Two ultradense stars collided and sent tremors through space. By matching those shivers with a map of millions of galaxies, scientists have just clocked the universe’s growth spurt with record precision. The result: 67.9 km/s per megaparsec—hinting at a way to solve the biggest argument in cosmology.
🎯 The term 'standard siren' echoes 'standard candle,' but while candles use light, sirens use gravitational waves—a clever twist on an old cosmic yardstick.