Name: 如果用一根吸管把尼亞加拉大瀑布灌進去呢？ (What if you funneled Niagara Falls through a straw?)
Uploaded: 2025-06-27T02:49:10.000Z
Duration: 3 min 37 s

第二類條件句型

This question comes from David, who asks, "What would happen if one tried to funnel Niagara Falls through a straw?"  The short answer is one would get in trouble with the International Niagara Committee, the International Niagara Board of Control, the International Joint Commission, the International Niagara Board Working Committee, and probably the Great Lakes-St.

這個問題來自戴維，他問道："如果有人試圖用吸管輸送尼亞加拉大瀑布，會發生什麼？  簡短的回答是，人們會惹上國際尼亞加拉委員會、國際尼亞加拉控制委員會、國際聯合委員會、國際尼亞加拉委員會工作委員會的麻煩，可能還會惹上五大湖-St.

Lawrence-River Adaptive Management Committee.

程度副詞

Also, the Earth would be destroyed.  Well, that's not quite right.

此外，地球也會被毀滅。  嗯，這不完全正確。

At the risk of stating the obvious, the real answer is, Niagara Falls wouldn't fit through a straw.

冒著說得太明顯的風險，真正的答案是，尼亞加拉大瀑布無法通過吸管。

If you tried to force it by, say, building a dam across the falls with a single straw-sized opening, what will actually happen is that a very small part of Niagara Falls will flow out through the straw, and the rest of the water will build up behind the dam until the dam overflows.  There are limits to how fast you can push fluids through openings.

如果你想強行通過，比如在瀑布上築起一個只有吸管大小的水壩，實際情況是尼亞加拉大瀑布的一小部分水會通過吸管流出，其餘的水會在水壩後面積聚，直到水壩溢出。  流體通過開口的速度是有限的。

If you pump a fluid from a wide, contained channel into a narrower one, it speeds up, but only to a point.

如果將流體從一個寬而封閉的通道泵入一個較窄的通道，流體的速度會加快，但僅限於一定程度。

For example, water always wants to boil, but is normally held together by air pressure.

例如，水總是想沸騰，但通常是由氣壓保持在一起的。

When a fluid flows through an opening fast enough, the pressure within the fluid drops due to the Bernoulli Principle.

當流體以足夠快的速度流過開口時，由於伯努利原理，流體內的壓力會下降。

Without enough pressure to keep the water from boiling, bubbles of steam form in a process called cavitation.  Increasing the pressure to try to push the water through harder surprisingly only makes it boil faster.

如果沒有足夠的壓力來防止水沸騰，就會在一種叫做空化的過程中形成蒸汽氣泡。  增加壓力，使水更加沸騰，但這隻會讓水沸騰得更快。

Page 17 of this Fluid Flow Basics of Throttling Valves PDF has a detailed description.

節流閥的流體流動基礎》PDF 第 17 頁有詳細說明。

Cavitation limits the total flow of water making it through the opening;

氣蝕會限制通過開口的總水流量；

though the higher the pressure, the faster the water-steam mix will move because more of it will expand into vapor bubbles.  Cavitation is also bad for the pipe itself because, when the bubbles do eventually collapse, the force of the implosion can erode the walls of the pipe and lead to structural failure.

雖然壓力越高，水蒸氣混合物的流動速度就越快，因為更多的水蒸氣會膨脹成氣泡。  氣蝕對管道本身也不利，因為當氣泡最終崩潰時，內爆的力量會侵蝕管道壁，導致結構失效。

A rough calculation suggests that Niagara Falls, at its base, could only be funneled into a pipe as small as around 10 meters across before cavitation starts to become likely.  Another limit on the water flow rate comes from the speed of sound.

根據粗略計算，尼亞加拉大瀑布的底部只能被導入一個直徑約 10 米的管道，然後才有可能產生氣蝕。  水流速度的另一個限制來自聲速。

You can use pressure to accelerate a fluid through an opening faster than the speed of sound in that fluid.

您可以利用壓力加速流體通過開口的速度，使其超過流體的聲速。

However, water very rarely reaches this limit in practice because the speed of sound in water is very fast.

然而，在實際應用中，水很少能達到這個極限，因為水的聲速非常快。

If you try to make water, which is pretty heavy, go that fast, it tends to start ignoring the turns in your pipes.  So how fast does Niagara Falls need to go to fit through a straw?

如果你想讓相當重的水流得那麼快，它往往會開始忽略管道的轉彎。  那麼，尼亞加拉大瀑布需要多快的流速才能通過吸管呢？

All we need to know is the flow rate over the falls and how much area it needs to fit through.

我們只需要知道瀑布的流速以及需要通過的面積。

The flow rate over Niagara Falls is at least 100,000 cubic feet per second, which is actually mandated by law.

尼亞加拉大瀑布的流量至少為每秒 10 萬立方英尺，這實際上是法律規定的。

The Niagara River supplies a total of 300,000 cubic feet per second to the falls, but much of it is diverted into tunnels to generate electric power.  Since people get mad if you turn off the world's most famous waterfall, they are required to leave at least 100,000 of those cubic feet per second flowing over the falls for everyone to look at: 50,000 at night or during the off-season.

尼亞加拉河每秒為瀑布提供總計 30 萬立方英尺的水量，但其中大部分被引流到隧道中用於發電。  如果關閉世界上最著名的瀑布，人們會很生氣，是以他們必須讓瀑布每秒至少有 10 萬立方英尺的水流過瀑布，供人們觀賞：夜間或淡季時則為 5 萬立方英尺。

Needless to say, if you divert the water into a straw, you'll be in violation of the 1950 International Treaty establishing the 100,000 cubic feet per second minimum.  A typical straw is about 7 millimeters in diameter.

不用說，如果你把水引入吸管，就違反了 1950 年國際條約規定的每秒 10 萬立方英尺的最低值。  典型的吸管直徑約為 7 毫米。

To find out how fast the water flows, we just divide the flow rate by that area.

要知道水流速度有多快，我們只需用流速除以該面積。

Apparently, our water will be going one quarter of the speed of light.  On the plus side, we don't have to worry about cavitation anymore because at those high energies, everything's a plasma and the concepts of boiling and cavitation don't even apply.

顯然，我們的水將以四分之一光速流動。  好的一面是，我們不必再擔心氣蝕，因為在高能量下，一切都是等離子體，沸騰和氣蝕的概念根本不適用。

Instead, the water molecules will be causing all kinds of exciting nuclear reactions.  On the downside, no machine could actually accelerate that much water to relativistic speeds.

相反，水分子會引起各種令人興奮的核反應。  缺點是，沒有機器能把這麼多水加速到相對論速度。

Particle accelerators can get things going that fast, but they're typically fed from a small bottle of gas.

粒子加速器也能達到如此快的速度，但它們通常由一小瓶氣體提供能量。

You can't just plug Niagara Falls into the accelerator input.

你不能把尼亞加拉大瀑布插入加速器輸入端。

Or at least, if you could, the scientists would get awfully mad.  But that's maybe for the best, since the power of the particle jet created by this scenario would be greater than the power of all the sunlight that falls on Earth.

至少，如果你能做到，科學家們會非常生氣。  但這也許是最好的結果，因為這種情況下產生的粒子噴流的能量將大於落在地球上的所有陽光的能量。

Your waterfall would have a power output equivalent to that of a small star, and its heat and light would quickly raise the temperature of our planet, boil away the oceans, and render the whole place uninhabitable.  In which case, one would be in very, very big trouble with the International Niagara Committee.

你的瀑布輸出的能量相當於一顆小恆星，它的光和熱會迅速升高我們星球的溫度，沸騰海洋，使整個地方無法居住。  在這種情況下，國際尼亞加拉委員會就會給你帶來非常非常大的麻煩。