For the finale, he creates a rainbow by shining a bright light into a glass sphere containing a single drop of water.

最后，他用亮光照射一个玻璃球，里面只有一滴水珠。彩虹出现了。

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The light that we see with our human eyes as a band of rainbow color falls in the range of what's called visible light.

我们用肉眼看到的彩虹色的光属于可见光。

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Black is an absence of light, so it is not in the rainbow.

黑色是光所缺乏的颜色，因此它不在彩虹里面。

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Researchers have trapped a rainbow - slowing light to a near-stop - in an array of 25, 000 "invisibility cloaks", each smaller than a hair's breadth.

BBC: 'Cloaking' idea traps a rainbow

The website explains how a rainbow is made from light and water - with help from the sun.

BBC: rainbow