6.0望远镜
章节大纲
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Observe and discuss that there are more stars in the sky than anyone can easily count and that they are not scattered evenly in the sky. Investigate how magnifiers make things appear bigger and help people see things they could not see without them.
::观察和讨论天空中的星星比任何人都能轻易数得清的多，而且它们在天空中不是均匀分布的。调查放大镜是如何让东西看起来更大，帮助人们看到没有放大镜就看不到的东西的。
Look up at the night sky.
You can see hundreds of stars.
There are too many to count.
Most of these points of light are stars like our Sun.
A few are planets.
::抬头看看夜空。你可以看到数百颗星星。太多了，数不清。这些光点大多是像太阳一样的恒星。有些是行星。
Planets are within our solar system.
They orbit the Sun like the Earth.
Compared to stars, planets are close.
The stars are very, very far away.
::行星在我们的太阳系内。它们像地球一样绕太阳运行。与恒星相比，行星离我们很近。星星非常非常遥远。
Planets do not produce their own light.
We see planets because they reflect light.
Stars produce their own light.
Some stars are bigger than our Sun.
Some stars are smaller.
Our Sun is an average size star.
::行星本身不发光。我们看到行星是因为它们反射光线。恒星自己发光。有些恒星比太阳还大。有些恒星更小。我们的太阳是一颗中等大小的恒星。
Why does the Sun look so big?
Objects that are close look large.
Objects that are further away look smaller.
The Sun looks big because it is close.
::为什么太阳看起来这么大？近处的物体看起来很大。距离越远的物体看起来越小。太阳看起来很大，因为它离我们很近。
Light is the fastest thing in the universe.
Even light can take many years to travel from a star.
Light from the Sun takes less than ten minutes to get to Earth.
When you look at stars, you look into the past.
::光是宇宙中最快的东西。即使是光也需要很多年才能从一颗恒星传播出去。来自太阳的光不到十分钟就能到达地球。当你仰望星空时，你看到的是过去。
Scientists use telescopes to study the night sky.
Telescopes do not make stars look bigger.
They are too far away.
Instead, they allow more light to be collected.
Telescopes let us see more stars.
Even with a telescope, stars are only points of light.
::科学家们用望远镜研究夜空。望远镜不会使恒星看起来更大。他们太远了。相反，它们可以收集更多的光。望远镜让我们看到更多的恒星。即使用望远镜，星星也只是光点。
Galileo built the first telescope in 1608.
His first telescope used a lens.
Lenses bend, or refract, light.
Many people still use this type of telescope.
They help us see close objects better.
::伽利略于1608年制造了第一台望远镜。他的第一架望远镜使用的是透镜。透镜使光弯曲或折射。许多人仍在使用这种望远镜。它们帮助我们更好地看清近距离的物体。
You can see the surface of the Moon.
You can see Saturn’s rings.
Are planets close to us?
Compared to stars, they are close.
::你可以看到月球的表面。你可以看到土星的光环。行星离我们近吗？与恒星相比，它们很近。
Newer telescopes use mirrors.
Mirrors allow more light to be collected.
This helps us see more stars.
Most scientists use telescopes with mirrors.
::较新的望远镜使用镜面。镜子可以收集更多的光。这有助于我们看到更多的恒星。大多数科学家使用带有镜子的望远镜。
Large telescopes are placed on mountain tops.
Why do you think that is?
It is because Earth’s atmosphere distorts light.
On a high mountain there is less air to look through.
Can you think of a better place to put a telescope?
::大望远镜被安放在山顶上。你认为这是为什么？这是因为地球的大气层扭曲了光线。在高山上，可以透过的空气较少。你能想到一个更好的放置望远镜的地方吗？
Telescopes on top of Mauna Kea in Hawaii.
What is higher than a mountain?
Some telescopes are in outer space.
In space there is no distortion.
The Hubble Space Telescope has been in orbit for more than
20 years.
It sends back very clear images.
The Hubble helps scientists find answers to questions.
::什么比山还高？一些望远镜在外层空间。在空间中没有扭曲。哈勃太空望远镜已经在轨道上运行了20多年。它能传回非常清晰的图像。哈勃望远镜帮助科学家找到问题的答案。
(a) The Hubble Space Telescope orbits Earth at an altitude of 589 km (366 mi). It collects data in visible, infrared, and ultraviolet wavelengths. (b) This starburst cluster is one of the many fantastic images taken by the HST over the past two decades.
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a)哈勃太空望远镜在589公里（366英里）的高度绕地球运行。它收集可见光、红外线和紫外线波长的数据。(b)这个星暴星团是HST在过去二十年里拍摄的许多奇妙的图像之一。
