Unveiling the Mysteries of Dark Matter and the Universe's Earliest Galaxies with the World's Largest Radio Telescope

Scientists are proposing to use the 21-cm forest, a feature of light absorption by hydrogen surrounding early galaxies, as a probe to investigate the mysteries of dark matter and the formation of the universe's first galaxies. Dark matter, which makes up 85% of the matter in the universe, does not interact with light, making its nature and role in galaxy formation unknown. The Square Kilometre Array (SKA), the world's largest radio telescope, could soon make it feasible to detect and study the 21-cm forest, providing insights into dark matter properties and the thermal history of the universe.