LIGHT ON THE DISCWORLD
There are (at least) four forms of light on Discworld:
• common light — to see things by. Its speed was measured to be equal to that of sound by the Ephebian philosopher Febrius in his "Give me a shout when you see it, OK?" experiment involving two hills, a lantern, and an assistant with a very loud voice. Splits into eight colours (ROYGBIV+ octarine) in a strong magical field.
• meta-light — to see dark by. Widely used in the moving picture industry.
• dark light — absorbed by Uberwaldian Deep Cave Land Eels: light within darkness. Heaver than normal light so mainly found under the sea or in deep caves in Uberwald.
• light fantastic — not strictly light at all but the opposite of light: the light that lies on the far side of darkness.
Also related is
• dark — not the absence of light, as it is in Roundworld, but a thing in its own right. Relates to light as knurd relates to drunk (in which case Roundworld ‘dark’ is ‘sober’). Thanks to The Science of Discworld Chapter 22 we know that dark is a privative.
The speed of dark is known to be greater than that of light. It must be, otherwise the dark wouldn’t be able to get out of the light’s way.
This led to an epic discovery by the famous* Troll mathematical physicist Big Al Onestone, who originally worked as a clerk in a patient office†.
* Well, he was famous in Slakki
† A doctor’s waiting room, so named because you wait in it, and have to be patient.
He became famous when he devised his THEORY OF SPECIAL, GENERAL, AND TOTALLY INDISCRIMINATE RELATIVISM.
• common light — to see things by. Its speed was measured to be equal to that of sound by the Ephebian philosopher Febrius in his "Give me a shout when you see it, OK?" experiment involving two hills, a lantern, and an assistant with a very loud voice. Splits into eight colours (ROYGBIV+ octarine) in a strong magical field.
• meta-light — to see dark by. Widely used in the moving picture industry.
• dark light — absorbed by Uberwaldian Deep Cave Land Eels: light within darkness. Heaver than normal light so mainly found under the sea or in deep caves in Uberwald.
• light fantastic — not strictly light at all but the opposite of light: the light that lies on the far side of darkness.
Also related is
• dark — not the absence of light, as it is in Roundworld, but a thing in its own right. Relates to light as knurd relates to drunk (in which case Roundworld ‘dark’ is ‘sober’). Thanks to The Science of Discworld Chapter 22 we know that dark is a privative.
The speed of dark is known to be greater than that of light. It must be, otherwise the dark wouldn’t be able to get out of the light’s way.
This led to an epic discovery by the famous* Troll mathematical physicist Big Al Onestone, who originally worked as a clerk in a patient office†.
* Well, he was famous in Slakki
† A doctor’s waiting room, so named because you wait in it, and have to be patient.
He became famous when he devised his THEORY OF SPECIAL, GENERAL, AND TOTALLY INDISCRIMINATE RELATIVISM.