Tag Archives: Astronomy

Jew of the Week: Abraham Zacuto

The Rabbi Who Saved Columbus

A page from Zacuto’s astronomical tables

Avraham ben Shmuel Zacut “Zacuto” (1452-1515) was born in Salamanca, in what is today Spain, to a religious Sephardic Jewish family. He studied both Jewish law and astronomy, becoming the rabbi of Salamanca and simultaneously an astronomy teacher. He invented a new type of astrolabe and a novel method for determining latitude at sea, which would become vital to navigators and sailors. In 1478, he published HaChibur haGadol, “The Great Book”, with detailed and easy-to-use astronomical tables. It was translated to Spanish in 1481, and Latin shortly after. This made Rabbi Zacuto world-famous and when the Jews of Spain were banished in 1492, he was immediately hired by King John II of Portugal to serve as his royal astronomer. Zacuto argued that a sea route to India was possible, and this convinced John II to finance Vasco da Gama’s famous voyage to discover the route to India, opening European sea trade with the Far East. Da Gama used Zacuto’s astrolabe and tables, and Zacuto personally trained and taught the sailors. Zacuto had also argued, based on the Zohar—the “textbook” of Jewish mysticism, dating back to Rabbi Shimon bar Yochai in the 2nd century CE—that the Earth must be spherical, and it would be possible to journey west, not east. This information was instrumental in convincing Christopher Columbus to launch his own voyage. In fact, Columbus relied heavily on Zacuto’s astrolabe and astronomical charts. In a well-known story from his third voyage, Columbus was marooned on a Caribbean island and facing both hostile natives and his own rebellious sailors. The natives refused to provide food and resources to Columbus, so he came up with a ruse. Consulting Zacuto’s tables, Columbus saw that a lunar eclipse was imminent. He told the native chief that if he will not provide resources to the sailors, the moon would go dark and God would punish them! The eclipse came and the natives panicked, giving Columbus’ men all that they needed to survive. Back in Europe, the next king of Portugal, Manuel I, followed the Spanish in expelling his Jewish subjects. Zacuto was offered to stay in Portugal if only he converted to Christianity, even just nominally. Of course, he refused, and left with his people. He first settled in Tunis, where he wrote his monumental Sefer Yuhasin, a highly-acclaimed work describing the entire history of the Jewish people. He later fulfilled his dream of making it to the Holy Land and lived his last years in Jerusalem. Rabbi Zacuto is considered one of history’s greatest and most consequential astronomers. The Zagut Crater on the moon is named after him.

Happy Lag b’Omer!

The Hidden History of Lag b’Omer

Did the Talmud Predict Today’s Crisis in Israel?

Words of the Week

The blessing in life is when you find the torture you are comfortable with. That’s marriage, it’s kids, it’s work, it’s exercise. Find the torture you’re comfortable with and you’ll do well. You’ve mastered that, you’ve mastered life.
– Jerry Seinfeld

Jews of the Week: The Minkowskis

Three Renowned Scientists

Hermann Minkowski

Hermann Minkowski (1864-1909) was born in what is now Lithuania, then part of Russia, and previously a part of Poland, to a wealthy Jewish family. His father was a merchant who paid for the construction of the famous Kovno Synagogue. In 1872, the Minkowskis fled the persecutions of the Russian Empire and settled in Germany. Hermann Minkowski went on to study mathematics and physics. In 1883 he won the Mathematics Prize of the French Academy of Sciences. He got his PhD two years later and taught at the Universities of Bonn, Konigsberg, Gottingen, and Zurich (where he was Albert Einstein’s teacher). Minkowski solved a number of big math problems, and actually improved upon Einstein’s theory of relativity, coming up with what is now called “Minkowski space-time”. He gave the mathematical proof for unifying space and time into a singular space-time continuum. Sadly, Minkowski met an untimely death at a young age from sudden appendicitis.

Oskar Minkowksi

His older brother was Oskar Minkowski (1858-1931), who studied biology and medicine. He went on to become a professor at the University of Breslau. (Since Jews were barred from holding such positions at the time, Minkowski had to nominally convert to Christianity.) In 1889, Minkowski did a number of operations on dogs and showed the link between the pancreas and diabetes. Together with Josef von Mering, Minkowski discovered how the pancreas controlled blood sugar levels, which later led to the discovery of insulin. Today, the Minkowski Prize is awarded each year for breakthroughs in diabetes research. His son was Rudolph Minkowski (1895-1976), who studied astronomy. He did important work dealing with supernovae, and later became the head of the famed Palomar Observatory, where he discovered a number of asteroids and nebulae. He also made important contributions in astrophysics, and won the Bruce Medal in 1961 for outstanding lifetime achievement in the field. The Minkowski Crater on the moon is named after him.

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Words of the Week

In God there is no time or beginning to start, for He always existed and is
everlasting and in Him there is no beginning or end at all.
– Rabbi Chaim Vital, Etz Chaim

Jew of the Week: Jeff Hoffman

NASA’s First Jewish Astronaut

Jeffrey Alan Hoffman (b. 1944) was born in Brooklyn. He was always fascinated by outer space, and went to study astronomy at Amherst College in Massachusetts. Hoffman went on to get a PhD in astrophysics from Harvard, researching cosmic x-rays and gamma rays. He built one of the first aerial gamma ray telescopes. After this, he did postdoctoral work in the UK, eventually working as a project scientist for the European Space Agency. In 1975, Hoffman returned to the US to work at MIT. His main area of focus was x-ray bursts, and he authored over 20 papers on the subject, becoming the world expert on it. One time, he heard his wife reading a passage in a book saying that there will never be a Jewish astronaut. This inspired Hoffman to pursue just that, and he applied to NASA. In 1978, he was selected for NASA’s astronaut training program, together with Judith Resnik. The two became NASA’s first Jewish astronauts. Hoffman went on his first mission in 1985 aboard the Space Shuttle Discovery, during which the crew deployed two satellites and conducted numerous scientific experiments. At this point, Hoffman became just the second Jewish man in space (following Russian cosmonaut Boris Volynov). During his fourth trip to space, Hoffman was responsible for repairing the Hubble Space Telescope. Before that flight, his rabbi asked him if he would take some Judaica with him, and Hoffman happily agreed. He took a mezuzah—which he affixed to his cabin with Velcro—a tallit, as well as a dreidel and mobile menorah, since it was during Chanukah. (Click here to see Hoffman spin a dreidel in space!) On another flight, Hoffman took a Torah with him and made sure to read it while flying over Jerusalem. During his last mission in 1996, Hoffman set a new record, becoming the first astronaut to spend 1000 hours aboard space shuttles. All in all, he spent more than 50 days in space, and logged over 21 million space miles travelled. Since retiring as an astronaut, he has been teaching as a professor at MIT, and visiting professor at the University of Leicester. He has also written a book called An Astronaut’s Diary.

When Jews and Greeks Were Brothers: The Untold Story of Chanukah

Words of the Week

…Science can only be created by those who are thoroughly imbued with the aspiration toward truth and understanding. This source of feeling, however, springs from the sphere of religion.
– Albert Einstein