:Fig. 35.3 As scientists learned more about space, the geocentric model of the universe gave way to the heliocentric model
? TEST TUBE 1. Make a timeline to illustrate how our understanding of the universe has changed over time. How the universe began
In 1927, astronomer Georges Lemaître (1894–1966) proposed that the universe started from a single point, which exploded and began expanding to become the universe. His theory was initially rejected by famous scientists, including Einstein.
In 1929, astronomer Edwin Hubble confirmed Lemaître’s idea that the universe is expanding when he observed that galaxies are moving away from Earth.
Hubble’s law states that the more distant a galaxy is from us, the faster it is moving.
)Fig. 35.4 Georges Lemaître Eureka
Edwin Hubble (1889–1953) proved that there are many more galaxies beyond our Milky Way, which had previously been mistaken for gas and dust clouds. The Hubble Space Telescope was named in his honour.