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  • Hey, Vsauce, Michael here. 93% of all the humans who have ever lived are dead. For every

  • person alive right now, there are 15 people who are no longer alive. The Earth is dangerous...but

  • where is the most dangerous place on Earth? Ignoring freak occurrances, where is the most

  • persistently perilous place on the surface of our planet?

  • Well, let's being with temperature. Extreme heat and extreme cold can kill within hours,

  • if not minutes. In cold environments, without clothing, the human body, by itself, doesn't

  • do a very good job of maintaining a high enough temperature to live. It just takes too much

  • work. Even when you feel comfortable and warm, nearly half of your daily caloric intake is

  • used merely to keep your body's temperature where it should be.

  • If you took a human and stripped them naked and put them in an environment at 0 degrees

  • Celsius, they would die from having too cold of an internal temperature within about 20

  • minutes. We need warmth. But one thing we need more immediately than that is Oxygen.

  • And that brings us to the summit of Mount Everest. This place, on the surface of Earth,

  • has incredibly thin air. At the top of Mount Everest there is only 1/3 as much breathable Oxygen

  • as there is down at sea level.

  • Climbers can endure the conditions for short periods of time if they acclimate for months,

  • but, if you were to teleport from wherever you are right now directly to the summit of

  • Everest, you would most likely die within only 2-3 minutes because there isn't enough

  • Oxygen.

  • Death would come even more quickly if you were at the bottom of the Mariana Trench.

  • There, you would be submerged under nearly 7 miles of water, about 11 km, causing the

  • pressure around your body to exceed 15,000 pounds per square inch.

  • At normal swimming depths you could always hold your breath, but that far down, with

  • that much pressure, your lungs would collapse immediately, and without Oxygen, your brain

  • would go unconscious in 15 seconds, and you'd be dead in under 90.

  • You would die pretty much just as quickly as someone who walked into outer space without

  • a suit on.

  • But falling into a molten lake of lava is probably the most spectacular way to go. Contrary

  • to what you see in many movies, your body wouldn't just burn a little bit and slowly

  • sink as if it were in quicksand; instead, there would be a lot of fireworks. Hot, molten

  • lava is liquid rock, 4 times as hot as your oven can ever get. And the human body is

  • mainly made up of water which, when exposed to that kind of heat, turns into steam...explosively.

  • There's a fantastic video right here on YouTube where a guy throws a bag of organic material

  • containing a lot of moisture into hot lava. It doesn't just sink in- it causes a miniature

  • eruption. I highly suggest you go watch it.

  • But, what if we want to measure danger not by how quickly you would die, but by the actual

  • total number of fatalities caused. Well, for this, we're going to need to get much, much

  • smaller. Like, microscopic.

  • In 1918, influenza killed nearly 100 million people, which, at the time, was 3% of the

  • world's entire population. But places where, and when, the plague has spread rapidly are

  • even scarier. Between 1347 and 1353, a third of everyone in Europe died because of the

  • bubonic plague, an infection caused by Yersinia Pestis.

  • It's easy to think of the plague as something from way back in the past, but it is still

  • here. Of course, now we have antibiotics which can help in most cases, but, believe it or

  • not, in America alone, 5-15 people still get the plague every year.

  • In terms of total fatalities, however, the plague and influenza are nothing compared

  • to the danger caused by this guy: plasmodium.

  • It's a micro-organism that can get into our blood because of mosquito bites, and causes

  • Malaria. Across the totality of human history, the number of deaths attributed to Malaria

  • is unbelievable. Researchers like Nobel Laureate Baruch Blumberg have studied the history of

  • the human genome and human migration, and determined that of all the humans who have

  • ever existed, it is likely that half died from Malaria.

  • So, in terms of total fatalities across all of human history, a place where plasmodium

  • could enter the blood stream because of a mosquito bite, statistically speaking, could

  • be called the most dangerous place on Earth.

  • But let's switch gears for a moment and talk about places that are dangerous not because

  • of Earth, or Earth's creatures, well, actually, just one specific creature: us.

  • La Oroya is a mining town in Peru where the murder rate is low but pollution is high.

  • The town's smelter emits pollution into the air, and temperature inversions in the atmosphere

  • above the town trap gasses within, causing the town to have 85 times more arsenic in

  • its air than is deemed safe.

  • But that's nothing compared to Lake Karachay in Russia. It was named the most polluted

  • spot on Earth by the World Watch Institute on Nuclear Waste.

  • The lake contains so many radioactive pollutants that you can receive a lethal dose of radiation

  • merely by standing for one hour near certain parts of the lake.

  • The Global Peace Index ranks countries by how safe they are. It takes into account a

  • number of factors including crime and political corruption. The safest country, according

  • to the Index, is Iceland. And the least safe is Somalia.

  • But for the highest murder rate, you'll have to go to Juarez, Mexico, where out of every

  • 1 million inhabitants, each year, 1,477 of them are murdered.

  • I've always found it amazing just how many serial killers Miami seems to have on the

  • show "Dexter," but Miami is a big city, and so, despite all those serial killers, it's

  • murder rate in the show is not the highest of any fictional town from a TV show. That

  • honor goes to Cabot Cove, the town where "Murder She Wrote" occurred. An analysis of "Murder

  • She Wrote" episodes revealed 274 murders, but a population in the town of only 3,500,

  • making Cabot Cove's murder rate 1,490 per million inhabitants.

  • Until recently that number was unmatched by reality, but last year, the city of San Pedro

  • Sula in Honduras reported a murder rate of 1,588 murders per million inhabitants.

  • Let's conclude by revisiting pollution, specifically the Chernobyl accident, and a certain oxymoronic

  • danger. For 10 days in 1986, radioactive isotopes spilled out of a blazing reactor core, forcing

  • mass evacuations. It's more than 25 years later now, and many parts of the exclusion

  • zone remain incredibly lethal. But, without humans there, many parts of the exclusion

  • zone have seen wildlife flourish, especially endangered species which can go to the exclusion

  • zone, live, reproduce, and be safe...from us. We managed to ruin a place to the point

  • at which it endangered our lives and we had to leave, and, in doing so, we left parts

  • of it a little bit safer for other forms of life.

  • You can read more about all of these topics by following links down in the description

  • below.

  • Keep learning, and, as always, thanks for watching.

Hey, Vsauce, Michael here. 93% of all the humans who have ever lived are dead. For every

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你知道地球上最危險的地方在哪裡嗎? What's The Most Dangerous Place on Earth?

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    VoiceTube 發佈於 2013 年 06 月 27 日
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