- 1610: Galileo
- 1676: Ole Rømer
- 1687: Isaac Newton
- 1781: William Herschel
- 1838: Friedrich Bessel
- 1861: William and Margaret Huggins
- 1912: Henrietta Leavitt
- 1917 Einstein
- 1920: Harlow Shapley
- 1929 Edwin Hubble
- 1948: Ralph Alpher
- 1949: Fred Hoyle
- 1963: Maarten Schmidt
- 1964: Arno Penzias and Robert Wilson
- 1978: Vera Rubin and Kent Ford
- 1989: Margaret Geller and John Huchra
- 1992: John Mather and George Smoot
- 1995: Robert Williams
- 1998: Saul Perlmutter and Brian Schmidt
- 2010: Wendy Freedman
1920 Activity: Inverse Square Law
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This chart shows the inverse square relationship for a larger range of distances. For example, imagine two Cepheid variables that have the same period, and therefore the same brightness. Star A is nearby and known to be 10 light years distant. Star B is in a globular cluster and is 40 times fainter. The chart shows that a difference of 40 times in brightness corresponds to a difference of 6.3 in distance. So the globular cluster must be 63 light years away.
Use the chart or calculate to figure out the following distances, then place your mouse over the Answer button to see if your answer agrees with the experts.