# The Expansion of the Universe: From the Hubble Law to the Hubble Space Telescope, and Beyond(!) ## **About Hubble’s Law** Hubble’s Law shows our Universe to be ever-changing, expanding its limits in space and time simultaneously. These findings were revolutionary in the 1920s. Read on to learn why. ## **What did Hubble do, and how did he find his Law?** In 1929, the American Astronomer Edwin Hubble made a simple graph showing that galaxies farther from each other move away from each other systematically faster. He drew a simple straight line on the velocity vs. distance plot shown here, summarizing the trend that now bears his name as “Hubble’s Law.” The law, represented today as: *Velocity= (Hubble’s Constant) x Distance* implies that the Universe is expanding, and Hubble’s Constant measures how fast. ## **How do Hubble’s galaxies look through the Hubble Space Telescope?** In this [interactive version](https://www.thinglink.com/card/1295138622952964097) of Hubble’s graph, based on his original [published](https://ui.adsabs.harvard.edu/abs/1929pnas...15..168h/abstract) figure, **yellow** circles mark individual galaxies, and **green** labels show identifiying [NGC numbers](https://en.wikipedia.org/wiki/New_General_Catalogue) (or names) for each galaxy. Click on a yellow circle to learn more about each galaxy and see a Hubble Space Telescope image of it superimposed on all-sky images. \[clicking online graph goes to \]