doesn't go off near my mobile phone, or the Wi-Fi router or my microwave. That’s because

輻射量超過測量極限了

a Geiger counter only measures ionizing radiation — that is, radiation with enough energy

輻射是很可怕的 至少某些輻射是

to rip electrons off atoms. And it’s measured in units called sieverts. If you're exposed

我意思是說我的蓋格計數器在我的手機、wifi基地台 或微波爐

to more than two sieverts all at once you'll probably die shortly after that. But we’re

旁時並不會嗶嗶響

exposed to low levels of ionizing radiation all the time. Bananas for example are rich

因為蓋格計數器只測量游離輻射

in potassium and some of that potassium is naturally radioactive. So when you eat a banana

這是一種強度足以將電子剝離原子的輻射

you're actually exposed to about 0.1 microsieverts of radiation. That’s one ten millionth of

而他的測量單位叫做「西弗」

a sievert. Let’s use a banana for scale of radiation doses. You know, since people

如果你短時間一次暴露在2西弗下

eat bananas we become radioactive too. So you're actually exposed to more radiation

你大概很快會死掉

if you sleep next to someone than if you sleep alone. But I wouldn't worry about that because

但是我們長期的暴露在少量的游離輻射下

that dose is insignificant compared to the natural background radiation of earth. I mean

例如香蕉 本身富含元素「鉀」

there’s ionizing radiation coming out of the soil in the rocks, in the air, and even

而少部分鉀是有放射性的

from space. The level of radiation here in Sydney is about .15 microsieverts per hour,

所以當你吃下一根香蕉 你差不多暴露在

and that's about average globally. The level’s usually between .1 and .2 microsieverts per

0.1微西弗的輻射之下

hour. But there are places with significantly higher levels. So who on earth do you think

等於千萬分之一西弗 （0.1微西弗=一千萬分之一西弗）

receives the maximum dose of ionizing radiation? Let’s answer that question by going to the

當我們吃下香蕉 我們就變的有放射性

most radioactive places on earth. Some places you’d expect to have high levels of radiation

所以當你晚上睡在某人身旁時 比起你獨自睡覺

might surprise you. I’m in Hiroshima and that is the Peace Dome. It was about 600 meters

你會接收到更多輻射 但是不需要擔心

above that dome where the worlds first nuclear bomb was detonated over a city. It was detonated

比起地球和宇宙的背景輻射 這只是九牛一毛

there to have maximum destructive impact. Well the level of radiation today almost 70

游離輻射來自、土壤、岩石、空氣

years later is only 0.3 microsieverts per hour. I'm about to get into an elevator. We're

甚至是太空

going down in a mineshaft. This is an old uranium mine. This is the mine where uranium

在雪梨這裡的游離輻射指數 大約是一小時0.15微西弗

was discovered. It's also the place where Marie Curie obtained her raw material. 1.7

而全球平均大約是一小時0.1~0.2微西弗

microsieverts per hour. That's about 10 times the natural background that you would have.

但有些地方輻射還是比較高

Nowadays most of the uranium has been removed. But in this wall there’s still a small piece

所以誰是地球上接收到最多輻射量的人呢？

and you can see under UV light it floresces. Look at that. Fluorescent uranium ore. This

我們將要到全球輻射最多的幾個地方

is the lab of Marie Curie. She won two Nobel prizes, one in physics and one in chemistry.

來解答這個問題

And she conducted a lot of her work here. And this is her office. She would have sat

一些你以為會有高輻射線的地方 實際的輻射量

right there. Apparently there are only a few parts of this area which are still radioactive.

可能會讓你驚訝 這裡是日本廣島的「原爆圓頂」

One is this doorknob. Well it climbs not not much but — But that's like 10 times the

在那圓頂上方約六百公尺 就是史上第一顆原子彈

background. Yeah. More than 10. And another is the back of her chair. You can still detect

引爆整個城市的地方

alpha particles coming off this spot right here. Apparently after she was working in

炸彈在那裡引爆以便產生最大的破壞力

the lab she would come, oopen the door leaving traces of radium here and then go and pull

70年後 如今這裡的輻射線

out her chair. Welcome to New Mexico. This is the Trinity bomb test site where the world’s

只有一小時0.3微西弗

first nuclear bomb was set off. Right here. Right in the spot. This whole area was vaporized.

(亞西莫夫 捷克共和國) 我將要坐電梯到地下去

In fact, there was so much heat liberated by that bomb that it fused all of the desert

這是首次發現鈾礦的礦坑

sand into this green glass. And you can still find it here. They've actually named this

這也是居里夫人（知名學者，以發現放射性元素聞名） 獲得她的研究材料的地方

mineral after the test. It's called Trinitite. Yeah. This is the only place on earth that

一小時1.70微西弗

this has ever been made. The level of radiation here is about 0.8 microsieverts an hour. The

大約是背景輻射的十倍

Trinitite itself is a little bit more radioactive. I got readings of two or three microsieverts

時至今日 大多數的鈾礦已經被移除

an hour off them. Now which place has higher levels of radiation then anywhere we've seen

但是仍有一面牆保留了一些鈾礦

so far? The answer is an airplane. You know, as you gain altitude there's less atmosphere

在紫外線下會發出螢光

above you to shield you from cosmic rays. So the level of radiation inside the plane

鈾礦的螢光

can go up to 0.5 microsieverts per hour at 18,000 feet, up to one microsievert per hour

這是居里夫人的實驗室 她獲得兩座諾貝爾獎

at 23,000 feet, over two microsieverts per hour at 30,000 feet, and over three microsieverts

一個是物理學 另一個是化學獎

per hour at even higher altitudes and towards the poles. That is Chernobyl nuclear reactor

她在這裡做了很多實驗

number four. It melted down on April 26, 1986. So, what happened was so much heat was generated

這是她的辦公室 她以前就站在那裡

inside that reactor that it basically blew the top off spreading radioactive isotopes

很明顯的 這裡只有少數區域

throughout this whole surrounding area and over into Europe. And that is why we can still

仍然有輻射

detect the contamination here today. Now, right now it's reading around five microsieverts

例如這個門把

an hour. If I stayed here for one hour my body would receive a similar dose to what

上升中但是不很快 沒有到背景輻射的十倍？

you’d receive when you get a dental x-ray. So this is not a huge amount of radiation.

