Lis Brack-Bernsen facts for kids

Lis Brack-Bernsen (born March 2, 1946) is a talented scientist from Denmark and Switzerland. She is a mathematician and a historian who studies the history of science, especially ancient Babylonian astronomy. She is a special professor at the University of Regensburg in Germany.

Becoming a Scientist

Lis Brack-Bernsen was born in Copenhagen, Denmark. She studied mathematics and physics at the University of Copenhagen, finishing in 1970. She then earned her Ph.D. in the history of mathematics in 1974 from the University of Basel in Switzerland. Her Ph.D. paper was about ancient Mayan tables.

After her studies, she worked as a researcher at different universities. These included the University of Copenhagen and Stony Brook University in the United States. She also worked in Grenoble, France, and Regensburg, Germany. However, she took a break from research to raise her family.

In 1997, she completed a special qualification called a habilitation at Goethe University Frankfurt. This allowed her to become a university lecturer. She moved to the University of Regensburg in 1999.

Discoveries in Ancient Astronomy

Lis Brack-Bernsen is known for her important work on Babylonian astronomy. She helped organize special workshops called the "Regensburg" series. These workshops brought together experts to discuss Babylonian astronomy. They had meetings in cities like Regensburg, Amsterdam, Durham, and Berlin.

Understanding the Lunar Six

One of Lis Brack-Bernsen's biggest discoveries was figuring out how Babylonian astronomers predicted the "Lunar Six". These were six time measurements related to the moon and sun. They are found on an ancient clay tablet called TU 11.

The Lunar Six measurements helped predict when the moon would rise or set compared to the sun. Four of these measurements were taken around the full moon. Two were taken around the new moon. For example, one measurement (ŠU₂) was the time from moonset to sunrise. Another (NA) was from sunrise to moonset.

Babylonian astronomers were very good at observing the sky. But they also developed ways to predict these values. This helped them even when they couldn't see the moon clearly.

Predicting Moon Movements

Brack-Bernsen found that the Babylonians used a special pattern called the Saros cycle to predict the Lunar Six. The Saros cycle is about 223 months long. After one Saros cycle, the moon and sun return to similar positions.

The Babylonians noticed that the moon's setting or rising time changed slightly each day. They could measure this change. Then, they used a formula to predict the Lunar Six values for a new month. They would take the old value from one Saros cycle ago and adjust it.

For example, to predict the NA value for the current month (n), they used the NA value from 223 months earlier (n-223). They would subtract one-third of the combined ŠU₂ + NA value from that earlier time.

• NA_n = NA_n-223 - 1/3(ŠU₂ + NA)_n-223
• ŠU₂_n = ŠU₂_n-223 + 1/3(ŠU₂ + NA)_n-223
• ME_n = ME_n-223 + 1/3(ME+GE₆)_n-223

This showed how advanced Babylonian astronomy was. They could predict complex moon movements.

Lunar Theory and Observations

Brack-Bernsen's work helped us understand how Babylonian astronomers used observations to create their "lunar theory." This theory explained the moon's movements. The Lunar Six values were very important for this.

The Saros cycle is about 6585 days long, plus a few hours. These extra hours change because of how the moon and sun move. The Lunar Six measurements helped astronomers understand these small changes. By combining these measurements, they could figure out how the moon's speed changed. This was called "lunar anomaly."

This discovery helped modern researchers understand ancient Babylonian texts better. It showed how their observations led to their complex predictions.

Awards and Recognition

In 2009, Lis Brack-Bernsen was chosen to be a member of the Academy of Sciences Leopoldina. This is a very respected science academy in Germany.

In 2017, a special book was published in her honor. It was called Studies on the Ancient Exact Sciences in Honour of Lis Brack-Bernsen. This book celebrated her important contributions to the field.

Selected Publications

Lis Brack-Bernsen has written many articles and books about her research. Here are a few examples:

Articles

• "On the Construction of Column B in System A of the Astronomical Cuneiform Texts" (1969)
• "Some Investigations on the Ephemerides of the Babylonian Moon Texts, System A." (1980)
• "Bisectable Trapezia in Babylonian Mathematics" (with Olaf Schmidt) (1990)
• "On the Babylonian Lunar Theory: A Construction of Column Φ from Horizontal Observations." (1990)
• "TU 11: A Collection of Rules for the Prediction of Lunar Phases and of Month Lengths" (with Hermann Hunger) (2003)
• "Eclipse Prediction and the Length of the Saros in Babylonian Astronomy" (with John M. Steele) (2005)

Books

• Die Basler Mayatafeln: Astronomische Deutung der Inschriften auf den Türstürzen 2 und 3 aus Tempel IV in Tikal (1976)
• Zur Entstehung der Babylonischen Mondtheorie: Beobachtung und theoretische Berechnung von Mondphasen (1997)