声音,多少世纪以来我们始终只闻其声,未知其形。1947年,一幅照片让我们终于见识到“声音”的庐山真面目。这张非同寻常的照片拍摄于气候潮湿的加勒比海上空。当时,一架喷气式战斗机开足马力,超过了1220公里/小时的速度———音速。它所产生的强有力的冲击波使周围的水分子发生冷凝现象,形成一道雾墙。当飞机的速度终于超过音速的时候,随着一阵巨大的轰鸣声,机头穿过雾墙。这道雾墙,就是著名的“音障”(高速飞行的物体如飞机、火箭的速度增加到接近音速时,前方的空气因来不及散开而受到压缩,密度、温度突然增加,阻碍该物体向前飞行,这种现象叫做音障———译注)。声音,便以这种方式展现在我们面前。 Sound, how many centuries we have always heard the sound, unknown shape. In 1947, a photo finally allowed us to see the true meaning of “voice”. This extraordinary picture was taken over the humid Caribbean Sea. At that time, a jet fighter jet ran full speed, exceeding the speed of 1,220 km / h-the speed of sound. The powerful shock wave it produces condenses the surrounding water molecules and forms a fog wall. When the speed of the aircraft finally exceeds the speed of sound, with a huge roar, the nose through the fog wall. This foggy wall is the famous “sound barrier” (high-speed flying objects such as aircraft, rockets increased speed close to the speed of sound, the front of the air was too late to spread compressed, density, temperature suddenly increased, hinder the object forward Flying, this phenomenon is called sound barrier --- translation). Sound, in this way show in front of us.