A mechanism for hitting yourself in thehead with a baseball after a four-second delay

这个装置能让你在扔出棒球4秒后被这个棒球砸中脑袋。

We could use a springboard, a greasedchute, or even a dangling sling-anything that redirects the object upwardwithout adding to or subtracting from its speed. Of course, we could also trythis:

它可以是一个跳板、一个润滑过的滑槽，甚至是一个悬空的吊索——任何能够偏转物体而又不增加或减少它的速度的东西都行。当然了，我们还可以试试这个：

I ran through the basic aerodynamiccalculations for a baseball thrown at various speeds. I will give these heightsin units of giraffes:

我进行了一些基础的空气动力学计算，得出了以不同初速度扔棒球能达到的高度。我将以长颈鹿的高度作为比较对象：

The average person can probably throw abaseball at least three giraffes high:

平常人大概至少能把棒球扔到3只长颈鹿这么高：

Someone with a reasonably good arm couldmanage five:

一些臂力不错的人大概可以扔到5只长颈鹿这么高：

A pitcher with an 80 mph fastball couldmanage ten giraffes:

投手扔出的时速130千米的快球能飞到10只长颈鹿这么高：

Aroldis Chapman, the holder of the worldrecord for fastest recorded pitch (105 mph), could in theory launch a baseball14 giraffes high:

阿罗鲁迪斯•查普曼保持着世界最快投球的纪录（时速170千米），理论上他的球能飞到14只长颈鹿这么高：

But what about projectiles other than abaseball? Obviously, with the aid of tools like slings, crossbows, or thecurved xistera scoops in jai alai, we can launch projectiles much faster thanthat. But for this question, let's assume we stick to bare-handed throwing.

但如果投掷物不是棒球呢？很明显，在弹弓、十字弩或是回力球运动中那些弧形掷球器等工具的帮助下，我们能以更快的速度把东西扔出去。但在这个问题中，我们还是要求要徒手扔。

A baseball is probably not the idealprojectile, but it's hard to find speed data on other kinds of thrown objects.Fortunately, a British javelin thrower named Roald Bradstock held a “randomobject throwing competition,” in which he threw everything from dead fish to anactual kitchen sink. Bradstock's experience gives us a lot of useful data.4 Inparticular, it suggests a potentially superior projectile: a golf ball.

棒球可能不是理想的投掷物，但问题是很难找到其他投掷物的速度记录。幸运的是，一个叫作罗阿尔德•布拉兹托克的英国标枪运动员曾举办过一个随机物品投掷大赛。在比赛中他扔过从死鱼到厨房水槽在内的一大堆东西。布拉兹托克的经历给了我们许多有用的数据4。在这些数据中，一个很有潜力的理想投掷物是——高尔夫球。

Few professional athletes have beenrecorded throwing golf balls. Fortunately, Bradstock has, and he claims arecord throw of 170 yards. This involved a running start, but even so, it'sreason to think that a golf ball might work better than a baseball. From aphysics standpoint, it makes sense; the limiting factor in baseball pitches isthe torque on the elbow, and the lighter golf ball might allow the pitching armto move slightly faster.

专业运动员扔高尔夫球的记录少之又少。但十分幸运的是，布拉兹托克曾经这么干过，他声称扔过155米（从投掷点到第一次触地点）的距离。他扔之前是有助跑的，但尽管如此仍然有理由相信扔高尔夫球是比扔棒球更好的选择。这也说得通：在投掷棒球的过程中制约因素是手肘上的力矩，而投掷更轻的高尔夫球能让手臂运动得稍快一些。