（家儿爸爸译）
IT’S A ROUND , ROUND WORLD!
圆圆的地球
WE ALL KNOW IT’S FACT…
我们都知道这个事实
But HOW do we know that the earth is round?
Join Intrepid young scientist-adventurer Joulia Copernicus on a journey through time and space as she explains the ins and outs of how we learned about the shape of the earth-and the other planets!
A Junior Library Guild Selection
但我们是怎样知道地球是圆的呢？
加入无畏的年轻科学冒险家乔莉亚·哥白尼的时空之旅吧。她向我们展示了人们是如何了解地球及其他行星形状的来龙去脉！
美国少年图书馆协会选书
Sure looks flat from here.
从这里看肯定是平的。
What would happen if you tried to walk to the edge of the earth? Would you find it?
如果你想走到地球的边缘会发生什么？你能找到它吗？
Of course not！Our planet Earth isn’t flat.
IT’S ROUND!
I know that, you know what, everybody knows that! But have you ever wondered HOW we know the earth is round?
当然不是！我们的地球不是平的。
它是圆的
我知道，大家都知道！但是你有没有想过我们怎么知道地球是圆的？
Some people will tell you that Christopher Columbus proved Earth is round.
WRONG!
When he sailed the ocean blue in 1492, Columbus already knew the earth was round.(Actually, most people knew the earth was round back then.)
有人会告诉你，哥伦布证实地球是圆的。
不对！
1492年，当哥伦布在蓝色的海洋中航行时，他已经知道地球是圆的（事实上，当时大多数人都知道地球是圆的）
Columbus was actually looking for a shorter route to Asia, but that’s a whole other story…
哥伦布实际上是在寻找一条去亚洲的较短路线，但那是另一回事。
Ancient Greek, Islamic and Indian scholars theorized that Earth was round WAY before Columbus’s time.
哥伦布时代以前，古希腊、伊斯兰和印度学者已经从理论上提出地球是圆的。
Sailors like Columbus didn’t have the scientific equipment we have today. But he and his crew could tell Earth was round from their very own ships.
像哥伦布这样的船员没有我们今天拥有的科学设备。但他和他的船员可以从他们自己的船分辨出地球是圆的。
怎样？
People who lived long before Columbus noticed that when ships sail away from you, they seem to disappear from the bottom when they sail toward you, the appear from the top.
生活在比哥伦布更久以前的人们注意到，当船只驶离你时，它们似乎从底部消失，当它们驶向你时，从顶部出现。
On the Earth, you’d see the entire ship the entire time.
在地球上，你会一直看到整艘船。
Not only that, but the crow’s nest of a ship is only useful if Earth is round.
不仅如此，只有地球是圆的，船上的瞭望台才有用。
A crow’s nest is a lookout point at the top of mast.
瞭望台是桅杆顶端的了望台。
Being higher up allows you to see farther over the curve of the earth.
On a flat Earth, you’d see the same thing whether you were high or low.
更高可以让你在地球的曲线上看得更远。
在平坦的地球上，无论高低，你都会看到同样的东西。
If you don’s have a crow’s nest handy, another way to prove the earth is round is by viewing a lunar eclipse.
如果你附近没有瞭望台，另一种证明地球是圆的方法是看月食。
The sun is HUGE! It would take 1.3 million Earths to fill it up.
太阳很大！需要130万个地球才能填满它。
Do you know what else the sun is ?
你还知道有什么关于太阳的吗？
ROUND!
圆的
The earth casts a shadow just like your body does on a sunny day . Your shadow appears on the ground, but the earth’s shadow extends into outer space. If the moon moves into that shadow, it’s called a lunar eclipse.
地球投下一个阴影，就像你的身体在晴天一样。你的影子出现在地面上，但地球的影子延伸到了外太空。如果月亮移动到那个阴影中，那就叫做月食。
During a lunar eclipse, you can see the shape of Earth’s shadow on the moon.
在月食期间，你可以看到月球上地球影子的形状。
Can we start howling now?
我们现在可以开始大叫了吗？
The shape of that shadow is …
ROUND!
阴影的形状是。。。
圆的！
Another way to prove Earth is round is by comparing constellations.
