《那些古怪又讓人憂心的問題》第37期:冰球一擊(2)

But a hockey puck moving at Mach 8 would have a lot of problems, starting with the fact that the air ahead of the puck would be compressed and heated very rapidly. It wouldn't be going fast enough to ionize the air and leave a glowing trail like a meteor, but the surface of the puck would (given a long enough flight) start to melt or char.

但一個以8馬赫速度運動的冰球會碰到很多問題。首先冰球前方的空氣會被急速壓縮，因而溫度會急劇上升。它不會像隕石那樣速度快到足以電離空氣並在身後留下一條發光的尾跡，但（只要時間足夠長）冰球的表面將開始融化或碳化。

The air resistance, however, would slow the puck down very quickly, so a puck going at Mach 8 when it leaves the launcher might be going a fraction of that when it arrives at the goal. And even at Mach 8, the puck probably wouldn't pass through the goalie's body. Instead, it would burst apart on impact with the power of a large firecracker or small stick of dynamite.

而空氣阻力將使冰球迅速減速，所以當一個被以8馬赫的速度發射出來的冰球到達對方球門時，它的速度可能比初始速度慢多了。就算它仍保持8馬赫的速度，也不太可能擊穿對面守門員的身體。相反它會因爲劇烈的撞擊而四分五裂，威力相當於一個大型爆竹或者一小條炸藥。

If you're like me, when you first saw this question, you might've imagined the puck leaving a cartoon-style hockey-puck-shaped hole. But that's because our intuitions are shaky about how materials react at very high speeds.

如果你是像我這樣的人，那麼在第一眼看到這個問題時你想到的可能是冰球會在守門員軀體上留下一個動畫片裏那種冰球形狀的洞。但這只是因爲，我們對於各種材料在極高速下會發生什麼的直覺是十分不正確的。

Instead, a different mental picture might be more accurate: Imagine throwing a ripe tomato-as hard as you can-at a cake.

相反，實際的場景更可能是這樣的：想象一下你以最大的力氣把一個熟透的西紅柿往一個蛋糕上砸。

That's about what would happen.

這有助於你想象那個冰球砸中對面守門員後會發生什麼……

1 Though it uses hydrogen instead of air, and when you shoot your eye out, you really shoot your eye out.

1． 不過它用的是氫氣而不是空氣，而且它不僅會讓你驚得眼珠子都掉出來，它會真的把你的眼珠子射出來。