- Algenib (stars.astro.illinois.edu)
ALGENIB (Gamma Pegasi). Though the brightest star of Pegasus is Enif, the Epsilon star, the stars of the Great Square are of such obvious note that Bayer gave them Alpha through Delta. Delta (Alpheratz), the brightest, actually belongs to Andromeda as Alpha Andromedae, leaving Alpha, Beta, and Gamma Pegasi (Markab, Scheat, and Algenib) ranking 3-2-4 in the constellation and 2-1-3 in the Square, Algenib the faintest of them.
- Hollow Earth (Wikipedia)
The Hollow Earth is an obsolete concept proposing that the planet Earth is entirely hollow or contains a substantial interior space. Notably suggested by Edmond Halley in the late 17th century, the notion was disproven, first tentatively by Pierre Bouguer in 1740, then definitively by Charles Hutton in his Schiehallion experiment around 1774.