Right now, you are reading this through eyes that — strictly speaking — aren't really there.
You, your phone, the chair you're sitting on, the planet under your feet: everything solid in your world is built from atoms. And every atom is about 99.9999999% empty space.
The architecture of nothing
An atom's nucleus — the part holding nearly all its mass — is roughly 100,000 times smaller than the atom itself. The classic scale comparison: if the nucleus were a peanut sitting on the pitcher's mound, the atom's electrons would be whizzing around somewhere in the highest bleachers of the stadium. Everything between is void.
This isn't a metaphor. It's measured physics. Ernest Rutherford proved it in 1909, when his gold-foil experiment fired alpha particles straight through a sheet of gold as if the atoms weren't there — because, almost entirely, they aren't.
The sugar-cube calculation
Here's the part that breaks brains. Squeeze the empty space out of every atom in your body and your entire mass collapses into a speck of nuclear matter. Do it to all 8 billion people on Earth, and the whole human species fits into the volume of a single sugar cube — while still weighing about 400 million tonnes, exactly the same as before.
Physicists have pinned this down precisely: nuclear matter has a density of roughly 2.3 x 10^17 kg/m^3. A neutron star is just this principle scaled up to an entire star — a single atomic nucleus the size of a city, held together by gravity instead of the strong force.
Then why is everything solid?
Because "empty" doesn't mean "undefended." Your electrons push violently against the electrons in everything you touch, and the Pauli exclusion principle forbids electrons from crowding into the same quantum state. At the bottom, touch is an electromagnetic shove.
So you have never truly touched anything. Not your phone, not your chair, not the person you hugged this morning. You are a precisely arranged storm of electric fields — 99.9999999% absence, and somehow, all presence.
What should tomorrow's post unpack — black holes, CRISPR, or something stranger? Tell me in the comments.