# Weighted Clothes In A Low Gravity Environment

Would weighted clothes be enough to simulate Earth-like gravity in a low-gravity environment?

If even by using centrifugal force on a space station would feasibly only produce a gravity that is a fraction of Earth norms, could that be supplemented by clothing made of heavier materials or bulkier construction?

• Welcome Muffinman. Please take our tour and browse the help center as and when for guidance as to our ways. Enjoy the site. Dec 5, 2021 at 16:52
• Honestly I'd rather go with mildly magnetic boots and a suit that makes every muscle-based action provide resistance against movement, the kind of resistance that you'd feel in a 1g environment. Doesn't need to be heavy, just provide resistance, like small springs or something. Dec 5, 2021 at 20:01
• @Rubrikon Problem with that is the fact that this would stretch out the person's body. Not a medical professional, but I think this solution is a sufficiently low-gravity environment for the human body would be comparable to hanging someone by their feet, and leaving them hanging for (presumably) a long time. I think that has some spinal implications. Maybe it isn't that signifcant, however? Perhaps OP could write that the people living in these low-gravity environments have more back problems than people in environments with gravities suited to their species. Dec 5, 2021 at 21:46
• What is the objective of having the weight? Is it to prevent muscle atrophy associated with long duration space flight? Is it just to simulate weight so that the wearer's movements feel more natural? Is it to stick them to the floor? Dec 6, 2021 at 3:44

I remember reading an interview to an astronaut, a long time ago, where they asked him how it felt to move objects in the microgravity of space.

The astronaut said that the objects, even big ones, were not heavy but felt massive.

To get a similar feeling to something you might have experienced on Earth, I think you can recall how does it feel to push or pull a floating boat. You don't feel its weight, but you feel its mass.

If in space you wear weighed clothes you are increasing your inertia: in a low gravity environment, like the moon surface, you could have six times more mass than on Earth and move with the same effort, for example. That would balance the reduced gravitational pull. In microgravity that would not work, because no matter how much you increase your mass, you are still multiplying it by 0.

Nevertheless, it would do nothing for the physiological effects of gravity and the lack thereof, which is the main reason for worrying about having gravity in space.

• The primary physiological effects of low gravity are muscle mass loss, bone mass loss, and heart atrophy. All of these are driven, at least in part, by the fact that it is too easy to move around / exist in low gravity. So wearing weighted clothes on the moon sounds like an easy way to challenge your heart, muscles, and bones. Dec 6, 2021 at 14:54
• * you are still effectively multiplying it by 0 (microgravity != zero gravity) Dec 6, 2021 at 22:55
• The question specifically asks about low gravity, perhaps provided by centrifuge, and not microgravity. Dec 7, 2021 at 21:23

It depends on just what aspects of Earth gravity you're trying to simulate. There are two different processes here: actual movement, and the energy your astronaut expends in order to move (and all the related physiology).

(Note that for simplicity, I'm assuming a low-gravity environment with a breathable atmosphere, so the astronaut doesn't have to wear a space suit.)

For movement,extra weight is not going to help much, if at all. The problem is that all masses fall at the same rate in a given gravitational field, so that if you're in lunar gravity, you still have to adopt the same bounding gait you seen in videos of the Apollo astronauts. Their suits massed 180 lbs/81 kg, so about the same as their own body weight.

I doubt that it's going to help much, if at all, with traction, either. Unlike the racecar downforce examples, adding mass to increase traction also increases the mass you need to accelerate, cancelling out the benefit. (Just my opinion, though: if someone can show otherwise I'll change my mind :-))

Where it is going to help is with physiology. Carrying around that extra weight means your astronaut gets more exercise, and has more force exerted on bones &c, thus avoiding osteoporosis which is a problem in long-term zero-g (and presumably low-g) missions. Compare it to the experience of spending a week or two backpacking: when you get home and take off that pack, you tend to bounce while walking.

• Not certain that the added mass will necessarily help with osteoporosis. We still need to do more studies on the effect of low gravity on humans... something that we won't be able to do until we actually colonize the moon, mars or a suitably-sized ring station. Dec 6, 2021 at 0:35
• @Corey: I'm certainly not an MD, but you'll find a lot of info (some from reputable medical sources) about the benefits of weight-bearing exercise in treating bone loss, e.g. health.harvard.edu/staying-healthy/… Extending it to adding weight in low gravity seems logical. Dec 6, 2021 at 3:12
• Weight-bearing training certainly helps in microgravity environments, agreed. Long-term living in low gravity environments will have its own challenges I suspect. Dec 6, 2021 at 3:33

## When in a low gravity environment, resistive equipment is better than mass based equipment

In a low-gravity environment (like the Moon), you are going to want to optimise for volume used by equipment. One problem with making something more massive is that you increase it's volume proportionately. For example, you need ~6 times the mass to have the equivalent Earth weight, the volume that mass will take will be 6 times the volume of the equivalent Earth weight. So after a point, you will want to move towards something that outputs a (tuneable) consistent force, regardless of environment, that people have to work their muscles against.

So, assuming your aim is to prevent or minimise muscle and bone loss, then you should take a leaf out of NASA's book and their exercise regime on the ISS. They have developed specialised exercise equipment to stave off these issues as much as possible (though in microgravity it's not possible to stave it off indefinitely). Astronauts need to exercise for 8 hours each day to counteract these effects.

