Cool Jobs: Motion by the numbers

Scientists create and study motion with the help of geometry
Dec 15, 2016 — 7:05 am EST
car crash

Car accidents are an all-too-common occurrence. To analyze what happened — and hopefully move toward design improvements that limit future accidents — safety engineers rely on geometry. Theirs is just one of many important and interesting careers that rely on this field of math.

Daisy-Daisy /iStockphoto

This is one in a series on careers in science, technology, engineering and mathematics made possible with generous support from Arconic Foundation.

Without warning, a car-sized object slams into a stopped car. It hits the front on the driver’s side. The oncoming car is traveling at 90 kilometers (56 miles) per hour.

Thor, a high-tech crash dummy, sits in the driver’s seat of the stopped car. The force that caused the wreck flings Thor around like a rag doll.

Greg Shaw and his team watch the grisly smashup. Shaw notes that the crash lasts around 120 milliseconds. He describes this amount of time as a bit longer than an eye blink. A biomechanical engineer, Shaw deliberately crashes cars for a living.  He works at the Center for Applied Biomechanics at the University of Virginia in Charlottesville.

Shaw’s cool job uses geometry, a field of math that involves shapes — especially points, lines, planes, curves and surfaces. Many other exciting jobs also rely on geometry. Here we meet three people who use this math to explore how people and objects move.

The science of crashing cars

Shaw’s work combines thrilling action with careful research. He tries to reduce deaths and injuries by making cars safer for their occupants. He collects data on accidents after they’re over. He also collects data during the crashes that he simulates in his lab. Since 2008, Shaw has worked with the Crash Injury Research Engineering Network (CIREN). It’s a program of the National Highway Traffic Safety Administration. CIREN is made up of medical and engineering teams that are located around the United States. Shaw is on the University of Virginia and Inova Fairfax Hospital team, a CIREN group in Virginia.

Working alongside a CIREN crash investigator, Shaw probes accidents serious enough to send people to Inova Fairfax Hospital in Falls Church, Va.

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crash test

 The team examines the medical charts of patients who participate in their investigations. The search is on for clues. These might include photographs or descriptions of the person’s injuries. Such evidence can tell a lot about how someone got hurt.

The researchers also examine the wrecked cars. This allows them to measure how much the smash-up had deformed each vehicle.

The duo also looks for clues inside the car. They search for any sign that an occupant made contact with parts of the car during the crash. For example, sometimes a person’s head will hit one of the car’s A-pillars. These two components support a car by keeping its windshield in place. Heads often are injured when they slam into an A-pillar. Scuff marks on the surface of an A-pillar and scrapes on someone’s forehead also can point to that structural pillar as the source of that injury, Shaw notes.

Newer cars have devices called event data recorders (EDRs), notes Shaw. These are like an airplane's “black box,” or flight data recorders. EDRs record data immediately before and during car crashes, including a car’s speed right before the impact. They also record whether the driver had braked. 

After analyzing all of these data, the team brainstorms how a car might be modified in a way to increase occupant safety.

In the lab, Shaw and his team focus on collisions known as “frontal oblique impacts.” These are frontal impacts that hit closer to one side than the other. For example, if something smashes into the body of a car near the headlight on the driver’s side, striking at a 30 degree angle, this is a frontal oblique crash.

A degree is a unit of measurement for angles. Each degree equals one 360th of the circumference of a circle. So for a frontal oblique impact with a 30 degree angle, there is a space between the incoming object and the car that is equal to one-twelfth the circumference of a circle (360° ÷ 30° = 12).

Shaw found that the crashes he studies follow a pattern. Typically, one vehicle is stopped at a traffic light. A second car approaches from the opposite direction. The driver of that second car loses control of the vehicle and swerves into the stopped car’s lane. Then it slams into the front end of the stopped car. It does so at an angle that is about 15 degrees from a head-on collision.

Such crashes are common. And they often result in occupants becoming seriously injured or killed, Shaw notes. That’s why he chose to study them.

