Hundreds of Millions of Light-Years Away, Newton’s Law Still Holds, Scientists Report

Newton Was Right Again

According to НВ — Техно: A research team has demonstrated that the law of universal gravitation remains valid across cosmic distances measured in the hundreds of millions of light-years. Using the Atacama Cosmology Telescope (ACT), scientists from the University of Pennsylvania tested Isaac Newton’s classical gravitational law, first formulated more than 300 years ago, and found it still applies on enormous intergalactic scales.

The findings, published in Physical Review Letters, run counter to an alternative framework called modified Newtonian dynamics (MOND). Instead, they reinforce the standard cosmological model, which attributes the unusually high velocities observed in galaxies to the presence of dark matter.

What the Study Revealed

The investigation centered on clusters of galaxies separated from one another by hundreds of millions of light-years. Researchers analyzed subtle distortions in the cosmic microwave background, radiation that emerged roughly 380,000 years after the Big Bang. A key part of the project involved data from the Atacama Cosmology Telescope, a facility about the height of a four-story building.

The measurements showed that gravitational strength decreases in direct proportion to the square of the distance, matching Newton’s formula. This same expression was later incorporated into Albert Einstein’s general theory of relativity. The experiment thus lent weight to the standard cosmological model, which holds that the accelerated motion of galaxies is driven by invisible dark matter-though its exact nature and physical composition remain unknown.

The study, assigned DOI 10.1103/rk8v-rcm3, opens fresh avenues for understanding cosmic processes and confirms that fundamental physical principles continue to apply even on universe-spanning scales. The news was published on August 25 at 19:01.

These results matter for cosmology’s future, as they validate longstanding ideas about gravity while challenging a prominent alternative theory. The work also highlights how dark matter shapes the Universe’s large-scale structure, even as its true character stays mysterious. This milestone could guide new experiments and theoretical models in astrophysics, a field that seeks to explain some of the most complex phenomena in existence.

These findings not only reaffirm Newton's principles but also deepen the intrigue surrounding dark matter. For those interested in the latest theories about how dark matter might behave under different forces, a recent study suggests that dark matter particles could lose mass due to an unseen "dark force." This research adds another layer to our understanding of the universe. Read more about this fascinating concept here.