http://www.engadget.com/2010/07/16/inside-apples-black-lab-wireless-testing-facilities/
注意下面这段：
"Ruben and the crew led us through another hallway and into a separate lab
where more interference testing
was going on using "heads" and "hands." The heads are made of plastic and
filled with a liquid mixture that
replicates the contents of... well, your head. The hands are made from a
kind of high-test foam rubber"
原来苹果用塑料头和泡沫手来测试 iphone4, 怪不得有 proximity sensor 和 death
grip 的问题。
