Dig deeper at pwnphysics.blogspot.comOn this day in physics: 27 March 1845- Happy Birthday to Wilhelm Rontgen, a German Physicist and 1901 Nobel Prize winner who would have turned 171 today. He was the first to discover radiation first known as Rontgen rays and now referred to as X-rays. Word of the Day- The Drake Equation is an equation developed by Frank Drake in 1961 which uses probabilistic factors which are multiplied together to estimate the number of extraterrestrial intelligent species in the galaxy or universe. Per wikipedia: "The number of such civilizations, N, is assumed to be equal to the mathematical product of (i) the average rate of star formation, R*, in our galaxy, (ii) the fraction of formed stars, fp, that have planets, (iii) the average number of planets per star that has planets, ne, that can potentially support life, (iv) the fraction of those planets, fl, that actually develop life, (v) the fraction of planets bearing life on which intelligent, civilized life, fi, has developed, (vi) the fraction of these civilizations that have developed communications, fc, i.e., technologies that release detectable signs into space, and (vii) the length of time, L, over which such civilizations release detectable signals". Check it out here. By this equation and even conservative estimates there are somewhere between 1000 and 100,000,000 civilizations in the Milky Way alone.Keywords: Drake, Equation, Roentgen, Extraterrestrial.