Star Flaws the Skywalker twins drift apart 20 August 2015

In the original Star Wars trilogy, one of the big revelations is that main characters Luke Skywalker and Princess Leia are actually twins separated at birth.

In a paper for the Physics Special Topics module, students Duleep Vasudevan, Tom Griffiths, Mark Phillips and Katie Herlingshaw from the Department of Physics and Astronomy have worked out that in the film Star Wars Episode V: The Empire Strikes Back, Luke and Leia do not actually remain the same age due to relative velocity time dilation - Einstein’s theory of relativity - which results in time ticking more slowly on an object that is moving at a higher speed.

The calculations made were based on the twins’ journeys to Cloud City. Leia travels from the neighbouring system of Anoat, while Luke travels from the much more distant planet Dagobah. Luke’s journey was estimated to be 25 times longer than Leia’s.

The Millennium Falcon; Source: Wikipedia

Additionally, as Leia travels in the Millennium Falcon, a much larger ship with more powerful engines than Luke’s X-Wing Starfighter, the students assumed that it reaches a higher speed.

Leia’s journey yields a time dilation of 62.6 days; however Luke experiences a time dilation of 700.8 days (1.92 years).

The students concluded that Luke is therefore 1.75 years younger than Leia, possibly rendering them the first twins ever to have over a year between their ages.

In the second scenario the students considered gravitational time dilation - the slowing of time due to gravity. Cloud City, a mining station, floats above the clouds of the planet Bespin, a gas giant very similar to Jupiter. An observer at a distance far from the planet would see time pass more quickly than an observer on the surface.

Lead author Thomas Griffiths said: “For Luke to become the same age as Leia he would have to orbit the gas giant for 9.77 million years.”