是的 超過三倍

And one of the reasons why the radiation level is not too high is because they actually removed

另一個地方是實驗室的椅背

a couple meters worth of topsoil from this whole area, then they dumped it somewhere.

你仍然可以探測到阿法粒子 來自這個點

That's why we can stand here. We're driving into the Fukushima exclusion zone now. I'm

很明顯的 當她結束實驗以後/N她走進這裡

just watching as the levels on my Geiger counter go up as we approach the zone. See those black

打開門 然後拉開椅子

bags at the side of the road? The Japanese are doing now exactly what the people in Chernobyl

留下了輻射痕跡

did, collecting up meters and meters of topsoil. The mask is probably overkill. It's just to

歡迎來到新墨西哥州

stop radioactive dust from getting into my lungs. This is definitely one of the most

這裡是Trinity核彈試爆計畫的場所

radioactive places where I've been. Even though the release of radioactive material was less

全世界第一個核彈就在這裡

than Chernobyl, only about 10%, because it's much fresher—only three years since the

這個地點上引爆

accident— much less of it has decayed. So I've been getting readings up around 5 to

當時整個區域都蒸發了

10 microsieverts an hour. And I think we won't be staying here for too long because of that.

事實上因為核彈的的高熱

I'm about to go into the hospital at Pripyat. And this is where the firemen were taken after

沙漠中的沙都融化成了綠色玻璃

they fought the fires at the Chernobyl reactor. And in the basement of this building they

直到現在你都可以找到它們

have left all the firemen's clothing. Once they realize it was so contaminated they chucked

他們還以核爆替這種玻璃命名

it down there. (Inaudible) But you can see there's a huge pile of their gear there. Right

被叫做Trinitite（鈾玻璃石）

outside the door I'm getting 500 microsieverts an hour just outside the door. One thousand

這是地球上唯一製造出這種物質的地方 （譯註：其他核試場其實也有）

five hundred microsieverts an hour. You know if we stayed here for a couple hours we’d

這裡的輻射量大約

receive our annual dose of background radiation. That basement was the most radioactive place

0.8微西弗 鈾玻璃石本身的輻射量比較高

I visited and it's one of the most radioactive places on earth. If I'd stayed down there

大約是2~3微西弗

for one hour I would’ve received 2000 microsieverts. That's a years worth of natural background

哪個地方擁有比 目前我們看過的地點都要高的輻射量呢？

radiation. Every yellow pixel here represents a banana. Now that might seem like a lot,

答案是天上的飛機

but consider that in a CT scan the patient receives about 7000 microsieverts. That's

當海拔越來越高 可以保護你遠離宇宙輻射的大氣層

three years worth of natural backround radiation. It's been estimated that the people living

就越來越薄

around Fukushima will receive an additional 10,000 microsieverts over their lifetime due

所以飛機在18000呎時 你會接收到大約一小時0.8微西弗的輻射

to the nuclear power disaster. For comparison US radiation workers are limited to a maximum

23000呎時大約1微西弗

of 50,000 microsieverts per year. But that's less than another occupation. Astronaut. An

33000呎時大約一小時2微西弗

astronaut on the space station for six months will receive about 80,000 microsieverts worth

而在更高高度和航向南北極時 可以高到3微西弗

of radiation. But not even they are exposed to the highest levels of ionizing radiation.

（車諾比 烏克蘭） 這是車諾比四號核電廠

So can you guess who is? The answer is a smoker’s lungs. A smoker’s lungs on average receive

他在1986年4月26日當天爐心溶解

160,000 microsieverts worth of radiation every year. That's due to the radioactive polonium

反應爐產生的大量熱量

and radioactive lead in the tobacco that they're smoking. So not only are they exposed to carcinogens

基本上炸掉了反應爐頂

and toxins they also receive very high levels of radiation. So it's not the people of Fukushima

散播放射性同位素到附近區域

or Chernobyl or radiation workers or even astronauts that receive the highest dosage

以致於整個歐洲

of ionizing radiation. That honor goes to your ordinary average smoker. Hey. As you

所以直到今天 在這裡還可以探測到輻射污染

can see over the last few months I've been traveling around the world actually filming

我仍然可以偵測到一小時5微西弗的輻射量

a documentary for television. It should be on in the middle of next year. But being in

如果我留在這裡一個小時 我大約會接收到

places like Chernobyl and Fukushima reminded me of this book The Day of the Triffids and

照射一次牙科X光的輻射量

it's about a post-apocalyptic world in which plants take over. I know it sounds like a

這不是很高的輻射量

crazy idea but it's actually a brilliant book so you should really check it out if you're

而輻射量不是很高的其中一個原因是

looking for something to do over the holidays. Now you can download this book for free by

他們移除了這裡幾公尺的表土

going to audible.com/Veritasium or you can pick any other book of your choosing for a

並丟棄在某個地方

one month free trial. Audible is a great audiobook website with over 150,000 titles in all areas

所以我們可以安全的站在這裡

of literature including fiction, nonfiction, and periodicals. So I really want to thank

（日本福島縣） 正開車前往福島

audible for supporting me and I want to thank you for watching.

進入隔離區了