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Climate change

Climate change

On Tuesday I went to one of the general evening physics run by the local group of the Institute of Physics, mainly Paul Stevenson and others on the committee. Future talks here. It was on climate change and the figure that really stood out for me in the talk is above. It is taken from the newly released physical science bit of the 5th report of the IPCC (Intergovernmental Panel on Climate Change). Basically it shows the temperature averaged over the whole of the Earth and over a decade of time, as a function of time. I.e., the average temperature in the 1980s, in the 1990s, etc. The y-axis is in ÂșC and is I think the difference in temperature in a decade relative to the average temperature between 1961 and 1990.

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Ducklings demonstrating superposition

Ducklings demonstrating superposition

Semester 2 starts on Monday, so I’m revising my lecture notes for my course on partial differential equations. This includes what is called the principle of superposition, which underlies what we know as the interference of waves. This picture (from a user called Spiralz on Wikimedia) shows interference off beautifully. Perhaps this is clearest on the left at about the same height as the ducklings, where the waves set up by the rear duckling intefers with that of its mother to produce a cross-hatched appearance on the water surface due to the addition (superposition) of the two waves going in different directions at that point. Beautiful physics, cute ducklings, what’s not to like.