And for retrofitting older buildings to be more energy effcient, wood is a good insulator.

为使旧建筑更节能，木材是很好的绝缘体。

Since these are not connected to each other, the result is an insulator.

它们彼此之间互不连接，因此成为了绝缘体。

It also turned out that gutta percha was a great insulator for undersea cables.

事实证明，杜仲胶是海底电缆的绝佳绝缘体。

And since asphalt is an insulator, it traps that heat over the course of the day.

因为沥青绝缘，昼捕热。

Most of the material is an insulator, but its surface can carry an electric current.

大部分这种材料都是一个绝缘体，但其表面仍可带一支电流。

All right, let's begin. Show of hands, who here is familiar with the concept of topological insulators?

好吧 开始上课 请举手告诉我 在座的哪位对拓扑绝缘体的概念比较熟悉？

The Earth's crust is an incredible insulator, and it keeps this massive, inexhaustible heat source beneath us invisible.

地壳的隔热效果很棒，能让这个巨大、用之不竭的地底热能来源不被注意到。

We do a fair amount in tiles and in insulators for electrica appliances. But kitchenware and tableware are our mainlines.

我们经营相当数量的瓷砖，以及电器用品的绝缘体。但是厨房用具和餐具是本公司主要系列产品。

A topological insulator acts like both at the same time, which we used to think was impossible!

一个拓扑绝缘体就像两个同时起作用，而这在过去被我们认为是不可能的。

And in an insulator, like rubber, electrons can't really flow at all.

而在橡胶一类的绝缘体中，电子实际上根本无法流动。

They're also good insulators for heat and electricity.

它们也是热和电的良好绝缘体。

Someone douses the fire, and she lowers the pot into an insulator they made out of clay and straw.

有人把火弄熄，她把锅子放到他们自己做的保温器里头，是用泥土和草做成的。

Diamonds are electrical insulators, not conductors.

钻石是电绝缘体， 而不是导体。

Nowadays, scientists are working to develop topological insulators, and some think they could be as important for future technologies as semiconductors are today.

当前，科学家们正在致力于研发拓扑绝缘体。其中有些人认为拓扑绝缘体对于未来的技术就像今天的半导体一样重要。

Now, while chemically pure water is an insulator, most water is impure.

现在， 虽然化学纯水是绝缘体，但大多数水都是不纯的。

The effects of high pressure can also work in reverse, causing some metals to lose conductivity or become insulators.

高压也能产生相反的效果，可能会使一些金属失去导电性或变成绝缘体。

So we’ve got insulators and conductors with free electrons moving around in them.

所以我们有绝缘体和导体， 其中有自由电子在其中移动。

The electrons in insulators, on the other hand, have a tough time getting enough energy to break free and flow.

另一方面，绝缘体的电子难以获得足够的能量去摆脱束缚进行流动。

Well, you need a better insulator than just air.

嗯，你需要一个比空气更好的绝缘体。

The  air is the insulator doing the job of keeping electricity constrained within the conductors.

空气是绝缘体，负责将电流限制在导体内。