Enlarge (credit: Corey Gaskin)

Back in 2010, Gary Wolf, then the editor of Wired magazine, delivered a TED talk in Cannes called “the quantified self.” It was about what he termed a “new fad” among tech enthusiasts. These early adopters were using gadgets to monitor everything from their physiological data to their mood and even the number of nappies their children used.

Wolf acknowledged that these people were outliers—tech geeks fascinated by data—but their behavior has since permeated mainstream culture.

From the smartwatches that track our steps and heart rate, to the fitness bands that log sleep patterns and calories burned, these gadgets are now ubiquitous. Their popularity is emblematic of a modern obsession with quantification—the idea that if something isn’t logged, it doesn’t count.

Enlarge / Galaxy rotation has long perplexed scientists. (credit: NASA/James Webb Telescope)

One of the biggest mysteries in astrophysics today is that the forces in galaxies do not seem to add up. Galaxies rotate much faster than predicted by applying Newton’s law of gravity to their visible matter, despite those laws working well everywhere in the Solar System.

To prevent galaxies from flying apart, some additional gravity is needed. This is why the idea of an invisible substance called dark matter was first proposed. But nobody has ever seen the stuff. And there are no particles in the hugely successful Standard Model of particle physics that could be the dark matter—it must be something quite exotic.

This has led to the rival idea that the galactic discrepancies are caused instead by a breakdown of Newton’s laws. The most successful such idea is known as Milgromian dynamics or Mond, proposed by Israeli physicist Mordehai Milgrom in 1982. But our recent research shows this theory is in trouble.