SCIENCE LAB SCHOOL : EGGED ON

With these researchers - crackups were common. The egg drop challenge is familiar to many students learning about physics :

Swaddle an egg in cotton balls and masking tape or other materials, then drop it off your school's roof.  The exercise shows how hard it is to create a structure that will keep eggs from cracking.

Once the eggs are broken, teachers may reveal insights into the physics of impact, including the claim that eggs sitting vertically crack less often than eggs sitting horizontally. But is that really true?

After running egg drop challenges for her students, Tai Cohen, an engineering professor at the. Massachusetts Institute of Technology, decided to test that theory.

What she found suggested the truth was more complicated, and in a new paper in the journal. Communications Physics, she and her colleagues report that eggs lying horizontally are less likely to crack.

Dr. Cohen's team, armed with more than 200 eggs, crushed some of them in a device that allowed them to record the force needed to crack the shells. 

Eggshells cracked under about the same force regardless of whether they were lying down or sitting up.

Researchers dropped eggs from eight millimeters or so to allow them to see a variety of outcomes. If dropped from bigger heights, all the eggs broke.

Eggs dropped so they landed on their sides were substantially less likely to crack. When they hit, the shell was able to compress, absorbing some of the blow.

Eggs dropped on their ends, where the shell is stiffer, did not show such flexibility.

The World Students Society thanks Veronique Greenwood.