Over those distances, even a sharp laser beam would spread to thousands of kilometres wide by the time it reached Earth.

在这种距离下，即便是聚焦良好的光束到达地球时也会分散到上千公里宽的面积上。

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Light sent into the oil layer was confined there, bouncing between the metal and air boundaries. The beam spread out ever more quickly, generating a trumpet-shaped glow (see image).

当把光传入油层后，就被约束在那里，光线在金属和空气的边界之间不断反弹，于是产生了喇叭状的辉光(见图片)。

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Powder can be spread onto a tray and then solidified in the required pattern with a squirt of a liquid binder or by sintering it with a laser or an electron beam.

将粉末洒向一个托盘，然后用一小盘液体粘合剂把粉状物按需要的形状进行固化，或者用激光器或电子束管将其烧结成所需形状。

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When the disease has spread such that one radiation beam cannot safely encompass all of it, the disease is treated with chemotherapy.

CNN: What is Hodgkin lymphoma's effect on the lymphatic system?

This lets a built-in microprocessor adjust the brightness and the spread of the Nao's beam accordingly.

WSJ: The Petzl Nao: A Smarter Light | At Play