Water is very nearly incompressible, so the impact isn't spread out over time-it comes as a single sharp shock. The momentary force on the glass is immense, and it breaks.
水几乎是不可压缩的，因而冲击不会随时间被消散掉，而是像给杯子结结实实来了一锤，瞬时间会对杯子产生巨大的作用力，然后杯子就碎了。
This “water hammer” effect (which is also responsible for the “clunk” you sometimes hear in old plumbing when you turn off the faucet) can be seen in the well-known party trick of smacking the top of a glass bottle to blow out the bottom.
你在聚会上看到的猛击玻璃瓶子顶部会把瓶底打碎的现象就是由这种“水锤”效应产生的。如果你关闭连着老式管道的水龙头，有时也会听到由此产生的沉闷的咚咚声。
When the bottle is struck, it's pushed suddenly downward. The liquid inside doesn't respond to the suction (air pressure) right away-much like in our scenario-and a gap briefly opens up. It's a small vacuum-a few fractions of an inch thick-but when it closes, the shock breaks the bottom of the bottle.
当瓶子被猛击时，它会被突然往下推。瓶中的液体没法即时对吸力（气压）产生响应——就像我们这里一样——于是瓶底会短暂地出现一个空隙。当这个1厘米厚的真空区域最终闭合后，冲击波就会击碎瓶底。
In our situation, the forces would be more than enough to destroy even the heaviest drinking glasses.
而在我们假设的情形下，产生的冲击力足以击碎最厚实的杯底。
The bottom is carried downward by the water and thunks against the table. The water splashes around it, spraying droplets and glass shards in all directions.
碎掉的瓶底被水流推着砸到桌上，发出梆梆声。杯子里的水也会在周围溅开来，水珠和碎玻璃飞得到处都是。
Meanwhile, the detached upper portion of the glass continues to rise.
与此同时，和杯子下半部分分离的上半部分会继续向上飞。
After half a second, the observers, hearing a pop, have begun to flinch. Their heads lift involuntarily to follow the rising movement of the glass.
0.5秒后，两个旁观者在听到一声巨响后吓得往后退了一点。他们的头也不由自主地跟随着飞到天上的杯子向上抬起。
The glass has just enough speed to bang against the ceiling, breaking into fragments . . .
杯子的速度恰好够一头撞到天花板上，然后裂成碎片……
. . . which, their momentum now spent, return to the table.
……随着动量的消散，它们最终又回到了桌面上。
The lesson: If the optimist says the glass is half full, and the pessimist says the glass is half empty, the physicist ducks.
这个故事告诉我们：如果乐观主义者说杯子是半满的，而悲观主义者说杯子是半空的，那么物理学家就该跑路了。
1 Even a vacuum arguably isn't truly empty, but that's a question for quantum semantics.
1． 其实就算是真空，你也可以说它不是真的是空无一物，不过这已经牵扯到量子语义学了。