What is Dark Matter?

I would love to help you explore the mysterious world of dark matter! Before we dive into the cosmos, I want to make sure I tailor our session perfectly to you.

To help me customize my explanations, what is your current background in science or physics? Are you interested in a high-level overview, or would you prefer a deeper dive into the actual mechanics?

I'm a beginner! Keep it simple with a high-level overview.

Welcome to the session! I'm so excited to help a beginner dive into one of the most fascinating mysteries in modern science.

Your path

Evidence for Dark Matter

What Could Dark Matter Be?

Dark Matter vs. Dark Energy

The Ghost in the Cosmic Machine

Imagine looking out at the night sky and realizing that everything you can see—every star, planet, glowing gas cloud, and galaxy—is just a tiny fraction of what is actually out there. In fact, all that familiar stuff, which scientists call ordinary or , makes up a mere 5% of our universe.

So, what is the rest? Roughly 27% of the cosmos is made of a mysterious, invisible substance we call dark matter. The word "dark" is actually a bit of a misnomer; it is not like dark paint or charcoal, which you can see because they block light. Instead, dark matter is completely invisible because it does not interact with the at all.

Because it doesn't interact with light, we cannot take a picture of it. However, we know it is there because of its massive gravitational pull. Just like a heavy bowling ball sitting on a mattress, dark matter has mass, which means it exerts gravity and pulls on the visible things we can see, like stars and galaxies.

A 2D pie chart showing the composition of the universe divided into three slices of 5%, 27%, and 68%.

I've started sketching out a simple pie chart above to help you visualize this strange cosmic recipe. It really puts into perspective how little of our universe is made of the ordinary matter we are familiar with.