The Cosmic Gas Mystery Unraveled

The universe is full of surprises, and one of its biggest puzzles has finally been cracked. For a long time, scientists have known that ordinary matter, the stuff we can see and touch, makes up only a small part of the universe. But where is the rest of it? This question has baffled astronomers for decades. Now, a breakthrough has been made. A group of astronomers have used something called fast radio bursts (FRBs) to track down the missing matter. These bursts are quick, bright radio signals that come from far-off galaxies. When these signals travel through the universe, they slow down as they pass through gas. By measuring this slowdown, scientists can figure out how much gas is out there. The findings are clear: most of the missing matter is in the form of hot, thin gas floating between galaxies. This gas is part of something called the cosmic web, a vast network of matter that stretches across the universe. The discovery provides the first detailed measurements of how ordinary matter is spread out in the universe. So, what exactly is this ordinary matter? It's made up of protons and neutrons, the building blocks of atoms. Everything we see around us, from stars to planets, is made of this stuff. But there's a lot more of it out there than we can see. A small amount is in stars and the space between them within galaxies. The rest is spread out in the space between galaxies. Previous studies hinted that this missing matter might be gas spread throughout the intergalactic medium. But it's hard to measure because it's so spread out. That's where FRBs come in. By studying 60 of these bursts, scientists confirmed that about 76% of all ordinary matter is in the intergalactic medium. The rest is in galaxy halos, stars, or cold galactic gas. This matches what computer simulations had predicted, but now there's solid evidence. The discovery also sheds light on how matter moves around the universe. Gravity pulls matter into galaxies, but supermassive black holes and exploding stars can blow it back out. This process acts like a cosmic thermostat, keeping the universe's temperature in check. The recent findings show that this feedback is very efficient, pushing gas out of galaxies and into the intergalactic medium. With more powerful telescopes on the way, who knows what other secrets the universe might reveal? FRBs are opening up a new way to explore the cosmos, allowing scientists to trace the invisible matter that fills the vast spaces between galaxies.