We find out if street lights are affecting plants and birds. Plus we ask how high can a mountain be here on Earth?
It certainly isn't a lot of fun for moths which think they're navigating by the moon and end up going round and round a light instead. Ten years from now we'll hopefully be able to get rid of all these lights as everyone will be wearing glasses with built-in night vision. David Cooper, Fri, 31st May 2013
The only lighting that does not affect plants is the old mercury vapour, as most of the light output is in the green part of the spectrum, where the eye is most sensitive, and where plants are not photosensitive. They are not used as grow lamps at all, as the plants just wither and die under them unless they also get sunlight. Also have the benefit of a 20 year lifetime as well, but the need to recycle them is the only drawback.
Sean, that's not true. I grew a cheeze plant very successfully in a dark corner of my hallway under a low pressure mercury lamp. It had lush green foliage and reached 6ft under a single 80W spot lamp. The lamp came from a garden centre, sold as a 'daylight bulb'. Eventually it was the lamp that faded first, the output dropped too much and after 30 years the bulbs were not available, so I replaced it with daylight CFL lamps, which also worked.