直到不久之前，对质子半径最好的测量是0.877飞米（千万亿分之一分尺），误差为在0.007飞米。

Until recently the best estimate of the proton radius was 0.877 femtometres with an uncertainty of 0.007 fm

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在讨论原子级别时间的时候，物理学家用起皮秒（百万兆分之一秒）甚至飞秒（千万亿分之一秒）来都没任何不便。 这是一方面。

Physicists have no trouble using, on the one hand, picoseconds (trillionths of a second) or even femtoseconds (quadrillionths of a second) to discuss time at the atomic scale.

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在摆弄了10几年实验装置以后，Hinds博士的团队已经成功证明在千万亿分之一的精度下，电子的确是“完美”的球形。

After more than ten years of fiddling with their set-up, Dr Hines's team has succeeded in determining that the electron is round to within one part in a million billion.

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