» How Physicist Build a Bridge
You start a bridge by sending a small piece of string across a chasm and then feeding it with thicker and thicker pieces of rope, and then construction materials. Physicists at Fermilab’s Wilson Hall had a clever way to do this:
Now they could call in a construction crew, build scaffolding up twenty stories and just connect the cable like that. Not pretty but it would get the job done. But they wanted something pretty. But wait, things are a little easier. We don’t actually need to get the heavy duty cable across to begin with, we can start with a lightweight string, and use that to pull across increasingly heavy cables. The Niagara Falls Bridge for example started when a young boy flew a kite across the falls.
Unfortunately kites don’t work inside. Well maybe we could have someone throw a baseball across the gap with the string pinned to it. Maybe but the physicists were more inspired by the 0 brawn approach: two people go up to 20th story offices, each with a ball of string. They drop the balls (holding on to an end) all the way down to the ground 20 stories below. Below a third guy ties the ends together. Wind the string up. voila, we have our bridge.
July 29, 2009, 9:38am Comments
