It’s November 30th 2020, which means we have just three teaching weeks to go until the end of term. I am currently teaching two modules: *Mechanics 1 and Special Relativity* for first-year students and *Vector Calculus and Fourier Series *for second years. We’re now getting to the “and” bit in both modules.

I didn’t want to present the two topics mentioned in the title of the second year module as completely disconnected, so I decided to link them with a lecture in which I use the divergence theorem of vector calculus to derive the heat equation, the solution of which led Joseph Fourier to devise his series in *Mémoire sur la propagation de la chaleur dans les corps solides* (1807), a truly remarkable work for its time that inspired so many subsequent developments.

That gives me an excuse to repost the following “remarkable” poem about Fourier by William Rowan Hamilton:

In the first-year module I will be spending most of this week talking about potentials and forces before starting special relativity next week, at the proper time.

*This day and age we’re living in*

*Gives cause for apprehension*

*With speed and new invention*

*And things like fourth dimension*

*Yet we get a trifle weary*

*With Mr. Einstein’s theory*

*So we must get down to earth at times*

*Relax relieve the tension*

*And no matter what the progress*

*Or what may yet be proved*

*The simple facts of life are such*

*They cannot be removed*

As time goes by, the other thing drawing nigh is the loosening of Ireland’s current Level 5 Covid-19 restrictions which were imposed about six weeks ago though, judging by the crowds drinking in Courthouse Square on Saturday night, a lot of folks have thrown the rules out the window already.

I think it’s a dangerous time. The daily cases are still hovering around the 250-300 mark and will undoubtedly start climbing even before Christmas itself:The chances of us getting back to anything normality during the early part of next year are exceedingly slim.

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