This meadowlark perches on a prairie flower singing its mating song.
这只草地鹨落在草地上，正唱着一支求偶的歌。
It's customary for meadowlarks to sing toward the rising sun.
通常他们会对着升起的太阳唱。
This one, however, was mistaken by the lights of Rapid City at 2 AM.
然而这只鸟被拉皮特城凌晨两点的灯光弄糊涂了。
Despite being 60 miles south of the Rapid City border and well within the boundaries of Wind Cave National Park,
尽管它们生活在离拉皮特城边界60英里的地方，而且还是在风穴国家公园里，
this songbird was singing out much too late to attract a mate.
这只鸟唱歌求偶的时间也太晚了。
Have you ever tried attracting a mate by calling them at 2 AM?
你试过在凌晨两点给你的求爱对象打电话吗？
My mother told me nothing good happens after midnight.
我妈妈说半夜一到就不会有好事发生。
So why was this songbird so confused, mistaking the bright lights of Rapid City for the rising sun at 2 AM?
那么为什么这只鸟这么傻，把拉皮特城凌晨两点的灯光当成太阳了呢？
Improper lighting and the over-illumination of residential neighborhoods, business signage,
不合时宜的灯光，居民区过亮的灯，商业区的标志
and street lights brighten our night sky, creating an orange hue above the city for miles outside its border.
以及街灯点亮了我们的夜空，在城市上空形成了一片橘色的光幕，在数英里外都能看到。
Over 100 years ago, all creatures could look up and see a spectacular starry night sky.
100多年前，所有的生物抬头就能看见繁星点点的夜空。
But now, eight out of ten children will never see the Milky Way from where they live.
但现在，每10个孩子里就有8个无法在住处看见银河。
Light pollution doesn't only impact our view of the universe,
光污染不仅影响我们观察宇宙，
it also impacts our environment, our individual health, and energy consumption.
还影响我们的环境和个人健康，还会消耗能源。
The three main components of light pollution include sky glow as well as glare and light trespass, which I will also explain.
光污染的三个主要组成部分是天空光、强光和光线干扰，这些我都会解释。
Glare is the excessive brightness that causes us visual discomfort.
强光是指过于明亮导致人眼不适的光线。
We often illuminate areas in attempt to increase safety.
我们通常会照亮一些位置以保证安全。
As children, we're afraid of the dark, so we flip on a night switch because "the night is dark and full of terrors."
作为孩子，我们会害怕黑暗，所以我们会打开开关，因为晚上很黑，我们很害怕。
And as adults, we do that now on a much grander scale.
作为大人，我们更容易这样做。
A 2015 study published in the Journal of Epidemiology and Community Health looked at statistics
2015年发布的流行病与公众健康日志研究了
where researchers studied lights that were turned on at certain hours, dimmed, or turned off completely,
调查员在定时开灯、灯光暗淡的地区和没有灯的地区记录的数据，
and found that it had no impact on traffic collisions or crime.
发现灯光对交通事故和犯罪行为没有影响。
I want you to take a very close look at this picture. Mentally note what you see.
请大家仔细看看这张照片。先在脑子里记下你们看到的东西。
With properly shielded lights, we can actually see what was there the entire time.
再挡上部分灯光，这个过程中其实我们一直可以看见周围的物体。
Brighter does not mean safer.
亮度越高并不意味着越安全。
The third component of light pollution is light trespass.
光污染的第三个组成部分是光线干扰。
To understand this, I want you to envision your bedroom.
要理解这一点，请想象一下你的卧室。
Could you sleep at night with no curtains?
如果没有窗帘，你晚上可以睡着吗？
Or do you need those blackout shades tucked into every single crevice of that window pane,
你是否需要用遮光板挡上窗缝的每一丝光线
just in order to get a good night's sleep?
好保证整晚安睡？
If so, that is because of light trespass,
如果是，这就是因为光线的干扰，
the shining of light where it's unneeded, and unintended, and unwanted, from another source originating somewhere other than your own.
这些不需要的、不受控制的光线传播不是来自你家，而是别处。
Now that we've looked at what causes light pollution, let's take a look at where light pollution is.
现在我们明白了导致光污染的原因，我们再看看光污染是什么。
Here is a global map with light pollution depicted by various colors.
这是一幅已经用不同颜色标出不同光污染程度的世界地图。
Let's zoom in to our local area of impact. This is Rapid City.
我们拉近点看看我们在的这块区域。这就是拉皮特城。
We are on the front lines of a battle of lights versus dark.
