If my Mars colonists don't want to be crippled, they need to bear their own weight as close to Earth normal as possible for their waking hours. How about shoes (leather from goats and sheep) with magnetic bits engineered inside the soles. Then, for the other part of the equation, what about hard or soft flooring that contains iron or steel particles. If that won't work, what about belt, shoes, or other clothing containing weighted fabric or inserts? Now, how about the babies who can’t walk and may never do so if their bones aren’t strengthened in some manner? What about the food animals? Can they put shoes on the animals' (sheep, goats, etc.) hooves such as horses wear? What do we do about fowl? Can a magnetic device be attached the the bottom of their feet? I can’t think how artificial gravity could work on a planet’s surface. No convenient alien technology here, just orphaned settlers.
2$\begingroup$ What issues are you aware of with low gravity? There's quite a lot of issues that are associated with low gravity, not all of which are helped by such shoes. Understanding which of those issues you perceive as important may help direct our answers. $\endgroup$– Cort AmmonSep 21, 2016 at 4:00
$\begingroup$ Russian astronauts have survived +500 days in absolutely no gravity, and they wer not "crippled". Their possibilities for exercise on MIR were rather limited, compared to ISS or spending the day as farmer and construction worker on Mars. $\endgroup$– KarlSep 22, 2016 at 3:13
1$\begingroup$ The Defense Dept would consider 500 days a TDY (temporary duty assignment). These colonists would be conceived, born, and live their entire lives in 1/3 Earth normal gravity. "Bone remodels in response to stress in order to maintain constant strain energy per bone mass throughout. To do this, it grows denser in areas experiencing high stress, while resorbing density in areas experiencing low stress. On Mars, where gravity is about one-third that of earth, the gravitational forces acting on astronauts' bodies would be much lower, causing bones to decrease in mass and density.: (Wikipedia). $\endgroup$– Phyllis StewartSep 22, 2016 at 18:31
The first generation born on mars could be genetically manipulated to be better fit for the enviroment. Similar solution can work for animals. In fact we don't know much about how low gravity will affect pregnancy.
Aside from that, I agree with Andreas Heese's answer.
As per the effects that low gravity has, this flow chart by the NSBRI (National Space Biomedical Research Institute) should serve as guideline:
You may also want to see how Men and Women Adapt Differently to Spaceflight:
Of course Mars has other challeges such as the lack of magnetic field, the ambient temperature, and the isolation and psicological stress of the settlers.
$\begingroup$ Mars is not microgravity. $\endgroup$ Sep 22, 2016 at 2:08
$\begingroup$ @Karl yeah, you are right. Mars gravitational accelarion is 0.378g, what's that, decigravity? As long as we don't have information on the effects of prolonged decigravity on humans - microgravity should serve as guideline. $\endgroup$– TheraotSep 22, 2016 at 2:51
$\begingroup$ It's a bit less than half of earths gravity. Why would there be any problems? $\endgroup$ Sep 22, 2016 at 3:06
$\begingroup$ @Karl for same reason they are in micro gravity, we are not used to be in different gravity, and our systems heavily exploit gravity presence, in way which will wonder you. For the moment no one knows will there be or will it not to be a problems with mars gravity. Do you never wondered yourself, how how for god shake 1 cell is able to convert to adult mammal? We talking about very complex biological machine, and our current knowledge do not allow us to predict results, so preparing to worst case scenario is pretty wise if there will be problem, if not, fine, better for us. $\endgroup$ Sep 22, 2016 at 14:12
2$\begingroup$ Flying animals adapt best to low gravity (1/3 Earth normal). Fish will swim in circles unless a light source is provided to give them proper orientation for "up and down." The fetus must orient head down before birth. Don't you think that is a matter of gravity assistance? If land and water animals have trouble, of course human fetuses will as well. Wikipedia: Bone remodels in response to stress in order to maintain constant strain energy per bone mass throughout. To do this, it grows denser in areas experiencing high stress, while resorbing density in areas experiencing low stress. $\endgroup$ Sep 22, 2016 at 18:45
I am assuming you did some research and found out that under orbital gravity (ISS), bones lose density. I also assume that this is fully true, understood well, and also applies for low gravity of mars. I am not sure about that, or if it even is a problem at all, but i don't want to research or discuss that, as it is out of focus for the question.
Putting on heavy shoes does not increase your bone stability. It doesn't even increase the "weight" of your body, it's just dead weight... on your shoes. While it becomes harder to walk, it will strengthen your muscles, but to increase bone density, you need weight to REST on the bones. So you'd need to shoulder huge weights, so they'd push down on your body. Wearing super heavy clothing might help (and it might look cool having everyone walk around in platemail).
But i think the basic problem of bones requiring stress to fully develop couldn't be handled this way. These days in space, bone density problems are countered by intensive special training. Maybe you can have facilities where adults can train hard to keep their bodies healthy? I have no idea how to solve the problem for animals or infants, though. Maybe a special diet or medicine could solve the problem for you?
