Saturday, February 2, 2008

Geometry and Roller Coasters

Have you ever thought about geometry when you're riding a roller coaster? Of course you haven't! You will be happy to know, however, that the designer of the roller coaster did. If you've ever ridden an old wooden roller coaster, you probably have seen wooden supports like the ones found in this picture of The Beast at Paramount's Kings Island.


So you're at the very top of the first big drop of a world famous roller coaster. If you're an average person, you're thinking, "OMG, I am really high up."

If you're a nerdy geometry teacher, you're thinking, "OMG, look at all the triangles."


Here I have pointed out three of the literally thousands of triangles found in The Beast. Why so many triangles? The reason lies in a simple property of triangles.

If the lengths of the sides of a triangle are fixed, the angles are fixed, too. In a wooden roller coaster, the sides of the triangles are made of wood. The wood is nailed together and cannot stretch, so the size and shape of each triangle is unchanging. Putting triangles into the structure of the coaster makes it strong and rigid.

This is a property that is unique to triangles. You can find many quadrilaterals with equal length sides but different angles. Pentagons are even worse. Only the triangle has angle measures determined by the length of its sides.

So next time you're speeding down a track at 60+ mph. Take a moment to stop and appreciate the geometry all around you.

1 comment:

Unknown said...

As a civil engineer who took both 'STATICS' and 'DYNAMICS' classes in my undergraduate days in order to understand how to design buildings, bridges and any other structure that had to support various weights and resist forces, I was always amazed that the shape of the simple triangle could be used to analyze the vertical and horizontal forces that exist within a structure like a roller coaster in order for the structure to be 'stable' (i.e., to not collapse). The simple principal that for a non-moving structure:

The sum of Vertical forces = 0, and
The sum of Horizontal forces = 0,

was like a beautiful revelation to me. HOWEVER, it still did not settle me down when I arrived at the top of a roller coaster and prayed to myself, "Dear God, I sure hope a Purdue engineer designed this thing!" Knowing math principles is not the solution to a fear of heights!

In my career of 30 years, the use of geometry in solving many of the day-to-day problems in the world has been a wonderful discovery. "How will I use this stuff?" has been answered again and again by a world that is based on geometric position, natural geometric configurations and spatial relationships. I look forward to more of the 'how' on this blog!!! - an old engineer