Corsicana Daily Sun, Corsicana, Texas

Lifestyles

October 2, 2012

Slate: The physics of cracking an egg

(Continued)

All these methods have one thing in common: They rely on applying just enough force to the center of the egg — the egg equator, if you will — to crack the shell without shattering it. And science has finally come up with an explanation for what comes naturally to most home cooks: Eggs crack best around their equators, says MIT mechanical engineer Pedro Reis, because of their geometry. He and a young colleague, Arnaud Lazarus, have just published a paper in Physical Review Letters demonstrating a link between an eggshell's geometry (it belongs to a class of shapes known as ovoids) and a mechanical property called rigidity — the quality that, along with strength, determines how much force an object can withstand before it cracks.

Scientifically, strength and rigidity are distinct, though related, concepts: The shape of an eggshell can determine its rigidity without affecting its strength. Reis explains the distinction by pointing out the difference between two eggshells, one of which is unbroken, and the other of which has tiny cracks in the shell. The two eggshells have the same rigidity, but the latter has less strength, because it breaks under less applied force than the egg with no cracks.

Reis' and Lazarus' model is a mathematical formula that predicts what will happen when you poke thin, shell-like structures at specific points. That is essentially what it takes to crack an egg: a sharp, targeted strike at the specific point where the egg's structure is weakest. The shell has a threshold beyond which it can't absorb any more force, and once that threshold is crossed, the shell will crack.

Reis became interested in studying eggshells after successfully walking on a few cartons of eggs without breaking them, a popular party trick among the geekerati. "I didn't believe it until the first time I did it, but you can actually stand on a carton of eggs," he said. The key is to align the eggs so that the narrow pole is pointing upward, and step in such a way to distribute your weight over the entire surface area, to avoid overloading any one eggshell. (It helps to go barefoot, Reis says.) Usually, it takes a little more than 5 ½ pounds of force to crack an eggshell — much less than the weight of a human being — but the precise amount of force needed depends on the direction in which that force is applied and how much the force is distributed (or not) over the surface of the shell.

Text Only
Lifestyles
  • Reunions for 7-26-14

    G. W. Carver High School Alumni Reunion

    The Ex-Students Reunion of G.W. Carver High School, Dawson will be held July 25-27 at Dawson Elementary School.

    July 25, 2014

  • Dresden UMC to hold first Lord’s Acre

    Dresden United Methodist Church will hold its first Lord’s Acre Vendor Craft Fair and Flea Market on Oct. 4, 2014.

    July 25, 2014

  • 7-19-14 Anniv-BurnsNow.jpg Burns 50th Anniversary

    Chuck Charles Burns Sr. and Pamela Johnston Burns celebrated 50 years of marriage on June 27, 2014.

    July 18, 2014 2 Photos

  • Reunions: CHS Class of 1959, G.W. Carver High School

    The Corsicana High School Class of 1959 will have its 55th reunion on the weekend of Oct. 3 through 5, 2014.

    The ex-students of G. W. Carver will celebrate its 30th annual reunion July 25 to 27 at Dawson High School.

    July 18, 2014

  • Around the U.S. — Man using 'blowtorch' to kill spider started fire

    SEATTLE — A man who used a can of spray paint and a lighter as a makeshift blowtorch to kill a spider in his laundry room started a blaze that caused $60,000 worth of damage, Seattle fire officials said Wednesday.

    July 16, 2014

  • Familiar Faces - Five Generations Familiar Faces

    Local students graduate from University of North Texas

    July 11, 2014 1 Photo

  • samantha stroube daviss.jpg Mom to be remembered

    As females we are always concerned with how we look, how our outfit fits us, do our shoes and handbag coordinate?...silly minor “girly” things. But as girls we reserve that right to worry about all that stuff.

    July 10, 2014 1 Photo

  • samantha stroube daviss.jpg Cutting the cord

    Being a parent is one of the most demanding jobs — both physically and emotionally.

    July 2, 2014 1 Photo

  • Christmas in July: TV week of holiday programming

    NEW YORK — The Hallmark TV channels are beginning a week's worth of holiday programming on the Fourth of July — but think ornaments and egg nog instead of fireworks and hot dogs.

    July 2, 2014

  • Familiar Faces

    Ronald W. Deskin, MD receives 2014 Ashbel Smith Distinguished Alumni award

    June 27, 2014