Undergrad If gravity is not a force, what is holding us down?

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Gravity is conceptualized as the curvature of spacetime rather than a traditional force, which alters how objects move. When free-falling, an object follows a geodesic, a natural path in curved spacetime, until it encounters a surface that stops its fall. The sensation of being "held down" is actually a result of the ground pushing upward against the object, not a gravitational force acting downward. This upward push is due to the Earth's continuous acceleration, which is a manifestation of spacetime curvature. Understanding gravity in this way emphasizes the geometric nature of gravitational interactions as described by general relativity.
  • #61
paradisePhysicist said:
On a more serious note though, I think the movie will be easier to visualize since its already visual. On the other hand, the book may be so well written that it is easy to visualize also.
Understanding is the goal. A visual understanding is not.
 
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  • #62
As someone not familiar with the math's I find Vsauce's youtube video below very informational for those trying to get a grasp on why no forces are involved. I would recommend you watch it all though for a quick snippet check out timeframe 16:15 - 17:25, this demonstrates how straight paths come together on a curved surface. Possibly continue watch through to 20:40.

 

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