This was America's first-ever looping coaster⁠, but its thrilling flip came at a price.

這是美國第一座環形雲霄飛車，但其刺激的翻轉技術是有代價的。

The ride caused numerous cases of severe whiplash, neck injury, and even ejections, all due to its signature loop.

這座雲霄飛車造成許多嚴重的揮鞭式頸部扭傷、頸部受傷，甚至彈出意外，而這一切都是因為其標誌性的環形軌道。

Today, coasters can pull off far more exciting tricks without resorting to the "thrill" of a hospital visit.

如今，雲霄飛車可以達成更刺激的特技，不用冒上可能會進醫院的「刺激」感。

But what exactly are roller coasters doing to your body, and how have they managed to get scarier and safer at the same time?

但是雲霄飛車對身體究竟有什麼影響、又如何變得更恐怖卻更安全呢？

At the center of every roller coaster design is gravity.

雲霄飛車的設計核心是重力。

Unlike cars or transit trains, most coasters are propelled around their tracks almost entirely by gravitational energy.

跟汽車和交通列車不同的是，雲霄飛車在軌道上幾乎完全仰賴重力能行駛。

After the coaster crests the initial lift hill, it begins an expertly engineered cycle⁠: building potential energy on ascents and expending kinetic energy on descents.

雲霄飛車抵達第一個頂峰後，就展開了精心設計的循環：攀升時增加位能、滑落時消耗動能。

This rhythm repeats throughout the ride, acting out the coaster engineer's choreographed dance of gravitational energy.

這個節奏在整個運行過程中不斷重複，展現雲霄飛車工程師精心設計的重力能之舞。

But there's a key variable in this cycle that wasn't always so carefully considered: You.

但在這個循環中，有一個並未總是謹慎考量的關鍵變數：你。

In the days of the Flip-Flap, ride designers were most concerned with coasters getting stuck somewhere along the track. This led early builders to overcompensate, hurling trains down hills and pulling on the brakes when they reached the station.

在「搖擺鐵路」時期，雲霄飛車設計師最擔心的是車廂卡在軌道上。這導致早期建築師矯枉過正，讓車廂奮力衝下坡道，並在到站時緊急煞車。

But as gravity affects the cars, it also affects the passengers.

但如同重力影響車身一般，它也影響著乘客。

And under the intense conditions of a coaster, gravity's effects are multiplied.

而在雲霄飛車的極端環境條件下，重力的影響倍增。

There's a common unit used by jet pilots, astronauts, and coaster designers called "G-force".

噴射機駕駛員、太空人和雲霄飛車設計師都使用一個稱為 G 力（G-force）的單位。

One G-force is the familiar tug of gravity you feel when standing on Earth.

1G 力就是你站在地球上時所感到的熟悉引力。

This is the force of Earth's gravitational pull on our bodies.

這是地球對我們身體的引力。

But as riders accelerate and decelerate, they experience more or less gravitational force.

當乘客加、減速時，他們會感受到更多或更少的引力。

Modern ride designers know that the body can handle up to roughly 5Gs, but the Flip-Flap and its contemporaries routinely reached up to 12Gs.

現代遊樂設施設計師都知道人體能承受的最大重力約為 5G，但「搖擺鐵路」和同期其它設施的重力常常高達 12G。

At those levels of gravitational pressure, blood is sent flying from your brain to your feet, leading to light-headedness or blackouts as the brain struggles to stay conscious.

在那種程度的重力壓力下，血液會快速從大腦竄流至腳部，因為大腦無法維持清醒意識而導致暈眩或昏厥。

And oxygen deprivation in the retinal cells impairs their ability to process light, causing greyed out vision or temporary blindness.

而視網膜細胞缺氧會損害其處理光線的能力，導致視力模糊或暫時性失明。

If the riders are upside down, blood can flood the skull, causing a bout of crimson vision called a "redout".

如果乘客因翻轉而身體倒立，血液可能湧入頭顱，導致見紅症狀，也就是所謂的紅霧視症。

Conversely, negative Gs create weightlessness.

相反地，負重力會產生失重狀態。

Within the body, short-term weightlessness is mostly harmless.

在人體內，短暫的失重基本上無害。

It can contribute to a rider's motion sickness by suspending the fluid in their inner ears, which coordinates balance.

它可能會使內耳中協調平衡的液體懸浮，造成乘客暈車。

But the bigger potential danger—and thrill—comes from what ride designers call "airtime".

但更嚴重的潛在危險及刺激感來自設施設計師所謂的「飛行時間」。

This is when riders typically experience seat separation, and, without the proper precautions, ejection.

這時乘客通常會經歷座椅分離，若沒有適當的預防措施，乘客就會被彈出。

The numerous belts and harnesses of modern coasters have largely solved this issue, but the passenger's ever-changing position can make it difficult to determine what needs to be strapped down.

現代雲霄飛車上無數的安全帶和輓具已經大幅解決這個問題，但乘客不斷變化的坐姿可能使需要繫帶的部位難以判斷。

Fortunately, modern ride designers are well aware of what your body, and the coaster, can handle.

幸好，現代雲霄飛車設計師很清楚人體和車身所能承受的極限。

Coaster engineers play these competing forces against each other to relieve periods of intense pressure with periods of no pressure at all.

雲霄飛車工程師運用競爭力量的相互作用，以調適壓力最密集和最疏散的情況。

And since a quick transition from positive to negative G-force can result in whiplash, headaches, and back and neck pain, they avoid the extreme changes in speed and direction so common in thrill rides of old.

由於正、負 G 力的瞬間變化可能導致揮鞭式頸部扭傷、頭痛、背部和頸部疼痛, 他們改善了過去刺激性遊樂設施中常見的問題, 避免速度和方向上的極端變化。

Modern rides are also much sturdier, closely considering the amount of gravity they need to withstand.

現代的雲霄飛車要穩固得多，它們所需承受的重力也被仔細考量。

At 5Gs, your body feels 5 times heavier, so if you weigh 100 pounds, you'd exert the weight of 500 pounds on the coaster.

在 5G 狀態，你的身體會重上五倍，所以如果你的體重是 100 磅（約 45 公斤），你會在雲霄飛車上施加 500 磅（約 225 公斤）的重量。

Engineers have to account for the multiplied weight of every passenger when designing a coaster's supports.

工程師在設計雲霄飛車負重度時，必須考量到每一位乘客的加成重量。

Still, these rides aren't for everyone.

不過，這些設施不是所有人都喜歡的。

The floods of adrenaline, light-headedness, and motion sickness aren't going anywhere soon.

腎上腺素飆升、頭重腳輕感以及旅行暈眩暫時還沒有解法。

But today's redundant restraints, 3D modeling, and simulation software have made roller coasters safer and more thrilling than ever.

但今日多餘的束縛、3D 模型以及模擬軟體讓雲霄飛車變得更安全且比以往更具刺激感。

Our precise knowledge about the limits of the human body have helped us build coasters that are faster, taller, and loopier, and all without going off the rails.

我們對於人體極限的精確知識有助我們建造更快、更高、更多環的雲霄飛車，而不會有脫軌風險。

In terms of human evolutionary instincts, roller coasters don't make a lot of sense.

就人類演化上的直覺來說，雲霄飛車不太合理。

So what makes us love them?

那麼我們為什麼熱愛它們呢？

Check out this lesson on why some people love to be scared.

看看這堂課，了解有些人喜歡被驚嚇的原因。