30 JAN 2015 by ideonexus
Science of the Rainbow
The spectrum depends upon light of different colours being slowed by
different amounts: the refractive index of a given substance, say glass or
water, is greater for blue light than for red. You could think of blue light
as being a slower swimmer than red, getting tangled up in the
undergrowth of atoms in glass or water because of its short wavelength.
Light of all colours gets less tangled up among the sparser atoms of air,
but blue still travels more slowly than red. In a vacuum, where ther...20 MAY 2011 by ideonexus
Color is the Light Beams Things Do Not Want
But the reflected light-waves do more for us than this. They not only make us see things, but they make us see them in different colours. What, you will ask, is this too the work of the sunbeams? Certainly; for if the colour we see depends on the size of the waves which come back to us, then we must see things coloured differently according to the waves they send back. For instance, imagine a sunbeam playing on a leaf: part of its waves bound straight back from it to our eye and make us see t...All other wavelengths are being absorbed.