The Young Scientists

If you've hung laundry on a line, you know that pinning up a sheet leaves it perilously close to the dirt. If you drape it over a line, the air doesn't get at both sides of the sheet easily, because you have it folded. If you drape it over two lines, you get better air circulation, but it pulls the clothes-lines close together. So, at the cost of a little more effort, you pin it to two lines, letting it dry in a U-shape.

OK, now suppose you and your sister are playing in the yard. The above-mentioned sheet looks like an interesting place to sit.

It isn't.

Suppose it is windy enough that plausible deniability is possible. Your mother pins the sheet back up and you and your sister keep playing in the yard.

Clearly the pins don't hold a lot of weight.

How much weight will they hold?

There's a way to find out. The California lawn is new, and there's plenty of exposed dirt, and a shovel leaning against a wall.

Unfortunately, the experiment gets interrupted before more than about a half dozen shovels of dirt land in the sheet--not enough weight to pull it down. So you never learn the answer.