The first telescopes refracted light, and today reflectors dominate, but there is a third way to make light focus, and it ...

For centuries, telescopes have relied oncurved glass lenses to bend light and bring the cosmos into focus. While effective, these traditional lenses come with a major drawback—the more powerful they ...

For centuries, cameras and telescopes have relied on curved glass or plastic lenses to bend light and bring images into focus ...

For centuries, lenses have worked the same way: curved glass or plastic bending light to bring images into focus. But traditional lenses have a major drawback—the more powerful they need to be, the ...

Other scientists had speculated that using mirrors rather than lenses might correct this problem, but Newton was the first to put such thoughts into practice. He cast a two-inch metal mirror and ...