... What the heck IS it?
No, really: think about it - really think about what light is, what it means.
It's always there, even by proxy, i. e. by its very absence - but WHAT is it?
Light is defined as a wavelength visible to the eye.
But why is it visible to the eye?
And, more importantly, where does it come from?
I want you to think about it until you can think no more
(Maybe then you'll know. ;)
In the meantime, you gotta see this (and in the next nanosecond you shall, whether you want it or not):