Growing up, Shaw didn’t picture himself having a career involving geometry. He was first interested in the design aspects of engineering, like the skills that he uses when he brainstorms ways to modify cars so people will be safer. He now finds geometry “a useful and necessary tool” for his work.

The geometry of video games

Geometry also fuels another cool field of work: creating video games.

Ryan Bown works at the University of Utah in Salt Lake City. “I [have] always loved art and video games,” he says. About eight years ago, he decided to fuse the two loves. Bown does 3-D modeling, texture art and design for video games.

Before immersing himself in the artistic side of video games, Bown spent 10 years creating art for galleries and museums. “I created abstract work based on fractal geometry,” he notes. Fractals are complex geometric figures. These figures have the same shape at all levels of size, from the microscopic to the gigantic.

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Head modeling
The process of building a human-like head in a video game starts with simple shapes, as shown in this image created by Ryan Bown. More shapes are added as the modeling process continues. This builds up the resolution of an image, adding greater detail to games, notes Ryan Bown.
Ryan Bown

Bown has worked on six video games in the last five years. They have included a horror game called Erie. He worked as part of the Erie team while he was in graduate school at the University of Utah.

“My role on Erie was lead artist with some design [work],” he says. “I was responsible for the look and feel of the game.” Bown created most of the artwork for the environment of the game, he notes. By “environment” he means the virtual place where events in the game happen.

This job would not be possible without math, he notes: “I use geometry every day.” Geometry helps him break down complex characters, objects and props “into simple, primitive shapes such as cubes, cylinders and spheres,” he notes.

In game design, geometry is used to determine how characters can behave, Bown notes. For example, designers use navigational meshes. These are geometric boundaries. They are used to define where objects and non-player controlled characters (NPCs) can go within a game. NPCs can be friendly characters that a player encounters during game play. They also can include enemies, which are characters that prevent players from reaching their goals, Bown explains.

Navigational meshes typically restrict objects or NPCs to a volume of the virtual space. This volume is defined by the game’s designer. Shapes such as cubes and cylinders have volume because they have three dimensions: length, width and height. A designer might use a navigational mesh to restrict the movement of an enemy (such as a dragon) to one section of a cave, for example.

Lately, Bown has been working on what he calls “serious” games. These are ones “intended to teach or train the player through game play,” he explains.

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A screenshot of Dino Lab, a serious game that uses dinosaur bones to teach students critical thinking skills.
The Gapp Lab, in collaboration with the Natural History Museum of Utah.

For instance, Bown and his students recently created a serious game called Dino Lab. They created the free game as a joint project with the Natural History Museum of Utah. Dino Lab uses dinosaur bones to teach students critical thinking.

Teachers and students can register for the game on the Research Quests website. The research quest project uses online tools — including 3D models of dinosaur bones and short videos with museum scientists. The goal is to help a viewer identify different types of dinosaurs and determine what likely led to their deaths.

“As a kid, I loved learning math,” Bown notes. “I found it challenging, but it was kind of magical.” He points out that people use math every day without thinking about it. It may be something as simple as estimating how long it takes to get to school. And it may be something that seems to require skills that are more physical than mathematical, such as making the perfect pass in football by calculating the angle at which the ball must travel.

Racing to the finish line with the help of geometry

Jessica Deneweth Zendler directs the Michigan Performance Research Laboratory at the University of Michigan in Ann Arbor. This biomedical engineer is a kinesiologist (Keh-NEES-ee-OL-oh-jist), or scientist who studies how people move. Kinesiologists can even help people improve how their bodies function by showing them ways to move that put less stress on their muscles, bones and joints. Using correct motions also can enhance someone’s physical fitness. This includes their performance in sports, such as running. It might even help them recover from injuries or lessen their risk of injury.

Michigan Performance Research Laboratory
Jessica Deneweth Zendler at work in the Michigan Performance Research Laboratory, which she directs.
Michigan Photography

In February 2016, Deneweth Zendler’s lab began offering four types of running assessments. A so-called novice version is designed for people who are new to running and want help on how to get off to a successful start. Performance assessments help people who have some particular goal for their running. Postpartum assessments cater to women who recently had a baby and want to start running or to return to the sport. Injury assessments analyze what might underlie the injuries or chronic pain that some runners suffer.

