Henrietta Leavitt Calibrates the Stars
3.09.2000

Humanity's understanding of the relative brightness and variability of stars was revolutionized by the work of Henrietta Swan Leavitt (1868-1921). Working at Harvard College Observatory, Leavitt precisely calibrated the photographic magnitudes of 47 stars to which all other stars could be compared.

Aristarchus' Unbelievable Discoveries
8.11.1997

Here lived one of the greatest thinkers in human history. Aristarchus lived on the Greek island of Samos, a small island in the center of the above picture that can be identified with a good map.

Hypatia of Alexandria
13.01.2002

Sixteen hundred years ago, Hypatia became one of the world's leading scholars in mathematics and astronomy. Hypatia's legendary knowledge, modesty, and public speaking ability flourished during the era of the Great Library of Alexandria.

Hypatia of Alexandria
27.01.1999

Sixteen hundred years ago, Hypatia became one of the world's leading scholars in mathematics and astronomy. Hypatia's legendary knowledge, modesty, and public speaking ability flourished during the era of the Great Library of Alexandria.

Albert Einstein Describes Space and Time
8.01.2000

Albert Einstein (1879-1955) is considered by many the greatest astrophysicist and single most significant Person of the 20th Century. He is pictured here in the Swiss Patent Office where he did much of his defining work.

Kepler Discovers How Planets Move
6.06.1999

Johannes Kepler used simple mathematics to describe how planets move. Kepler was an assistant to the most accurate astronomical observer of the time, Tycho Brahe. Kepler was able to use Brahe's data...

Isaac Newton Explains the Solar System
23.07.2000

Sir Isaac Newton changed the world. Born in 1643, Newton was only an above-average student. But he went home from Cambridge one summer in 1665, thought a lot about the physical nature of the world, and came back two years later with a revolutionary understanding of mathematics, gravitation, and optics.