alterg.com
alterg.com

How Does an Anti-Gravity Treadmill Work?

alterg.com
alterg.com

The "anti-gravity treadmill" was originally invented by Robert Whalen, a biomechanics researcher at NASA Ames Research Center, in the 1990s.

Whalen knew that astronauts on the International Space Station have to exercise for hours each day to combat the loss of bone mass and muscle in microgravity. But the treadmill on the ISS has always left a lot to be desired. In lieu of gravity, it uses straps around the shoulders and hips to anchor the astronaut to the treadmill. The bungee system doesn't do a good job of replicating the magnitude or types of force that runners experience here on Earth. And to make matters worse, it's pretty uncomfortable to run in. Astronaut Sunita Williams, who was the first person to run the Boston Marathon in space, described her experience in a NASA press release: "During the marathon my foot sometimes went numb and tingly from the straps' pressure on my hip. Also, I had to use moleskin where the harness rubbed my neck raw."

NASA

Whalen designed a treadmill that would let astronauts run in a more natural way. The design, patented in 1992, encloses a treadmill and the astronaut's lower body in an airtight chamber. Lowering the air pressure inside the chamber pushes the astronaut down, simulating gravity. Whereas the ISS's old treadmill allowed Williams to run on about 60 percent of her Earth weight, Whalen's treadmill would have allowed her to exercise at her normal Earth weight. That's important for keeping the muscles and bones healthy for when astronauts get home.

But Whalen's idea never made it off the ground. In 2005, the technology was licensed to a company called AlterG, which appears to have coined the term "anti-gravity treadmill." Instead of adding weight to astronauts in space, AlterG uses the technology to take the weight off of rehab patients recovering from leg and foot injuries.

NASA

AlterG's product looks like a bounce house for your lower body. To use it, you put on a pair of tight neoprene shorts. The shorts have a sort of skirt attached, and the skirt is lined with zipper teeth. You step onto the treadmill, inside a hole in its plastic casing, and zipper yourself in so that, from the waist down, you're encased in an airtight plastic bag. As you stand there, the treadmill measures your weight, and you tell it how intense you want your workout to be. The the machine uses "unweighting technology" to make you feel up to 80 percent lighter—so if you weigh 100 pounds, you could feel as light as 20 pounds on the treadmill. The terms "anti-gravity" and "unweighting technology" are enthusiastic descriptions for what the machine actually does, which is inflate the plastic bag around your lower body to lift you off the surface of the treadmill.

Despite its perhaps overhyped name, the anti-gravity treadmill seems to be doing good things in physical rehab clinics, because it allows patients to exercise without exacerbating an injury. Here's NASA's glowing review of the anti-gravity treadmill:

Professional and college sports teams across the United States feature the AlterG treadmill in their training facilities. Injured soldiers walk and run with the technology’s assistance at military hospitals and rehabilitation centers. Seniors get essential exercise using the support the machine provides, as do people with bariatric weight issues who cannot normally support their own weight. The treadmill has been a proven option for neurological uses as well, including helping patients re-learn proper balance and gait and transition to independent movement after traumatic brain injury.

A variety of peer-reviewed studies also suggest it helps people get back on their feet again.

A true anti-gravity machine—one that is not acted on by gravity—would of course have even more exciting applications, particularly in spaceflight. Unfortunately, for now at least, those machines only work in science fiction.

nextArticle.image_alt|e
iStock
Why Are Mugshots Made Public Before a Suspect is Convicted by the Court?
iStock
iStock

Jennifer Ellis:

Several reasons.

1. Mugshots can help find people when they have absconded, or warn people when someone is out and dangerous. So there is a good reason to share some mugshots.

2. Our legal system requires openness as per the federal constitution, and I imagine most if not all state constitutions. As such, this sort of information is not considered private and can be shared. Any effort to keep mugshots private would result in lawsuits by the press and lay people. This would be under the First and Sixth Amendments as well as the various Freedom of Information Acts. However, in 2016 a federal court ruled [PDF] that federal mugshots are no longer routinely available under the federal FOIA.

This is partially in recognition of the damage that mugshots can do online. In its opinion, the court noted that “[a] disclosed booking photo casts a long, damaging shadow over the depicted individual.” The court specifically mentions websites that put mugshots online, in its analysis. “In fact, mugshot websites collect and display booking photos from decades-old arrests: BustedMugshots and JustMugshots, to name a couple.” Some states have passed or are looking to pass laws to prevent release of mugshots prior to conviction. New Jersey is one example.

a) As the federal court recognizes, and as we all know, the reality is that if your picture in a mugshot is out there, regardless of whether you were convicted, it can have an unfortunate impact on your life. In the old days, this wasn’t too much of a problem because it really wasn’t easy to find mugshots. Now, with companies allegedly seeking to extort people into paying to get their images off the web, it has become a serious problem. Those companies may get in trouble if it can be proved that they are working in concert, getting paid to take the picture off one site and then putting it on another. But that is rare. In most cases, the picture is just public data to which there is no right of privacy under the law.

b) The underlying purpose of publicity is to avoid the government charging people and abusing the authority to do so. It was believed that the publicity would help protect people. And it does when you have a country that likes to hide what it is up to. But, it also can cause harm in a modern society like ours, where such things end up on the web and can cause permanent damage. Unfortunately, it is a bit of a catch-22. We have the right to know issues and free speech rights smack up against privacy rights and serious damage of reputation for people who have not been convicted of a crime. The law will no doubt continue to shake out over the next few years as it struggles to catch up with the technology.

This post originally appeared on Quora. Click here to view.

nextArticle.image_alt|e
iStock
What Happens When You Flush an Airplane Toilet?
iStock
iStock

For millions of people, summer means an opportunity to hop on a plane and experience new and exciting sights, cultures, and food. It also means getting packed into a giant commercial aircraft and then wondering if you can make it to your next layover without submitting to the anxiety of using the onboard bathroom.

Roughly the size of an apartment pantry, these narrow facilities barely accommodate your outstretched knees; turbulence can make expelling waste a harrowing nightmare. Once you’ve successfully managed to complete the task and flush, what happens next?

Unlike our home toilets, planes can’t rely on water tanks to create passive suction to draw waste from the bowl. In addition to the expense of hauling hundreds of gallons of water, it’s impractical to leave standing water in an environment that shakes its contents like a snow globe. Originally, planes used an electronic pump system that moved waste along with a deodorizing liquid called Anotec. That method worked, but carrying the Anotec was undesirable for the same reasons as storing water: It raised fuel costs and added weight to the aircraft that could have been allocated for passengers. (Not surprisingly, airlines prefer to transport paying customers over blobs of poop.)

Beginning in the 1980s, planes used a pneumatic vacuum to suck liquids and solids down and away from the fixture. Once you hit the flush button, a valve at the bottom of the toilet opens, allowing the vacuum to siphon the contents out. (A nonstick coating similar to Teflon reduces the odds of any residue.) It travels to a storage tank near the back of the plane at high speeds, ready for ground crews to drain it once the airplane lands. The tank is then flushed out using a disinfectant.

If you’re also curious about timing your bathroom visit to avoid people waiting in line while you void, flight attendants say the best time to go is right after the captain turns off the seat belt sign and before drink service begins.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios