You Stole My Dark Matter!

Image (Credit): This NASA diagram reveals changes in the rate of expansion since the universe’s birth 15 billion years ago. The more shallow the curve, the faster the rate of expansion. The curve changes noticeably about 7.5 billion years ago, when objects in the universe began flying apart as a faster rate. Astronomers theorize that the faster expansion rate is due to a mysterious, dark force that is pulling galaxies apart. (NASA)

ScienceDaily reports that astrophysicists found some small galaxies lack Dark Matter after encounters with larger galaxies. In the article, “How Galaxies Can Exist Without Dark Matter,” we learn that the astrophysicists found seven galaxies stripped of dark matter after collisions with galaxies about 1,000 times more massive.

Astrophysicist James Bullock from the University of California, Irvine and Pomona College, who was part of the team that made the discovery, stated:

The observation that there are dark matter-free galaxies has been a little bit worrying to me…We have a successful model, developed over decades of hard work, where most of the matter in the cosmos is dark. There is always the possibility that nature has been fooling us.

Just when we think we have figured things out, a wrench is thrown into the works. It does keep things interesting.