The “egg drop challenge” is a rite of passage in science classrooms. The goal is simple: drop an egg from a height and try to keep it from breaking. The challenge is more than just messy fun — it teaches basic physics, impact force, and structural design. Conventional wisdom says that you should drop the egg vertically, on its end, because that’s where it’s strongest.

But around three years ago, Tal Cohen started to doubt that. Cohen, a mechanical and civil engineering professor at MIT, conducted a new study that turns the assumption on its head — or rather, on its side. Published in Communications Physics, the paper finds that eggs dropped horizontally, on their sides, are actually less likely to crack.

The Egghead Experiment

Every year, the MIT Department of Civil and Environmental Engineering carries out an egg-dropping experiment with students. It’s simple but effective. “We follow the scientific literature and talk to the students about how to position the egg to avoid breakage on impact,” Cohen says.

Her team didn’t start out with the goal of rewriting physics folklore, it just happened gradually.

“About three years ago, we started to question whether vertical really is stronger,” she said. After years of advising students in the egg drop challenge, Cohen and her colleagues decided to run a few quick lab tests using leftover eggs. The results were confusing. So they dived deeper — ultimately dropping 180 eggs and crushing 60 more in carefully calibrated tests.

The researchers conducted two types of experiments: static and dynamic. In static tests, the researchers slowly pressed down on eggs placed vertically or horizontally using a mechanical testing machine. Surprisingly, the force needed to crack the eggs vertically and horizontally was almost the same — around 45 newtons. But one key difference emerged: eggs lying on their sides compressed more before breaking.

That difference matters.

“The horizontal egg compressed more under the same amount of force, meaning it was more compliant,” said Joseph Bonavia, a Ph.D. student and co-author on the paper. “If you are falling from a height, you don’t want to lock your knees. You’ll break your bones. You want to bend your knees — that’s what the egg is doing.”

In engineering terms, the eggshell is stiffer when it’s vertical. But stiffness isn’t toughness. It’s the tougher structure — the one that can bend and absorb energy — that survives a fall.

Sideways Wins the Drop

The dynamic drop tests were more realistic; you’re more likely to drop an egg on something than push and compress it. They released eggs using a custom-built solenoid device from three short heights: 8, 9, and 10 millimeters. Even from such tiny drops, patterns emerged. Horizontally dropped eggs were more likely to survive.

Simulations confirmed it. The egg’s equator allowed more time to absorb impact — and less cracking.

“Even though both orientations experienced similar peak forces, the horizontal eggs absorbed energy better and were more resistant to breaking,” said Avishai Jeselsohn, an undergraduate researcher and co-author.

Eggs cracked differently too. Horizontal eggs split cleanly around their middle — the way we crack them while cooking. Vertical drops tended to cave in from the blunt end, creating spiral fractures.

And yes, the team had to buy their eggs in bulk. Cohen and her team picked up more than 200 eggs from Costco. None were eaten after testing. But her dog enjoyed a few uncracked leftovers.

Stiffness Isn’t Strength

So why has the vertical myth persisted for so long?

In part, it comes from confusing strength with stiffness. In architecture, arches are stronger under vertical load — a comparison often drawn with eggs. That analogy may hold for static pressure, but it breaks under real-world impact. An egg’s ability to survive a fall depends less on how stiff it is and more on how much energy it can absorb without cracking.

“Cracking an egg for cooking involves applying locally focused force for a clean break to retrieve the yolk, while its resistance to breaking from a drop involves distributing and absorbing energy across the shell,” Brendan Unikewicz, another graduate student and study co-author, told Smithsonian Magazine.

Even some fracture mechanics experts believed the vertical claim. The MIT team’s work challenges this dogma with data — and a bit of humor.

Their paper opens by comparing the debate to the fictional war in Gulliver’s Travels, where the empires of Lilliput and Blefuscu argue over which end of an egg to crack. “In our own society,” they write, “there exists a similar ‘common sense’ idea about the best orientation for dropping an egg.”

“It’s great to see an example of ‘received wisdom’ being tested scientifically and shown to be incorrect,” said David Taylor, a professor at Trinity College Dublin who was not involved in the study. “There are many such examples in the scientific literature, and it’s a real problem in some fields because it can be difficult to secure funding to challenge an existing, ‘well-known’ theory.”

Cohen hopes their results — and the painstakingly recorded crack patterns — inspire a bit more intellectual humility. “We hope our work inspires students to stay curious, question even the most familiar assumptions, and continue thinking critically about the physical world around them,” she said.