What Fabric is the Fabric of Space Made of?
A series of questions and speculations from someone who knows just enough astro-physics to be spaced out.
I'm a bit confused by the idea of gravity bending space. What is space? Is it a physical thing? Is space the 3 dimensional volume of the universe? Is this a concept of dimension and not a physical thing? What exists as space that can bend? Is it particles? What would they be, dimension particles? What is meant by the "fabric of space"? What's this fabric made of, Newtsteinium?
Sound doesn't travel through a vacuum because there is no matter to transmit the pressure wave. Does gravity affect a vacuum? Can you bend or in any way rearrange a vacuum? Can you poke a hole in a vacuum? What is different between a vacuum and what we call space? If a volume or vacuum is spherical or peanut shaped the distance between any two points is a straight line. How do you bend distance?
I don't get the visual depictions of bent space. They usually show three dimensional orbs deforming a two dimensional fabric of space. The orb sits on this fabric, bending it down as if there were some giant source of gravity below. Does that make sense? Basically it boils down to gravity is the result of bent space. Why does the space bend? Because of gravity. Which means bent space causes gravity and gravity causes bent space. Talk about circular logic.
As drawn, an object heading straight for a planet would reach a point and then start falling into the depression toward the bottom. Does that ever happen? How does bending space explain the acceleration mass gets from gravity? Does changing something's direction speed it up. A car doesn't speed up in a turn because it turns. Why would something entering a gravity well as depicted speed up?
Is there space between molecules, between the nucleus and electrons in an atom? Is space bent around an atom? Is there a lower limit to the size of space that can be bent? Doesn't gravity come from each and every particle and not the planet as a whole? Does a planet have countless numbers of bits of bent space bending around every atom? How does that work?
If it's a metaphor or a way to conceptualize it, I still don't get it. I don't see why you need to bend space to bend the path of light any more than you need a curved road to bend the path of a car. You need a force. Forces don't come from nowhere, they come from something that physically exists. By the same token, don't forces affect only things that physically exist? If space is a volume can it be affected by gravity? The mass in space is, but the emptiness in between? I'm no Einstein, but whole concept of bending space strikes me as like poking a hole in a vacuum.
Do I have a better explanation? I don't. But the folks at the following sites might. The plasma-electric alternative to the standard model of the universe. The Electric Universe or Thunderbolts. Agree or disagree, I can pretty well guarantee you'll find it interesting and thought provoking at least.