The Invisible Gas That Gave Us Galaxies

The video explores the intergalactic medium (IGM), a vast, invisible gas filling the space between galaxies. Discovered in the 1960s through quasar observations, the IGM is mostly hydrogen with some heavier elements. It plays a crucial role in understanding galaxy formation and evolution. The IGM's spectra reveal information about the early universe, including the formation of the first galaxies. Galaxies engage in a cycle of gas exchange with the IGM, known as galactic recycling, which is vital for star formation. However, the reasons behind galaxy death remain unclear, prompting further research into the IGM's role.

How can studying the intergalactic medium help us learn about the early universe?

In what ways do galaxies interact with the intergalactic medium, and what implications does this have for their evolution?

What challenges do astronomers face in understanding why some galaxies stop forming new stars?