The Surprising Age of Galaxies: Only 100 Years Old
One hundred years ago, Edwin Hubble's photograph of the Andromeda nebula marked the discovery of galaxies and challenged the prevailing belief that the Milky Way was the entire universe. Hubble's calculation of the distance to Andromeda, about 2 million light-years away, revealed the vastness of the cosmos and led to the realization that there were other galaxies beyond our own. This discovery revolutionized our understanding of the universe and set the stage for further advancements in astrophysics.