Cahit Arf

Have you ever tried completing a difficult puzzle? Mathematics is, in fact, a vast puzzle that helps us understand the secrets of the universe.Cahit Arf was one of history’s greatest puzzle solvers! He was a world-renowned Turkish mathematician who proved that mathematics is not merely about numbers but a matter of patience and discovery. Let us get to know this mathematical genius who smiles at us from our banknotes!

^{Cahit Arf portrait on the 10 Turkish Lira banknote (Photo: Şehrinaz İrem Canbaba)}

Cahit Arf was born in 1910 in Thessaloniki. Due to the wars of that era, he and his family were forced to move frequently. They first settled in Istanbul, then Ankara, and finally İzmir.

Cahit Arf was born more than a century ago, before the founding of the Republic of Türkiye! At that time, there were no smartphones, computers, or calculators as we know them today; all mathematical problems were solved using only paper, pencil, and mental power.

A very special event changed his life when he was still in fifth grade. A young teacher recognized his talent and encouraged him to tackle difficult geometry problems. This teacher’s support opened the door to a magical world. Soon after, he began solving problems that even his classmates found impossible!

^{(Generated by Artificial Intelligence)}

Seeing his extraordinary talent, his family sent him to St. Louis High School in France to receive a better education. Cahit was so intelligent and hardworking that he completed this demanding high school program in just two years, instead of the usual three!

After returning to Türkiye, he did not pause his scientific journey. He passed a special examination and completed his university education at the prestigious École Normale Supérieure in France, a renowned institution that trained many leading scientists.

After university, Cahit Arf went to the University of Göttingen in Germany to continue his research, where he worked with the highly famous mathematician Helmut Hasse. He tackled alone a complex topic that even other mathematical geniuses avoided as “too difficult,” and solved the problem in just a short period of one and a half years!

He discovered several unique mathematical terms named after him. These include the “Arf Invariant”, “Arf Rings”, and the “Hasse-Arf Theorem”, named jointly with his mentor. The formulas he discovered are still used today by scientists around the world to solve complex problems.

After his groundbreaking discoveries, Cahit Arf received numerous job offers from countries such as the United States and Canada. However, he chose to serve his own country and returned to Türkiye, where he worked as a professor at Istanbul University and Middle East Technical University.

He also played a major role in establishing TÜBİTAK, a vital institution supporting science in our country, and served for many years as Chairman of its Science Board. He firmly believed that becoming a scientist always requires great passion and patience.