Some of the issues that are important if you want to have people in space for long periods of time. One is that people will tend to lose bone and muscle mass. We know this. If you have to put a cast on your leg, and you take the cast off after a few weeks, you’ll see that your muscles have shrunk in size. And if you measured the bone strength, you’d also see that might have gone down a little bit, too. And so, it’s very interesting that our body has that ability to adapt to the loads that are put on it, so that bones and muscles aren’t static, they’re always changing. While we think of bone as being a solid thing that doesn’t change very much, it changes too. And it turns out that in weightlessness, you lose bone. And then you also cause the muscles that work against gravity, what are called the postural muscles, they’ll start to shrink and lose strength. There are other things in the cardiovascular system, the heart and blood vessels. And if you think about it, standing up in gravity means you have to work against gravity in order to keep blood pumping to your head. So, if you couldn’t keep blood pumping in the head, you’d pass out every time you stood up because when you’re lying down, you don’t have to push against gravity. But when you stand up, you got to work against gravity to keep blood flowing to your head. And your heart and blood vessels have a really nicely worked-out system to make that happen every time. But that system can also change in weightlessness. And then the other area that changes is the system that has to do with balance. Again, maintaining your balance is something that you’re doing against gravity, right? If you didn’t have gravity present, you wouldn’t have to worry about falling. But you obviously do have to worry about falling, and we have a very highly developed sense of balance to keep us upright and to prevent us from falling. And when you see what skaters do, you realize just how exquisite a system it is. But when you go into weightlessness, your balance system changes. You don’t really notice it while you are in weightlessness, but when you come back, you do notice it, that your balance has changed and you have a little bit of trouble maintaining your balance. And what it shows is that while you’re in space, your brain is trying to allow you to function in weightlessness. And so, it re-adapts you to be weightless, which you don’t notice until you come back and find out that you’re now back on Earth with a balance system that’s been adapted to space. You know, all life developed here on Earth with gravity being present, so life evolved under the influence of gravity, and then we grow up with gravity being present, so we learn how to walk and catch a ball and ice skate or whatever, all with gravity being present. And what if you were to grow up without gravity? What about the systems that depend on gravity, like your muscles or your balance system or the heart and blood vessels? Would they develop normally, or would they be different in some way? One reason why you might think that it would go down a different pathway is from an experiment that was done some time ago by two neuroscientists called Hubel and Wiesel. And what they did is they had a kitten, and they put a patch over the eye of the kitten. And then the kitten grew up to be a cat, and they removed the patch. And so, the question is, can the cat see out of that eye? Now, there’s nothing wrong with the eye, right? But it just hasn’t seen anything, there hasn’t been any light coming in. And the answer is that the cat can’t see out of that eye because what happens is that the brain goes down a different pathway when it develops and the connections that would ordinarily develop to that eye don’t develop. And that can’t be undone, that’s a permanent change. So, the brain of that cat is fundamentally different from the brain of a cat that grew up seeing out of that eye. That cat grew up with a different brain, in essence. So, then you wonder, well, what about gravity? What if you don’t have the forces that gravity produces? Is your balance organ going to develop in the same way, or will it be different? If somebody grew up in space, could they come back to Earth and function, or would they really be a different person?

100 thoughts on “Gravity and the human body – Jay Buckey”

  1. I think they wouldn't be able to walk once they got here if they grew up out there. Just watch a toddler learning to stand upright and put one step in front of the other. It's a process that takes duration, and repetition. Day after day, with practice, the toddler eventually gains the ability to walk…

  2. Use resistant band style suit too make it harder too move in weightlessness, this would make muscles work a lot harder and would be similar too gravity. Removing the suit would make them feel like they took off gravity in a sense… and on earth they actually might feel like they have less resistance.

  3. Personally I think you could make the eye see again you just shine bright light in the eye of the cat till the brain realizes and then eventually the cat would start creating those pathways again and boom… cat seeing again.

  4. Yeah, I think so too. The cat's brain would simply adapt to seeing light, and the eye would start to see again after a few weeks or months of adaptation.

  5. Do any organs increase in size in space (such as the brain) because they would have access to increased resources? Also, would someone born in space be able to grow much taller than someone on earth as the heart and bones do not need to be as strong?

