《那些古怪又讓人憂心的問題》第11期:大家一起跳
EVERYBODY JUMP
Q. What would happen if everyone on Earth stood as close to each other as they could and jumped, everyone landing on the ground at the same instant?
Q．如果地球上的所有人都儘可能擠在同一個地方，一起跳起，然後全部在一剎那間同時落地，會發生什麼？--托馬斯.貝內A. THIS IS ONE OF the Most popular questions submitted through my website. It's been examined before, including by ScienceBlogs and The Straight Dope. They cover the kinematics pretty well. However, they don't tell the whole story.
A．這個問題是所有提交到我的網站中的問題中問得最多的問題之一。之前ScienceBlog．com和Straight Dope1都曾分析過這個問題，運動學的部分他們已經講得很明白了，我這裏就不再重複一遍了。不過他們並沒有告訴你事情的全部。
Let's take a closer look.
我們不妨來仔細分析一下。At the start of the scenario, the entire Earth's population has been magically transported together into one place.
首先，全球的人口都被魔法運輸到了同一個地方。This crowd takes up an area the size of Rhode Island. But there's no reason to use the vague phrase "an area the size of Rhode Island." This is our scenario; we can be specific. They're actually in Rhode Island.
整個人羣的面積和羅得島的面積相當。不過我們爲什麼要用"和羅得島的面積相當"這種含糊的說法呢？這是我們的場景，我們說了算。我們就讓所有人都真的來到羅得島上好了。At the stroke of noon, everyone jumps.
隨着正午的到來，大家一起跳起。As discussed elsewhere, it doesn't really affect the planet. Earth outweighs us by a factor of over ten trillion. On average, we humans can vertically jump maybe half a meter on a good day. Even if the Earth were rigid and responded instantly, it would be pushed down by less than an atom's width.
和其他地方討論得到的結果一樣，這個舉動對地球一點影響都沒有。地球的質量是所有人類質量的10萬億倍以上。正常人良好發揮時平均可以垂直跳起0.5米左右的距離，即使地球是剛體2並能瞬時做出響應，它也只會被向下推不到一個原子寬度的距離。
Next, everyone falls back to the ground.
接下來所有人都落到了地上。Technically, this delivers a lot of energy into the Earth, but it's spread out over a large enough area that it doesn't do much more than leave footprints in a lot of gardens. A slight pulse of pressure spreads through the North American continental crust and dissipates with little effect. The sound of all those feet hitting the ground creates a loud, drawn-out roar lasting many seconds.
嚴格來說，落地這個過程確實會傳遞給地球巨大的能量，但是受力的面積太大了，產生的影響最多也只是在好多花園裏留下一堆腳印而已。一股輕微的壓力波會穿過北美大陸並消散掉，幾乎不會產生任何影響。所有人落地時產生的巨大聲響可能會持續幾秒鐘。Eventually, the air grows quiet.
最終，一切都安靜下來。Seconds pass. Everyone looks around. There are a lot of uncomfortable glances. Someone coughs.
幾秒鐘過去了。大家都開始四下環顧。尷尬的目光。一些人開始咳嗽。
A cell phone comes out of a pocket. Within seconds, the rest of the world's five billion phones follow. All of them-even those compatible with the region's towers-are displaying some version of "NO SIGNAL." The cell networks have all collapsed under the unprecedented load. Outside Rhode Island, abandoned machinery begins grinding to a halt.
一個人掏出了手機。幾秒鐘後，餘下的50億人都拿出了手機。所有的人，即使手機兼容當地網絡的那些人，都將看到手機屏幕上有一句相同的話：無信號。所有的手機網絡都在史無前例的重壓下崩潰了。羅得島外，沒人操縱的機器開始慢慢地停了下來。The T. F. Green Airport in Warwick, Rhode Island, handles a few thousand passengers a day. Assuming they got things organized (including sending out scouting missions to retrieve fuel), they could run at 500 percent capacity for years without making a dent in the crowd.
羅得島上位於沃裏克的T．F．Green機場每天能夠處理的旅客吞吐量只有幾千人。即使我們能夠把一切安排得井井有條（包括派出隊伍尋找並運回燃料），機場以500％的運力持續運行數年，也不會有任何可見效果。The addition of all the nearby airports doesn't change the equation much. Nor does the region's light rail system. Crowds climb on board container ships in the deep-water port of Providence, but stocking sufficient food and water for a long sea voyage proves a challenge.
就算周圍所有機場一起來幫忙，事態也不會有任何緩解，加上當地的輕軌系統也是杯水車薪。絕望的人們爬上停泊在普羅維登斯深水港的集裝箱船，但蒐集長途海上航行所需的食物和淡水又是一個巨大挑戰。Rhode Island's half-million cars are commandeered. Moments later, I-95, I-195, and I-295 become the sites of the largest traffic jam in the history of the planet. Most of the cars are engulfed by the crowds, but a lucky few get out and begin wandering the abandoned road network.
島上50萬輛私家車幫助疏散，用不了多久，I-95、I-195和I-295公路上將出現史上最嚴重的交通擁堵。絕大多數汽車中都塞滿了人，有一小羣幸運的人逃出了羅得島，開始沿着廢棄的道路網去往其他地方。Some make it past New York or Boston before running out of fuel. Since the electricity is probably not on at this point, rather than find a working gas pump, it's easier to just abandon the car and steal a new one. Who can stop you? All the cops are in Rhode Island.
在汽車耗盡燃油前，一些人把車開到了紐約或者波士頓。由於此時幾乎是不可能有電力供應的，因而與其花功夫去找一個還能工作的油泵，還不如直接拋棄這輛車再去偷一輛車。沒有人能阻止你，所有警察都還在羅得島呢！
The edge of the crowd spreads outward into southern Massachusetts and Connecticut. Any two people who meet are unlikely to have a language in common, and almost nobody knows the area. The state becomes a chaotic patchwork of coalescing and collapsing social hierarchies. Violence is common. Everybody is hungry and thirsty. Grocery stores are emptied. Fresh water is hard to come by and there's no efficient system for distributing it.
島上的外圍人羣開始向鄰近的馬薩諸塞州和康涅狄格州涌去。任何兩個相遇的人幾乎都不可能說同一種語言，也幾乎沒有人熟悉這片區域。整個州變成了由時分時合的社會階層組成的、混亂無序的羣體。暴力隨處可見，每個人都又飢又渴，雜貨店早已被洗劫一空，淡水資源難以獲取，有效的分配機制也無法建立起來。Within weeks, Rhode Island is a graveyard of billions.
不出幾周，數十億人將在羅得島上死去。The survivors spread out across the face of the world and struggle to build a new civilization atop the pristine ruins of the old. Our species staggers on, but our population has been greatly reduced. Earth's orbit is completely unaffected-it spins along exactly as it did before our species-wide jump. But at least now we know.
倖存者們散佈在世界各地，努力嘗試在舊文明的廢墟之上重建新文明。人類不至於滅絕，但人口將會銳減。諷刺的是，地球的軌道沒有受到絲毫影響，仍然像人類驚天一跳之前那樣默默旋轉着。但至少我們知道了後果。
