State of the art, one of the seven wonders of the Ancient World, the great lighthouse of Alexandria, built around 280 B.C., towered some 450 feet above Egypt's greatest harbor. At that height, it ...

As intensive work continues to restore the Cape Hatteras Lighthouse, new issues have been uncovered near the top of the tower ...

Making a traditional glass lens requires a lot of experience, skill, and patience grinding a piece of glass to the required shape, and is not for the casual experimenter. Making a glass Fresnel ...

Though still only in the prototype stage, this flat lens could one day be used on space telescopes, and perhaps even on ...

If you are a Hackaday reader, you probably know what a Fresnel lens is. You find them in everything from overhead projectors to VR headsets. While it seems commonplace now, the Fresnel lens was an ...

The actual lighthouse Fresnel lens remains property of the U.S. Coast Guard. The lighthouse building is the property of the Bureau of Land Management. In 2008, the land was designated an Outstanding ...

Fresnel lenses are all around us, but this vase puts the commonplace technology to work in an entirely new way. Borrowed From Old Lighthouses, A Method For Super-Powerful Solar Power With the help ...