You are 99.99% Empty Space

You are 99.99% Empty Space - An Essay

By Damon Nomad


Introduction

I should be able to see through you, actually through everything. Did you know that we are almost completely empty space? This is not a joke. Everything around you right now is almost completely empty space. I'm not talking about science fiction or metaphysical concepts of reality. The hard science of physics tells us about this reality. What are we an optical illusion or a holographic shadow? Go ahead, do an internet search and you can get back to this short essay. It's probably easier to go ahead and read this essay, you are already here. You can check Google later.

The Deceptive Model of the Atom

You probably came across it first in middle school or grade school science and it got repeated in high school. The Bohr (no it wasn't Bore) model of the atom. It looks like a little solar system, the nucleus in the middle with the electrons orbiting around. The nucleus is where most all of the mass is, the neutrons and protons. A neutron and proton have close to the same mass, and they have two thousand times the mass of an electron. The classic Bohr model gave you the image of the electrons zipping around the nucleus like the moon circling the earth. You probably remember there are fixed orbits, known as orbital shells. Those shells fill up in a pattern that helps explain the structure of the periodic table of the elements. Chemistry is all about how these energetic little electrons behave. The mental cobwebs are coming loose right? You can just recall the s, p,d, f, and g orbital shells. This is a useful exercise for bookkeeping to understand basic chemistry and science. That is why it has been around for so long, but it is a horrible pictorial representation of the atom. It is stuck in our brains, that little solar system model where things are all so close together. Not a lot of white space between those orbiting electrons and the nucleus.

With his image, you can picture trillions of those little solar systems of Carbon, Oxygen, Nitrogen, Calcium, and Hydrogen atoms all packed together making up your body. You are not surprised you are not transparent, what craziness is Damon Nomad talking about? There is something like 7 x 10 E27 atoms that make up an average-sized person. The problem is that picture of the atom from your middle school science book is not drawn to scale, not even close to scale. What would the picture look like if it was drawn to scale? Let's use a hydrogen atom. That's the simplest element, a single proton as the nucleus with a single electron zipping around the proton. Pretty much like the earth and moon.

What would the right scale look like, how far away from the proton is the electron orbiting? If the proton was about the size of a baseball, how far away would the electron be in this model? What do you think? Ten feet, keep going . . . a hundred feet . . . keep going. Okay fine the electron is roughly three miles away from the baseball-sized nucleus, picture that in your mind. The atoms of your body have nearly all the mass concentrated in a small space about the size of a baseball and the electrons in the outer part of the atom are about three miles away, that's three miles of empty space. Picture assembling a bunch of atoms that look like this. Hundreds of them, or billions of them. It's going to look like a giant void with tiny dots barely visible. Material objects are not like this, why are things so solid? It's the model of these simple orbits that causes the confusion. We need a better conceptualization of what the atom is like, especially these orbiting electrons.


A Spinning Fan and a Beehive

The conceptualization used to teach us the basic concept of orbital shells has polluted our minds, well not really. But it did not come with the appropriate warnings for those who do not have advanced degrees in the physical sciences. Depending on how old you are, there is a lot about atomic and nuclear structure that has been discovered in the last several decades. Unfortunately, a lot of the answers come from quantum mechanics. The weird and strange world of particle physics. Electrons are not like moons orbiting a planet. Quantum mechanics teaches that electrons essentially occupy all of the space within the outer radius of the atom. Their precise location is indeterminate, you cannot determine their location at a point in space the way you can as the moon orbits the earth. An electron's location is smeared out across the atom, mathematically as a probability density function. As with many things in quantum mechanics, the answers make no sense for macroscopic creatures like us. But the experiments and predictions from the complex mathematics of quantum physics have constantly proven the science to be correct. Sadly, it's quantum mechanics that tells us that the atoms we are made up of are not mostly empty space. It is sad because no one can explain why quantum reality behaves in these strange ways. The greatest minds of physics, admit as much. The quantum world exhibits properties and behaviors that contradict many fundamental aspects of our real-world experiences of causation, time, distance, and motion.

Two visual analogies are frequently used to try and give some sense of what is going on. One is the swarm of bees buzzing around a hive moving so fast that from a distance it looks like some fuzzy mass floating in the air. You know they are individual bees but your eyes cannot resolve the tiny fast-moving creatures. The term electron cloud is sometimes used to further this analogy. The other is the old-fashioned fan, that blows air. When it is turned off, you can see the individual blades, you could even stick your finger in between the blades if you took off the protective cage. But once it starts spinning the blades become a fuzzy blur and you wouldn't try and stick your finger in there. Not the best analogies in the world, but it's better than trying to drill through the complex physics and mathematics of quantum mechanics.

Atom Smashers

It wasn't really until the twentieth century that the structure of the atom was revealed. The discovery of the neutron in 1932, that is not so long ago. Scientists started building atom smashers more formally called particle accelerators. A fundamental question they were exploring with these atom smashers: What are the fundamental particles? The particles that cannot be subdivided further and from which all matter is composed. This is an idea that can be traced back to the Greek philosopher Democritus in 400 BC. He proposed the idea that all things are made up of indivisible atomic particles. Atom comes from the Greek atomos, indivisible. We have been chasing this question for centuries, and it wasn't until 1913 that the atomic nucleus was discovered. Before the twentieth century, the belief was that atoms were the fundamental building blocks. Atoms could not be broken apart, they were the building blocks of matter that Democritus had contemplated.

In the 1930s we split the atom and the debate raged into the 1950s and 1960s. There was a growing consensus that protons, neutrons, and electrons were the fundamental particles. Many people alive today were around while these debates were swirling through the scientific community as our science books were being written. In 1964 quarks were proposed as elementary particles that were the building blocks of protons and neutrons. The Stanford Linear accelerator found evidence of their existence in 1968, that's definitely not very long ago.

To many people interested in science growing up in the sixties and the seventies, the proton and neutron were like billiard balls, tiny solid things. Surely protons and neutrons could not be smashed apart in an atom smasher. Not only could they be smashed apart, each one is composed of three quarks. Guess what, the quarks are not packed together like billiard balls in a rack. In fact, the proton and neutron also seem to be mostly empty space!!! Imagine a quark to be the size of a golf ball. On this scale, the outer edge of the proton is about fifty yards away, that's right the mighty proton looks like a half-empty football field with three golf balls rattling around inside. The same quantum mechanics explanation we used for electrons answers this apparent paradox. You can see how this paradox cascades, we keep finding smaller and smaller fundamental particles separated by vast seas of empty space. Maybe matter is nothing but a hologram! No, I am not going down that rabbit hole.

Physicists are now pretty happy with what they have, what they call the standard model consisting of seventeen elementary particles, but I'm not holding my breath. Someone will probably come along and smash them into a bunch of vibrating strings, a story for another day.