Was Newton Wrong?

Dark matter has recently made its way into the discussions of the scientific community, leaving scientists to wonder: what is it and how did it get there? But some scientists are asking: is dark matter even real?

Dr. Stacy McGaugh seems to be focused on the latter.

McGaugh, Head of the Astronomy Department at Case Western Reserve University, was invited to lecture at Baldwin Wallace University on March 3rd as part of a series of astronomy lectures hosted by the university’s astronomy department.

McGaugh discussed several theories regarding Dark Matter in the astronomical community during his lecture: “Dark Matter or Modified Gravity?”

Less than five-percent of matter is baryonic, or ordinary matter that makes up most of what we know about, according to McGaugh.

McGaugh began by explaining the dark matter tree, where the roots are the issues that lead scientists to infer that dark matter exists and the growth represents the possible explanations.

It has been recently discovered that there is more mass than previously known due a mathematical inconsistency within spiral galaxies, according to McGaugh.

Beyond galaxies are large-scale structures. These large structures were first noticed in the early 1980’s and have since allowed insight into how the matter of the universe is grouped. McGaugh notes that gravity will form structures but slowly, and so there must be extra mass.

To account for the additional mass in the universe, some scientists have described dark matter as WIMPs, or weakly interacting massive particles. WIMPs exist everywhere, including inside our bodies, according to McGaugh.

McGaugh also talked about the theory of “cold dark matter,” in which there is some new fundamental particle that does not interact with light and is essentially invisible.

Yet, regardless of existing theories, dark matter has not yet been discovered as McGaugh points out.

What scientists do know is that rotation curves of spiral galaxies should decrease after peaking, yet they actually flatten. This is in violation of Newton’s laws, according to McGaugh.

This leaves the possibility that the equation is simply wrong and that dark matter may not really exist, says McGaugh.

An equation, known as MOND or the Modified Newtonian Dynamics, was developed to modify Newton’s equation. Though McGaugh found himself suspicious of the equation at first, along with several other scientists, it was found to work. Not only did it appear to work, it was more accurate than the prior theories, according to McGaugh.

This being said, McGaugh does acknowledge that it does not appear that every scientist is on board with this idea that the laws of gravity simply need to be modified in order to account for unknown mass in the universe.

Have we been wrong for centuries about what we believe gravity to be? Or is most of our universe composed of this dark matter that we haven’t quite figured out yet?

With no conclusive evidence just yet, it appears that the conflict will live to see another day.