“The FRBs (fast radio bursts) shine through the fog of the intergalactic medium, and by precisely measuring how the light slows down, we can weigh that fog, even when it’s too faint to see,”

The results revealed that 76 percent of the universe’s normal matter lies in the space between galaxies, also known as the intergalactic medium. About 15 percent resides in galaxy halos, and the remainder is concentrated within galaxies—in stars or in cold galactic gas. This distribution lines up with predictions from advanced cosmological simulations but has never been observationally confirmed until now.