No matter if they are raw, soft-boiled or hard-boiled: At least for mathematicians eggs were hard nuts to crack for all times. Even if the little cell of life looks as simple and harmonic as a ball or a three-dimensional ellipse, it is very hard to describe with a simple formula, because eggs have only one symmetry axis.
The reason why nature chose to protect growing life in such a strangely shaped sphere is not completely clear yet. Scientists suppose that the construction survived in evolution, because the egg can't roll away that easily and just spins round instead.
But it's a fact that the eggshell is extremely robust, if you consider that it's shell is only a third of a millimetre thin. "I bet you can't crush a raw hen's egg just with your thumb and middle finger, if you only touch it at the tapered ends!" This is a popular and surprising bet: If the egg is healthy and without a crack the attempt will fail despite of all mobilised force. Really robust eggs can withstand weights of up to seven kilos. And with two fingers you simply have no chance. The imposed pressure smartly spreads over the whole shell because of its drawn-out shape. The delicate little "cupolas" can stand the pressure. This advantage has been used by church architects, bridge-builders and igloo-constructors since all times.
As even and harmonic as an egg? What fascinated painters, sculptors and jewellers since long times looks everything but even if you observe it under a modern electron microscope: The plain lime surface looks like a complicated brushwood, if you take a closer look at it. And the side view of a broken egg-shell appears to look like the edge of a spectacular Mars-canyon.
"This lime-shell is an extremely intelligent design," explains ornithologist Prof. Dr. Gerhard Spitzer, Vienna: "When the hen incubates the eggs at a temperature of the nest of up to 42 degrees, the growing chick, which evolves from a so-called blastodisc at one end of the egg, has to get oxygen from the outside. And at the same time it must be able to exhale carbon dioxide through pores in the shell." In contrast, egg white and egg yolk are the providers of nutrient depots needed by the chick.
Just think of the energy an egg contains! Scientists have detected 35 of about 100 chemical elements in the average 60 grammes of a hen's egg, as well as all vitamines except of vitamin C (but mainly vitamins A, D, E, K and B12).
The energy-package contains 77 calories of nutritional value, also phosphor, iron, magnesium and extremely high-value protein. Unfortunately, the masterpiece of nature also contains that much of cholesterol that you allready exceed the daily recommended value of 300 miligrammes with two eggs (each has about 250 milligrammes of fat). But the reason why you nonetheless may make an exception at Easter is the high amount of contained lecithin, which strongly regulates the absorption of cholesterol into the blood.
Anyhow Dr. Ingrid Kiefer, nutritionist at the Institute of Social Medicine, stays cautious: "With everythong in life staying moderate is a good choice. But two or three eggs on Easter Sunday normally shouldn't be a problem for healthy human beings."