另一种证明地球是圆的方法是比较星座。
People living on the bottom half of the earth(the Southern Hemisphere) see different constellations than people living on the top half( the Northern Hemisphere). That’s because they’re each looking at a different part of the sky.
生活在地球下半部分（南半球）的人看到的星座与生活在上半部分（北半球）的人看到的星座不同。那是因为他们各自看着天空的不同部分。
Constellations are imaginary pictures in the sky formed by groups of stars.
星座是群星在天空中形成的假想图。
If Earth were flat, we’d all see the same constellations.
如果地球是平的，我们都会看到相同的星座。
The Big Dipper is also called Ursa Major, which means Great Bear.
北斗七星也叫大熊星座，意思是大熊。
*sigh* the Big Dipper… again?
*唉，北斗七星。。。再一次？
But we don’t need a view of outer space to tell that Earth is round.
但我们不需要从外太空的角度来判断地球是圆的。
That’s supposed to be a bear?
那应该是只熊吧？
How would we explain day and night if Earth were flat?
Everyone in the world would have daytime and nighttime at the same time!
如果地球是平的，我们怎么解释白天和黑夜？世界每个人同一时间可能处在白天或晚上！
That’s not the case, though. Since our round Earth spins on an axis, some people have day while others have night.
但事实并非如此。因为我们的地球绕轴旋转，有些人有白天，有些人有夜晚。
Earth spins on its axis once each day. This is called ROTATION.
地球每天绕它的轴心旋转一次。这叫做自转。
Earth travels around the sun once each year. This is called a REVOLUTION.
地球每年绕太阳运行一次。这叫做公转。
People who live east of us see the sun come up earlier. People who live west of us see the sun come up later.
住在我们东部的人看到太阳升起得更早。住在我们西边的人看到太阳晚些升起。
Scientists divided the earth into time zones. A time zone map helps people figure out the time difference between two areas and helps them set their clocks.
科学家把地球划分为时区。时区地图可以帮助人们计算出两个区域之间的时差，帮助他们设置时钟。
Unfortunately, not everyone checks their clocks.
不幸的是，不是每个人都检查他们的时钟。
IN SEATTLE
在美国西雅图
Oh, Jouly-bean How is Grandma’s girl doing?
（奶奶）哦，豆豆奶奶的女儿怎么样了？
IN NEW YORK
在美国纽约
Grandma…It’s 11 o’clock at night….
（孙子）奶奶…现在是晚上11点。
Today, most people know the earth is round because we’ve seen pictures of it that were taken from outer space!
今天，大多数人知道地球是圆的，因为我们看到了从外太空拍摄的地球照片！
In 1972, astronauts aboard Apollo 17 took the first photo of the ENTIRE Earth from outer space. This picture is called ”The Blue Marble.”
1972年，阿波罗17号上的宇航员从外太空拍摄了整个地球的第一张照片。这幅画叫做“蓝色玻璃球”
“The Blue Marble” is the most famous picture of Earth EVER taken.
“蓝色玻璃球”是有史以来最著名的地球照片。
We also have pictures of all the OTHER planets in the solar system.
我们还有太阳系所有其他行星的照片。
Did you know that in outer space sunlight is white, not yellow? It’s the earth’s atmosphere that causes sunlight to appear yellow to us!
你知道外太空的阳光是白色的，不是黄色的吗？是地球的大气层让我们觉得阳光是黄色的！
Planets are objects that orbit the sun and are…ROUND！
行星是围绕太阳运转的物体，是…圆的
If all the other planets in our solar system are round, we can reason that Earth is round too!
如果我们太阳系中的其他行星都是圆的，我们也可以认为地球也是圆的！
The more we explore out solar system, the more we learn about this planet we call home.
我们对太阳系的探索越多，我们对这个我们称之为家园的行星的了解就越多。
Neptune?Square. Just kidding. It’s round.
海王星？方的。只是开玩笑。它是圆的。
Sometimes, a fact is repeated so often (like Earth being round), that we take it for granted. We never stop to wonder HOW we know it.
有些时候，一个事实经常被重复（就像地球是圆的），以至于我们认为这是理所当然的。我们从不停下来想是怎么知道的。
The good thing is that you can almost always figure out HOW by making careful observations of the world around you !
