The following experiment1 will give you an idea of what it is like to pick strawberries for a living. One problem with picking a strawberry is that a ripe berry is easily bruised. If it is bruised, no one will buy it. So the strawberry picker must pick the berry off the plant without hurting it. Sound easy? Well, maybe so—if you have all the time in the world and are picking only one berry. But what if you have to earn enough money to provide for your family? Then, you have to pick about ten thousand strawberries in a twelve-hour workday. That turns strawberry picking into a very different job, doesn’t it? To pick ten thousand strawberries in twelve hours, you have to pick about • 1 strawberry every four seconds • 14 strawberries every minute • 840 strawberries every hour So how can we get an idea of what the strawberry picker’s hands are doing as she or he picks a berry? Let’s use a twelve-inch length of string in place of a strawberry plant. Tie this piece of string around something firm, like a chair back or a door handle. Then, tie a granny knot2 in the string. Have someone keep track of how long it takes for you to do it. How fast can you tie the knot? Practice doing it until you can tie a granny knot in four seconds or less. Then, try doing the same thing with fourteen separate lengths of twelve-inch string. The idea is to get fourteen separate knots tied in less than a minute. Now, imagine tying 840 knots in an hour and 10,080 knots in twelve hours. Are you getting an idea of what strawberry picking is like?