Atoms can absorb and reemit light—this is an everyday phenomenon. In most cases, however, an atom emits a light particle in all possible directions—recapturing this photon is, therefore, quite hard. A ...

Atoms can absorb and reemit light - this is an everyday phenomenon. In most cases, however, an atom emits a light particle in all possible directions - recapturing this photon is therefore quite hard.

The Tibetan Plateau is a vast elevated plain almost five kilometers above sea level, sometimes called the Roof of the World. It is bordered to the south by the world’s highest mountain range and to ...