Bluebeard

Thanks to all of you who sponsored me to have my beard dyed blue in aid of Practical Action. This charity was called Intermediate Technology and was supported in the 1980s by some of my heroes. It works to use sensible technology to make life better for poor people in remote places. As such, it is a good outworking of Physics principles. I'm raising money for solar powered wells.
The dye experiment has been problematic. We put on three lots of dye but I was left with a pale turquoise "blue rinse". Beard hair is too strong. I've been told that peroxide bleaching would break up the hair allowing it to absorb more dye. I've tried the chemists but you can't buy it any more following high profile bomb plots. However I have learned a lot about Chemistry in the process. I'll keep you posted...

Water meter

It hasn't rained very much in the south for months. Funnily enough, the only day of rain coincided with our visit to Oxford! It has become common to have a water meter if you don't have many people living in your house. I was interested to note that the volume was measured in cubic metres. Note from the photograph that it measures to the nearest 1000th of a cubic metre, which is actually a litre. You are not billed to that precision though.
The booklet that came wih the metre alarmed me. The number of people is a discrete variable and so this data should really have been plotted as a bar graph. Whereabouts should one person read their typical usage volume??