• Aug. 29, 2020, 7:06 p.m.

    If we were to construct a ring around Earth, so far out it was outside in space.
    If this ring was not in any means connected physicly to earth, will it had to spinn with the earths spinn?
    If the ring was to spinn, will you then feel wightlessness? Or if the ring was stationary, will you then feel gravity or weightlessness?

    Could you use this ring as an anchor for a spacehook?

  • Sept. 4, 2020, 2:38 a.m.

    Try to imagine the ring not as a stiff ring, but a series of small closely spaced asteroids loosely joined together by pieces of weak elastic.

    This is because no material bond can really withstand too much tension over such an enormous distance.

    So this means:
    - The ring must not require any force on it to stay in place. Essentially it must be in a stable orbit.
    - Being in a stable orbit just means it should obey simple orbital mechanics. In other words, yes it does spin around the Earth, and being in a stable orbit its speed of spin will be determined by the radius of its orbit.
    - Would you feel weightless? Objects in orbit are in 'free-fall'. They are at rest in a gravitational field, not accelerating, in other words, you would not experience any/much gravity when in orbit. If you were on your stationary ring, you would float, because you would also be in orbit, at the same speed around the Earth and the same distance above the Earth, so you would not experience any acceleration.

    Can it be a ring for a space hook? Yes, but any force on the ring must still be counterbalanced, or the ring would loose orbital speed and come apart. Therefore to maintain a stable orbit, either the ring must increase in rotation when bringing an object up, or decrease down, and conversely decrease orbital radius if bringing an object up, or increase radius if putting one down.

  • Sept. 30, 2020, 5:46 p.m.

    Thank you for answer.
    I have indeed tryed to wrap my head around your answer. But I dont get it fully yet.
    If this ring is not connected to earth, then why dont you feel any gravity? As long as the ring is not spinning you on this ring dont have that «constant falling» as spacestaions or satelites do. If the ring spinns let say in same valocity as an satelite, you would feel weightless, but why must the ring spinn?
    If the ring are connected to earth would not the centrifugal force press you away from earth? Or will you then have that «constant falling» effect as satelites have?
    I also have a question about Mars, as we like to imagine to cultivate and make a new earth there. Many belive that would take a few years to acomlise, but seing how fast enviorment changes here, I would like to thing its an endavour that would take 1000 of years on Mars. Building a glass dome round Mars would speed things up. But unlikely to happend as the materials and work to manage that would be astonomical. But building a planetary ring round Mars, would that be an option?

  • Oct. 24, 2020, 11:04 p.m.

    Again imagine the ring is not a ring, but a whole series of ISS space stations. There is no gravity in the ISS, because your 'motion' as a person is the same as the ISS.

    My answer was saying the ring should be in orbit, as in moving around the Earth, as there is no physical material that could withstand the enormous forces required if it was stationary. However, if you want gravity to be experienced on the ring, then the ring as you say should be stationary (or close to). Then all parts of the ring would be falling towards the Earth as well. If you can create an imaginary material that retains its shape then I suppose it is possible for the ring to be stationary.

    Well, if the ring is orbiting it depends on its altitude. Satellites that are closer to Earth must orbit faster than those further away.

    Sure - you can build a 'ring' around any planet! A glass dome around a planet wouldn't do much in my opinion, because it would just be the same as it is now. To fill it with atmosphere, perhaps dome around the canyons first?

  • Nov. 6, 2020, 7:15 a.m.

    Isaac did a video about Orbital rings. I suggest you check that out. On such a structure you would feel gravity and could hang stuff down from it.

  • March 29, 2021, 1:54 p.m.

    Thank you both for answers!
    Indeed I really need to read more about the math on this topic.
    Its hard to grasp this consept of velocity, gravitation and the construction of a ring around a planet..
    It will be a nightmare to accomplis