That chronic pain often afflicts the knees and feet. And where it shows up can be quite specific. For example, one knee may hurt a lot and the other remain pain-free. Some runners have chronic pain but don’t know the specific cause of it. Others have chronic pain due to injuries, such as stress fractures. These fractures, found in such places as the shin bones and feet, are a type of injury that many runners experience, Deneweth Zendler notes.

She conducts all four types of assessments. Here's what an injury assessment looks like. Researchers in her lab start by giving each runner a full physical exam. Tests will measure the runner’s strength and range of motion. They also examine the athlete’s joints and posture. Next, the team places special sensors on the runner’s body. These allow her team to assess the runner’s biomechanics. By that, she means such things as the angles that a runner’s joints make while that person is running on a treadmill. Typically, they focus on joints in the hip, knees and ankles.

treadmill
Jeff Plotzke, a distance runner in Michigan, runs on a treadmill in the Michigan Performance Research Laboratory. He is completing a performance assessment.
Michigan Photography

By analyzing data from the exam and treadmill tests, the team diagnoses what is behind a runner’s injury, Deneweth Zendler says. Then they offer corrective advice. This is aimed at teaching runners how to change the angles their joints create as they run. The research team may even provide runners with exercises to help them use or strengthen particular muscles. Runners can follow this advice on their own or along with help from a physical therapist.

Several weeks after an assessment, Deneweth Zendler’s team contacts runners for an update on their progress. She says they often report that they “feel like they are running faster or some of their injuries are getting better.”

Since childhood, Deneweth Zendler has enjoyed math, problem-solving and physics. She says she has “always been very interested in how the body moves.” Much of that interest stems from her experiences as a lifelong athlete. She grew up playing soccer. She continued to play the sport throughout college. Now she is a recreational athlete, focusing on endurance running and competitive cycling.

Not surprisingly, Deneweth Zendler often uses her “ability to think mathematically” when working in the lab. After all, she observes, geometry and other forms of math are “hidden everywhere in life.”

Geometry empowers people to discover new things about the world around them. This is true whether they are scientists like Shaw and Deneweth Zendler, artists and designers like Bown or high school students encountering the subject for the first time. With its mix of visually appealing shapes (often showcased in art) and roots in logic and critical thinking, geometry has much to offer people in all walks of life.

Power Words

(for more about Power Words, click here)

A-pillar     (in automotive design) A component that supports a vehicle by keeping its windshield in place. Each vehicle has two of these. 

abstract     Something that exists as an idea or thought but not concrete or tangible (touchable) in the real world. Beauty, love and memory are abstractions; cars, trees and water are concrete and tangible.

angle     The space (usually measured in degrees) between two intersecting lines or surfaces at or close to the point where they meet.

biomechanics     The study of how living things move, especially of the forces exerted by muscles and gravity on the skeletal structure.

biomedical     Having to do with medicine and how it interacts with cells or tissues.

biomedical engineer     An expert who uses science and math to find solutions to problems in biology and medicine; for example, they might create medical devices such as artificial knees.

chronic     A condition, such as an illness (or its symptoms, including pain), that lasts for a long time.

circumference     The size of a circle or other geometric object by measuring the distance all of the way along its outer edge.

component     An item that is part of something else, such as pieces that go on an electronic circuit board.

control     A part of an experiment where there is no change from normal conditions. The control is essential to scientific experiments. It shows that any new effect is likely due only to the part of the test that a researcher has altered. For example, if scientists were testing different types of fertilizer in a garden, they would want one section of it to remain unfertilized, as the control. Its area would show how plants in this garden grow under normal conditions. And that give scientists something against which they can compare their experimental data.

data     Facts and/or statistics collected together for analysis but not necessarily organized in a way that give them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.

degree     (in geometry) A unit of measurement for angles. Each degree equals one three-hundred-and-sixtieth of the circumference of a circle.

diagnose     To analyze clues or symptoms in the search for their cause. The conclusion usually results in a diagnosis — identification of the causal problem or disease.

