem.