… are stationary lens-shaped and sometimes multilayered clouds that form at high altitudes. They are formed when moist air is forced to flow upward around mountain tops. Due to their shape, they have been offered as an explanation for some UFO sightings.

the place where the most UFO sightings occur in Britain. By: RHiNO NEAL

(January 31, 2011) Leonard Susskind gives a lecture on string theory and particle physics that focuses on the geometry of a black hole near the horizon. He describes how standard concepts from quantum physics can explain the physics that occur at this point. In the last of course of this series, Leonard Susskind continues his [...]