by Qcmbr 27 Replies latest jw friends
Purely guessing here but I was thinking,
calcium chloride and sodium carbonate when mixed make chalk so maybe either the chlorides or purely the strong alkaline of the calicium carbonate may have some kind of bleaching effect.
If my theory is correct, an analogy would be looking into a bucket of soap and asking why it is so clean.
Chalk (or any other 'white' substance) appears white (or whitish) when two conditions are true:
No no look!
RED GREEN YELLOW!!!
Evanescence
I used to eat chalk in kindergarten. It wasn't half bad.
Sunlight is made a mixture of seven colours (as can be seen in the rainbow where they get separated by a natural process)and if all seven colours get reflected by an object then it appears white, if it absorbs all of them it appears black.
So white chalk reflects all sunlight colours.
Evanescence,
Chalk may appear red, green, blue, or some other colour other than white when one or both of the two conditions I stated are not met.
Specifically, if the light is not composed of the full visible spectrum (and is therefore coloured), or if the pigments in the chalk absorb part of the light spectrum, it will not appear white.
Sunlight is made a mixture of seven colours (as can be seen in the rainbow where they get separated by a natural process)and if all seven colours get reflected by an object then it appears white, if it absorbs all of them it appears black.
Sunlight is composed of more than the visible spectrum (for example if also includes ultraviolet light), and the visible part of the light is a 'spectrum' of colours, not seven discrete colours. Because the wavelengths of different coloured light differ, when light is refracted through water droplets in the atmosphere, the different colours of light are bent at different angles, causing them to appear independantly, producing the familiar rainbow.
So white chalk reflects all sunlight colours.
White chalk reflects all colours of light from lightbulbs too.
Ah so we got ourselves some tricky chalk do we?
They may appear pink, blue, purple or red but if you look beyond what you see you'll see the truth those chalks are hiding something!
Evanescence
