PROGRESS IN ASTRONOMY

• THE 20TH CENTURY HAS BEEN A REMARKABLE PERIOD FOR ASTRONOMERS WITH NO SIGNS THAT THEY HAVE STOPPED MAKING FASCINATING NEW DISCOVERIES OR THAT THEY HAVE YET SOLVE ALL OF THE UNIVERSE MANY PUZZLES

ASTRONOMERS:
Henry Norris Russel

• showed that all the stars are going through a life cycle of birth, maturity and old age

Harlow Shapley

• used variable stars as yardstick to give the first good estimate of the enormous size of our own galaxy the "milky way"

Edwin Powell Hubble

• showed the some nebula's, faint and cloudy spots visible through telescope are actually extremely distant "island universe"