Bright idea
We’ve long lamented the decline of the incandescent bulb (take a look at our report on Swiss company Righi Licht in issue 88). The flat, harsh light of an LED simply can’t compete with the warm glow of a traditional light bulb, even if they are wasteful (more than 95 per cent of the energy they use tends to vanish as heat). But now out-of-favour filaments look to be making a comeback. Scientists at the Massachusetts Institute of Technology have shown that by surrounding the metal coil with a photonic crystal structure, energy that would be lost as heat can be bounced back to the coil and therefore saved. This “light recycling” innovation will, we hope, lead to renewed demand for the humble filament bulb and spell the end of those cold and clinical LEDs.