# Help Me I’m…Falling?

Me and my dad during free fall.

Growing up in a skydive family, I was always looking up. Both my parents skydived and ever since I was little I would watch each person fall through the sky and land back safely on the ground. As I got older, I started thinking more about the science involved in skydiving. Here’s
what I found out.

To start with, I looked up the probability of dying due to a skydiving accident. I know that there are a lot of people who think that going up into an airplane and then jumping out of it miles up into the air is crazy, but not as crazy as driving to the supermarket.  Discovery News did the math and found that you are 24 times more likely to die in a car crash than to die skydiving. This would be considered a relative risk, or a risk that is measured to increase the risk of something else. However, this could also be an absolute risk, the number of events per something.  In skydiving, there is estimated 3 million jumps per year, take the fatality of 21 people in 2010, and you get a .0007% chance of dying from skydiving. Basing it off a car crash again, there are about 10 million car crashes that result in 40,000 fatalities; you are looking at a .0167% chance of dying in a car crash. Just by looking at the data, it would seem that skydiving is safer than something everyone does every day.

Newton’s law of gravity says that what goes up must come down. With that being said, what does gravity do to the way we fall? Each person is different; different heights and weights. What would happen to someone who was 5’6 and weighed 150 pounds, or 6’0 and 150 pounds? The way gravity works is that your body mass affects how fast you fall through the air. The heavier you are, the faster your velocity will be, and vice versa. With the two heights and weights I mentioned above, the weight is the same, so the taller person has more surface area, making him slower than the 5’6 person.  Therefore, if you are ever skydiving and you get stuck in a rainstorm, you will be falling faster than the water because you have more surface area, meaning that your terminal velocity will be greater than the raindrops.

After freefall, there comes a certain amount of time, and altitude, that you need to pull your parachute. The parachute resists the air resistance, therefore slowing you down. It creates a large surface area with a large amount of drag.  But, does the size of a parachute affect how fast you fall?  There are a lot of at home science experiments you can do to test it yourself. But, without testing it, I’ll explain it using physics. As I explained before, the greater the surface area, the slower you will fall. There are many different types of skydiving parachutes, known as canopies. The most common are the rectangle parachutes and the circle parachute.

A study done by Emily B. Schisler tested the descent rate of the different types of canopies. Her hypothesis stated that she believed the circle canopy would fall the slowest.  She tested four shapes; circle, rectangle, square and parallelogram of equal area. This was one on a small scale, 360 centimeters to be exact. She concluded that the circle parachute had the slowest time, meaning the most air resistance, and the rectangle had the fastest descent rate. This agreed with her alternative hypothesis.

I am under rectangle canopy on my descent

When I went skydiving, I was underneath a rectangle canopy and we descended in about 15 minutes from 4,000 feet. However, there are different types of rectangle canopies, all varying in size. Some can be bigger and others smaller. It depends on the skydiver’s weight. After researching this topic a little more, I feel more comfortable knowing that there is less risk in skydiving than driving a car, and if I were to pursue a skydiving hobby, I would know what kind of parachute to get in order to end up safely on the ground.

## 2 thoughts on “Help Me I’m…Falling?”

1. Qian Chen

First of all, I have to say I respect you as being a skydiver because I haven’t done any extreme sport in my entire life… Both of my parents and I thought all of those sports were dangerous ( my parents even thought basketball was a pretty dangerous sport so…). However, your research on the comparison between the death rate of a car crash and one time skydiving proves to me that those extreme sport are not even more dangerous than what we are doing in the daily life, though maybe I will still remain blank for the experience of skydiving… I am curious about how bad weather will affect the risk rate between car crash and skydiving. Although skydiving has a lower death rate, I believe it is more dangerous for skydiver to meet some bad weather or natural disasters. Hope you can write a blog about that!

2. Jose Ignacio Arango De Diego

Honestly, I’m extremely terrified about the idea of skydiving thousands of feet of the ground. It must be a whole new experience trying to do this. I liked your post a lot because if gives a very different view towards the safety of skydiving. I like how you compared the risk of dying in skydiving to dying in a car accident. But my biggest fear about skydiving is the human error rate. Most of the injuries and deaths caused in skydiving have to do with human error. Not opening the parachute correctly for example, and many other situations where our mind and body fail to work properly. I live you here with a page that have various other examples about comparisons between the risks of skydiving and other activities. http://www.livescience.com/5350-truth-skydiving-risks.html