Glass mirrors were the latest cutting edge technology in the middle ages, but the convex mirror was the only shape possible.

玻璃镜子中世纪最新的尖端技术，但凸面镜唯一可能的形状。

It did have kind of these convex mirrors.

它有这种凸面镜。

These mirrors are convex, causing rays to converge into a real image, which is then magnified through an eyepiece or projected directly onto a digital sensor.

这些镜子凸面的，使光线会聚 成真图像，然 目镜放大或直接投射到数字传感器上。

Remember, the substance of  what she's found so far is that if you look at any convex solid, then the average area for its shadow  is going to be proportional to its surface area.

请记住，到目前为止她发现的质内容， 如果您观察任何凸面体，那么其阴影的平均面积将与其表面积成正比。