Back in December, International Space Station astronaut Tim Peake said he was “yet to master” a somersault in space. Jump forward half a year — just days before his June 18 return to Earth — and Peake’s pulling off more gravity-defying somersaults than Sonic the Hedgehog. On top of that, he’s worked out something interesting: somersaults in space don’t make people dizzy in the same way they do on terra firma. And there’s a good explanation for it.
Just in case you’re too mesmerized by the sight of space gymnastics to take in any of the physics lessons Peake is talking about, Digital Trends decided to play the role of responsible adult and reach out to a leading astrophysicist to explain this strange phenomenon.
“On the ground the brain takes cues both from the motion of fluid in our inner ear, which is affected by our motion and by gravity, as well as from our vision to determine our position and motion,” says Professor Eamonn Kerins, an astrophysicist at the School of Physics & Astronomy in the UK’s University of Manchester.
“Many of us can experience motion sickness as passengers in cars due to changes in motion which alter the g-force we experience. Many astronauts on the International Space Station, during their initial time in space, can experience similar symptoms in the form of space sickness. This is because the orbit of the ISS around Earth virtually cancels out the effects of gravity. The near-weightless environment of micro-gravity feels pretty much like a sensation of falling. It’s a bit like the feeling we get when our car drives at speed over a small hill in the road, only the feeling is continuous for the ISS astronauts.”
“Tim spoke about how his brain eventually learned to ignore cues from the inner ear and started to rely only on visual cues to determine his orientation and movement,” Kerins continues. “This allowed him to overcome feelings of space sickness and the remarkable video also shows that, as a result, he is resilient not just to the effects of a near zero-g environment but also to significant changes in g-force, as when his colleague spins him around.”
Thanks, Eamonn! That’s just what we were about to say!