alt Hacker News> I guess it looks like it's down since it's a slice but the effect is an inward sphere?
Yes, gravity is a vector field: every point in space near a heavy body has a vector pointed at the center of the body with a magnitude of the field strength. https://en.wikipedia.org/wiki/Gravitational_field
Whenever someone uses fabric sheet analogy, they need to shout that the X-Y of the sheet is a 2 dimensional analog of X-Y-Z space, and the Z direction of the sheet is the field magnitude, with the slope indicating direction.
All models are wrong, but some are useful (for understanding).
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Other thing is I believe they say gravity is strongest at the center of the sphere/core but I would think the mass is split evenly away from the core eg. maybe 2/3 radius from the center where it's equal mass on each side. But probably doesn't make sense wouldn't be a ball.
The next thing they do after showing you the sheet is to roll a ball around the stretched part to demonstrate an orbit. Explaining how that analogy works starts to take more math than the actual field you’re trying to explain!