雙語暢銷書《艾倫圖靈傳》第2章:下一個星期(27)
Alan also saw that Einstein avoided philosophical discussions of what space and time 'really were', and instead concentrated on something that could in principle be done. Einstein placed great emphasis on 'rods' and 'clocks' as part of an operational approach to physics, in which 'distance', for instance, only had meaning in terms of some well-defined measuring operation, not as an absolute ideal. Alan wrote:
艾倫還看到，愛因斯坦避開了哲學式的關於"時間和空間到底是什麼"的討論，相反地，他把注意力集中在一些可以做到的事情上。愛因斯坦強調，"木棒"和"時鐘"是物理學中可操作的研究手段，但像"距離"這樣的東西，只有在一些嚴格定義的測量操作中才有意義，不能絕對理想化。艾倫寫道：
Its are always the same distance apart, as you stipulate that that distance is your unit and your ideas have to go by that definition. … These ways of measuring are really conventions. You modify your laws to suit your method of measurement.
如果你站在自己的角度來定義距離，並讓你的想法滿足你的定義，然後你問，兩個點之間的距離是否一樣，這就是無意義的……
No respecter of persons, he preferred a piece of working of his own to that supplied by Einstein 'because in this way I think it should seem less “magicky”.' He reached the very end of the book, and gave a masterly derivation of the law* which in General Relativity would supplant Newton's axiom, that a body subject to no external force would move in a straight line with constant speed:
儘管如此，艾倫並不崇拜別人，相比於愛因斯坦的方法，他還是更喜歡他自己的方法。他說："這樣我纔會覺得它看起來不那麼怪。"他看到書的最後幾頁，輕鬆地給出了一個推導，說廣義相對論中的短程線運動定律，會取代牛頓的慣性定律：
He has now got to find the general law of motion for bodies. It will have, of course, to satisfy the general Principle of Relativity. He does not actually give the law, which I think is a pity, so I will. It is: 'The separation between any two events in the history of a particle shall be a maximum or minimum when measured along its world line.'
他現在知道了固體運動的一般規律。當然，這將滿足廣義相對論。他沒有直接給出定理，我覺得這是個遺憾，所以將由我來給出。那就是："對於一個粒子發生的兩個事件之間的間隔，當沿着其自身的世界線測量時，會取到最大值或最小值。"
