My friend Katherine emailed this photograph of light striking one of my paintings 10 713.4km away, on the other side of the world. . .
If the speed of light = 299 792 458 miles - or 482 469 194 kilometres - per second, how long would it take light to travel the distance between Cape Town and Dunedin? (It's late. I will have to wait till morning before attempting this sum - unless there's someone out there willing to give it a go?).