Einstein's theory of general relativity is the only way that we understand gravity, and through that prickly tangle of mathematics we have come to know something called "space-time," a four-dimensional structure (three dimensions of space and one of time) woven together into a unified fabric.
In the language of relativity, matter and energy bend and warp the fabric of space-time, and in response the bending and warping of space-time tells matter and energy how to move, something we collectively experience as "gravity."
In order for the math of general relativity to work, this fabric of space-time has to be absolutely smooth at the tiniest of scales. No matter how far you zoom in, space-time will always be as wrinkle-free as a recently ironed shirt. No holes, no tears, no tangles. Just pure, clean smoothness. Without this smoothness, the mathematics of gravity simply break down.
But general relativity isn't the only thing telling us about space-time. We also have quantum mechanics (and its successor, quantum field theory). In the quantum world, everything microscopic is ruled by random chance and probabilities. Particles can appear and disappear at a moment's notice (and usually even less time than that). Fields can wiggle and vibrate with a will all their own. And nothing can ever be known for certain.
-- excerpt, rest at link above --
“We have now sunk to a depth at which restatement of the obvious is the first duty of intelligent people.” ― George Orwell
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Thu Apr 30, 2020 9:30 am
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