Practically all of the matter we see and interact with is made of atoms, which are mostly empty space. Then why is reality so… solid?
BIG THINK
At a fundamental level, all of the macroscopic structures we see and interact with are composed of the same few subatomic particles, whose interactions are known. Yet the atom, the building block for all materials solid, liquid, gas, and more, found on Earth and beyond, is mostly empty space, with very little volume taken up by “substantive” particles. And yet, our classical, macroscopic reality is somehow just as it seems, despite the minuscule nature of the components that make it up. How is this possible?
One thing you can be sure of, as you measure and observe the Universe around you, is this: the physical objects you see, touch, and otherwise interact with all occupy a volume of space. Whether in the form of solid, liquid, gas, or any other phase of matter, it costs energy in order to reduce the volume that any tangible material occupies, as though the very components of matter themselves are capable of resisting the impetus to occupy a smaller amount of three-dimensional space.
And yet, seemingly paradoxically, the fundamental constituents of matter — the particles of the Standard Model — occupy no measurable volume at all; they’re simply point particles. So how, then, can substances made out of volume-less entities come to occupy space at all, creating the world and Universe as we observe it? That’s what Pete Sand is curious about, asking:
“How can this chair be a chair and also a quantum probability and also mostly empty space?
How do those different realities co-exist?
How can the same “object” follow one set of physics at a conventional scale and another set of physics at the quantum scale?”
Let’s start by breaking down the matter we’re familiar with, step-by-step, until we go all the way down to the quantum rules that underpin our existence. Finally, we can work our way up from there.
