Yeah, but did she have her own event horizon?
It’s thought that gravity starts to work differently round about the Planck scale. Of course 1 Planck mass is actually a quite weighty ~22 micrograms which isn’t much lighter than the smallest insect.
To which you could’ve said “Why yes according to Newton’s law of universal gravitation all objects have their own gravitational field: how astute of you dear chum!”. At which point though your lunch money may’ve been stolen.
On a similar note, when Chuck Norris does pushups, he really does push the Earth down.
The planet under our feet doesn’t negate the effect. It does dwarf it, but even if the planet weren’t there, the gravitational force between you and say your very close friend is too small to be of any use to you. For example, in the movie Gravity, while Hot Lady and Macho Man are floating in space, even if they get really close, their gravity is so small that it’s negligible.
For a worse example, in one of those silly Bruce Willis movies where he’s in space and lands on an asteroid and walks around … nuh uh. Even for a pretty darn big asteroid, he’d kinda bounce into it. My gosh, even on the moon (which is pretty damn big, WAY bigger than any asteroid) people walk in a floaty kind of way, with very heavy space suits on.
Excellent post, but nit pick:
r^2 = distance between the objects in meters, squared
If we’re going to be nitpicking, the formula, like any formula in science, doesn’t have any particular units associated with it. F is the force, not the force in newtons; m is the mass, not mass in kilograms; r is the distance, not the distance in meters; and so on.
They used astronomy to measure the azimuth, and built stone buildings to house the pendulums. They did it on two opposite sides of the mountain. It think they were some way shorter than 60 feet.
And you’d be surprised at how precise scientific instruments can be, too. I’ve used analog calipers that could measure things to within a precision of 1/50 mm, just by sliding bits of metal against each other.
Yeah no shit! That’s how they kill us physics students on exam days. :smack:
The instrument used at Schiehallion was a 10 foot (3 meter) zenith sector. The combined deflections from readings on the north and south sides of the mountain was 11.6". That means on each side, the plumb line was deflected about 5.8", which translates to ~.08 mm deflection at 3 meters. A US dollar bill is about .1 mm thick.
Since he expressed G in specific units, the other units are appropriate, for consistency. Since we’re nitpicking! 