一個多世紀(jì)以來，今年是春天最早到來的一年

一個多世紀(jì)以來，今年是春天最早到來的一年

As if 2020 hasn’t already been the longest decade of our lives, we’re now told that spring is set to make its earliest arrival in 124 years.

似乎2020年還不是我們生命中最長的十年，我們現(xiàn)在被告知，這個春天將是124年里最早到來的一次。

This shift has largely to do with our quirky calendar system, resulting from more than a century of leap years and the impact of those extra days over time, according to the Farmer’s Almanac. Every year, it takes Earth 365.25 days to revolve around the Sun, according to NASA. In order to compensate for that extra quarter of a day, our calendar system adds an extra day, February 29, every four years or so.

據(jù)《農(nóng)民年鑒》稱，這種變化主要與我們古怪的歷法體系有關(guān)，這是由一個多世紀(jì)的閏年和這些額外天數(shù)的影響造成的。據(jù)美國國家航空航天局稱，地球每年繞太陽公轉(zhuǎn)一周需要365.25天。為了彌補(bǔ)多出的1 / 4天，我們的日歷系統(tǒng)每四年左右增加一天，即2月29日。

Madison Dapcevich

“To keep our yearly calendars consistent with our orbit around the Sun, every four years we add one day. That day is called a leap day, and the year it's added to is called a leap year,” writes the space agency.

“為了使我們的年歷與我們圍繞太陽的軌道一致，每四年我們增加一天。這一天被稱為閏日，加上這一天的那一年被稱為閏年。”

There’s a quick trick to determining whether a year will be one that leaps. If the last year is divisible by 20, like this year’s 2020, then we will add the extra day. But if it is divisible by 100, it skips a leap year. Hold up, there’s more. Under our current calendar system, most century years, for example, 1700, will skip February 29 unless the year is divisible by 400, which was the case in 2000. That last rule is what has put us in this earlier-than-usual spring equinox.

有一個快速的技巧可以判斷這一年是否會是一個飛躍的一年。如果最后一年能被20整除，就像今年的2020年，那么我們將增加額外的一天。但是如果它能被100整除，它就跳過了一個閏年。等等，還有更多。在我們目前的日歷系統(tǒng)中，大多數(shù)世紀(jì)年，例如1700年，將跳過2月29日，除非這一年能被400整除，這是2000年的情況。這最后一條就是讓我們比平常更早進(jìn)入春分的原因。

Illumination of the Earth during various seasons as the planet orbits around the Sun. The top position represents the spring equinox while the bottom shows the fall. The summer solstice is depicted on the left and the winter solstice the right. Gritsalak karalak/Shutterstock

Now to the astrophysics bit.

現(xiàn)在是天體物理學(xué)解釋部分。

The axis of the Earth is tilted 23.4 degrees, which is what causes the cycle of our seasons. During part of the year, the Northern Hemisphere is tilted toward the Sun, positioning this part of the world closer to it and thus providing more heat (aka summer), while the Southern Hemisphere of our planet is tilted away. In six months, these seasons will again shift. But the spring and fall equinoxes mark two days a year when both hemispheres receive roughly the same amount of light from the Sun.

地球的地軸傾斜23.4度，這就是造成我們的季節(jié)循環(huán)的原因。在一年中的一部分時間里，北半球是斜向太陽的，這使得世界的這一部分離太陽更近，因此提供了更多的熱量(也就是夏天)，而地球的南半球則是斜向太陽的。6個月后，這些季節(jié)將再次變換。但春秋分點(diǎn)標(biāo)志著一年中的兩天，兩個半球接收到的太陽光線大致相同。

“Most years, the Spring Equinox is on the 20th or 21st. For the first time since 1896, it occurs on the 19th in all of the US time zones,” tweeted a WBAL-TV meteorologist Tony Pann in Baltimore, Maryland.

“大多數(shù)時候，春分是在20日或21日。這是自1896年以來的第一次，它于19日在美國所有時區(qū)發(fā)生。wbal電視臺的氣象學(xué)家托尼·潘恩在馬里蘭州巴爾的摩市發(fā)的一條推特上說。

The vernal equinox marks the moment the Sun crosses the equator from south to north, which occurs at 11:49 pm ET in the US and in the early hours of Friday, March 20, in the rest of the world. You can check Time and Date to see when your hometown will see its equinox.

春分標(biāo)志著太陽從南到北穿過赤道的時刻，美國東部時間晚上11點(diǎn)49分，世界其他地區(qū)是3月20日星期五的凌晨。你可以查看時間和日期，看看什么時候你的家鄉(xiāng)會看到春分。