Now, when light enters glass, it's a different refractive index, so it actually bends the light.

现在，当光线进入玻璃时，因为它的折同，所以它际上会弯曲光线。

This substance has a high refractive index, meaning the speed of light passing through it is greatly reduced.

这种物质的折很高，意味着光穿过它的速度会大幅降低。

To combat this rain visibility problem, 3M actually developed these elements, which are retroreflectors that have different refractive indices.

为了解决雨天能见度的问题，3M 公司际上开发了这些元件，它是具有同折的逆反器。

And on this side, we have elements that have a 2.4 refractive index and work better in wet conditions.

而在另一侧，有折为 2.4 的元素，它在潮湿条件下表现更好。

So on this side, we have elements that have a refractive index of 1.9, and they work well in dry conditions.

在这一侧，有折为 1.9 的元素，它在干燥条件下表现良好。

So where the retroreflectors act ideally under dry conditions, as soon as water is on top of them, their refractive index is lowered by a ratio of 1.33.

因此，当反器在干燥条件下理想工作时，一旦水覆盖在其上，它的折就会降低到 1.33 的比例。

Some have the regular glass beads on them, and other ones have the 3M elements on them with the 1.9 refractive index or the 2.4 refractive index or a combination of those.

有的上面有普通的玻璃珠，有的上面有折为 1.9 或 2.4 的 3M 元件，或者是它的组合。

" In addition, refractive index can also be used to 'invisibility', for example, objects with high borosilicate glass materials can also be 'invisible' when moving in glycerol with a refractive index close to its own, " Chu noted.

“此外，折也可以用来‘隐形’，比如高硼硅玻璃材料的物体在折接近自身的甘油中运动时也可以‘隐形’，”褚指出。

This is actually one of the principles of realizing the " invisible cloak" , when the fabric of a garment and the air refractive index are the same, people can be freely " invisible" after wearing it, said the expert.

这位专家说，，这其也是现 “隐形斗篷”的原理之一，当一件衣服的面料与空气折相同时，人穿上后就可以自由 " 隐形" 。