Simon Avery wrote:

The Natural Philosopher wrote:

Hello The


We have a glass block wall in our kitchen, and would
really like to put a blue light behind it. I am thinking
some sort of neon / fluorescent (sp?) light would look


TNP| I think blue is argon, or mercury vapour actualy, neon is
TNP| mainly orange.


This was explained recently on a kiddies program in a way that even I
kinda got the idea - it /is/ Neon. What happens is that Neon also
emits shedloads of ultra violet light. To get different colours, the
inside of the tube is coated with pigments that react in different
colours when energised by ultraviolet.

So the neon creates ultraviolet.
The UV transfers energy to the coating.
Coating glows and emits colour of choice.



I think not actually. In the USA any fluorescent light is called a
'neon' light, and what you have descrbed is what we call fluorescent
lights. They are normally filled with mercuty vapiour and an inert
halodegn as well - I think argon normally. The tubes are caietd with
phosphors to re-emit UV in the visible spectrum.

Traditionally what WE call a 'neon light' is a pure discharge tube - not
a coated one - of which the original ones were red/orange and contained
neon. The sort used to make advertising signs. I don't know what gasess
are in the red, blue green and yellow ones, but I am pretty sure it
ain't neon.