If you’ve ever wished you could walk up walls and across ceilings (and who hasn’t) in pants like ones in the hilarious Wallace & Gromit stop-action film The Wrong Trousers, there’s good news from a group of physics students at the University of Leicester – it’s scientifically possible! There’s a few caveats but more on that later.
In the film, Wallace (the human) gives Gromit (the dog) a pair of robotic Techno Trousers from NASA so he can walk himself. The vacuum created in the shoes allowed wall and ceiling walking – a benefit for astronauts in zero gravity that caused problems for Wallace and Gromit.
The fourth-year students determined the boots would need a raised rubber insulator to create a cavity with lower pressure when the vacuum is applied. According to student Katie Raymer, the amount of vacuum power needed to hold a person wearing the pants to a ceiling is surprisingly low.
We observed the difference in pressure between the atmosphere and the cavity and found that the vacuum generator needs to be powerful enough to reduce the atmospheric pressure inside the boot cavity by approximately 18% in order to create a vacuum capable of supporting Wallace and the trousers. This corresponds to a low vacuum, which has a similar strength to a vacuum cleaner.
Using a conventional wireless vacuum, the battery power to maintain this amount of suction would only last 20 minutes. Electric power would work better, but there’s that cord length issue.
Would NASA really use Techno Trousers? The students pointed out that outer space is a near-perfect vacuum, which means the pressure differences needed to hold the boots to the ceiling would be beyond the capabilities of conventional vacuum cleaners. Magnetic generators would work better, providing the surfaces are iron or steel.
The Wrong Magnetic Trousers – sounds like an excellent sequel.