The dark is what is.

Almost all of the universe is dark, and that is where the discoveries are. The dark is not empty. It is what is there, waiting to be seen.

6 · The walk · the universe

In the 1970s the astronomer Vera Rubin measured how fast stars orbit at the edges of galaxies. They were moving far too fast. Held by the matter we can see, those galaxies should have flung their outer stars away. Something unseen was holding them together.

Today we call it dark matter. Astronomers can weigh it by its pull, but nobody has yet seen what it is. Then, in 1998, two teams found something stranger still: the expansion of the universe is speeding up, driven by what is now called dark energy. Put the measurements together and the universe’s budget reads like a riddle. All the ordinary matter there is, every star, planet, cloud and person, is about one part in twenty.

What the universe is made of

Shares of everything there is, from the Planck satellite’s map of the oldest light

Stars, planets, gas and people are ordinary matter, about one part in twenty of the universe. The rest is dark, and it is where the discoveries are.

The dark is not a hole in the universe. It is most of it: real, present and steady, shaping everything while we learn to see it.

Unlit is an invitation

Your organisation has a dark too: everything true about your work that nobody has looked at yet. It is easy to mistake for nothing. A plain “we don’t have that” could mean the question lies outside your world, or squarely inside it, waiting.

The Observer’s Index tells the two apart. Where a question lands on ground nobody has looked at yet, the index shows it as unobserved: present, unlit, and marked as an invitation. That is where the next look is worth most.

And the dark never goes stale. Each look lights its share of what is still dark, however much was lit before it, so a late look lights as large a share of what remains as an equally strong first look did. There is always fresh ground ahead.

For your organisation: you can see what your organisation hasn’t looked at yet, and send your next good look where it will discover the most.

Where we’re heading

The dark as a frontier: every unlit place shown plainly, and every one an invitation.

See the Observer’s Index

What stands under this piece

Proved: a theorem in our own maths. Built in: how the index works. From the field: something observed, by scientists or in our own index. Likeness: a comparison, not a proof.

From the field: About 5% of the universe is ordinary matter, 27% dark matter and 68% dark energy.
Built in: Where nobody has looked yet, the index shows it as unobserved, an invitation, never as nothing there.
Proved: Each look lights its share of what is still dark, whatever came before.
Likeness: The universe’s dark and our index’s dark are a likeness we love. It is a picture, not a proof.