Why are some measurements standard and others vary?
Time: 24 hours in a day(thank the Egyptians and Greeks), 60 minutes in an hour, 60 seconds in a minute. Is that standard? do other cultures hold different things.
Distance: Obvious mile vs. kilometers. English vs. Metric system. Why do these vary and not time? or does time vary also.
Money: Are there any monetary systems that are not base 10? (Other than those based on teeth...Speaking of which, do those actually exist?)