手机版
The higher up you are, the faster time passes - by bringing relativity back to Earth.
Past experiments have confirmed Albert Einstein's theory of relativity by comparing atomic clocks on the Earth's surface with ones placed in high-altitude jets and rockets.
But ABC Science reported on September 22 that Dr James Chin-Wen Chou and colleagues from the National Institute of Standards and Technology (NIST) in the US, have used the latest generation of atomic clocks to measure changes in time at a more down-to-Earth scale.
The researcher's first experiment involved lifting one clock above the other allowing them to measure the change in the Earth's gravitational pull over distances of less than a meter.
Their results confirmed time moves quicker, and hence a person ages faster, when they stand a couple of steps higher on a staircase.
The difference isn't much, about 25 billionths of a second over a 79 year life time, but it will have more practical applications in areas like global positioning systems and geophysics.
The key to both experiments is the quantum logic atomic clock, which uses the oscillation of a single aluminium ion to maintain precise timing. The atom vibrates between two energy levels allowing the clocks accuracy down to a second in 3.7 billion years.
参考译文：
如果把相对论应用到地球上来，你站的越高，时间流逝得越快。
以往的试验论证了艾尔波特•爱因斯坦的相对论，试验将地面上的原子钟和高空火箭和喷气式飞机上的原子钟进行比较。
美国国家标准与技术研究院物理实验室的詹姆斯•周钦文（音译）教授和同事一起，用最新一代的原子钟在较为接近地面的位置测量时间的流逝。
在第一项试验中，研究人员将两个钟分别放在距离不到一米的地方，在地球引力作用下测量时间的流逝。
结果再次证明，对于站在比地面高几个阶梯的楼梯上的人来说，时间过得越快，他们也要比站在地面的人们衰老更快。
当然，这种衰老速度差异微乎其微。在一个人79年的生命中，可能才只有250亿分之一秒的差别。但是却可以应用于全球定位系统和地球物理学等领域中。
两个实验的重点是量子铝原子钟，它利用单一铝离子的震荡来精准测量时间的流逝。原子在两个能量等级之间震荡，钟的精确度为运行37亿年后误差不超过正负一秒。
