A new feature on Google Maps Street View, which rolled out world-wide Wednesday, lets users zip through imagery dating back to Street View's beginning in 2007. The update also lets you view Street View in different seasons and during the night.
谷歌(Google Inc., GOOG)街景地图周三在全球范围内新增了一大特色，用户可以浏览追溯至街景功能2007年推出时的影像。此次更新版还可以让用户浏览到不同季节以及夜间的街景。
'For the longest time we've had Street View users asking that we either preserve the imagery we had or that we give them the ability to go back in time and look at imagery the way it was before,' said Luc Vincent, the Google Maps Street View director of engineering. Users want to see how their old neighborhood looked years ago, the building of iconic landmarks, or cities before and after natural disasters, he said.
谷歌街景地图工程部门负责人文森特(Luc Vincent)表示，长久以来，街景用户一直在问它们，到底是保存这些影像，还是给用户回到从前、浏览过去图像的能力。他说，用户希望看到他们的老街区几年前是什么样子，看看标志性建筑或者是城市在自然灾害之前和之后的样子。

'We like to think we were building a 3-D image of the world, and now the mirror is actually 4-D,' Mr. Vincent said.
文森特说，公司希望它们一直在建造全世界的3D图像，而现在实际上是4D了。
If you see an hourglass in the upper left corner of a Street View panorama, that means there is past imagery you can peruse. Just click the hourglass and a thumbnail of past images will appear. A timeline in the thumbnail allows you to move through history.
如果你看到谷歌街景网页左上角有一个沙漏，就意味着你可以查看过去相应的街景图片。只要点一下这个沙漏，就会出现过去图像的缩略图。根据缩略图的时间轴，你就可以回顾历史了。
When you see the period you want to explore, click it and the whole Street View will change. At that point, you can wander around in the past as you would in the current version.
当你看到你想要回顾的时期，只要点一下，整个街景页面就会改变。那时候，你就可以像在当前版本一样在过去徜徉。
Before the update, about 6 million miles worth of Street View imagery was available. With the time-machine feature, you can find about 12 million miles worth of sidewalk-level, interactive photos to explore.
在此次更新版发布前，谷歌街景采集的累计里程达到了600万英里（约966万公里）。在推出“时光机”功能后，用户可以查看大约1,200万英里（约1,932万公里）的便道交互式图像。
The time machine will be available in almost every location where Street View is in operation.
这项“时光机”功能在谷歌街景记录的几乎所有地点都可以实现。
For major metro areas, there will be 20 or more so-called time slices to check out, while for most locations, there will be two or three, Mr. Vincent said.
文森特表示，对于主要的都市区，谷歌街景提供了20个甚至更多的时间片段可供浏览，而对于大多数地点，则提供了两到三个时间片段。
'What we've done before now was give users the freshest imagery, because that's typically what's most useful to them,' he said. 'From now on, every time we add imagery, it will be with a time-machine layer.'
文森特说，在此之前，公司给用户提供的都是最新的图像，因为通常来说这对他们是最有用的。他说，从现在开始，每次我们添加图像，都会附上一个时光机器按钮。
For now, Street View's time-machine feature is only available on desktops, but Mr. Vincent said he would like to see it eventually offered on mobile as well. The hope is that users will find the older Street View maps just as useful as the new photos.
Google Inc.
目前，谷歌街景的“时光机”功能只适用于台式机，但文森特说，他希望最终这项功能也能在手机上使用。该公司希望用户最终感觉这些街景历史图像和新图像一样有用。
'This is something educators and scientists could use,' Mr. Vincent said. 'We want this to be a resource for the world. That's why we were intent on launching it world-wide all at once.'
文森特补充道，教育工作者和科学家可以利用这项功能。他说，公司希望这成为全球的一项资源；这就是为什么公司有意将更新版在全球同步上线。