The investigation of light and optical properties stretches back centuries, at least to the ancient Greeks, Egyptians, and Mesopotamians. In fact, even artificial lenses date back to as early as ...

Evidence suggests ancient civilizations, including the Greeks, may have had early optical knowledge and devices like ...

Instead of a concave lens near the eye ... Kepler's advance created a new challenge, however. Because his telescope offered a much greater field of view, astronomers had plenty of room to improve ...

The Euclid space telescope has, by chance, discovered its first Einstein ring, and it is absolutely stunning. Beyond its aesthetic appeal, this perfectly circular Einstein ring has allowed researchers ...

In a ray diagram, a concave lens is drawn as a vertical line with inward facing arrows to indicate the shape of the lens.

Draw a ray which passes from the object through the centre of the lens. Some ray diagrams may also show a third ray. Peep holes contain concave lenses. They are set into doors so the occupant can ...