我们处在光线和黑暗搏斗的前线。
Zooming in closer to South Dakota, I want you to envision that you're downtown at Main Street Square,
再靠近点看看南达科他，请设想一下你就住在主街广场附近的小区，
you've got your blanket, your chair, you're ready to stargaze.
你带上毯子、椅子，准备看星星。
And then you look up, and you realize you can see relatively very few stars.
然后你抬头，发现只看得见很少的星星。
You cannot even see the Big Dipper.
连北斗七星都看不见。
So you pack up all your belongings, you get in the car, you drive to the city limits,
于是你再带上东西，回到车上，一路开出城市边界，
where now you're in the orange zone, where eight out of ten Americans live, and we have a local observatory.
现在你就在橘色这块区域里，5分之4的美国人就住在这里，这里还有一个观星点。
You look up, you still cannot see the Milky Way.
你抬头，还是看不见银河。
You keep on driving, you go deep into the Black Hills National Forest,
你继续开，开进黑山国家森林深处，
and then you see it, the sky glow the meadowlark was singing toward.
然后你看见了草地鹨对着歌唱的天光。
To get to a naturally dark sky, you would have to drive two hours north, to the corner of northwest South Dakota,
为了看见真实的黑夜，你得往北开两个小时的车，开到南达科他的西北方的角落，
an area called Slim Buttes, which has a Class 1 dark sky, a naturally lit sky,
那个叫做斯利姆巴特的地方，你在那可以看见清晰度一级的夜空，那是真正由自然光点亮的天空，
where the stars from the Milky Way shine so bright it will cast a shadow of you on the ground.
银河系的星星这样亮，它们还会把你的影子投在地上。

Rapid City is a Class 9 sky, the brightest depicted on the map,
拉皮特城的夜空清晰度只有九级，是地图上最亮的部分，
where light pollution is 100 up to 200 times brighter than our natural darkness.
光污染程度是自然夜空的100到200倍。
You cannot make out the North Star.
你也看不见北斗星。
But the thing is Rapid City is not alone.
但并不只有拉皮特城是这样。
Light pollution plagues every modern city and town.
每个现代化城镇都被光污染笼罩着。
The good news, however, is that light pollution could possibly be the simplest problem to solve
但好消息是，光污染大概是最好解决的问题，
and could literally be done overnight, simply with the flip of a switch.
一晚上就可以搞定，只需要轻轻扭动开关。
So if at any point in this presentation you decide that it's important to protect our dark skies,
所以如果我的演讲让你们觉得保护夜空很重要，
I ask you to turn off your light in front of you, simply by twisting it off.
我邀请大家观赏你们面前的小灯，只要轻轻一扭就可以。
Now just like in real life, here's a hint:
就像在现实生活中，这里有个提示：
You can ask your neighbor to shut off their light as well
你也可以让你的邻居关上灯，
if their light is trespassing into your area and inhibiting your view of a TEDx presentation.
如果他们家的光照进了你家，打扰到你看TEDx的演讲的话。
Even if we all turn out our lights, more is needed to be done.
即使我们把灯都关上了，我们还有更多事要做。
One hundred years ago, this is the view from Skyline Drive you would have seen.
这是我们100年前可以看见的天际线大道。
Today, this is a picture taken this year during the Rapid City Dark Earth Hour.
这是今年地球一小时时拍摄的拉皮特城的夜晚。
Which one do you prefer? So what are we going to do if we all turn out our lights and it's still bright?
你们更喜欢哪一个呢？如果我们都关掉灯，但还是很亮，我们应该做什么呢？
We need to protect nocturnal habitats, stargazing opportunities, and our nocturnal plants and animals.
我们应该保护生存在夜间的生物，保护我们看星星的机会。
Now, bats. There's an idea. I know what we can do.
蝙蝠是个好主意。我知道我们应该做什么了。
Let's call Batman! He'll know what to do! Send the bat signal! Right?
我们可以让蝙蝠侠来！他肯定知道要做什么！给蝙蝠侠发个信号！
Oh, wait, maybe he didn't get the memo either.
等等，也许他也收不到信号。
So let's shift our focus to nocturnal plants.
让我们把焦点转到夜间植物。
In the Black Hills, there's a moonflower that blooms only in dark nights.
黑山上有一种月光花，只在晚上开放。
Earth evolved with bright days and dark nights.
地球在白天和黑夜中切换。
Another example of nocturnal life that needs darkness is the owl.
