I'm looking outside now and that's electromagnetic radiation - visible light.

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When it is ground into nanoparticles it can still block harmful ultraviolet radiation, but it allows visible light to pass straight though, which means modern sunscreens can appear completely transparent, while offering the same protection as the old white stuff.

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The telescope gathers and focuses electromagnetic radiation (usually, but not always, visible light) to make far-off objects seem brighter and closer.

FORBES

Even something too small to emit visible light will probably give off radio waves and infra-red radiation (Jupiter does).

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Richer said that up to half of the stars in the universe were obscured by space dust and would soon be visible for the first time, thanks to ALMA's ability to pick up sub-millimeter radiation waves that pass through the dust unchecked.

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