I was listening to a discussion that involved Eric Weinstein wherein he opined just how weak gravity was. He said something like., “We are all being held in our chairs by gravity yet when we are done, we will easily get up and walk away. Gravity is incredibly weak”.
On the other hand, the sun’s gravity is able to pull in something the size of a comet from as far away as the Ort Cloud - 100,000 AU away! A trip out and back that can take as long as 30 million years. Think of it, a comet leaves its interior pass of the sun going as fast as 100,000 MPH (!) headed back out, and travels for 15 MILLION years, until the sun’s gravity slows it down and eventually (Al Pacino voice) pulls it back in. That seems incredible strong.
Gravity is weak in how it is distributed comparison to other forces, but unlike the strong and weak interaction the range of its influence is infinite, and unlike electric charge there is only positive mass (that we are aware of) so there are huge clumps of matter that create vast fields which dominate their local neighborhood, and affect structures on different scales.
The reason gravity is really weird is that it doesn’t fit in our otherwise unified Standard Model of particle physics based upon quantum mechanics, and creates singularities in spacetime where our best model of gravitational physics (General Relativity) breaks down. Which suggests that gravity is either fundamentally different than all other forces, or that there is a deeper theory that somehow decomposes into QM and GR even though those theories share virtually nothing in common in terms of mechanics.
The description I like: When an apple is hanging from a tree, it’s being pulled upwards by the electromagnetic forces in the thin little stem. And being pulled downwards by the gravitational force of an entire planet. And the stem wins.
My grandsons were tossing the TV remote back and forth. I reached in to catch it. Well, it bonked my wrist. Hurt kinda like the funny bone in an elbow.
Somehow I was was surprised to see the remote on the floor. The battery door clear across the room. Still looking for the batteries.
Yep gravity gonna get us all.
It is indeed, weird.
(Alas, my motor skills aren’t what they used to be.)
All of this is all over my head, but I did hear Eric say in that same talk that it’s possible there might be a grander theory that would encompass GR in much the same way that GR superseded Newtonian mechanics but still encompassed it. Obviously he said it better than that.
“Gonna”? I have been a victim of gravity many more times than I’d care to admit.
TIL, In July 2012, Chumbawamba announced they were splitting up after 30 years! Whoa.
If I’ve done the back-of-the-envelope calculation correctly, if the moon and the earth were positively charged by a few hundred million protons (on the order of femto-grams), the electrical repulsion would cancel out the gravitational attraction.
If gravity is so strong than how come the hardest place to reach in the solar system is the Sun? Huh? Explain that! Well, explain that without reference to Hohmann orbits.
