The core element of any rollercoaster design is – gravity. Gravitational energy is the driving force that propels most coasters around their tracks. The expertly engineered journey begins with the coasters slow trek up the initial lift hill and then drop; followed by multiple cycles of building up potential energy on ascents and expending the kinetic energy on descents. This repeating rhythm is the coaster engineer’s “choreographed dance of gravitational energy”.
That’s what gravity has to do with the ride; now we’ll get into what gravity has to do with the person. To measure gravity’s effect on a human body, engineers use a unit called “G-force”. One G-force (1G) is equal to the amount of gravity you feel normally when standing on the Earth. It is the force of Earth’s gravitational pull on our bodies. When the G-forces increase, you effectively weigh more. For example, if you weigh 100 pounds, and you experience 3G, you will experience what it feels like to weigh 300 pounds. On a rollercoaster, you may experience up to 5G because this is the known amount that the body can safely handle.
There is also negative G’s, which are the inverse. They create weightlessness. It is possible to get motion sickness from negative G’s because the fluid in your inner ears, responsible for coordinating balance, is suspended in mid-air. On a rollercoaster there’s an experience called air time. It’s when you are suspended out of your seat experiencing negative G’s, floating.
To make the ride as pleasant as possible, without painful repercussions, designers are well aware of the limits of the Body and the coaster. The engineers play these contrasting forces against each other, to relieve periods of intense pressure with periods of no pressure at all. They avoid dramatic or extreme changes in speed and direction because a quick transition from positive to negative G-force can result in whiplash, headaches, and back and neck pain.
So what exactly does riding a rollercoaster do to our bodies other than make us feel either super heavy or weightless?
- The positive G-forces cause your blood to rush to your feet. No matter what, gravity causes your blood pressure to be higher in your feet than in your head, and your heart and circulatory system is used to working with that. As gravity forces increase your blood flows to your feet more and your heart finds it harder to get it back up to your brain. As long as you don’t surpass 5G, the regulated maximum for a rollercoaster, you’ll be perfectly ok.
- The negative G-forces cause your blood to rush to your head. Your body is not naturally designed to experience this at all (because it is the reverse of the way our bodies are supposed to work) so it is less tolerant to negative G-force. This is the occurrence of blood rushing to your head when you hang upside down.
- The anticipation and thrill of the ride get your heart rate and blood pressure to increase. A study by doctors at the University Hospital of Mannheim in Germany found that a roller coaster rider’s average heart rate jumps to 155 beats per minute. Interestingly enough, the peak didn’t occur at the highest, fastest, sharpest turn, but rather at the slowest, because it was the slow climb before the first big drop that caused the most pounding. With all that extra blood flowing around your body, there’s extra oxygen and fuel feeding your cells which helps keep you alert and awake which is probably a good thing as far as your enjoyment is concerned.
- Your neck muscles have to work hard to protect your spine by rapidly adjusting to compensate for all the sudden movements and keep your head from flopping around more than your spine can handle. It’s recommended that you keep your eyes open and your head facing forward because doing so allows you to see future movements coming up, which speed up your reactions, and reduces head movements.
- Your brain moves around within its fluid-filled sac inside your skull. Not to worry, it’s not even close enough to cause any damage.
- Our vision isn’t the only thing that orients us. Humans have a complicated organ in our inner ear which, through a series of small curving tubes, liquids, and tiny hairs, tracks the movements of our heads and helps us be aware of our movements. When the information coming from your inner ear doesn’t quite match up with what your eyes are seeing (and what your brain thinks should be happening), then things get confused. The way your body responds to this confusion is (according to researchers in Toronto) dictated by your age. The younger you are the less affected you are by the internal confusion. Children’s bodies are already in a constant state of change so the disorientation is just exciting. Adults are the unfortunate ones who may potentially feel motion sickness, dizziness, and nausea.
- When you find yourself in a stressful situation, your body reacts by releasing a cocktail of hormones into your bloodstream. This is an automatic (not conscious) response to potential threats. These hormones include adrenaline, norepinephrine, and cortisol. Between the three, a series of “valuable” physical reactions are stimulated. Adrenaline and norepinephrine are released almost immediately after you become aware of the threat. Together they raise your heart rate, concentrate blood flow towards muscles, lungs, and the brain, give you a boost of energy, as well as make you more alert and focused. Cortisol arrives a bit more slowly. It helps regulate body functions while under stress. The sudden flood of these hormones is what makes most people “feel more alive” than they normally do in their day-to-day life.
- To hear screaming stimulates primal reactions. According to a study at the University of Geneva, the screams you hear as you start to fall are an important part of the way your body reacts to the “threat” of a roller coaster, obviously part of the excitement of the experience. Screams rapidly cycle through a multitude of high frequencies that our brains are actually programmed to react to in specific ways. All high-pitched noise like screaming (or, for example, emergency alarms) stimulate a region of the brain called the amygdala. This is the region associated with fear, and which controls our responses to threats. The amygdala also controls the release of endorphins, our body’s self-prescribed painkiller. During life-threatening situations, this helps us ignore injuries, but the rest of the time it just makes us feel pretty good.
Modern-day knowledge about the limits of the human body have brought about roller coasters that are faster, taller, and loopier – and all without going off the rails or causing people harm. Whether you’re a rollercoaster lover or hater, they are amazing feats of engineering. And admit it, even though they’re scary, they’re exciting!