On a light rainy day last year, two researchers attempted the Wall of Death for the first time. This amusement park attraction near Parma, Italy, looks like a giant wooden barrel with the top cut off. But on that gloomy day, exercise physiologists had taken possession of the wall for scientific research: they intended to test the wall’s potential as a new form of exercise on the lunar surface.
Usually, daredevils on motorbikes race down the inside flank of a circular Wall of Death, a feat that seems to defy gravity. But Gaspare Pavei and Valentina Natalucci weren’t planning on doing the stunt on motorbikes. In fact, they didn’t even have motorbikes. They planned on walking sideways halfway up the wall.
And Alberto Minetti says that if their calculations are correct, they could teach future lunar residents how to move at high speed along walls without tumbling to the ground.
Why would they do that? Minetti, a physiologist at the University of Milan in Italy, said his team was looking into how to provide lunar inhabitants with ways to keep their bodies strong.
And that’s no easy task, as the Moon’s gravity is only about one-sixth that of Earth. Lower gravity means our bodies don’t experience the same stresses as they do on Earth.
When you stomp on the pavement while running or do push-ups against Earth’s gravity (known as 1G), you build muscle and strengthen bones. But on the Moon or in space, your muscles weaken and your bones become brittle. Researchers say that just six months in space can cause as much bone damage as 10 years of aging. Scientists are looking for ways around this, Minetti explains.
Running horizontally along the curved wall of a cylinder, Uniform circular motionThis is called centrifugal force, which is the same force that causes water to collect at the bottom of a bucket when you spin it over your head. With enough force, the moon runners, or scientists mimicking lunar gravity in Italy, would be stuck to the wall. They would also experience a force very similar to the gravity we normally feel on Earth.
Like a bike
So on that dark day last June, Pavey and Natalucci from the Minetti lab took a major step forward for science.
They each wore a harness attached to a bungee cord that hung from a crane about 40 meters (130 feet) high. This elastic suspension effectively reduced Pavey and Natalci’s weight, mimicking lunar gravity.
Next, the scientists had to figure out how to transition from standing on the ground to running sideways along the wall of the cylinder.
Pavey was up first, sprinting straight into the wall like a kid trying his hand at parkour.
I was unlucky.
He slid slowly down to the ground on the bungee cord. After a few more failed attempts, Pavey took a cue from the bikers at the Wall of Death: He approached the wall at an angle. He spiraled counterclockwise up a small ramp at the bottom of the cylinder. Suddenly, Pavey was running nearly horizontally; his shoes slammed into the wall and his body was nearly parallel to the ground.
“Wow!” Minetti remembers exclaiming in excitement as he watched from the ground. “I knew the physics and the math predicted this,” he said, “but when you see it in person, it’s just not true…”
Horizontal advantage
It’s taken Minetti nearly two years to get to this point, figuring out how to rent a crane and use the Wall of Death’s spare time, and he also had to convince the university to agree to the experiment. “It wasn’t a very orthodox request,” he says.
As Pavey and Natalucci ran repetitively, the team collected data, including how far they traveled, how long their feet were in contact with the wall, and how long they spent in the air between steps.
From these data, the runner’s speed is calculated, The force was generated during their sprint.That amount is about three-quarters of agriculture, scientists reported in a May report. Royal Society Open Science.
The team calculated that running eight to nine laps a day on such a structure, even if they took breaks every few laps, should be enough to prevent bone density loss — a conclusion based on data from previous studies that tracked people’s bone density after rest and exercise.
Minetti’s team performed these experiments on the Wall of Death in just one day. Now he has additional questions, such as whether wall running can directly counteract the effects of bed-rest experiments. Scientists sometimes use these tests to mimic the effects of low gravity on healthy people.
The University of Milan also plans to build its own wall, the “Moon Wall” or “M Wall,” which will be custom built for the team’s laboratory tests.
Minetti points out a slight problem for would-be lunar runners: the need for speed. To be successful, he says, you’d have to run pretty fast — about five to six meters per second, which is roughly the equivalent of running a mile in five minutes.
Pavey says you don’t have to be an elite athlete to run that fast — about half as fast as Olympian Usain Bolt, the world record holder in the 100 meters. But running faster than the test run adds more artificial gravity, which could have greater benefits for your body. If Bolt were to sprint around a wall, for example, it probably wouldn’t be difficult for him to exceed 1G, Pavey says.
To confirm that, he added: “I’d be happy to test him.”
Source: www.snexplores.org
