Category Archives: Science & Technology

Jews in the World of Science and Technology

Jew of the Week: Erwin Chargaff

Discovering DNA Structure

Erwin Chargaff (1905-2002) was born in what is now Chernivtsi, Ukraine (then part of the Austo-Hungarian Empire). His family was of the little-known Bukovinian Jewish community that blended elements of Ottoman, Romanian, Austrian, and Ukrainian culture and had a mix of Ashkenazi and Sephardi heritage and practice. During World War I, the family moved to Vienna, where Chargaff went on to study chemistry. In 1925, he took a job as professor of organic chemistry at Yale University. He moved to the University of Berlin in 1930 to head the chemistry lab for the bacteriology and public health department. During this time, he made some important findings about bacterial membranes and lipids. When the Nazis came to power, Chargaff was forced to resign and fled to Paris. After spending a couple of years doing research at the Pasteur Institute, Chargaff returned to the States to become a professor at Columbia University for the next four decades. This is where he did some of his most famous work, including on the mechanism of blood clotting. His main focus, however, was on the chemistry of mysterious DNA. He soon discovered that DNA always contained equal amounts of the nitrogen bases adenine and thymine, and equal amounts of cytosine and guanine, suggesting that the two sets pair up. (This would become known as the first of “Chargaff’s Rules”.) His 1950 paper was instrumental in allowing Watson and Crick to solve the puzzle of DNA structure just a few years later. In fact, it was a conversation that Chargaff had with Watson and Crick in 1952 which led them to deduce DNA’s double-helix structure. Not surprisingly, Chargaff protested when Watson and Crick won a Nobel Prize while he was excluded. Chargaff did win many other prizes, including the Pasteur Medal, the Heineken Prize, and the National Medal of Science. After retiring from Columbia, he continued to do research at the Roosevelt Hospital until the age of 87! Chargaff was highly critical of genetic engineering and biotechnology, saying that it would inevitably be abused and lead to a “molecular Auschwitz”. (Many today would say he was right!) Chargaff is often considered one of the fathers of biochemistry, and “Chargaff’s Rules” are still a fundamental concept taught in biology classes today.

Lag b’Omer Begins Saturday Night!

The Hidden History of Lag b’Omer

Reincarnation in Judaism (Video)

Words of the Week

There are two nuclei that man should never have touched: the atomic nucleus and the cell nucleus. The technology of genetic engineering poses a greater threat to the world than the advent of nuclear technology.
– Erwin Chargaff

Jew of the Week: Daniel Kahneman

In Memory of a Nobel Prize-Winning Researcher

Daniel Kahneman (1934-2024) was born in Tel-Aviv to Lithuanian Jews who made aliyah from France. His uncle, Rabbi Yosef Shlomo Kahaneman, was the head of the famed Ponevezh Yeshiva. Kahneman spent much of his youth in Paris—including during the Holocaust years under the Vichy regime—before returning to Israel in 1948. He studied psychology and mathematics at Jerusalem’s Hebrew University, and later became a psychologist for the IDF, where he developed the standard recruitment interview. Kahneman then moved to the United States to study at UC Berkeley, and earned a Ph.D in psychology in 1961. He returned to Jerusalem to teach at Hebrew University, and was also a visiting professor at the University of Michigan and at Harvard. He researched a variety of fascinating subjects in cognitive psychology, including attention, judgement, memory, biases, happiness, and decision-making. His key conclusion was that people are actually not rational decision-makers, and tend to make counterproductive choices based on biases and preconceived notions. His classic 1998 paper on the “focusing illusion” demonstrates how people tend to overestimate a single factor when predicting happiness. For instance, although studies showed that people across America had relatively the same levels of happiness, people would believe Californians are happier because they overestimated the effects of nice weather. Kahneman is perhaps most famous for his work in integrating psychology with economics, or “behavioural economics”, earning him the 2002 Nobel Prize in Economics. Over the course of his career, Kahneman also taught at Princeton, UC Berkeley, and the University of British Columbia. He wrote several bestselling books and was awarded numerous prizes and honorary degrees. Sadly, Kahneman passed away last week. He has been hailed as one of the most important thinkers of the 20th century.

Words of the Week

Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less.
– Marie Curie

From the Archives: In Memory of Joe Liberman

Jew of the Week: Isaac Judaeus

The Caliph’s Doctor and the Father of Kabbalah

A 13th-century illustration of Isaac Israeli from a Latin translation of his “Book of Fevers”

Itzhak ben Shlomo (c. 832-932) was born to a religious Jewish family in Egypt. He became renowned as the greatest physician in the country, and in 904 was hired by Prince Ziyadat Allah III. Several years later, he became court physician to Caliph Al-Mahdi Billah of the Fatimid Dynasty, based in Kairouan, Tunisia. Recognizing his immense wisdom, the Caliph made Itzhak (known in Arabic as “Abu Yaqub Ishaq ibn Suleiman al-Israili”, and in Europe as “Isaac Judaeus”) his leading advisor and tutor. Itzhak wrote numerous medical, astronomical, and mathematical treatises which transformed the scientific knowledge of the day. For instance, he is the first person in history to mention performing a tracheostomy. His works were widely distributed for centuries afterwards, and made up much of the medical curriculum of the Middle Ages. Itzhak was also a great philosopher, kabbalist, and mystic. He fused together Greek Neoplatonism with traditional Jewish mysticism, paving the way for the forthcoming explosion of Kabbalistic texts and Jewish mystical circles. His main disciple, Dunash ibn Tamim, wrote a profound commentary on Sefer Yetzirah, the most ancient of Kabbalistic texts. In addition to inspiring many rabbis, he was studied and quoted by great non-Jewish scholars like Thomas Aquinas and Roger Bacon. Among his many other writings is a deeply philosophical commentary on Genesis. In his day, Isaac Judaeus was the world’s leading sage, doctor, and scientist, and Arabic texts of the time refer to him as “master of the seven sciences” and “more valuable than gems”.

Why Did Muslims Rule the Holy Land for 1300 Years?

Words of the Week

We do not have to accept theories as certainties, no matter how widely accepted, for they are like blossoms that fade. Very soon science will be developed further and all of today’s new theories will be derided and scorned and the well-respected wisdom of our day will seem small-minded.
– Rav Kook, First Ashkenazi Chief Rabbi of Israel