Thermocline

When the sun consistently heats the surface of a body of water two distinct layers can sometimes be created. This stratification is called a thermocline. Looking like a second water's surface this optical illusion can be deadly to scuba divers when it looks like they are reaching air and they haven't consulted their depth gauge. It is important to never rely too heavily on one perspective to determine the truth of the world. Rather than being subjective, truth is perspective.

Meeting a friend in the corridor, Ludwig Wittgenstein (1889-1951) said: "Tell me, why do people always say that it was natural for men to assume that the sun went around the earth rather than the earth was rotating?" His friend said: "Well, obviously, because it just looks as if the sun is going around the earth." To which the philosopher replied: "Well, what would it look like if it had looked as if the earth were rotating?"