Dark matter, the universe’s most mysterious substance, appears to obey the laws of gravity even on vast cosmic scales. This discovery, made by researchers from the University of Geneva and the University of Portsmouth, could eliminate the possibility of a fifth fundamental force of nature—but doesn’t completely rule it out. If such a force exists, it would be extremely weak, no stronger than about 7% of the gravity we experience every day.
For decades, scientists have been trying to understand dark matter, the invisible substance that makes up about five times more mass in the universe than “everyday matter” like atoms and stars. We know that atoms are made of protons, neutrons, and electrons, and these particles interact via four known fundamental forces: electromagnetism, gravity, the strong nuclear force, and the weak nuclear (Continue reading)
