In the late 1980s Ahmed Zewail developed methods for studying chemical reactions in detail. Chemical reactions in which molecules held together by atoms meet and reorganise into new compounds are one of nature's most fundamental processes. However this transition happens too quickly for us to easily see - in a matter of femtoseconds. One femtosecond is 0.000000000000001 seconds, which is to a second as a second is to 32 million years. By using laser technology to produce flashes of light just a few femtoseconds long, Zewail was able to visualise these reactions in slow motion - and to see what actually happens when chemical bonds break and new ones are created. Zewail's experiments led to the birth of the research area called femtochemistry, which enables us to understand why certain chemical reactions take place but not others. Image: Ahmed Zewail at the Nobel Prize award ceremony in Stockholm on 10 December 1999. In a few hours we will be revealing the 2026 Nobel Prize in Chemistry - stay tuned.