Can you answer the following Fermi question: How many people worldwide are having sex right now this minute?

In physics, particularly in physics education, a Fermi problem, Fermi question, or Fermi estimate is an estimation problem designed to teach dimensional analysis, approximation, and the importance of clearly identifying one’s assumptions. Named for 20th century physicist Enrico Fermi, such problems typically involve making justified guesses about quantities that seem impossible to compute given limited available information. The classic Fermi problem, generally attributed to Fermi, is ‘How many piano tuners are there in Chicago?’ A typical solution to this problem would involve multiplying together a series of estimates that would yield the correct answer if the estimates were correct. For example, we might make the following assumptions:

1. There are approximately 5,000,000 people living in Chicago.
2. On average, there are two persons in each household in Chicago.
3. Roughly one household in twenty has a piano that is tuned regularly.
4. Pianos that are tuned regularly are tuned on average about once per year.
5. It takes a piano tuner about two hours to tune a piano, including travel time.
6. Each piano tuner works eight hours in a day, five days in a week, and 50 weeks in a year.

I also want to find out if this Fluther question will be accepted by the moderators. Are all words in my question acceptable? What about the protection of minors using Fluther? I’m not even sure about the minimum age. Are there minor Flutherites?