During the week of 8 August 1904, a small group of mathematicians and scientists gathered in picturesque Heidelberg, Germany, known for its baroque architecture, cobblestone streets, and castle ruins that looked as if they were still protecting the old city. Home to Germany’s oldest university, which was founded in 1386, Heidelberg was a natural venue for the Third International Mathematics Congress.
One of the presenters at the congress was Ludwig Prandtl, a 29-year-old professor at the Technische Hochschule (equivalent to a US technical university) in Hanover. Prandtl’s presentation was only 10 minutes long, but that was all the time needed to describe a new concept that would revolutionize the understanding and analysis of fluid dynamics. His presentation, and the subsequent paper that was published in the congress’s proceedings one year later, introduced the concept of the boundary layer in a fluid flow over a surface. In 2005, concurrent with...
