What is the universe made of?

That's why our universe is cake-shaped.

On earth, every cubic square cm contains around  30,000,000,000,000,000,000 particles of oxygen. So nothing is basicly empty. The lowest ammout of particles per cubic square cm that humans ever managed to reach was 100, by using vacuum.

Now you might be wondering where i'm going with this. Now let's go to space.

The space between the planets in our solarsystem contains an amount of 10 oxygen particles per cubic square cm. But it can even go lower. If we leave our solarsystem and enter the interstellar space, you can only find 1 oxygen particle per Square METER.

So the answer, the question where the universe is made of, should be "Air".


I got this from Vsauce btw, i'm not the kind of smartass that could write that what's above here all by myself

I'm going to have to politely disagree with you on that one. I'll start on a large scale to prove that most of the universe is not matter.
The stuff of the universe we common folk know of in our universe are basically stars and planets and asteroids and moons and comets and stupid run-on sentences. These stars and planets and asteroids and moons and comets and stupid run-on sentences are contained in galaxies. These galaxies are in clusters. Clusters that we would say are humongous. Then we realize the fucking massive void right next to it that makes the cluster look like an ant to the void's Rosie O'Donnell. They're very large. To through some maths at you, this guy told me that the universe is 0.0000000000000000000042% matter. That is a very small number:

That's 21 / 5 * 10^21. Yeah.
Then we get inside the clusters. The galaxies are not shoulder-to-shoulder. They are certainly not touching, except in cases where they are colliding or merging or whatever they do. Galaxies are weird people.
Then we get inside the galaxies. We know that galaxies are comprised of solar systems and nebulae and black holes and all that crazy stuff. And, of course, an incredibly large amount of nothing between all these somethings.
Then the solar systems. THE SOLAR SYSTEMS. JUST LOOK AT HOW EMPTY THAT IS. THAT'S NOT EVEN AS EMPTY AS THE UNIVERSE.
Then the planets. We know that the planets are made of stuff, we can see it. So that's not that shocking.
Then, life. I.e., organisms, organs, tissue, cells, organelles, acids and the stuff that comprises all of it: atoms. There are billions upon billions of atoms in your vision, right now. Can you see a distinguish a single one of them? I bet you can't. So you know that they're small. Then think of what makes the atom. Protons are tiny, tiny things that do stuff, but that's not all. Electrons are even tinier things that do other stuff. Then you have to think about how electrons orbit the nucleus of the atom. Picture a cathedral. A massive cathedral. Now picture a fly circling the middle of the cathedral, from the very edge of the cathedral. That's a pathetic attempt at scaling the orbit of an electron. The rest of the space in the cathedral-atom is empty. Nothing. That is how empty an atom is. Any atom. All atoms.
So, the universe has comparatively barely any matter in it at all. What the rest is isn't as easy to figure out. It could be anti-matter, dark matter, Xenu's minions or just nothing.

Wow. And I thought I felt empty because of some psychological disturbance...