A main starting point for this kind of investigation i discovered was sitting down and thinking through what what do i know about luminous objects...

this is a list of things i came up with

  • Luminous objects can be charged up by light
  • they are often highly radio active
  • and in the dark are easily confusable with LED's
  • You often find them in nature e.g fungi
  • they may not appear to be luminous at all in the dark, and only under different lights e.g. purple light...
  • they can be commercially avaliable and can be bought cheaply e.g. kids glow in the dark stars
   Finally giving up on the list i decided to see what wiki had to say and so typed in 'Luminescensce' the site told me this basic info:
Luminescence is light that usually occurs at low temperatures, and therefore being cold body radiation. Luminescence can be created by chemical reactions, electrical energy, subatomic motions, or even stress on a crystal or other solids. The difference between luminescence and incandescence is that while luminescence is found at very low temperatures incandescence is light generated at high temperatures.
 So than they can be seen clearly and in the night, the dials, hands, scales and signs of aviation and navigational instruments and markings are often coated with luminescent substances, in a process known as luminising.
The following are types of luminescence:

Chemoluminescence
Bioluminescence
Crystalloluminescence
Electroluminescence
Cathodoluminescence
Mechanoluminescence
Triboluminescence
Fractoluminescence
Piezoluminescence
Photoluminescence
Phosphorescence
Fluorescence
Radioluminescence
Sonoluminescence
 and finally -Thermoluminescence
some of these are sub-types of others so I shall shortly cover what the main types are starting from the top of the list.