DeLand's Paradox is an illusion that can "disappear" a whole person

Let's say you are cornered by your worst enemy. They will kill you, but being an oddball enemy, they'll give you one request first. (And the request can't be "Don't kill me." They're on to that one.) I have a solution for you. Ask them to show you how DeLand's Paradox works. That will keep them busy for years while you… » 1/11/13 7:00am 1/11/13 7:00am

The Ultimate List of Reasons We Know the Earth is Definitely Round

In case you had any lingering doubts, here is some masterful cosmological/geological/geometrical instruction on our planet and its spherical — but not perfectly spherical — tendencies, courtesy of the ever-capable Henry Reich (better known as the creator, animator and narrator of MinutePhysics). Some great, if not… » 1/03/13 2:24pm 1/03/13 2:24pm

According to a 1918 science magazine, the Earth would transform into a …

In the May 1918 issue of the youth science and current events periodical My Magazine, an unnamed author played it particularly fast and loose with geophysics when he declared that the planet was slowly becoming a pyramid. "What sort of people will live on the tetrahedron?" screamed the author in the headline, somewhat… » 3/12/12 11:50am 3/12/12 11:50am

Delightfully weird Banach-Tarski video will make you wish you were a…

An oversimplified explanation of the mind-numbingly paradoxical Banach-Tarski theorem states that a solid sphere can be cut into non-overlapping pieces (geometricians would say that such a ball has been "decomposed"), and reassembled in a new arrangement, such that the end result is two identical copies of the original… » 1/05/12 3:15pm 1/05/12 3:15pm