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，因为的折射率不同，所以实际上会弯曲光线。

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

这种物质的折射率，味着光穿过的速度会大幅降低。

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

为解决雨天能见度的问题，3M 公司实际上开发这些元件，是具有不同折射率的逆反射器。

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，我有折射率为 2.4 的元，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，我有折射率为 1.9 的元，在干燥条件下表现良好。

Even when passing through natural materials with the highest refractive indexes, light can only bend so far.

即便光线穿过折射率最的天然材料，其弯曲程度也有限。

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，当反射器在干燥条件下理想工作时，一旦水覆盖在其上，的折射率就会降低到 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，有的上面有折射率为 1.9 或 2.4 的 3M 元件，或者是的组合。

" 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，折射率也可以用来‘隐形’，比如硼硅玻璃材料的物体在折射率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，，这其实也是实现 “隐形斗篷”的原理之一，当一件衣服的面料与空气折射率相同时，人穿上后就可以自由 " 隐形" 。