53K views · 280 shares | In this episode of "Science Unplugged," World Science Festival's own Brian Greene gets back to the basics and explains what E=mc² means. | Albert Einstein | Facebook

In his general theory of relativity, Einstein described gravity in terms of the curvature of space and time. Join Brian Greene for an introduction to the mathematics of curvature, which Einstein used to fashion his gravitational field equations. | World Science Festival

101K views · 235 reactions | If you race toward a beam of light, why doesn't the light approach you faster than the speed of light? If you race away from it, why doesn't the light approach you slower than the speed of light? In today's Daily Equation, Brian Greene describes the relativistic velocity combination law to provide an answer. | World Science Festival | Facebook