• Oct. 11, 2019, 7:29 p.m.

    I thought I remember a video where Isaac discusses concerns with mobility while in spin gravity. For example, there was an example about throwing a ball in the direction that the rotating platform is spinning that would cause the ball to "fall" up or down, but I cannot remember. I am not well studied in physics and would like a refresher on these forces and was hoping someone could point me to the video and/or other topics like this to help me learn more.

  • Oct. 19, 2019, 7:52 p.m.

    i'll look through the transcription in hopes of finding the video you had in mind and add it here.
    I don't know how much curious you are about the subject so I'll start by pointing you to video format themselves put in increasing order of comprehensiveness:
    Straight to the point, 5 min video for a very quick overview form Real Engineering www.youtube.com/watch?v=im-JM0f_J7s
    Most impressive summary of the subject, 30min long but you won't feel em go by. It goes over the problems of lack of gravity then proceeds to detail the possibilities to deal with it. It gradually explains 99.99% of everything you would want o know. From Cool Worlds www.youtube.com/watch?v=b3D7QlMVa5s
    If you've watched the previously mentioned video and are wondering about that weird flipping effect,
    i believe this video from Veritasium should help you out a bit: www.youtube.com/watch?v=1VPfZ_XzisU

    Finally, if you're still curious about the details it's worth noting that all of these videos and Wikipedia quick formulas are glossing over many aspects in order to simplify things a bit (a lot actually). For instance all of these are for the most part considering a rotating habitat far more massive than anything that needs to move inside it. Now no one has yet made a nice graphic video explaining the details so the most intuitive examples would be the slight slowing down/speeding up of the structure (and thus spin gravity) when something of non-negligible mass accelerate(tries to move) in the same/opposite "direction" * that the habitat is spinning. These can be compensated via carefully placed reaction wheels with relatively low response time. But this can potentially imply that some part of the structure will have to suffer from very high variations in tensile strength due to the fact that in the real engineering world things don't magically transfer forces across their volume and said forces are always looking to find a weak spot somewhere in the structure... This and other things could be added to the graph showing the relationship between size and rotation rate shown in the 30 min video, further decreasing our options considering only the technologies available to us in 2019.
    *i used the common folks definition of "direction" similar to the one used in the 30 min video, not a proper one.

  • Oct. 27, 2019, 3:12 a.m.

    @yvonm Thank you for the time you put in to this detailed response. These were indeed the videos I was remembering. I must have been on a science and engineering binge with the SFIA videos thrown into the mix. Now that you mention force-transfer I feel as if I've gone back to step 1 in understanding how all of this works. Thanks again! These are very good things for me to go look in to.