Dark Matter and Dark Energy Feb 10, 2011

by Sarah

The title Dark Matter refers to the astronomical term for the unknown and invisible matter that is the majority of our universe. Together, dark matter and dark energy make up 96% of the universe and are understood to be the force behind its expansion. Although scientists continue to study and debate the composition of dark matter, there is very little that is currently understood. Inspired by the concept, Crystal writes, “dark matter affects the speed, structure and evolution of galaxies, yet its nature remains a mystery.”  Here is a full description of dark matter and dark energy.

Although the term “dark matter” was initially coined by Fritz Zwicky in the 1930’s, when evidence for missing mass in galaxies was first discovered, it was the 1998 Hubble Space Telescope that confirmed the universe was expanding at an increased rate and put new scientific focus on dark matter and dark energy. It is believed that dark energy makes up approximately 70% of the universe and dark matter 25%. Most simply, dark energy is what propels the universe to expand, while dark matter is what continues to hold the galaxies intact. Very little else is currently known about the properties of either. The heated scientific race to explain dark matter and dark energy is explored in a new book The Four Percent Universe written by Richard Panek and released in January 2011. We have reprinted a question and answer with Richard Panek below, as it is an excellent laypersons guide to dark matter.

Q: What is the "four percent universe"?

Panek: It’s the universe we’ve always known, the one that consists of everything we see: you, me, Earth, Sun, planets, stars, galaxies.

Q: What’s the other 96 percent?

Panek: The stuff we can’t see in any form whatsoever. At a loss for words, astronomers have given these missing ingredients the names "dark matter" and "dark energy."

Q: What are dark matter and dark energy?

Panek: If you find out, book yourself a flight to Stockholm.

Q: So nobody knows? We're not talking about "dark" as in black holes?

Panek: No. This is "dark" as in unknown for now and possibly forever.

Read the full Q&A