經典科幻文學:《銀河系漫遊指南》第34章1

The aircar rocketed them at speeds in excess of R17 through the steel tunnels that lead out onto the appalling surface of the planet which was now in the grip of yet another drear morning twilight. Ghastly grey lights congealed on the land.
R is a velocity measure, defined as a reasonable speed of travel that is consistent with health, mental wellbeing and not being more than say five minutes late. It is therefore clearly an almost infinitely variable figure according to circumstances, since the first two factors vary not only with speed taken as an absolute, but also with awareness of the third factor. Unless handled with tranquility this equation can result in considerable stress, ulcers and even death.
R17 is not a fixed velocity, but it is clearly far too fast.
The aircar flung itself through the air at R17 and above, deposited them next to the Heart of Gold which stood starkly on the frozen ground like a bleached bone, and then precipitately hurled itself back in the direction whence they had come, presumably on important business of its own.
Shivering, the four of them stood and looked at the ship.
Beside it stood another one.

空中飛車載著他們以超過R17的速度通過那條鋼鐵隧道，一舉衝上荒蕪的行星表面，迎接他們的是又一輪黎明前的微光。詭異的灰色光芒象是凝結在大地的表面。
R是一個速度計量標準，代表着一種合理的行駛速度，與乘客的生理健康、心理安適以及不超過——這麼說吧——5分鐘的晚點相協調。因此，它顯然是一個根據環境的不同而幾乎無限可變的變量，因爲前兩個因素不僅絕對的隨速度而變化，還相對的隨着對第三個因素的知覺意識而變化。這樣的一個綜合方程式如果處理不好的話，就會出現壓力、潰瘍甚至死亡。
R17不是一個固定的速度，但它顯然是快得有點兒離譜的那種。
空中飛車以R17甚至更高的速度劃過天際，最後降落在靜靜的停在凍僵的地面上、象一塊漂白過的骨頭似的“黃金之心”號旁邊。放下乘客後，它就猛地向着來時的方向飛走了，大概是去執行它自己的什麼重要使命。
四個人站在原地看着他們的飛船，渾身發抖。
它旁邊還停著另外一艘。