Placeholder Image

字幕列表 影片播放

由 AI 自動生成
  • If you look at the wake behind a duck, or a kayak, or a ship, you might notice two unusual

    如果你看鴨子、皮划艇或船後面的尾巴,你可能會注意到兩個不尋常的地方。

  • things: first, the wake isn't simple (like the perfectly straight shock wake of a supersonic

    事情:首先,尾翼並不簡單(就像超音速飛機完美的直線震盪尾翼那樣)。

  • projectile is) - it's a fascinating, feathery, ripple-y pattern.

    彈丸是)--這是一種迷人的、羽毛狀的、波紋狀的圖案。

  • And second, that feathery pattern looks the same - same angle, same repeating pattern

    其次,那個羽毛狀的圖案看起來是一樣的--同樣的角度,同樣的重複圖案

  • of ripples along the edge, same reverse arcs in the middle - it looks more or less the

    沿著邊緣的波紋,中間同樣的反向弧線--它看起來或多或少地有了些許的變化。

  • same regardless of whether it's made by a duck, a kayak or a ship, even though they're

    不管是鴨子、皮划艇還是船做的都一樣,即使它們是。

  • all moving at different speeds and the waves are very different sizes.

    都在以不同的速度運動,而波浪的大小卻大不相同。

  • The reason water wakes always have this particular shape and pattern is because of the surprising

    水滸傳之所以總是有這種特殊的形狀和圖案,是因為出人意表的

  • physics of water waves.

    水波的物理學。

  • While there's a single speed of light waves, and a single speed of sound waves, there's

    雖然光波的速度是單一的,聲波的速度也是單一的。

  • no single speed of water waves.

    沒有單一的水波速度。

  • In water, longer waves travel faster, while shorter waves travel slower.

    在水中,較長的波浪行進速度較快,而較短的波浪行進速度較慢。

  • This phenomenon where different wavelength waves travel at different speeds is known

    這種不同波長的波以不同速度傳播的現象稱為

  • as dispersion, and it makes water waves both interesting and complicated.

    作為分散,它使水波既有趣又複雜。

  • Like a boat wake.

    就像一個船尾。

  • To explain the shape of a boat wake, we'll start by looking at water waves of just a

    為了解釋船尾的形狀,我們先看一下水波的形狀。

  • single wavelength (and speed).

    單一波長(和速度)。

  • A boat traveling across this simpler water creates a series of circular waves - if the

    船在這種簡單的水面上行駛,會產生一連串的圓形波浪--------若是

  • water waves are faster than the boat, the waves encircle it, but you don't get a wake.

    水波比船快,波浪包圍了它,但你不會有驚濤駭浪。

  • If the waves are slower than the boat, the boat outruns them and the circles all add

    如果波浪比船慢,船就會超過波浪,圈圈都會加。

  • together to create a V-shaped wake.

    一起形成一個V形的尾巴。

  • And if the waves are even slower, the boat will outrun them even more and they'll add

    如果海浪再慢,船就會比它們更快,它們就會增加。

  • together to a narrower V shape.

    合在一起,形成一個較窄的V形。

  • Slower waves make narrower wakes.

    較慢的波浪使波浪更窄。

  • Faster waves make wider wakes.

    波浪更快,浪花更寬。

  • But we need to remember that water waves are waves, that is, they repeat themselves.

    但我們要記住,水波就是波,就是重複。

  • So every circular wave is really the first of a series of circular waves.

    所以每一個圓波其實都是一系列圓波中的第一個。

  • This means that instead of creating just one v-shaped wake, a moving boat creates a train

    這意味著,移動的船不是隻產生一個V形的水花,而是產生一連串的水花。

  • of v-shaped wakes that are each exactly one wavelength apart.

    的V形波浪,每個波浪正好相隔一個波長。

  • The reason a real boat doesn't make straight v-shaped wakes is that a real boat makes waves

    真正的船之所以不會產生直的V形波浪,是因為真正的船會產生波浪。

  • of many different wavelengths.

    許多不同波長的。

  • And because of dispersion, different wavelengths travel at different speeds: the longer ones

    由於色散的存在,不同波長的傳播速度不同:較長的是

  • travel faster and shorter ones travel slower.

    走得快,短的走得慢。

  • Faster waves create wider wakes, and because faster waves also have longer wavelengths,

    較快的波浪會產生較寬的波浪,而且因為較快的波浪也有較長的波長。

  • that means that wider wakes are further apart.

