Placeholder Image

字幕列表 影片播放

自動翻譯
  • A calendar year is made of three hundred and sixty five days -- a number that refuses to

    一個日曆年是由三百六十五天組成的,這個數字不可能是一個完整的數字。

  • be divide nicely, which is why we end up with uneven months of either 30 or 31 days. Except

    這就是為什麼我們最終會出現30天或31天的不均勻月份。除了

  • for February -- the runt of the litter -- which only gets 28... except when it gets 29 and

    2月的小傢伙,只有28歲... 除了29歲的時候

  • then the year is 366 days long.

    那麼一年就是366天長。

  • Why does that happen? What kind of crazy universe do we live in where some years are longer

    為什麼會這樣?我們生活在一個什麼樣的瘋狂的宇宙中,有些年頭比較長

  • than others?

    比別人多?

  • To answer this we need to know: just what is a year?

    要回答這個問題,我們需要知道:究竟什麼是一年?

  • Way oversimplifying it: a year is the time it takes Earth to make one trip around the

    過於簡化:一年是地球繞地球一圈所需的時間。

  • sun. This happens to line up with the cycle of the seasons.

    太陽。這恰好與四季的循環相吻合。

  • Now, drawing a little diagram like this showing the Earth jauntily going around the sun is

    現在,畫一張這樣的小圖,顯示地球繞著太陽歡快地走,就是:"我的天啊!"。

  • easy to do, but accurately tracking a year is tricky when you're on Earth because the

    很容易做到,但準確地跟蹤一年是棘手的,當你'在地球上,因為你'。

  • universe doesn't provide an overhead map.

    宇宙不提供架空圖。

  • On Earth you only get to see the seasons change and the obvious way to keep track of their

    在地球上,你只能看到四季的變化,而跟蹤它們的明顯方法是:

  • comings and goings is to count the days passing which gives you a 365 day calendar.

    來來去去就是數著日子過,這就有了一個365天的日曆。

  • But as soon as you start to use that calendar, it slowly gets out of sync with the seasons.

    但只要你開始使用那個日曆,它就會慢慢與季節不同步。

  • And with each passing year the gap gets bigger and bigger and bigger.

    而且隨著時間的推移,差距越來越大,越來越大。

  • In three decades the calendar will be off by a week and in a few hundred years the seasons

    三十年後,日曆會偏離一週,幾百年後,季節也會偏離。

  • would be flipped -- meaning Christmas celebrations taking place in summer -- which would be crazy.

    將被翻轉 -- 意味著聖誕節的慶祝活動在夏天舉行 -- 這將是瘋狂的。

  • Why does this happen? Did we count the days wrong? Well the calendar predicts that the

    為什麼會出現這種情況?難道是我們算錯了日子?嗯,日曆預測

  • time it takes for the Earth to go around the sun is 8,760 hours. But, if you actually timed

    地球繞著太陽轉一圈的時間是8760小時。但是,如果你真的計時

  • it with a stopwatch you'd see that a year is really longer than the calendar predicts

    用秒錶看,你會發現,一年的時間真的比日曆上預測的要長

  • by almost six hours. So our calendar is moving ever-so-slightly faster than the seasons actually

    幾乎快了六個小時所以我們的日曆走得比季節走得更快一些

  • change.

    變化。

  • And thus we come to the fundamental problem of all calendars: the day/night cycle, while

    於是我們來到了所有曆法的根本問題:晝夜循環,而。

  • easy to count, has nothing to do with the yearly cycle.

    易算,與年輪無關。

  • Day and night are caused by Earth rotating about its axis. When you're on the side faceing

    白天和黑夜是由地球繞其軸線旋轉造成的。當你在面對地球的一側時

  • the sun, it's daytime and when you're on the other side it's night. But this rotation is

    太陽,是白天,而當你在另一邊時,是夜晚。但這種旋轉是

  • no more connected to the orbital motion around the sun than a ballerina spinning on the back

    繞日運動與芭蕾舞演員的背轉運動沒有任何聯繫。

  • of a truck is connected to the truck's crusing speed.

    卡車的速度與卡車的破碎速度有關。

  • Counting the number of ballerina turns to predict how long the truck takes to dive in

    計算芭蕾舞演員的轉身次數來預測卡車潛入的時間。

  • a circle might give you a rough idea, but it's crazy to expect it to be precise.

    一個圓可能給你一個粗略的想法,但它'瘋狂的期望它是精確的。

  • Counting the days to track the orbit is pretty much the same thing and so it shouldn't be

    算天數來追蹤軌道是差不多的事情,所以不應該'。

  • a surprise when the Earth dosen't happen to make exactly 365 complete spins in a year.

    一個驚喜,當地球dosen'不發生使正好365完整的旋轉在一年。

  • Irritatingly, while 365 days are too few 366 days are too many and still cause the seasons

    令人惱火的是,雖然365天太少,但366天太多,還是會造成季節性的

  • to drift out of sync, just in the opposite way.

    以漂移不同步,只是方式相反。

  • The solution to all this is the leap year: where February gets an extra day, but only

    解決所有這些問題的辦法是閏年:2月多了一天,但只是

  • every four years.

