Physicist And Stunt Rider Create World's First 'Einstein Flip'

Einstein was a keen cyclist and although there is no evidence to suggest he ever attempted a “360-degree back-flip with table-top”, or even a humble wheelie, it is claimed that inspiration for his theory of Special Relativity came to him while riding his bicycle.

One hundred years after the publication of his landmark papers on Special Relativity, Brownian Motion and the Photoelectric Effect, cycling and science will come together once more in another world first: a BMX bicycle stunt designed by a physicist.

The stunt was performed live and for the first time on 5th Jan 2005 at the official launch of Einstein Year at London’s Science Museum. It was commissioned by the Institute of Physics to mark the beginning of a year-long celebration of physics. Einstein Year is the UK’s contribution to the International Year of Physics in 2005.

Caitlin Watson, Einstein Year project manager, said: “Einstein Year is all about challenging people’s perceptions of physics – especially young people’s perceptions.

“Physics relates to all of our lives - from fun things like fizzy drinks to life-saving medical imaging technology. This innovative bike stunt is the perfect way of illustrating how fun and relevant physics can be to young people.”

Dubbed the ‘Einstein Flip’, the stunt is described as ‘pushing the boundaries of what it is humanly possible to do on a bike’ by Cambridge University physicist Helen Czerski, who collaborated with professional BMX rider Ben Wallace to create the manoeuvre.

In the stunt, 18-year-old Wallace, a competitor in extreme sports events around the world, launched off a six-feet high ramp and spun backwards through 360 degrees while simultaneously folding his bike underneath him in a move known to BMX devotees as a ‘tabletop’. At one point, onlookers saw Wallace upside down, travelling at 15mph, with his head 12-feet off the floor.

Czerski, a keen sportswoman and diver herself, said: “I spent a lot of time looking at the physics behind various stunts, trying to understand the limits of what is physically possible to determine how far we could push the parameters with our new creation. I then tested our ideas using a computer simulation to plot a new stunt.”

The stunt draws upon a variety of physics theories including the conservation of angular momentum and Newton's laws of motion.

Helen added: ‘When I first started to work out the details of this trick, I wondered if it was physically possible. But I did the maths - calculating Ben’s trajectory, where he will be at different times in the air, the shape and height of the ramp, his velocity and so on - and found that yes, it could work. Having said that, I wouldn’t want try this myself - however much I trust my physics calculations! There is simply no room for error.’

Ben would know: perfecting his repertoire of daring jumps, spins and tricks has cost him many bruises and broken bones. Although physics has helped him become a better rider, Ben says a healthy disregard for the laws of common sense will be almost as vital to his performance.