Luminous signs are easier to find when there is an emergency.
At the end of the nineteenth century, luminous signs were a new phenomenon.
neon
smoke and fire
curry
Luminous materials are substances that emit light after being exposed to a light source. This light emission can be immediate or can continue for a period of time after the light source is removed. Luminous materials are commonly used in safety signs, glow-in-the-dark products, and other applications where visibility in low light conditions is important.
they might cause fires
gives them thing to make fires and build tee pees
It would, indeed, be very useful for preventing fires. Basically it'll detect gas leaks, which are one of the most common sources of house fires.
It is luminous
Luminous.
It's non-luminous
A luminous ball of plasma is a hot, ionized gas that emits light and energy. Examples include stars like the Sun, which are giant luminous balls of plasma that produce light through nuclear fusion in their cores. Plasma balls can be observed in phenomena such as lightning, neon signs, and some types of artificial lighting.