| 陈小将 |
2021-04-20 15:27 |
time 时间
‘Time waits for no man’ – or so the saying goes. We can’t stop time and we can’t control it, although sometimes, in our minds, we think time flies – for example, when the weekend arrives, we feel it’s over in no time! But if this year in particular feels like it’s passing more quickly than others have done, there could be a scientific explanation why. 15OzO.Ud
Of course, we know a year is usually 365 days long. Clever scientists calculated this a long time ago. They also worked out that every four years, we need an extra day to keep our calendar in sync – this is called a leap year. But 2021 isn’t one of those years, and yet it’s not behaving like a normal year. Scientists and astrophysicists have done the math and discovered the Earth is moving faster than it ever has in the last 50 years. This means that 2021 is going to be the shortest year in decades. |(CgX
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Apparently, this is because the Earth is spinning faster on its axis, quicker than it has done in decades, and the days are therefore shorter. But they are only short by a tiny amount – around 0.05 milliseconds – so don’t panic if you haven’t noticed! However, long-term these milliseconds add up. Astrophysicist Graham Jones and Konstantin Bikos from Time and Date told The Independent newspaper: “If the Earth’s rotation continues to quicken, we may at some point require a negative leap second. If this happens, our clocks would skip a second in order to keep up with the hurrying Earth.” Since 1972, 27 leap seconds have only been added to our time and none have been taken away. <'\!
This really is only of concern for atomic clocks – the most accurate timekeeping devices in history. Studying the Earth’s rotation and then subtracting or adding a leap second to these clocks can ensure they remain aligned and keep us on time. But now, maybe we need to get a move on before this ‘shorter’ year is gone in a split second! Q\N >W+d
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