    每四年一次。

  • This works pretty well, as each year the calendar is about a quarter day short, so after four

    這很好用,因為每年的日曆都少了四分之一天,所以經過四次

  • years you add an extra day to get back in alignment.

    年你多加一天的時間來重新調整。

  • Huzzah! The problem has been solved.

    哈扎!問題已經解決了。

  • Except, it hasn't.

    只是,它沒有'。

  • Lengthening the calendar by one day every four years is slightly too much, and the calendar

    每四年加長一天的歷法,略顯過頭,曆法

  • still falls behind the seasons at the rate of one day per hundred years.

    仍以每百年一天的速度落後於季節。

  • Which is fine for the apathetic, but not for calendar designers who want everything to

    這對冷漠的人來說很好,但對日曆設計者來說就不一樣了,他們希望所有的東西都能被設計出來。

  • line up perfectly.

    排列完美。

  • To fix the irregularity, every century the leap year is skipped.

    為了解決不規則的問題,每隔一個世紀就跳過一個閏年。

  • So 1896 and 1904 were leap years but 1900 wasn't.

    所以1896年和1904年是閏年,但1900年不是。

  • This is better, but still leaves the calendar ever-so-slightly too fast with an error of

    這樣更好,但還是會讓日曆的速度稍稍過快,誤差為

  • 1 day in 400 years.

    400年中的1天。

  • So an additional clause is added to the skip the centuries rule that if the century is

    所以在跳過世紀規則中增加了一個附加條款,如果世紀是

  • divisible by 400, then it will be a leap year.

    除以400,則為閏年。

  • So 1900 and 2100 aren't leap years, but 2000 is.

    所以1900年和2100年不是閏年,但2000年是。

  • With these three rules, the error is now just one day off in almost eight thousand years

    有了這三條規則,現在近八千年來,誤差只差一天。

  • which the current calendar declares 'mission accomplished' and so calls it a day.

    目前的日曆宣佈'任務完成了&39;,並以此作為一天。

  • Which is probably quite reasonable because eight thousand years ago humans were just

    這可能是相當合理的,因為八千年前的人類還僅僅是...

  • figuring out that farming might be a good idea and eight thousand years from now we'll

    想出了農業可能是一個好主意,八千年後,我們';會。

  • be hopefully be using a calendar with a better date tracking system.

    希望能使用一個更好的日期跟蹤系統的日曆。

  • But perhaps you're a mathematician and a 0.0001 percent error is an abomination in your eyes

    但也許你'是個數學家,0.0001%的誤差在你眼裡是個可惡的東西。

  • and must be removed.

    並且必須拆除。

  • "Tough luck" says The Universe because the length of a day isn't even constant. It randomly

    "Tough luck"宇宙說,因為一天的長度甚至不是恆定的。它隨機地

  • varies by a few milliseconds and on average and very slowly decreases by about 1 millisecond

    以幾毫秒的速度變化,平均而言,非常緩慢地減少約1毫秒。

  • per hundred years. Which means it's literally impossible to build a perfect calendar that

    每一百年。這意味著它的字面上不可能建立一個完美的日曆,即

  • lasts forever.

    永遠持續下去。

  • In theory the length of a day will expand to be as long as a curent month -- but don't

    理論上講,一天的長度將擴大到和一個月一樣長--但不要。

  • worry in practice it will take tens of billions of years, and our own expanding sun will destroy

    擔心在實踐中需要幾百億年的時間,我們自己膨脹的太陽會毀滅。

  • the earth long before that happens.

    在這之前,地球早已。

  • Sorry, not quite sure how we got from counting the days of the months to the fiery unavoidable

    對不起,不太清楚我們是怎麼從數月的日子到火熱的不可避免的日子的

  • end of all human civilization -- unless of course we have an adequately funded space

    所有人類文明的終結 -- 當然,除非我們有足夠的資金支持的空間。

  • program (hint, hint) -- but there you have it.

    程序(提示,提示) -- -- 但你有了。

  • For the next eight millennia Leap years will keep the calendar in sync with the seasons

    在接下來的八千年裡,閏年將使日曆與季節同步。

  • but in a surprisingly complicated way.

    但方式卻複雜得出奇。

  • You can learn a lot more about orbits, different kinds of years and supermassive black holes

    你可以瞭解更多關於軌道、不同類型的年份和超大品質黑洞的知識。

  • and over at Minute Physics. As always, Henry does a great job of explaining it all in his

    和在Minute Physics。一如既往,Henry在他的文章中做了很好的解釋。

  • new video. Check it out.�

    新視頻。看看吧。

A calendar year is made of three hundred and sixty five days -- a number that refuses to

一個日曆年是由三百六十五天組成的,這個數字不可能是一個完整的數字。

字幕與單字
自動翻譯

影片操作 你可以在這邊進行「影片」的調整,以及「字幕」的顯示

B1 中級 中文 日曆 閏年 地球 季節 太陽 速度

What is a Leap Year?

  • 49 2
    fisher 發佈於 2013 年 03 月 24 日
影片單字