Some people have the genotype for red hair in addition to genes coding for dark hair (more eumelanin production). In this case, the red hair would be "masked" by the dark hair and the person would appear to have auburn or brown/black hair. ...
So the light rays commonly originate from an energy source such as the sun or a lamp in your room. It’s important to note that theoretically a ray of light travels in a straight line and by the time you visually perceive an object, it is the rays of light reflected or scattered off ...