posted on Dec, 24 2014 @ 06:04 AM
Common sense tells you the sky is up and the earth is down, but it is more like out and in from a perspective in orbit.
The earth looks flat too, like someone else pointed out, but you get into trouble with that when you have to map the curved surface.
Common sense is just being practical in your daily life, from a human point of view. It is flawed because of our perspective, but it works to keep you
out of trouble for the most part.