好的一面是，你几乎总能通过仔细观察周围的世界来找出方法！
WHAT ELSE DO YOU THINK YOU KNOW?
你还知道什么？
HOW TO BE A SCIENTIST
如何成为一名科学家
More than likely, you’ve never bothered to question Earth’s round shape. I’ll bet you can’t even remember a time when you didn’t think the earth was round! We just know ,don’t we?
更可能的是，你从来没有想过质疑地球的圆形。我敢打赌你一定记不起有一次你认为地球不是圆的！我们只是知道，不是吗？
Knowing that the earth is a sphere (not a perfect sphere, mind you-it bulges a bit in the middle) helps us understand many scientific concepts. The seasons, for instance. Or eclipses. Or the cause of day and night. And don’t forget gravitational force! And Earth’s magnetic field! The shape of our planet is the key to unlocking SOM MUCH SCIENCE.
知道地球是一个球体（不是一个完美的球体，请注意它在中间有点凸起）有助于我们理解许多科学概念。例如，季节。或者日蚀。或是日夜的原因。别忘了引力！地球的磁场！我们星球的形状是开启许多科学的钥匙。
But you don’t need to travel around the globe or blast into outer space to understand Earth’s shape.
但是你不需要环游地球或者冲进外太空去了解地球的形状。
TRY THIS!
What you’ll need:
a large ball
a piece of cardboard
A small figurine or toy
试试这个！
你需要什么：
一个大球
一块纸板
小雕像或小玩具
Remember the illustrations of ships that sailed on round and flat versions of the earth? You can model the same concept!
还记得那些在地球的圆形和平面上航行的船只的插图吗？你可以模仿同样的概念！
Hold the ball in front of you at eye level. Now hold your toy at the back of the ball, and slide it up over the top and toward you.You will notice that the first thing you see is the top of the toy. As it moves closer to you, more of it will appear, just like ships at sea. This proves that Earth is round!
把球举在你面前，与眼睛水平。现在把你的玩具放在球的后面，然后把它从球的顶部向上滑动，你会注意到你首先看到的是玩具的顶部。当它靠近你时，会出现更多，就像海上的船只。这证明地球是圆的！
Next, hold the piece of cardboard in front of you at eye level. Hol the toy at the far end of the cardboard. Then slide the toy closer to you. You will see the entire toy the entire time. It will just appear larger as it gets closer to your eyes. This is not how we see object move on the surface of the earth, so this proves that Earth is not flat.
下一步，把你面前的那块纸板放在眼睛水平的地方。把玩具放在纸板的另一端。然后把玩具滑到你身边。你会一直看到整个玩具。当它靠近你的眼睛时，它会显得更大。这不是我们看到物体在地球表面运动的方式，所以这证明了地球不是平的。
TRY THIS, TOO!
What you’ll need:
An area outside with a tall play structure
也试试这个！
你需要什么：
室外有高的游乐设施的区域
You can also demonstrate why a crow’s nest helps sailor spot land, shown in the illustrations. Find an area outside where you can see far into the distance at the horizon. First, look into the distance from the ground. Then climb a tall play structure and look in the same direction. You should be able to see farther from a higher position. If Earth were flat, you’d see the same view no matter how high you were.
您还可以演示为什么瞭望台有助于水手发现陆地，如图所示。找一个你能看到远处地平线的地方。首先，看看离地面的距离。然后爬上一个高的游乐设施，朝同一个方向看。你应该能从高处看得更远。如果地球是平的，不管你有多高，你都会看到同样的景象。
Remember to have fun experimenting, and never stop questioning what you THINK you know!
记住要有乐趣的实验，永远不要停止质疑你认为你知道什么！
Ellie Peterson（作者）
Is a middle school science teacher by day, author and artist by night (and any time when doodling can occur). She is inspired to teach readers to question how they know what they know. She believes that a good scientist looks at her assumptions before coming to conclusions.
白天是一名中学理科老师，晚上是作家和艺术家（任何时候涂鸦都可能发生）。她受到启发，教读者质疑自己是如何知道自己知道什么的。她相信一个好的科学家在得出结论之前会先审视自己的假设。
限 时 特 惠： 本站每日持续更新海量各大内部创业教程，一年会员只需98元，全站资源免费下载 点击查看详情
站 长 微 信： lzxmw777