dinosaur     A term that means terrible lizard. These ancient reptiles lived from about 250 million years ago to roughly 65 million years ago. All descended from egg-laying reptiles known as archosaurs. Their descendants eventually split into two lines. They are distinguished by their hips. The lizard-hipped line became saurichians, such as two-footed theropods like T. rex and the lumbering four-footed Apatosaurus (once known as brontosaurus). A second line of so-called bird-hipped, or ornithischian dinosaurs, led to a widely differing group of animals that included the stegosaurs and duckbilled dinosaurs.

engineer     A person who uses science to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need.

field     An area of study, as in: Her field of research was biology. Also a term to describe a real-world environment in which some research is conducted, such as at sea, in a forest, on a mountaintop or on a city street. It is the opposite of an artificial setting, such as a research laboratory.

flight data recorder     An electronic device used on aircraft to record the signals sent to or received by any of the electronic systems on an aircraft. Complex FDRs, which record more signals than simple ones, often store the voices of pilots and other people in a cockpit. Investigators may use such data to unravel what led up to an accident, for example.

force     Some outside influence that can change the motion of a body, hold bodies close to one another, or produce motion or stress in a stationary body.

fractals     Complex mathematical curves that have the same shape at all levels of size, from the microscopic to the gigantic. Fractals are particularly useful for describing jagged lines or rough surfaces.

fracture     (noun) A break. (verb) To break something and induce cracks or a splitting apart of something.

geometry     The mathematical study of shapes, especially points, lines, planes, curves and surfaces.

graduate school     A university program that offers advanced degrees, such as a Master’s or PhD degree. It’s called graduate school because it is started only after someone has already graduated from college (usually with a four-year degree).

kinesiologist     A scientist who studies how the human body moves and how it can function more efficiently (by putting a minimum of strain on tissues). 

microscopic     An adjective for things too small to be seen by the unaided eye. It takes a microscope to view such tiny objects, such as bacteria or other one-celled organisms.

model     A simulation of a real-world event (usually using a computer) that has been developed to predict one or more likely outcomes.

muscle     A type of tissue used to produce movement by contracting its cells, known as muscle fibers. Muscle is rich in a protein, which is why predatory species seek prey containing lots of this tissue.

physical     (adj.) A term for things that exist in the real world, as opposed to in memories or the imagination. It can also refer to properties of materials that are due to their size and non-chemical interactions (such as when one block slams with force into another).

physical therapist     A person trained in the treatment of physical disability through the use of exercise, massage or other non-medical treatments.

physics     The scientific study of the nature and properties of matter and energy. Classical physics is an explanation of the nature and properties of matter and energy that relies on descriptions such as Newton’s laws of motion. Quantum physics, a field of study which emerged later, is a more accurate way of explaining the motions and behavior of matter. A scientist who works in that field is known as a physicist .

range     The full extent or distribution of something. For instance, a plant or animal’s range is the area over which it naturally exists.

risk     The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard — or peril — itself. Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.

sensor     A device that picks up information on physical or chemical conditions — such as temperature, barometric pressure, salinity, humidity, pH, light intensity or radiation — and stores or broadcasts that information. Scientists and engineers often rely on sensors to inform them of conditions that may change over time or that exist far from where a researcher can measure them directly. (in biology) The structure that an organism uses to sense attributes of its environment, such as heat, winds, chemicals, moisture, trauma or an attack by predators.

simulate     To deceive in some way by imitating the form or function of something. (in computing) To try and imitate the conditions, functions or appearance of something. Computer programs that do this are referred to as simulations .

stress     (in biology) A factor, such as unusual temperatures, moisture or pollution, that affects the health of a species or ecosystem.  (in physics) Pressure or tension exerted on a material object.

virtual     Being almost like something. An object or concept that is virtually real would be almost true or real — but not quite. The term often is used to refer to something that has been modeled — by or accomplished by — a computer using numbers, not by using real-world parts. So a virtual motor would be one that could be seen on a computer screen and tested by computer programming (but it wouldn’t be a three-dimensional device made from metal).

Further Reading

To learn more about Dino Lab, see the Research Quests website.