Dirac pointed out that one of the only ways to measure a particle's position is by bouncing a photon off of it, and seeing where and how that photon lands on a detector.

狄拉克指出唯一的方法就是通过反弹一个光子，并观察它在检测器上的位置和轨迹来测量一个粒子的位置。

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This photomicrograph was obtained by scanning a beam of electrons across the sample while a detector kept track of electrons bouncing off its surface, betraying the specimen's outer shape.

这幅显微照片是通过扫描穿过样品的电子束而获得的，同时检测器对从样品表面反弹的电子进行追踪，这些电子显示了标本的外形。

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When you go through a metal detector at the airport with a conductor such as keys in your pocket, the alarm goes off.

当你带着一个导体（比如口袋的钥匙）走过机场的金属探测器时，机器会发出警报声。

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If a passenger sets off the metal detector, engages in suspicious behavior, or is listed on a watch list, secondary screening would be appropriate.

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It was harder, he said, on his eight-year-old daughter, who was forced to remove her skirt when visiting him (its studs set off a metal detector).

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The rest present them as a voluntary secondary security option in lieu of a pat-down, which is protocol for those who've repeatedly set off the metal detector or have been randomly selected for additional screening.

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