需要黑暗的夜间生物的另一个例子就是猫头鹰。
Owls see five times brighter than we do as humans
猫头鹰看见的画面比我们人类看见的亮5倍，
because in their eyes they have light detecting rods that are numbered at one million rods per square millimeter.
因为在它们的眼睛里，平均每平方毫米有100万根感光棒。
Just because we can see with lights at night doesn't mean other creatures can.
我们在夜间可以看见并不意味着其它生物也可以。
But even though we can see with artificial light at night, doesn't mean that it's healthy for us.
但尽管我们晚上可以用人造光源看见，并不意味这是健康的。
The American Medical Association states "all creatures need darkness to survive."
美国医学联盟声称，所有生物的生存都需要黑暗。
As light travels through our eye,
当光线进入我们的眼睛，
it goes to a tract of a nucleus cluster of thousands of cells that send messages to our glands.
它会进入成千上万个相连的细胞，细胞再把信息传递给腺体。
Those glands secrete a naturally occurring hormone called melatonin.
这些腺体会分泌一种自然产生的名叫褪黑素的荷尔蒙。
The great thing about melatonin is it has great antioxidant qualities
褪黑素的好处在于它有很好的抗氧化效果，
that rid our brain and body of free radicals that cause damage to our brain and body.
它可以保护我们的大脑和身体免受自由基的伤害。
The Journal of Epidemiology Research shows that exposure to artificial light at night
《流行病研究日志》表明，晚上接触过多人造光
has been linked to an increase in Alzheimer's, breast cancer, obesity, and depression.
可能导致患阿兹海默症、乳腺癌、肥胖和抑郁症的几率增加。
Let's take a look now at what our future holds.
我们看看未来会怎样。
The map I showed you of South Dakota is a one from 1997,
我给你们看的南达科他的地图是1997年的，
when in all reality, tonight's dark skies is much more closely, really, like the map of 2025.
我们现在看到的夜空地图更接近2015年的地图。
In only eight years, it's estimated that just eight dark sky places will remain in the United States.
据估计在8年内，美国8块自然夜空地区将得以保留。
So if we can't call Batman, what are we supposed to do?
那么如果我们联系不上蝙蝠侠，我们怎么办呢？
OK, I have another idea, hold on with me, this is a little bit better.
我还有另一个主意，认真听，这个主意更好。
Let's join the Dark Side. Maybe Kylo Ren and Darth Vader had it right all along.
让我们加入黑暗一边吧。也许凯罗·忍和黑武士一直都是对的。
But all joking aside, there really is something about the color spectrum.
撇开玩笑话，色谱上的确有值得我们研究的东西。
This is a color Kelvin chart, rating color by its temperature.
这是色温表，是用温度来给颜色评级的。
The International Dark Sky Association rates colors below 3,000 Kelvins as dark sky friendly
国际暗天协会把3000开氏温度以下的颜色称为暗天友好型，
because it doesn't impair night vision.
因为它不会影响夜间视物。
What else can we do? Address our fixtures, because dark skies doesn't have to mean dark ground.
我们还能做什么呢？固定光线方向，因为暗天并不意味着地面也要是暗的。
We can point lights down, where the light is intended.
我们可以让光线朝下，这才是需要光的地方。
The International Dark Sky Association estimates that all of the outdoor lighting
国际暗天协会预测室外灯发出的
wastes 30 percent of light that goes outward and upward where it is not needed or intended,
向外和向上等方向的光线，30%是被浪费了的，
wasting money and creating more carbon emissions.
不仅浪费了金钱，还造成更多碳排放。
In addition, this is a sample of a front porch light
除此之外，这前门灯就是一个例子，
that could be converted into a full cutoff fixture, reducing glare, sky glow, and light trespass.
我们可以把它改造成一个有遮蔽的灯，从而减少强光、天光和多余光线干扰。
Streetlights that point light outward and upward could be retrofitted to point the light downward.
街灯发出的向外和向上的光线可以被调整为向下。
Paris, the City of Light, took solving light pollution to a whole new level.
巴黎这座光之都，把解决光污染推向一个新的阶段。
They enacted a lights-out curfew of 1 AM or one hour past the last employee's departure time.
他们实行了凌晨一点后熄灯以及最后一个员工离开后一小时熄灯的制度。
I challenge you to find your reason for #LightsOut.
我希望大家找到你们关灯的理由。
I wish you all a very dark night.
希望你们都能拥有一个黑暗的夜晚。