1.) Converging lenses sometimes create an inverted image of the object. For example, when light enters the lens of our eye, an inverted image of the object we are looking at is formed at our retina. Why do you think we don't see everything upside down?

2.) Consider this hypothetical scenario: suppose an alien species from a distant planet arrives on earth. The aliens have three color receptors in their eye, similar to humans, but the spectral sensitivity of the different receptors does not overla.

a.) How would the alien's color v be different from our own?

b.) How might this affect the ensuing diplomatic negotiations between the airns and the earthling?