6$\begingroup$ +1 for martians wearing full platemail. It also makes sense with their intensive training in... martian arts. There is definitely not enough media about martian knighnjas™ $\endgroup$– xDaizuSep 21, 2016 at 12:02
1$\begingroup$ What about the fetuses, infants, and children. They are most at risk. I am not proposing heavy shoes. The idea is to create a higher magnetic pull by incorporating pairs of attracting elements in the footwear and the flooring. Gravity creates the needed stressors for bone formation and maintenance. A properly calculated magnetic pull could, I believe, create the same effect. Otherwise, unless the problem is solved, long term colonization on planets with gravity less than 90% Earth normal will never be possible. $\endgroup$ Sep 22, 2016 at 18:36
$\begingroup$ Your idea of special facilities and periods of intense training made me think of the low-tech solution of merry-go-rounds all over the place. Those spinning (everyone takes turns) are working their muscles and getting exercise, those riding get the extra "weight" (acting like gravity to stress the bones) - especially if the merry-go-rounds are constructed with walls or a deeply sloped floor, so people walk inside and more of that force can run head-to-feet not just sideways. Kids and even infants should be able to play inside, walk or crawl for extra gravity-like stress while developing. $\endgroup$– MeghaSep 23, 2016 at 1:26
Who says there are any significant health problems under mars gravity? We know that most effects of absolutely no gravity can be fought well with one hour of physical exercise (as can a lot of earth health problems, btw. ;-)), and Mars still has $0.4 g$. I think any planet able to hold an atmosphere at civilised temperatures is totally unproblematic with respect to gravity.
The main problem esp. early Russian cosmonauts experienced is loss of bone density and weakening muscles, like what is known on earth from people with e.g complicated bone fractures, requiring extremities to be immobilised for an extended period of time.
Bone (& muscle) tissue does not grow in response to gravity, but to the forces the muscles exert on them. The problem in zero g is that practically nothing does require any force at all. So you put an hour of exercise on the schedule of astronauts, and it helps a lot. As does very careful exercising for recuperating patients. They are not 100% fit when they return to earth, or to normal life, but far from having turned in wracks. The earliest Russian long-term cosmonauts had to be carried on stretchers after return. When the space shuttle brought back long term crew members from ISS, they walked down the gangway on their own.
A person that lounges about all day and watch TV turns sick, on Mars probably faster than on earth. Luckily there is no TV there, at least in the beginning. But work on Mars would still be work, especially outside in your (rather heavy and rigid) pressure suit. Ten kg rucksack feels like 4 kg only? Have one twice as large!
I wouldn't bet that raising children on Mars would be as uncritical. I certainly would not do it on a space station without a lot of animal experiments before. Maybe have a centrifugal kindergarten. ;-)
But the basic message would be the same: It's not gravity, it is your musclework that keeps the bones healthy.
$\begingroup$ they show you only that, because what else to show)) Which chemicals they are using, they will never tell you. I bet doping sportsmen's are working for space program)) most likely indirectly) $\endgroup$ Sep 22, 2016 at 14:19
1$\begingroup$ Persons living their entire lives on a planet with .3 Earth normal gravity and who weigh only half what they would on Earth will have significant bone formation challenges. Physical exercise must be weight bearing and be calibrated to replicate Earth's normal effects. Infants, children, and the elderly will be unable to participate. No chemicals can mimic gravity's effects. A process or application to produce the effects of artificial gravity must be developed to enable long term space colonization. $\endgroup$ Sep 22, 2016 at 18:53
$\begingroup$ u might find it interesting to read link , link , link This one is funny: selecting candidates for testing take look at exclusion criteria, there are obvious reasons, but still. $\endgroup$ Sep 22, 2016 at 21:41
Same as we do in space, I should think. Use weight training and anchored treadmills to retain as much muscle tone as possible in an effort to stave off osteoporosis. I don't see that having heavy shoes will do anything other than tone up the leg muscles.
Andreas answered as I typed the above, and he's right.
For children, you just have to do the best that you can. Over the course of many generations, they would ideally start to evolve and adapt to the new gravity, but the chances are that your colony will die out before then - to my mind, it'll be doubtful that enough children will survive to procreate more than another generation or two unless you were really strict on the weight training.
Obviously, the more time taken up in physical exercise/conditioning, the less time can be used for more productive (survival orientated) tasks. Chances are that the exercise will come second place.
I don't think you'd have large animals - chickens would probably be the best source of food and you could keep those in small/low coops to prevent them from harming themselves. Horses/goats/cows don't really have a place on Mars - if there were there, then they'd be an immediate food source.
1$\begingroup$ If the problem is solved for humans, it would be solved for all animals as well. Sheep, goats, pigs, fowl, fish, and rabbits could all be good protein sources. Cows are obviously far too inefficient for use. A wide variety of foods must be provided for health and emotional well-being. Remember, this is generations or persons living all their lives on Mars. I'm afraid genetic manipulation would be of doubtful effect. This is a purely physical question. $\endgroup$ Sep 22, 2016 at 18:58
Large Jumps? A person of normal bodily strength on mars should be able to jump a lot higher than on earth, lift heavier things, leap further. If you design the base without stairs or use some other design that forces them to do these things regularly then your people could maintain normal fitness by leaping around and hanging to the ceiling. Alternatively you can make a parabolic floor and rotate it so that real and centrifugal gravity combine.
$\begingroup$ Great idea! Lets give them centrifugal beds! xkcd.com/123 $\endgroup$ Sep 22, 2016 at 11:30
1$\begingroup$ The bones do not need aerobic exercise. They need weight-bearing activity. Besides, you can't teach toddlers to perform large jumps. Vitamin and mineral supplements won't have any effect. Weight-bearing only. In addition, the colonists will weigh only half what they would on Earth. This significantly compounds the issue. $\endgroup$ Sep 22, 2016 at 18:49
One important question is, will they ever return to earth? 0.4g is not 0g and I bet body will adapt to this environment with muscle and bone loss, but not too much to be crippled.
End result? If they are to return Earth, they will not be able to walk unassisted. But on Mars they would probably be even healthier.