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> And of course, if one also has a scale, the weight of the ball can be used to see whether the floor is level. Can you elaborate on this? Why would the weight
by jsweojtj 12y ago
> And of course, if one also has a scale, the weight of the ball can be used to see whether the floor is level.
Can you elaborate on this? Why would the weight be different if non-level? Unless you're meaning that the center-of-mass of the ball would be ~2 centimeters further from the center-of-mass of the Earth and 1/r^2 means a decrease?
- ctdonath 12y agoThe article depicts the difference between "level" (consistent radius from Earth's center) vs "straight" (line tangent to surface). A bowling ball rolled on a very long straight hall would (assuming nearly negligible resistance etc) actually accelerate toward the center, then slow down, reverse, and oscillate until it stopped in the middle (the lowest gravitational position) because relative to the curvature of the Earth a straight line is higher at the ends than at the center. A bowling ball rolled on a very long level hall would keep going (until resistance or confused staff stopped it) because there would be no gravitational change.
- dredmorbius 12y agoWhere the ball centered on would depend on how the hall was constructed. The low point could be anywhere, though it would likely be somewhere between the two endpoints. It would only be at the center of the hall if that's where the floor were tangent with the Earth's circumference.
- Someone 12y agoThe 1/r2 one. Going even more esoteric, I guess, in an idealized world, one can measure the deformation of the bowling ball due to gravity, and check whether it changes across the hall.