Sir

Countries that have adopted the euro as currency no longer commemorate their national identity with famous cultural figures on their banknotes: a sad loss. Gone, for example, are great scientists such as Carl Friedrich Gauss, who was portrayed on Germany's 10-mark note, Pierre and Marie Curie from France's 500-franc bill, and Alessandro Volta, with the demise of Italy's 10,000-lira note. For different reasons, Yugoslavia's ten-billion-dinar note honouring Nikola Tesla has also disappeared.

Happily, 2009 is witnessing a revival of 'scientific' banknotes — and not just in the United Kingdom, where the Bank of England's £10 note reminds us of the bicentenary of Charles Darwin's birth. The Republic of Turkey's latest banknotes depict Turkey's founder Mustafa Kemal Atatürk as before, but on the back they show portraits of notable intellectuals. For example, the Turkish 5-lira note commemorates Aydin Sayili (1913–93), a science historian who won a state-supported scholarship under George Sarton at Harvard University as a result of a chance meeting with Atatürk. The same banknote carries schematics of the Z-form of double-stranded DNA, rich in G–C base pairs, and a beryllium atom with orbiting electrons, both of which are echoed on a hologram foil strip on the right of the face sheet. The carmine 10-lira note portrays the Turkish mathematician Cahit Arf (1910–97) — known for his invariant, which is applied in knot theory and surgery theory — with geometric figures that are also reproduced on the hologram foil strip.

This departure reflects the significance paid to science and educational development in Turkey. The new notes delight scientists but they should also inspire young minds — in contrast to the depersonalized euros of a unified Europe, which just indicate denominations of currency.

Turkey has more than 100 universities, both state and private, most of which were set up during the past 15–20 years. These employ some 10,000 professors, many of whom have worked abroad. Against this thriving background, it is anticipated that Turkey's new banknotes will retain their value for a long time to come.