London - Researchers have used Einstein's theory of relativity to find the most efficient way for passengers to board an aeroplane.

And they have concluded that the time-honoured method of boarding by seat numbers is a waste of time, reports the British newspaper, The Sun.

Dr Eitan Bachmat, of Ben-Gurion University of the Negev in Israel, says airlines would be better off following the example of low-cost carriers who let passengers sit where they like.

Dr Bachmat said: "Back-to-front boarding is bad because it is designed for cardboard-thin passengers, or for the spacious surroundings of the first-class compartment.

"But there is no need to play with the rows. It doesn't matter which rows get on first."

Dr Bachmat stumbled across the theory when researching how to make computers run quicker.

He said: "It dawned on us that we could use the same geometry that appears in relativity theory." - Ananova.com