  6. "Gravities like dropping pebbles into a pond dividing one unit of space/ that was multiplied by one unit of time or mass. E2=mc2c4+p2c2.
    The greater the energy or mass, the greater the energy density E2 of super imposed inward spherical wavefronts generating heat by multiplying electrical potential along cubic dynameters compressing the wave amplitude now+4-0-4+-the shorter the expanding transverse wavefronts dividing from its source in unison wavefront by wavefront as time unfolds C2 forming an inward acceleration or gravitation."

  7. Let's just hope that by the time space travel is mainstream, they would have already figured out a way to make artificial gravity.

  8. Centripetal force is actually a good solution to produce artificial gravity in space. The only problem I can see is that it would be very expensive and difficult to put a giant cylindrical drum in space. looking at the ISS, those modules are quite small, too small to have some one stand up and not have the top part of the body feel an opposing force to your feet. And to have a centripetal force even a fraction of earth's gravity, it also needs to to have either a large cylinder or a fast spinning one. This problem can easily be fixed in due time. Through other means of traveling to space, I believe that artificial gravity shouldn't be much a problem. 

  9. How does a human brain adapt itself to weightlessness if most of our ancestors never had lived without the field of gravity?

  10. Let's all take a moment to thank Scott Kelly for his incredible mission: To stay in orbit, for a whole year. (Currently day 218)

  11. we would not adapt, we would acclimate which is what happens in adult astronauts but I wonder if it is possible for children to even develop in a low gravity atmosphere like that let alone acclimate to it?

  12. jellyfish experiment some in space? jellyfish born in space apparently did not have the balance organ Crystal thingy compared to those on earth.

  13. oh… new knowledge .. Our brain adapt to the situation around us….! And results or changes are permanent sometimes …#caseofthecat

  14. I thought that vestibulococlear organs is somewhat more complex than visual organs thus Hubel and Wiesel experiment might be not parallel in this example. Amblyopia that intentionally Hubel and Wiesel inflicted to the eye was successfully happened since visual pathway are only consisted by eye, nerves, and brain that damage to one organ might give effect that relatively big. Balance, in other hand, are not only controlled by inner ear, but also influenced by visual perception and lower extremities strength.

  15. Fascinating. But, ever notice that when the whole video only features white males, no one says a thing? When the video only features females or other skin colours, the top commenters will have something to complain about.

  16. You all wanna know some weird shit?… The truth is that we cannot truly leave the Planet Earth. All of this crap about Space Flight, Rockets, NASA etc.. it's all a lot of bullshit. We cannot and we'll hardly will ever able to leave this planet to move ourselves to another. That's the truth but people would never accept this truth.

  17. i always wonder if SSD patient's brain had evolve differently and how it affected thier focal points.?

  18. So all the computer screens on the super high tech space station are old fashioned Cathode Ray Tubes ?
    So it's a sort of Retro-Futuristic space station then ?

  19. it will be a different person since marine life in the deep have no bones humans might come back to earth with no bones

  20. I feel bad for whatever creature in the process of evolution who hadn't evolved the ability to pump blood against gravity, and evertime it tried to swim ubwards it passed out and it got used to this

  21. or what if you grew up with gravity that was more intense than Earth's? would your muscles develop like a body builders? or would you be the same and just be able to jump ten feet high with Earth's gravity because your body is so used to it being heavier?

  22. It must be awesome if you born in space and you'll write your birth place as "Space, 29 February or 01 March (I don't know I can't tell. It depends on where you are)" 😂

  23. Lets find out by doing some immoral experiments!
    Ya know what they say: Ya can't make a science omelette without breaking a few babies.

  24. If only the human body cant get weak, only stronger, imagine growing up on 4 or 5 times higher gravity, and coming to earth and here we go, we have a captain america on earth in real life xd

  25. I think the term person was too vague…as to me it sounds like when you say different person you are saying personality, while what you
    mean is physical characteristics…

  26. I actually liked the voice of the guy! It's not sleepy, it's kind of relaxed. Great video by the way 🙂

Leave a Reply

Your email address will not be published. Required fields are marked *