2022

This semester we are continuing to perform research for DARPA on analytical methods for hypersonic aerodynamics. It is a difficult task. My new students are transitioning well and former students are excelling in their new careers. I am teaching a new course on turbulence modeling. This should be placed online for everyone near the end of the spring semester 2022.

Foundations of Turbulence

The mathematical formulation of the problem of homogeneous turbulence is this: Given an infinite body of uniform fluid in which motions conform to the equations and, and given that at some initial instant the velocity of the fluid is a random function of position described by certain probability laws which are independent of position, to determine the probability laws that describe the motion of the fluid at subsequent times.

G. K. Batchelor in the Theory of Homogeneous Turbulence

On Nonsense

There is no reason to suppose that Carroll was in the slightest degree evasive in denying that he had intended his poem to mean anything at all. But, as he himself pointed out, words can mean much more than a writer intends. They can express meanings buried so deep in an author’s mind that he himself is not aware of them, and they can acquire meanings entirely by accident. Nonsense writing is a peculiarly rich medium for both types of “unintended” meaning.

Martin Gardner in the Hunting of the Snark