You're a Total Airhead. But Then, So Am I

I like to think of myself as a pretty solid fellow. You can't put your hand through me or anything. Lots of other things are solid too. Like my chair, my desk, my floor. I can sit on my chair, rest my elbow on my desk, and stand on my floor. All solid. Right? Wrong.

It turns our there's more empty space in my body, my chair, my desk, etc., than solid matter, by far. Consider this: Atoms are made of electrons in orbit around nuclei, which themselves are made of protons and neutrons. (We could break that down further, but doing so wouldn't be useful here.) A hydrogen atom has a diameter of only about one ten millionth of a millimeter. The proton at its center is one hundred thousand times smaller than that, and the single electron circling the proton is one thousand times smaller than that. Everything else in the atom is empty space.

I found a web site that attempts to make those distances imaginable. The designer of the site makes an electron a single pixel wide, and a proton one thousand pixels across, with a gap between them of fifty million pixels, or eleven miles. That's to scale. (Click here to visit the site.)

Since my desk, chair, and floor are all made up of atoms, and since atoms "contain so little material that they can barely be said to exist," you have to wonder what makes all these objects feel solid to the touch. Why, for example, doesn't my coffee pass through my cup?

The solidity of a substance in the result of strong electrical bonds between the electrons and their nuclei. So when I lean on my desk, it's the electrical bonds between these particles that keep the desk and my elbows from mixing.