When stars at the edges of galaxies spin faster than expected, we usually assume hidden dark matter. A new study avoids invisible particles. Scientists applied a mathematical trick to spacetime: to bypass singularities (points where equations break down), they 'cut' and glued it differently. At the seams, edge oscillations of the gravitational field spontaneously arise — creating extra pull that accelerates the stars.
A surprising twist: a trick designed to tackle mathematical problems in black holes unexpectedly explains the dynamics of entire galaxies. Dark matter, perhaps, is not a substance, but a feature of gravity at boundaries.
Astronomers once thought the odd rotation of galaxies was just a measurement error, until Vera Rubin proved the effect was real.
In science fiction, universes are glued with wormholes, but here, sheets of space are glued to bypass 'breakdowns' in equations, unexpectedly explaining star motion.