Was the Milky Way galaxy formed from an expanding nebula?

No, the Milky Way galaxy was not formed from an expanding nebula. Instead, it formed through a process known as hierarchical clustering, where smaller clouds of gas and stars merged over billions of years to create larger structures. This process involved the gravitational attraction of matter in the early universe, leading to the formation of stars, star clusters, and eventually, galaxies. The nebular hypothesis primarily describes the formation of individual stars and planetary systems, not entire galaxies.