Newton’s Law of Cooling

dӨ/dt = -k(Ө –S)

As always, a lovely morning at Emsworth.  Showery weather and a popular sporting event conspired to keep people away in their droves, but it was all good fun, and a  chance to catch up with fellow stall-holders.  Actual sales were few, but I did receive a commission to make two  lamp holders based on the shape and size of one of the large garden pots, and I shall enjoy making them. One of the sales was the mug referred to in an earlier post. The purchaser recognised the formula – Emsworthians are smarter than Wodehouse would have you believe, although Jeeves might well have known the basics of differential calculus.

What Changes as Time Passes?

A good friend of mine commissioned a set of mugs for a relative of his who was about to embark on a  degree course. Each mug boasts a famous  bit of Mathematics in gold lettering, and this one was especially apposite. Answers on a postcard please for what the complete formula is, and whose formula it is (Terry, you are banned from taking part!)