These are two excellent questions that won't find justice done to them in a comment on a discussion board like this. :-( I won't try sketch a semiclassical gra

These are two excellent questions that won't find justice done to them in a comment on a discussion board like this. :-( I won't try sketch a semiclassical gravity attack on the second question, which is the harder of the two, and for the first, I'll mainly feint and point you to Greg Egan at http://www.gregegan.net/SCIENCE/Rindler/RindlerHorizon.html http://www.gregegan.net/SCIENCE/Rindler/RindlerHorizon.html as a starting point. On the one hand, for a sufficiently massive black hole, the Rindler solution he explores is an excellent approximation. On the other hand, his exact solutions are (a) not fully applicable in the dynamical spacetime of a sufficiently massive black hole (even one with lots of symmetries and otherwise in isolation) because the Rindler horizon is a local structure while the BH horizon is a global one [1]; there is a local boundary that forms a point of no return for objects near enough a black hole though you have to calculate where that is; (b) Egan's rope is a classical object, whereas when we're at the level of cellular signal transduction, molecular bonds, and chemical bonds, classical simplifications are already probably cheats or at least misleading. On the other hand, there are lots and lots of particles involved, and tracing the evolution of each of them in some suitable coordinates would be an enormous amount of work. So I trust my own intuition only to the extent that (as Egan notes) there are some decent mathematical similarities between the Rindler horizon and a BH trapping surface. Sadly, there will be no contact with observation in our lifetimes, but we might make quick and dirty numerical solutions that will give a strong theoretical prediction. Additionally, it is at least plausible that we will be able to do small-scale tests of Rindler space in a few decades. Until then be wary of people offering glib responses, especially really wrong glib responses like "the hands will never pass through the horizon because of time dilation" etc., which are sadly commonplace in online forums. Finally, my own thinking was that a powered hyperbolic orbiter (rocketman!) with sufficient momentum dropping his hands past the local point of no return would end up with stumps, and what does the actual ripping is rocketman's momentum [2]. In my head is a picture of Wile E Coyote running into a quicksand (or cement or tar etc) trap and either being tripped up and pulled into the quicksand or being unlucky enough to have enough forward momentum that he leaves his feet behind on the first step. Roadrunner corretctly judged exactly where the local trapping surface was and so skimmed right over the trap; Coyote miscalculated where Roadrunner's trapping surface would be (given more global knowledge of the configuration) and then his own. - -- [1] In particular, BHs (i.e., compact masses sourcing a trapping surface) can last extremely long times compared to the age of the universe and can in principle be observed by anyone in the BH's Hubble Volume, while real objects cannot be Rindler observers for very long (what fuels the acceleration?), and the Rindler horizon is peculiar to the Rindler observer rather than a trapping surface. Nevertheless, one can take the analogy seriously [ https://arxiv.org/abs/1305.4986 https://arxiv.org/abs/1305.4986 for instance ] [2] So I can "cheat" here by having the ripping happen between bits of tissue that are all outside the horizon at the time of rip; the tissue that is already inside the horizon is then irrelevant, and it's mainly whole cells that fall in. The centres of momentum and mass of the unfortunate astronaut are highly dynamical during this, so it's not so shocking a cheat.