Extra-galactic nebulae

"Extra-galactic Nebulae" by Edwin Hubble is a groundbreaking work that revolutionized our understanding of the universe. Hubble's meticulous observations of distant galaxies provided evidence for the expansion of the universe, leading to the formulation of Hubble's Law and the realization that the Milky Way is just one of many galaxies in the cosmos. In this classic book, Hubble presents his pioneering research on extra-galactic nebulae, laying the foundation for modern cosmology and changing our perspective on the vastness of the universe. Hubble's work continues to inspire generations of astronomers and remains a seminal contribution to the field of astrophysics.