Busting the myth about achieving artificial gravity by rotating a body

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SUMMARY

The discussion centers on the misconceptions surrounding artificial gravity generated by rotating bodies, specifically in the context of space environments. Participants argue that true gravity is not present in space, and that centripetal force, which is often mistaken for gravity, requires an initial gravitational force to exist. The flawed premise of artificial gravity through rotation is highlighted, emphasizing that without a force pulling individuals down, they would not remain grounded on a rotating surface. The conversation concludes that while artificial gravity can mimic the effects of gravity, it fundamentally relies on inertial forces rather than true gravitational pull.

PREREQUISITES
  • Understanding of centripetal force and its relationship to gravity
  • Familiarity with inertial and rotating reference frames
  • Basic knowledge of Newtonian physics and fictitious forces
  • Concept of artificial gravity in the context of space travel
NEXT STEPS
  • Research the physics of centrifuges and their application in creating artificial gravity
  • Study the differences between inertial and non-inertial reference frames
  • Explore the implications of mass and spacetime curvature on gravitational forces
  • Investigate the design and operation of rotating habitats for long-term space missions
USEFUL FOR

Physicists, aerospace engineers, and anyone interested in the principles of artificial gravity and its implications for space exploration.

  • #31
lolsurround said:
You're wrong.
You might want to pick a reference a little higher level than that. Masses cause spacetime curvature that lead to inertial paths that intersect the surface of the planet. The surface of the planet is what pushes you out of the inertial path - so the only force acting on you is the contact force from the planet. What we usually call the "force of gravity" is the fictitious force caused by you not being in an inertial reference frame when you're on the surface at rest.
 
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  • #32
lolsurround said:
Why would it get locked for asking a legit question?
You aren't asking questions, you're making incorrect statements.
 
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  • #33
lolsurround said:
Why would it get locked for asking a legit question?
What was your question?
 
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  • #34
lolsurround said:
Why would it get locked for asking a legit question?

I see no question. I only see you claiming implicitly that physicists are wrong.
 
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  • #35
DaveC426913 said:
If you examine an astronaut in a closed rotating system that has air - from an external non-rotating reference frame - you will quickly see how the astronaut is drawn toward the outer wall and contacts it after a short time.

From the astronaut's point of view, this behaves sufficiently like gravity to do its job. i.e. Keep your feet on the floor and your milk in your glass.

Where is the disconnect?
The disconnect is that you're not getting my point. I understand what you mean but i see it as wrong. I disagree that the astronaut is drawn towards the outer wall. He starts with zero rotation together with the floor. As the floor speeds up, he holds on to it. When the floor is spinning and he let's go of it, he will not continue to be pushed towards the outer wall. He's in space and there will be nothing to draw him towards the outer wall. He will bump into the outer wall and for a while be pushed towards the floors rotational tangent, but he will not be pushed outside towards the wall.
 
  • #36
lolsurround said:
The disconnect is that you're not getting my point. I understand what you mean but i see it as wrong. I disagree that the astronaut is drawn towards the outer wall. He starts with zero rotation together with the floor. As the floor speeds up, he holds on to it. When the floor is spinning and he let's go of it, he will not continue to be pushed towards the outer wall. He's in space and there will be nothing to draw him towards the outer wall. He will bump into the outer wall and for a while be pushed towards the floors rotational tangent, but he will not be pushed outside towards the wall.
That's why I specified that it contains air. The air drags him along with the rotation.

In a vacuum, you would be correct that he could float without limit.
 
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  • #37
Thread closed temporarily for Moderation...
 
  • #38
So the OP is on a 10-day vacation from PF. They can contact the Mentors when they return to discuss whether this thread can be reopened. Thanks everybody for trying to help the OP.
 
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  • #39
Whelp, the update is that the vacation is permanent. Thread will not be reopened. Have a nice day. :smile:
 
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