Resume Reading — The Shrinking Earth


The Shrinking Earth

The farther out we peer into the universe, the punier our home planet seems.

Click on each date for more information. Sources:3rd century BCE: Eratosthenes measures diameter of Earth…By Amos Zeeberg

Click on each date for more information.

3rd century BCE: Eratosthenes measures diameter of Earth

2nd century BCE: Hipparchus approximates distance to Moon

The Billion-Dollar Telescope Race

When Warner Brothers animators wanted to include cutting-edge astronomy in a 1952 Bugs Bunny cartoon1 they set a scene at an observatory that looks like Palomar Observatory in California. The then-newly unveiled Hale Telescope, stationed at Palomar, had a 5-meter-diameter...READ MORE

Measuring the Universe:

1672: Gian Domenico Cassini cracks length scale of solar system out to Saturn

Blind Watchers of the Sky:

1838: Friedrich Bessel makes first measurement to star besides the Sun

Measuring the Universe

1913: Ejnar Hertzsprung measures distance to nearby galaxy

How Old Is the Universe:]
Measurement of Starlight:

1924: Edwin Hubble measures distance to Andromeda, nearest spiral galaxy

Alan Hirshfeld:
How Old Is the Universe

1929: Hubble finds more distant galaxy & evidence for expansion of universe

Alan Hirshfeld
Edwin Hubble: Mariner of the Nebulae:
The Expanding Universe: Astronomy’s “Great Debate,” 1900-1931:>

1952: Walter Baade doubles size of known universe by reinterpreting star distances

Alan Hirshfeld…..61…97H/0000112.000.html….83…10H/0000022.000.html

1965: Radio telescopes pick up distant quasar…141.1295S

2012: Hubble Ultra Deep Field shows galaxies in universe’s infancy

Ethan Siegel:

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