If you leave out mosquitoes, soggy french fries and 100-degree afternoons, I love everything about summer. Well, almost everything. There is one more summer pastime I can live without: roller coasters.
Don't get me wrong. Like most people, I think roller coasters are a marvel of modern engineering. They are spectacular machines that allow riders to soar through the air like birds. Not like normal birds, of course, because only crazy birds would fly loop-the-loops just for the heck of it. Most birds engage in aerial acrobatics either to catch a meal or avoid becoming one.
So what is it that makes some people love roller coasters and others (like me) prefer a lazy river?
From an early age, most kids like to be swung through the air. Whether your dad is gently tossing you over his head or your mom is pushing you on the swings, it's fun to glide through space. Interestingly, this type of movement helps develop your inner ear, the body's internal gyroscope, which enables you to know what position you're in.
During a roller coaster ride, your body is pushed, pulled, twisted, turned and even left weightless for a brief time. All of this is accomplished as the forces generated by the coaster interact with gravity.
Most roller coasters consist of a number of peaks and valleys with twists and loops thrown in to make the ride more exciting. When the coaster is pulled up the first hill, it gathers its maximum "potential" energy. For the rest of the ride, you are basically falling through space. That's why all of the subsequent hills are smaller than the first. If not, you wouldn't have enough momentum (energy) to get over the next hill.
As the coaster plummets downward, its potential energy is converted to "kinetic" (or actual) energy. Each time your body is redirected through a twist or turn, you are pushed or pulled from the seat and pads that hold you in place. It is these changes in force (plus seeing the scenery flying by) that makes the ride exciting or nauseating, depending on your point of view.
While your body is being tossed around, your inner ear is stimulated, which can make you dizzy. Also, your internal organs, which generally prefer the downward force of gravity, are being jostled. This is what gives you the sensation that your stomach is in your throat when you shoot to the top of a hill or swoop down the track at a steep angle.
From my perspective, a roller coaster is a large-scale version of being tossed in the air by your dad. If you like it, you will scream with joy. If you don't, you may throw something up yourself.
Bennett, a Washington pediatrician, is the author of "Harry Goes the the Hospital."