A New Look at Newton’s Second Law Could Explain Away the Existence of Dark Matter

From PopSci:

And all it takes to measure is a simple spinning disk here on Earth. When reached for comment, Dark Matter says: “Come on, you almost found me!”

Dark matter’s status as a mysterious and invisible lurker in the universe has frustrated scientists for years. Now, one hopes to solve the puzzle a different way: using a modified version of Newton’s second law that would eliminate the need for dark matter altogether. Researchers in Brazil have devised an experiment that could put the modified Newtonian dynamics (MOND) to the test, New Scientist reports.

Much indirect evidence for dark matter — supposedly 25 percent of the mass in the universe — comes from observing its invisible gravitational effect on visible galaxies and their stars. Deep underground experiments on Earth have attempted to directly detect the weakly interacting particles (WIMPS) that scientists believe constitute dark matter.

But dark matter’s existence is based on the assumption that Newton’s second law of motion holds true at all physical scales. In 1981, Israeli physicist Mordehai Milgrom hypothesized that Newton’s second law might change slightly at extremely small accelerations. That MOND proposal could in turn explain the irregularities astrophysicists have observed in the motion of galaxies and stars without the need for dark matter.

[Read more at PopSci]