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Re: Hypothetical Gravity Questions

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Posted by Sarah Jennewine on April 28, 1997 04:29:17 UTC

: : : Hello! I was wondering how much gravity our bodies can withstand before the effects of gravity become intolerable. The reason I ask is that it's obvious to me that the state of your body would start to deteriorate long before you even reached the event horizon of a black hole. Given that the farther you are from an object, the less the attraction there is between you and the object, what would be the safest minimum distance you could be to a black hole's event horizon without endangering your health?: : Well, the question you've posted is a little ambiguous. I assume by distance you mean standing distance(not flying away or racing toward).: : Any fighter pilot will tell you that nine G's and you lose conciousness(blackout) negative 3 G's and the same thing happens(red out): : On the other hand you might be fine with one Gee of acceleration jumping off of a twenty story building...until you hit the ground.: : Now, in terms of the sheering force of gravity as you approach the event horizon of a black hole, its reasonable to say that I have no earthly clue at what distance the effects would be detrimental, but I'm anxious to find out.: : Here's an idea. You build a scenario of some detail and I'll see if I can pick a few brains with nothing better to do. : : Here's some more ideas. Consider a person in orbit around the earth; they are essentially weightless, because the centripetal: : acceleration away from earth as they orbit is exactly balanced by the gravitational force toward the planet. Now, picture the: : same thing around a black hole. If you can accelerate yourself (slowly!) to a high enough speed to remain in a stable orbit around a black hole,: : you would experience zero gravity and therefore no physical or mental distortion. depending on your distance from the singularity;: : however, your speed might be so high that you would experience relativistic effects (although you might not notice them), and if you get too close to the: : event horizon, you might not be able to correct for small changes and get sucked in! : Hi, Bruce! I've read your comments in this forum and really like what you have to say. I'm curious: How do you know so much about black holes and physics in general? Now to my serious question: What is this centripetal acceleration AWAY from the Earth you're referring to? Isn't centripetal acceleration the acceleration TOWARD the center of a circle, not AWAY from it? Also, I thought that astronauts in orbit did in fact experience the Earth's gravity (Isn't it called microgravity?); it's just that gravitational attraction decreases with distance. Your ideas about orbitting a black hole seem sound, although we'd want enough gravity (9.8 m/s2 optimally) to retain the structure of our bodies. And we can easily correct our calculations for relativistic effects using Einstein's transformations.

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