New light on dark matter

A Case astrophysicist captivated the physics community this fall when he proposed that one of its foundational beliefs about how galaxies formed is likely incorrect.

Stacy McGaugh, director of astronomy in the College of Arts and Sciences, said findings from NASA’s James Webb Space Telescope do not support the standard model of galaxy formation. Instead, his research team found that something else was powering the evolution of the universe.

The news raced like a comet though physics circles, with dozens of news sites and science bloggers sharing the

new insights. According to the standard model of galaxy formation, NASA’s super telescope should have spied dim signals from small and primitive galaxies in the early universe. Instead, it observed large, bright galaxies, a discovery that contradicts the widely held view that dark matter was crucial to galaxy formation.

“Astronomers invented dark matter to explain how you get from a very smooth early universe to big galaxies with lots of empty space between them that we see today,” Mc- Gaugh said in a statement, adding, “What the theory of dark matter predicted is not what we see.”

The large, bright signals that Webb keeps seeing are compatible with another theory: Modified Newtonian Dynamics, or MOND. If MOND is correct, the implications are huge, McGaugh said.

“For one, it implies that we have been barking up the wrong tree with dark matter,” he told Newsweek. “The reason we haven’t detected dark matter in the laboratory despite decades of dedicated searches is because it is not there.”

Fathoming what is really going on will require a “major change in thinking,” he said, the likes physics hasn’t seen since the development of quantum mechanics a century ago.

The paper was published Nov. 12 in The Astrophysical Journal.