A gentler way

I have been asked to write a piece about carbon offsetting: in particular, its merits and demerits. So here goes. Carbon offsetting is the practice of paying someone else to take action to reduce carbon emissions somewhere else in order to compensate for one’s own carbon-emitting activities. Offsetting may be done individually or collectively. I…

Weighing global matter over lunch Here’s an interesting example of the power of estimation. Anyone can calculate the Earth’s weight, approximately, sitting in a chair without recourse to a computer, or even paper. It’s a good lunchtime exercise. We just need a few rough facts: the volume of a sphere is about 4 times its…