The principle they use is to apply a resistive device that outputs a known constant (calibratable) force that the astronauts work against. Some examples of this are:

• COLBERT treadmill: uses a set of elastic straps and springs to pull the astronaut towards the treadmill
• ARED (link #2): Provides resistive weightlifting training simulating the use of free weights on Earth. It uses vacuum cylinders to provide that simulated force.
• MARES (link #2): Used to measure and quantify the level of muscle loss on astronauts in a controlled manner.

Smarter Every Day has an excellent video on the subject.

On earth, people already sometimes wear weights when exercising. It would absolutely be possible to do so under lower gravity conditions. But it would not be equivalent to just living on earth, and my guess is that people wouldn't do it except possibly as preparation for traveling to a higher gravity body.

The biggest reason that it would feel very different from living on earth is already explained by L. Dutch. If you were on the moon but had tungsten weights spread over your body to give you your earth weight, then your mass would be six times as great, which would be very noticeable. Once you got moving, it would be six times as hard to stop. Until you got used to it, you would probably do things like smashing your burger into your face because of the momentum of the wrist weight on your arm.

You could always compromise, with more than your earth mass but less than your earth weight, or you could just learn to deal with the extra mass. But I expect people wouldn't do it because it just feels so much nicer to walk around unencumbered. Imaging growing up here on earth but being required to wear heavy weights your whole life just in case you some day wanted to travel to our balloon colonies in the atmosphere of Jupiter.

There is also the question of how well it would actually simulate the physiology of living in a stronger gravitational field, and the answer is that we really won't know until we actually have had a moon base for a while. There were a lot of unexpected side effects of microgravity, and there's still a lot they don't know about how to combat them. It seems clear that wearing weights would strengthen your skeletal muscles, and probably your bones, ligaments, and tendons. But the heart still wouldn't have to work as heard to pump blood up from your feet, and there would still be less of a pressure differential between your head and feet. We know that matters in zero g, and so it might also matter at least a little in 1/6 g.

Assuming the point of the weight is to make sure the wearer avoids muscle atrophy associated with long duration space flight...

The best solution is probably not heavy cloths, but rather a body covering that resists motion at all of the wearer's joints.

Some possible options here would be...

1. A conforming suit (like a wetsuit) made of a material that generally resists all movement. This is probably the simplest and most comfortable option for the wearer.
2. Putting braces at key points (knee, elbow, shoulders, hips, ankles, etc) that resist movement. This option may not exercise every muscle needed and could require the wearer to put on a lot of stuff each day.
3. Taking option 2 a bit further, making a full body suit (like a suit of armor, or a space suit) with resistance in all the points of movement. If the characters were going to need space suits or armor anyways, then this is a good fit.

when only talking about low-gravity environments. some aspects like muscle deterioration and bone density loss should be slowed down or stopped with heavier clothes in a low-gravity environment. others like problems with blood circulation, or pooling of fluids may not.

there is much still left to research to be honest. we don't know for example what the minimum amount of gravity is needed to alleviate all of those problems.

It would help with running.

Consider Formula One racecars.

http://formula1-dictionary.net/downforce.html

To be faster you need power, but there is a limit to how much power you can put on the ground. To increase this limit, force to ground must be applied on the wheels. Increasing weight can do this, but weight makes handling worse and require more power. So we need some virtual weight, we call it downforce and get it from airflow around the car. A wing can make a plane fly, but if we put it upside down, it can make a car NOT fly.

These cars have wings to push them down onto the ground so that they can improve friction with the ground and use that to push forward.

Usually people dont run fast enough to need wings to push them down. You could use weights. I was talking just yesterday about running underwater. It is hard to get traction because underwater persons built as I am weigh nothing or less, due to buoyancy. Pushing off the bottom tends to leave you in midwater with nothing to push against.

If I load up with weight belts to offset my buoyancy then I can run along the bottom and the main impediment to forward motion becomes water resistance.

In microgravity you could load up with weight belts or weighted clothes (I hope those are weighted pants you have on...) to offset your tiny weight, just as I put on weight belts in the pool to offset my effectively tiny weight. You will still have inertia with those weights and so plan ahead to stop. They are easy to make and require no tech, but just as with race cars weighted pants makes handling worse and requires more power.

Better would be fans! If you are in microgravity but in an atmosphere, you could direct the fans on your harness upwards and push down against the atmosphere: downforce fans, just as the cars have downforce wings. A fan angled down at a 45 degree angle would give you downforce but also a forward vector, so you could rollerblade the length of the space station at great speed. Fans could flip forward and act as brakes when you need to stop. Best fans can spin and point down, allowing you to jump huge distances and dunk the ball every time.

• Underwater is significantly different: you have a large upward force from buoyancy, and adding a small amount of mass relative to your bodyweight can result in a corresponding sized increase in your inertia / momentum, but a huge relative increase in ground contact force (since you started with near zero or negative). As jamesqf's answer points out, adding mass means you have more that needs to accelerate. Perhaps for overcoming air resistance in straight-line sprinting, this could help in very low gravity (making you a denser projectile while increasing force in proportion to(?) mass). Dec 6, 2021 at 6:07
• It would hinder running: yes, your traction goes up, but so does your inertia. For an Earth-based example, put on a suit of plate armor, and then try running around. The extra 20 kg or so you're carrying will make it take longer to get up to speed and harder to turn corners.
– Mark
Dec 7, 2021 at 1:12