There's another effect that comes in ... the Cosmic Microwave Background. This marks the first time that the Universe becomes transparent to light. The leftover photons from the Big Bang, now ...

effects, images, and designs to preview how your selection will appear. You’re also able to retain a transparent background—just leave everything the way it is, and refrain from adding a new ...

The atom cloud becomes more transparent, letting light through instead of scattering it. To observe the effect, Margalit and colleagues beamed light through a cloud of lithium atoms, measuring the ...

Nothing special about that, right? OK, but what if you could shine a second light on the substance and make it transparent for the first light field? That would be a bit strange, wouldn't it?