The human eye and the colorful world long 5 Flashcards
Why don’t the planets twinkle?
The planets are much closer to the Earth. If we consider a planet as a collection of a large number of point-sized sources of light, the total variation in the amount of light entering our eye from all the individual point-sized sources will average out to zero, thereby nullifying the twinkling effect.
What is actual sunrise ?
The Sun is visible to us about 2 minutes before the actual sunrise and about 2 minutes after the actual sunset because of atmospheric refraction. By actual sunrise, we mean the actual crossing of the horizon by the Sun. The apparent flattening of the Sun’s disc at sunrise and sunset is also due to the same phenomenon.
When is the path of a beam of light passing through a true solution ?
The path of a beam of light passing through a true solution is not visible. However, its path becomes visible through a colloidal solution where the size of the particles is relatively larger.
