They're light because of the effects of cosmological red shift.

质量很轻，这是因为宇宙红移的影响。

This red shift effect is the mapmaker's vital tool for measuring distance.

这种红移效应是地图制作者测量距离的重要工具。

And red shift was the key to the next vital stage in mapping the universe.

红移效应是绘制宇宙地图下一步骤的关键。

Interpreting redshift is the cornerstone of the quest to pin down the fate of the universe.

解释红移是确定宇宙命运的基石。

And as distant stars move further away from us, the wavelength of their light increases and shifts towards red.

当遥远的恒星离我越来越远时，它的光波波长逐渐增加，并发会生红移现象。

Remember, redshift stretches the wavelength of light.

记住，红移延伸了光的波长。

This is very similar to the Doppler redshift I've talked about in earlier episodes, and is called a gravitational redshift.

这和我之前讲过的多普勒红移非常相似，被称为引力红移。

They are shifted all the way into the infrared, so we're only really able to observe those galaxies by looking infrared.

红移的结果是进入红外线，所能通过红外线来观测这些星系。

That's just what galaxy redshifts are telling us.

这就是星系红移告诉我的。

So we call these effects blueshift and redshift.

所我称这些效应为蓝移和红移。

Out away from earth you drift, This is known from your redshift.

你远离地球漂流， 这是从你的红移中得知的。

You get this redshifting of the light.

你会看到光线的红移。

Redshift helps us understand how far away objects in deep space are.

红移帮助我了解深空中的物体距离我有多远。

This caused its wavelength to get longer and longer, which is called a redshift.

这导致其波长变得越来越长，这就是所谓的红移。

The light's going to be getting more and more red-shifted, as it's called.

光线将会变得越来越红移，正如我所说的那样。

Amazon Redshift is also now enhancing security by changing default behavior.

亚马逊红移现在也通过改变默认行为来增强安全性。

In my day, the farthest objects were Z of 5.

在我那个年代，最遥远的物体是红移为5的星系。

And so this is an example of that red shift that Hubble saw.

这就是哈勃观察到的红移的一个例子。

When light loses energy its wavelength gets longer — that's what cosmological redshift is.

当光失去能量，它的波长会变长，这就是宇宙学的红移。

The first is the star's redshift.

首先是恒星的红移。