What warps when you're traveling at warp speed? What is the difference between a wormhole and a black hole? Are time loops really possible, and can I kill my grandmother before I am born? Anyone who has ever wondered “could this really happen?”...
One of the most important anthropological overviews of European racial types ever published. Although some of its conclusions have since been eclipsed by DNA studies, this work remains a standard in racial typology. Harvard professor of...