Science & Technology

You're Almost Completely Made Up of Empty Space

If you look around yourself right now, you probably think that things are pretty "solid." You can sit in a chair, hold a glass of water, punch a wall in frustration. All of these things are great indicators that the world around you is made of solid matter.

Except matter isn't really solid when you actually take a close look at it. Everything around us is made up of atoms, tiny particles composed of a nucleus orbited by electrons. These tiny particles are filled with energy, but they have quite a bit of empty space. In fact, 99.9999999 percent of all of the matter around us is empty space. That means if you took the empty space out of every human on earth, you could compress the entire human population down to an object smaller than a sugar cube.

A Matter of Scale

In order to grasp this seemingly absurd claim, we need to scale up atoms about a million times. When you blow up an atom to 1 million times its size, it's about the size of a melon. The nucleus of the atom would be in the center of the melon, and the electrons would orbit on the skin. But even if the atom as a whole was blown up to the size of an everyday object, both the electrons and the nucleus at the center would still be too small to see with the naked eye. The entire melon-sized atom would be completely empty space — 99.9999999 percent empty space, more or less.

In more scientific terms, the sizes of atoms are dictated by how far out their electrons orbit. This creates an electron "shell" of sorts, inside of which there is a nucleus. Nuclei are generally 100,000 times smaller than the shell they are housed in. Those classic diagrams of atoms with electron orbits really don't do this scale justice.

What's in the Empty Space?

If everything around us is empty space, then why does everything still feel so solid? For the answer to this question, you need to know just what's in the "empty space."

Atoms aren't stagnant particles; they're filled with energy and surrounded by electrons constantly buzzing around in a sort of cloud. No two electrons can exist in the same space at the same time. This ultimately means that if you wanted to try and walk through a wall, which again is mostly empty space, your electrons and the wall's electrons would have to exist in the same space, making it impossible.

The best way of envisioning this is to picture a fan. As the blades spin rapidly, the internal "empty space" of the fan doesn't change in volume, but in position. Fans could be said to be mostly empty space, but you can't exactly put your hand through a moving one — the energy of the moving blades would stop you, possibly resulting in some pretty serious injuries. In the same way, the orbiting electrons resist being pushed out of their orbits. This is why the empty space inside of atoms can't be filled with other atoms.

But there's another reason you can't fit an atom into another atom, and it comes down to quantum mechanics.

Quantum Empty Space

Electrons are known as point sources, otherwise defined as a source of energy that can be understood as having a negligible dimension. This means that electrons have no volume, but they do have a wave function whose energy occupies the space. And thanks to the laws of quantum mechanics, that wave function doesn't just occupy one point — it's everywhere in the empty space at the same time.

All this confusing jargon means some interesting things when you think about how you interact with life around you.

When you inevitably type a comment about how blown away you are about the facts you learned in this article, your fingertips aren't actually touching the keyboard. What you're feeling and interpreting as touch is actually just the electromagnetic force from the electrons in your atoms pushing back against the electrons in your keyboard's atoms.

Extrapolated out, this means that you've never actually touched anything in your life. You're actually floating just above the chair you're sitting on thanks to incredibly small electromagnetic forces. Quantum mechanics and the interactions of subatomic particles make the seemingly average events of everyday life pretty extraordinary.

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Written by Trevor English April 19, 2019

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