时差N小时:鸡蛋和灯泡

What a light bulb and an egg have in common? Theshell of an egg and the glass exterior of a light bulbhave more than one thing in common. First, bothprotect something delicate inside: the exterior ofthe light bulb keeps the delicate internal wiringprotected and an eggshell protects a developingchick.The need to protect chicks and wiring requiresthat eggshells and light bulbs be structurally strong.

电灯泡和鸡蛋有什么共同点呢?鸡蛋的外壳和灯泡的玻璃外罩的相同点可不止一处。首先，两者都在保护内部脆弱的东西：灯泡的外罩保护精细的内部接线，而蛋壳保护还未孵化的小鸡。为了保护小鸡和灯丝，要求蛋壳和灯罩的结构性很强。

Second, both are made of thin material. A chick, ready to hatch, has to be able to peck its waythrough the shell. And because light bulbs are usually made of opaque rather than clear glass,the glass exterior must be thin so that light can shine through.

其次，两者都由薄型材料构成。一只待孵化的小鸡必须能够破开蛋壳钻出来。且因为灯泡通常由不透明的玻璃做成，所以玻璃外罩要很薄，这样灯光才能透过灯罩射出去。

So how can a structure be strong and yet made of thin material at the same time? By using acarefully-designed oval shape. Picture for a moment a square egg. If you took that imaginaryobject in your hand and squeezed it very hard between your thumb and finger, the pressureyou'd exert would be localized in the exact part of the flat surface your thumb and finger werepushing. Even a slight pressure would be great enough to break the thin shell into pieces.

那么什么样的结构即坚固同时又能由薄层的材料制成呢?通过利用一种精心设计的椭圆形。暂且先描绘一个方形的蛋。假设你把这个虚构的对象拿在手里，用拇指和食指用力挤压，你施加的压力会落在拇指和食指接触到的平面上。即使是轻微的压力也足以将薄薄的蛋壳打得粉碎。

But if you do the same thing to a real egg, the force you exert is not localized in one point, butis distributed into all directions around the surface of the egg. Though you can eventuallybreak an egg by doing this, it takes a great deal more force to do so. Of course, it's nocoincidence that the shapes of light bulbs and eggs are similar. When the light bulb wasinvented and perfected, it was patterned after a shape that nature had come up with hundredsof thousands of years ago.

但是如果你挤压一个真正的鸡蛋，那么你施加的压力并不着力在一个点上，而是分散在蛋壳表面的各个方向。尽管你最终还是可以将鸡蛋捏碎，但在那之前你要使更多的劲。当然，灯泡的形状跟鸡蛋相似并不是偶然现象。灯泡的发明和完善还是仿照了大自然几十万年前就有的形状。