The Magnus Effect
A great day for Computational Fluid dynamicsists, of which one area of my research expertise is in (the other being magnetostatics). Heinrich Gustav Magnus helped to explain an effect that now bears his name and allows the world to appreciate sport; what do I mean by that, you may ask? Well, Magnus helped to explain why when a forward-moving object (which is also spinning on an axis through it) giving rise to different pressures on either side of the object (typically a spherical ball) arcs or bends or swerves.
I am sure that Rafael Nadal (1986-) or Roger Federer (1981-) or Christiano Ronaldo (1985-) are unfamiliar with this law yet they use it to their advantage with a great deal of precision. A pressure difference can also be very useful, for example when such a difference exists on the top and bottom cambers of an airplane wing which is quite fortuitous as it keeps the plane aloft.
From Pressure Law to Water Molecule Discovery
Now Magnus studied with Jons Jakob Berzulius (1779-1848) and then with Joseph Louis Gay-Lussac (1778-1850) who is often credited for arriving at what is often called the pressure law for an ideal gas and which follows from the ideal gas equation PV=nRT (where symbols have their usual meaning). The law itself can be derived when V (and consequently the mass of gas) are held constant. In passing the name Gay-Lussac is one of the 72 great French Mathematicians, Engineers and Scientists who are on the Eiffel Tower, which I had the pleasure of viewing in 2008 when I went to watch the French Open final between Nadal and Federer (wow, this post really has a tennis undertone).
I do have one qualm about these names, however, which is the inclusion of J. Lagrange (1736-1813), who I have discussed on many occasions, not that I doubt his right to inclusion, only that he was, in fact, Italian (but he was later naturalized as French). Gay-Lussac was also responsible for realising that water consists of a molecule containing two hydrogen atoms and one oxygen atom, no mean feat making him a Chemical “Giant” to be revered.
Unsung Hero of Fluid Dynamics
Magnus went on to set up the best-equipped laboratory in Germany in the 1840s and, due to his exceptional teaching prowess, was able to attract great scholars to join him; one who springs to mind is Herman Helmholtz (1821-1894), whose equation I was led to during a separation of variables solution in my PhD thesis after first arriving at the Euler (1707-1783)-Poisson (1781-1840) -Darboux (1842-1917) equation. Poisson, by the way, is one of the 72 heralded on the Eiffel Tower, but amazingly, Darboux is not.
Magnus is perhaps not so well known as some of the other “Giants” that I have discussed, but being a fluid dynamicist, I had to pay homage to my “old friend”.
