At California University San Diego, L Caldwell has made the blackest of paints for the Concentrating Solar Power Plants of her research project.
Sunlight is focussed on it from an array of mirrors on the ground. The secret of the new paint lies in nanotechnology – creating a surface made up of layers of microscopic particles. It is designed to minimise reflection.
The research team claims that it can convert up to 90% of the sunlight it captures into heat. “The size of these particles matches the wavelengths of light, which is in the order of a few nanometres”, Prof Chen says. “So when light gets in, it will get trapped. It’s as though it gets lost in a miniature forest, and never comes out”. Some compare this to an eclipse or Czech black theatre:
Cinema art can also retain high energy in its blackness:
but it’s not so easy to release it.
Meanwhile, NASA’s Spitzer Space Telescope and its Event Horizon Telescope team are looking for a black hole at the centre of the Milky Way galaxy. They have an infrared image which shows the challenge: NASA/JPL-Caltech