Sufficient criterion for pulling
This is the whiteboard of my officemate Alexandra Tzella, a postdoc at the University of Edinburgh working on fluid dynamics with Professor Jacques Vanneste. I liked the board for many reasons: the different colours that appeared after each new conversation, the lovely combination of algebra, analysis and ad-hoc diagrams, and of course the brilliant and rather racy title. Sadly Alexandra and Jacques were not investigating criteria for attracting the opposite sex in bars, but the criteria for determining the speed of a moving front (such as a fire spreading). It turns out that if the equation at the top is satisfied, then the speed of the front is determined by the behaviour of the fluid around a particular unstable fixed point.
[The part of the board spilling out on the left is mine – some residual calculations from the last Edinburgh MathsJam!]