Radioactivity in old camera lenses is due mostly to the widespread use of thorium glass elements in the 1940s, ’50s, ’60s and ’70s. Thorium oxide is highly refractive and low dispersion; this translated into cheaper high-quality glass by allowing manufacturers to make lenses of lesser curvature.
It may be a false colour, near-infrared image, but nonetheless this hurricane – the eye of which is some two thousand kilometres across – that is currently raging in Saturn’s atmosphere, would be truly fearsome no matter which way you were looking at it.
Dietmar Eckell, a German photographer based in Thailand, has assembled an impressive collection of images of aircraft wrecks from across the world. The photos are to be featured in a book, “Happy Endings”, that Eckell plans to publish.
As the title suggests, the passengers and crew survived the crashes that brought each of the aeroplanes they were aboard to grief, and its these stories that Eckell now hopes to tell.
Almost 23 years after reunification, differences between the east and west of Berlin remain apparent, especially when seen from Earth orbit after dark, as this photo by current ISS commander Chris Hadfield makes clear.
It looks as if the east side of the German city continues to use street lights dating from the Cold War era, which are seemingly still going strong.