Cosmic Zoom

Dark Matter: The Invisible Scaffolding of Galaxies

Galaxies spin far too fast to hold together — unless something invisible, and five times more abundant than everything we can see, is holding them.

45 minFull course

This lesson is part of the full course

Unlock all 37 lessons, the seven optional math appendices and every download with a single one-time payment — future updates included.

Unlock the full course

One-time payment · Full access

We use cookies that are necessary to run this site. With your consent, we’d also like to use analytics cookies to understand usage and improve the course. See our Cookie Policy.