Home » News & Blogs » What's the matter with the Universe? About 31%.
Bookmark and Share
Bad Astronomy

What's the matter with the Universe? About 31%.

30 Sep 2020, 13:00 UTC
What's the matter with the Universe? About 31%.
(200 words excerpt, click title or image to see full post)

If you want to understand the Universe — and we do — you have to understand what's in it. I don't mean stars and planets and black holes and such. We need to be even broader.

How much energy is there in the Universe? How much matter? And to be a little more specific, what kinds of energy and matter?

We call this the mass/energy budget of the Universe. Like a household budget, it (hopefully) accounts for everything in it, divided by type. In the case of the Universe, we know it's made up of — in decreasing order — dark energy, dark matter, and normal matter. But how much of each?

A new study looked at just matter, and came up with a fairly narrow number: 31.5 ±1.3% of the Universe is made of matter (which, in turn, implies 68.5% is dark energy).

These numbers are pretty important. If the Universe had less matter, it would expand more rapidly — in a sense, the gravity of that matter slows the expansion.

The mass/energy budget of the Universe shows us that most of the stuff in the cosmos is dark energy, then next is dark matter, then finally the normal ...

Latest Vodcast

Latest Podcast

Advertise PTTU

NASA Picture of the Day

Astronomy Picture of the Day