Ask Ethan: What would the Universe be like without dark matter?

Ask Ethan: What would the Universe be like without dark matter?

Here in our own Solar System, it’s normal matter that dominates the massive objects we observe and measure. Humans, planets, moons, and even the Sun are all made up of the same types of ingredients at their core: protons, neutrons, and electrons, bound together into various nuclei, atoms, molecules, and even grander structures. When we observe the orbits of these celestial objects, there’s practically no room for dark matter at all; its presence…