If the Farmer’s Almanac is a wealth of information then their following rule of thumb is a white trailer trash cousin:
The human arm is approximately ten times longer than the distance between your eyes.
Of course Bossy thinks the Farmer’s Almanac probably never met Kate Moss.
Here’s how it works: Imagine you see a barn in the distance. And imagine that you know the barn is 100 feet wide. And if you know the barn is 100 feet wide how come you don’t know how far away it is? Never mind: you don’t know how far that barn is but you want to know. You need to know.
OK — so you hold one arm straight out in front of you with the thumb pointing up. Close one eye and align the edge of your thumb with the edge of the barn that is 100 feet wide but who knows in lord how far away.
Do you still have the thumb and barn aligned? Good. Now without moving anything, switch eyes. Your thumb perspective will jump sideways and the distance it moved will help you determine the distance to the barn!
Bossy understands. She’ll wait right here while you dive head first into one of these:
All better? OK — The Farmer’s Almanac wants you to imagine that your thumb jumped about five times the width of the barn — which everyone and their grandmother knows is 100 feet wide. So that means your thumb jumped about 500 feet.
We interrupt this equation for Bossy’s A.D.D. Question of the Day: What is the ratio of the length of your arm to the distance between your eyes? If you answered ten than you clearly haven’t had enough Martini.
So — to determine the approximate distance of the barn multiply 500 (the distance your thumb perspective shifted) by the Constant 10 (the arm to eyes ratio). Which equals 5000 feet! Which is like one-two-three-thousands of feet!
The following diagram illustrates the equation. Happy figuring!