timsabre Posted April 12, 2012 Share Posted April 12, 2012 Why should changing the type of light source for bog standard street/road lighting reduce light pollution. If a particular amount and temperature of light has been deemed necessary then surely the source is irrelevant. One simply chooses the lamp that provides the required amount of light with respect to ones budget. .... Although having said all that, if we just switched all the street lights to cheap LED then light pollution would be reduced because the output of each fixture would be considerably less. :P LED is more "turn on and offable" so if suitable control equipment is also installed, that can reduce light pollution by dimming/turning off when not needed. And well-designed fixtures can reduce upward light spill. You can't do anything about reflection off the ground though. Hull University has just replaced all its campus road lighting with LED fixtures (from low pressure sodium) and the light levels are a lot higher (the ones which haven't failed yet - there was a noticeable number of early failures). Regarding motorways (and indeed other roads), I understand that they are lit because statistically it reduces the number of accidents. Link to comment Share on other sites More sharing options...
dbuckley Posted April 12, 2012 Share Posted April 12, 2012 Why should changing the type of light source for bog standard street/road lighting reduce light pollution. The heyday of good lighting from an astronomical perspective was the old yellow sodium lamps, as they produced a single wavelenngth of light. Its all been downhill from there. What is more important now is light dispersion from the fitting; the light should go where it is intended, and not just everywhere within a 180 degree (or worse) angle. Link to comment Share on other sites More sharing options...
themadhippy Posted April 12, 2012 Share Posted April 12, 2012 Day= lightnight= darkTurn em all off,vehicles have headlights,and the torches are available in most high street ,and all the shops and offices that at midnight are lit up like a pink floyd finale,what a waste of energy. Heard some silly bint on the news last night claiming vehicles are more likely to break down were theres no street lighting,do they make cars now that are scared of the dark? Link to comment Share on other sites More sharing options...
kerry davies Posted April 12, 2012 Share Posted April 12, 2012 Thanks Hippy. I heard that and put it down to my age and early onset. Alvar Liddell would have stabbed her in the eye with his cut-glass accent. They should either turn off all office lighting or create pretty patterns like the Shell building used to do at Christmas. Link to comment Share on other sites More sharing options...
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