Light matter is the matter that brightness of the Sol. This concept created by AarexWikia04.

Because of light matter's emission of energy, over time it will decay into other materials such as ordinary matter, dark matter or matterium. The larger surface area to volume ratio means that large chunks of light matter will decay more slowly than small chunks, and also that the decay rate of light matter drops off with temperature (with very hot light matter possibly increasing in mass).