    這意味著,更寬的湖泊更遠的距離。

  • Similarly, slower waves create narrower wakes, and because slower waves also have shorter

    同樣,較慢的波浪會產生較窄的波浪,而且由於較慢的波浪也有較短的波浪,是以,較慢的波浪會產生較窄的波浪。

  • wavelengths, narrower wakes are closer together.

    波長較窄的波段,距離較近的波段。

  • When you add together narrow, closely spaced wakes, with wider, more widely spaced wakes,

    當你把窄小的、間隔緊密的湖泊,與寬大的、間隔較寬的湖泊加在一起。

  • with even wider, even more widely separated wakes, and so on, voilá!

    與更寬、更寬分開的湖泊,以此類推,voilá!

  • The shape of a boat wake!

    船尾的形狀!

  • Look at the beautiful repeating feathery ripples out on the edge, and the wider repeating arcs

    你看,美麗的重複的羽毛狀波紋在邊緣出,還有更寬的重複的弧線。

  • inside the wake itself.

    內的喚醒本身。

  • If you replace these sharp lines with smoother waves at the appropriate angles and spacings,

    如果你以適當的角度和間距將這些尖銳的線條換成更平滑的波浪。

  • you get an even more convincing boat wake.

    你會得到一個更有說服力的船尾。

  • And we can do the same again in 3D to get a really realistic-looking boat wake.

    而且我們還可以用3D技術再做一次同樣的處理,以獲得一個看起來非常逼真的船尾。

  • So in summary: wakes have the shape they do because water waves travel at different speeds.

    所以綜上所述:湖泊之所以有這樣的形狀,是因為水波的傳播速度不同。

  • Slower water waves create narrow, closely spaced V-shaped wakes, and faster water waves

    較慢的水波會產生窄小的、間隔緊密的V形波浪,而較快的水波則會產生窄小的、間隔緊密的V形波浪。

  • create wider V-shaped wakes that are further apart.

    形成較寬的V形波浪,距離較遠。

  • When you add all these different v-shaped patterns together, at the correct angles and

    當你把所有這些不同的V形圖案加在一起,以正確的角度和

  • spacings determined by water's dispersion relation, you end up with the unique shape

    由水的分散關係決定的間距,你最終會得到獨特的形狀。

  • of a water wake.

    的水醒。

  • SPONSORSHIP MESSAGE: Watch an extended, ad-free version of this

    贊助資訊。觀看本片的無廣告擴展版

  • video on Nebula.

    星雲上的視頻。

  • Ok, there are some caveats to the science in this video, and you can find out about

    好吧,這段視頻中的科學有一些注意事項,你可以瞭解一下。

  • them in the extended version over on Nebula, the Streamy-award-nominated independent streaming

    他們的加長版在Nebula上,獲得Streamy獎提名的獨立流媒體。

  • service that's the co-sponsor of this video.

    服務,是這個視頻的聯合贊助商。

  • Nebula was created by and for a collection of educational video creators including Real

    星雲是由和教育視頻創作者集合創作的,包括Real

  • Engineering, Mike Boyd, Up and Atom, Jordan Harrod - and me - and Nebula has partnered

    工程部、邁克-博伊德、Up和Atom、喬丹-哈羅德--還有我--和星雲合作了。

  • with CuriosityStream, which offers thousands of documentaries and nonfiction titles to

    與CuriosityStream合作,該公司提供了數千部紀錄片和非小說類書籍,以滿足用戶的需求。

  • give you access to both in one go!

    讓你一次就能獲得這兩樣東西!

  • I recommend Magic Numbers, Hannah Fry's fun series about mathematics: how it's influenced

    我推薦《神奇的數字》,漢娜-弗萊關於數學的趣味系列:它是如何影響的。

  • science, how science has influenced math, the question of whether math is invented or

    科學,科學是如何影響數學的,數學是發明還是

  • discovered, and more.

    發現,以及更多。

  • Sign up for CuriosityStream using the link in the description and you'll also get access

    使用描述中的鏈接註冊CuriosityStream,您還可以訪問

  • to Nebula, including the extended version of this video as well as an ad-free viewing

    到星雲,包括該視頻的擴展版以及免廣告觀看。

  • experience across the site.

    整個網站的體驗。

  • Oh yeah, and you'll also get 26% off an annual subscription to CuriosityStream.

    哦,對了,你還可以享受到26%的優惠,每年訂閱《好奇心流》。

If you look at the wake behind a duck, or a kayak, or a ship, you might notice two unusual

如果你看鴨子、皮划艇或船後面的尾巴,你可能會注意到兩個不尋常的地方。

字幕與單字
由 AI 自動生成

單字即點即查 點擊單字可以查詢單字解釋