h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Well done Orcus, correct.

The black body used is in fact white platinum, and there will be a CCR* rating for the lights somewhere (even if it isn't on packaging you, the public, get to see).

It's sad that I remember this guff after so many years, it really is!


*Colour Correlation Ratio.

Gnomon (post 13, nightlight):

Some years ago (10?) in the US there were flat panel low power lights available which were sufficient for that purpose for a, say, 2 or 3 x 1 yard area.
They seemed to be LCD panels about 3" square & 1/4" thick, greenish light. I say LCD but may be LED. After a while, dead, tiny points, then patches appeared - a few years, I was told. Not expensive to replace when about 50% had gone dark.
The problem would be when plugged in - UK plugs are so much deeper than US.
At the time they were left plugged in permanently & used an amazingly small amount of electrickery.

I'm pretty sure I've seen them in UK but can't remember where. (does that help, I wonder?)

In NZ you new houses tend to have LEDs fitted into the walls for that purpose, with a wall switch.

My sister uses solar torches( no idea of the English word for that). They load energy during the day and when it gets dark, about 10,( summertime) they start to illuminate the patio. They put themselves off with the first sun rays. They have an atractive design and the light is bluish-white, perfect for those hot long summer nights al fresco. YOu only need the light to take YOUR beer and little more.

At home, I don´t put off the light of the kitchen until bed time. I´ve heard a lot of times in the media that the main use of energy is the moment when you switch the light on; so it is better to leave it on instead of putting it off/on all evening.

***
What do you thing of solar energy?

Traveller in Time watching television
"The Mythbusters did some tests with switching/ leaving on the lights.

There is only a very short moment of increased power use on switching on any light. Worst are fluorescent lights, you have to leave them off at least 0,3 seconds to compensate for the ignition power.

They also did some tests concerning life span and again the difference was neglectible, incandecent lights die first, leds slowly fade away switching them on and off is not a factor in their life span.

The research was limited to a single light of any type for each destructive test. "

I have a torch which advertises itself as having a "white LED", but definitely shines with a blue light.

It's powered by Daz

IIRC 'white' LEDs are usually blue ones with a white phosphor coating, in the same way as CFLs. Bit tricky getting a single LED to emit all those different wavelengths...