The prestigious award, often referred to as the Nobel Prize of mathematics, was given to Lars Ahlfors in 1936 and continues to inspire awe. No other Finn has received the medal since Ahlfors.
A replica of the medal is on public display at the Kumpula campus, in a glass case next to the door of the lecture hall named after Lars Ahlfors in the Exactum building. For a while, there was some uncertainty within the Department of Mathematics about the location of the original medal. According to Tuomas Hytönen, it was supposed to be in a safe in the basement of the Exactum building. However, the safe was empty. A round of phone calls confirmed that the medal was in storage at the University Museum. Hytönen wanted to see it with his own eyes.
The Medal Briefly Ended Up in a Pawnshop
Lars Ahlfors, a pioneer in the field of complex analysis, moved to Stockholm during the war and had to pawn his medal to support his family. In 1944, Ahlfors moved to Switzerland and was invited to Harvard the following year. By then, his financial situation had improved, and he took the medal with him to the United States, where he worked at Harvard until retiring at the age of 70. After retirement, Ahlfors moved to Boston, where he continued his mathematical research until his death.
Mathematician and academician Olli Lehto wrote about Ahlfors’ life’s work in the 1/2007 issue of Tieteessä tapahtuu magazine, describing the final chapter as follows:
“His (Ahlfors’s) life ended on October 11, 1996, in Pittsfield, Massachusetts. Ultimately, Lars and Erna Ahlfors returned to Finland in the autumn of 2004. According to their wishes, their daughters and their families came to Finland and placed Lars and Erna’s urns in the Ahlfors family grave in Hietaniemi. The trip was timed so that the daughters could attend the inauguration ceremony of the new Exactum building of the Department of Mathematical Sciences, where they donated their father’s Fields Medal to the University of Helsinki.”
The Medal Found Its Place of Honor
The medal was given a place of honor in 2007 at the Arppeanum in an exhibition titled “Mathematics – Tradition and Applications”, held in celebration of Ahlfors’ 100th birthday. Matti Lehtinen described the exhibition in the Solmu mathematics magazine with a touch of mystery:
“The original medal is usually kept in a safe, and a replica is on display in the lobby of the university’s Department of Mathematics at the Kumpula campus. The real and original medal can now be seen for a while at the Arppeanum before it is once again locked away. The locks seem to be well-suited for their purpose, as opening the cabinet and retrieving the medal for the exhibition proved to be a challenge.”
Museum curator Helena Hämäläinen hands Tuomas Hytönen the medal retrieved from deep within the storage. The medal must not be touched with bare hands, so Hytönen has put on rubber gloves.
Size of the medal:
- Diameter: 6.3 cm
- Edge height: 0.3 cm
- Weight: 154 g
A suspicion arises about the authenticity of the medal, as according to the International Mathematical Union (IMU), the Fields Medal should weigh 169 g. The diameter is also supposed to be slightly larger. Fields Medal | International Mathematical Union (IMU)
It remains unresolved whether the medal was at some point replaced or whether the goldsmiths of that era were simply less precise. Tuomas Hytönen performs a quick calculation that suggests the medal is made of genuine material. However, calculations alone cannot definitively prove its authenticity.
“Based on these measurements and assuming the medal is of uniform thickness, I calculated its density to be 16.47 g/cm³. The density of gold is 19.32, silver 10.49, and copper 8.96. As a gold-silver alloy, this would correspond to about 16-karat gold; as a gold-copper alloy, about 17-karat. In reality, the medal is thicker in the middle, so the actual density and gold content are slightly lower than this estimate. The website’s claim of 14-karat gold therefore seems quite plausible,” Hytönen explains.
The museum’s conservation and collection facilities are located in Vantaa, but the new exhibition of the Helsinki University Museum Flame has opened in the university’s main building.
“Unfortunately, Ahlfors’ medal is not on display in the current exhibition but remains in storage,” says museum curator Helena Hämäläinen.