If space is expanding, how come I know it? Wouldn't I just be getting bigger too? Somehow, it turns out that like concentrations of matter slow or stop the expansion of space, so it mostly takes place between the galaxies. Why matter would do that, I don't know.
But it seems evident that we can say that in the last 13 billion years, space has expanded by a factor of 42/13 or 3.231. Isn't it odd that we know that?
We live in an amazing time. The first paper that Einstein wrote was in 1905, and the question it addressed and settled was: is matter made of atoms? We just found out 99 years ago that matter's not a seamless pudding.
What we have come to know since and during my lifetime is phenomenal. We've found that time stands still for the photons of light. We've found that atoms are made of nuclei and electrons. We've found that nuclei are made of protons and neutrons, and that those are made of quarks. And now we're finding that quarks are made of tiny vibrating strings of energy. When I say tiny, I mean that if an atom were the size of the solar system, a string would be the size of a tree. And we're finding that space itself is totally weird. It's not an empty vacuum at all. It turns out to be a turbulent sea of strings, smaller than we can detect. They combine accidently into particles from time to time, for a bit, called "virtual particles." So what we see, in empty space, are particles that we can detect springing into existence out of nothing, and then disappearing again. Say what? Is that amazing or what?
Space itself is never still: particles pop into existence and go out again in less than a trillionth of a nonosecond. "Virtual" quarks, photons, and electrons paired with positrons appear and disappear. These virtual particles are attracted to matter, and so they form a cloud around electrons (for example) that partially cancels the electron's electro-magnetic field. (Kunzig, 2000, p. 66)
One of the great questions of science has been the nature of matter. What's been found so far is that matter is made up of molecules, which are in turn made up of atoms, which are in turn made up of quarks. Like one of those Russian dolls-within-dolls.
Matter is mostly empty space. If you took away the empty space between atoms, pushed them together until they were touching, the human body would be compressed to about the size of a pencil eraser. Or to put it another way, the human body is 99.996% empty space.
But since atoms are also mostly empty space, you could push them together until the nuclei were touching. If you did, the human body would be too small to see.
Atoms consist of nuclei and electrons. The electrons have very little mass, and they orbit around the nuclei in roughly the way planets orbit around a star. I say roughly, because their orbits aren't circles, and the orbiting objects aren't confined to their orbits. Their orbits are just where they're most likely to be. One orbital, for example, consists of two lobes of probability space on opposite sides of the nucleus, and the electron seems to appear and disappear, hopping back and forth. How odd. (Kunzig p. 66)
The nucleus is made up of neutrons and protons. In 1973 it was discovered that the proton is made up up three quarks, which together make up 2% of the proton's mass. Here's where it gets fun. They're bouncing around inside the nucleus at near-light-speed, surrounded by a flickering cloud of other particles: gluons and quarks materializing and disappearing. Gluons have no mass, and they move at light-speed (and since only light can move at light speed, that means they are a kind of light). They "transmit" the force that binds the quarks together (as physicists say), in an odd way.
Inside the proton, it's been discovered that the force that binds the quarks together gets weaker as they get closer together, and stronger as they get farther apart. They're reined in like bungee-jumpers when they separate. How does that happen? It turns out that's because gluons have a charge (not an electromagnetic charge, because that's what electrons do, but a charge called "color"), and because they do, they're like little bar magnets lining up in the field of a big bar magnet and thereby amplifying it's field. Two quarks inside each others' gluon clouds would feel only a feeble attraction, but as they get farther away the gluon amplification increases because more gluons pop into existence between them. Virtual gluons are what holds quarks inside protons together. (Kunzig, p. 67)
There are lots of other particles besides those that make up atoms. One of these is light. Light is an odd thing. It travels in discrete packets called photons. Photons have no mass, and no charge, and they travel at 186,000 miles a second. As you approach the speed of light, time slows down. Photons go so fast that time has stopped for them. A photon leaves the surface of a star and travels through space for 12 billion years, let's say, and then strikes your eye as you look up one night. For that photon, the moment it left the star and the moment it struck your retina, are the same moment. No time has passed for it, at all.
Interesting stuff, huh? Back in the 70s I read a book called Occult Chemistry, by one of the most famous Theosophical psychics, Claude Ledbetter, I think his name is. Something like that.
Anyway, he had the power of microscopic vision. When he looked at neutrons, he could see the quarks within like glowing lights inside a bubble of fog. When he looked inside quarks, he could see they were made up of vibrating strings of energy. He called them anu, and he said the strings are coiled like baskets, with an opening at each end. The coils of energy themselves are rainbow colored, and vibrate musically. Energy is sucked in one end and spewed out the other. The anu zoom around like little speedboats.
Reference: article in Discover, July 2000, by Robert Kunzig, called The Glue That Holds the World Together.
Here's a copy of The Nature of Matter you can download: