Johns Hopkins’s other engineering lab: The Voodoo Drop at Six Flags

Biomedical engineering and physics students gather data on amusement-park rides

Biomedical engineering and physics students from Johns Hopkins University learn about physiologic responses by tracking heart rates and other measures while riding rollercoasters like the Joker’s Jinx at Six Flags in Upper Marlboro, Md., on Oct. 28. (Michael Connor for The Washington Post)
Biomedical engineering and physics students from Johns Hopkins University learn about physiologic responses by tracking heart rates and other measures while riding rollercoasters like the Joker’s Jinx at Six Flags in Upper Marlboro, Md., on Oct. 28. (Michael Connor for The Washington Post)

A countdown began: “Five. Four. Three. Two. One.” Luiza Brunelli Bührer waited in the front car of the roller coaster, and checked her watch to see how fast her heart was beating: 86 beats per minute. Next to her another college freshman put her hands over her eyes. The Johns Hopkins University classmates grabbed hands, bracing.

A sudden blast, and the roller coaster shot forward into a tunnel — from 0 to 60 miles per hour in just over three seconds. Then a 360-degree loop.

The little yellow cars roared up hills and streaked down, veered crazily around turns on the bright green track, raced upside-down and sped, finally, back to the start.

“Oh, God,” Brunelli Bührer said as her car clattered to a stop. “I think I enjoyed it.”

Her classmates staggered out, laughing, or moaning.

Emma Meihofer patted the device strapped around her waist. “We should save the data,” she said.

Every fall, professors bring more than 100 first-year students at Johns Hopkins to Six Flags America in Prince George’s County to learn biomedical engineering and physics in a, literally, heart-stopping way.

It’s a long-running experiment, one that began more than 20 years ago but shut down — along with most other things — during the pandemic. This fall, professors were delighted to once again unleash students onto roller coasters and free-fall drops for lessons they expect will be far more memorable than most of their lectures.

It’s a vivid sign that things are returning to normal — even if their version of normal is an amusement park full of people chattering excitedly about vectors, baroreceptors and z-axes.

Most of the students are biomedical engineering majors, who have been working on health-equity projects, interactive electronics and other challenges in their biomedical engineering design class this fall. Now they’re riding roller coasters to help understand the cardiovascular system.

“You learn more when you do things,” said Eileen Haase, a professor of biomedical engineering at Hopkins.

Biomedical engineering students at Johns Hopkins University rode roller coasters at Six Flags America to measure heart rate and acceleration. (Video: Aubrey Morse for Johns Hopkins University)

Latched into their seats, they learn about physiological responses, such as the control of blood pressure, by recording heart rate during changes in ride acceleration. “We have reflexes in our body that help keep things pretty much at steady state,” Haase said. There’s a reflex that kicks in when someone has their head down, for yoga or while gardening, for example, to keep the person from passing out, and that gets stimulated on the rides, Haase said.

Using a small device, students measure heart rate and acceleration to see how their bodies are responding to the rapid changes as the ride whips them around.

An amusement park is basically a massively scaled-up physics lab, said Reid Mumford, an instructional resource adviser at Hopkins. But here, the students are part of the experiment.

In his lab on the Hopkins campus, they did a one-meter drop with their phones. At Six Flags, it’s the students that plummet.

He brought about 30 of his students along to collect data on their phones, and to confront common challenges: balky equipment, lost data, scrambled results.

Most introductory lab experiments are designed to work well, Mumford said. “That’s not how the real world is.” So giving them something imperfect, with “all sorts of weird variations, is fun. It helps them to think on their feet a little more.”

Professors were tackling their own IRL problems. Physics as a field tends to be a leaky pipeline for women and minorities, Mumford said. The trip is intended to be a disarming experience that helps build community.

The students are brilliant, Haase said. But some need to learn to work in teams.

Students from all over the world arrive on campus in Baltimore not knowing anyone. “This group of students — this age group — has been through so much,” Haase said.

After more than a year of virtual school at home in Brazil, Brunelli Bührer said, “It feels really good to be back — living with my friends and having experiences outside the classroom.”

When the school buses rolled into an empty parking lot at Six Flags on a recent afternoon, a Bon Jovi song was blasting from park speakers. But it echoed strangely through the empty space, with stores closed and only a few rides creaking to a start. Students with backpacks and Hopkins hoodies had the park to themselves for an hour, before it opened to the public.

“I’m a roller-coaster junkie,” said Divyansh Lalwani, an 18-year-old from India. “I absolutely adore and love roller coasters.” He has been on what’s billed as the world’s fastest roller coaster, and on a floorless ride that suspends riders over the sea.

Others planned to just watch, from stable ground.

Meihofer, a 19-year-old from South Carolina, strapped on a device that would monitor her heart rate and acceleration on the ride.

“Is it supposed to be blinking?” someone asked, looking at the colored lights on top of the white box. “Maybe you’re supposed to press it?” someone else asked.

They were measuring how their heart rate changes with the acceleration, Meihofer explained, but fear and adrenaline could affect the data.

Brunelli Bührer dashed forward to snag the front car. “I’m excited,” she said. “My heart rate is definitely going to go up.”

After the ride, as they tottered away, laughing, Sofia Arboleda pulled out a laptop to download Meihofer’s data. “That was scary,” said Kenzi Griffith, 18, from Hawaii. “The first five seconds we just got going really fast. And upside-down.”

Meanwhile, Mumford was rolling out a tape measure on the Harley Quinn Spinsanity pendulum ride, with giant spokes lit by blue and red lights shining against the darkening sky. He used a pocket device to beam a laser to the top of the structure, and recorded the distance. An app on his phone recorded changes in air pressure.

“We’re doing problem sets in real life,” said Sami Muhammad, 17, a physics student from New Jersey.

With so few people in the park, a worker counted the students going on the ride, and divided them into two even groups to distribute the weight.

“Engineering!” students joked.

Arboleda and Griffith looked at the spinning, climbing ride — which suspends people for a moment staring down at the ground before swinging back again — and ducked under the ropes. “Noooooooo!” their lab partners called after them.

Then they went to the Voodoo Drop, a 140-foot tower with a free-fall ride. The calculations were pretty easy on this one, Muhammad said. Behind him, a girl screamed as the ride dropped. “Now I’m sending the data file to myself,” he said, tapping on his phone.

The funnel cake stand opened. Other people had started to drift into the park. Students snapped photos of the sky, streaked with pink clouds, on their phones. They pulled one another onto rides.

Lalwani skidded back to the platform of a roller coaster, his hair standing on end. “Amazing!” he said

Knowing his own nerves might mess with the data, he had started the ride trying to meditate. That didn’t work for too long. “I just forgot — caught up in the moment,” he said, laughing.

But when they had gathered around to download and analyze the last data and work through the last problems, everyone celebrated. “Having all those like-minded people around one computer, sharing a moment of intrigue, sharing a moment of excitement — not just for the rides, but for the science behind it,” Lalwani said. “That, to me, was very beautiful.”