What do you think?
Rate this book


280 pages, Hardcover
First published March 14, 2008
The electric field of the incident sunlight causes electrons in the molecules to oscillate, and re-radiate the light; this is what is meant here by the word ‘scattering.’ The degree of scattering is inversely proportional to the fourth power of the wavelength of the light; blue light being of shorter wavelength than red, it is scattered the most. Consequently, we see blue sky except when we look in the direction of the sun at sunrise or sunset, where the long path through which the light passes depletes the blue light, leaving a predominately longer wavelength red light.
let’s start with some observational details, obtained from a study of more than fifty rivers by Luna Leopold and coworkers. They are of interest in connection with the apparent regular ‘sinuosity’ of rivers the world over. From their study of more than 50 rivers, the following statements can be made:
(i) No river, regardless of size, runs straight for more than 10 times its width.
(ii) The radius of a bend is nearly always 2-3 times the width of the river at that point.
(iii) The wavelength (distance between analogous points of analogous bends) is 7-10 times the (average) width.”