In 1964, Russian astrophysicist Nikolai Kardashev (born April 25, 1932) defined three levels of civilizations, based on the order of magnitude of power available to them:Continue reading There is most probably no Kardashev Type-III civilization in the Universe. Here’s why
In 1950, the Italian physicist Enrico Fermi was chatting with his colleagues at the Los Alamos National Laboratory(1). They talked about
But, there is no reliable evidence aliens have visited Earth and we have observed no intelligent extraterrestrial life with current technology nor has SETI found any transmissions from other civilizations. The Universe, apart from the Earth, seems “dead”.
So, where is everybody?
The Earth is our one and only home. As Carl Sagan said (Pale Blue Dot: A Vision of the Human Future in Space), “On Earth, everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.”.
But will we ever leave our home and visit other stars in the future?
Our galaxy, “The Milky Way” is a barred spiral galaxy (a spiral galaxy with a central bar-shaped structure composed of stars) some 100,000-120,000 light-years in diameter, which contains 100-400 billion stars. It may contain at least as many planets as well. Our Sun (the Solar System) is located within the disk, about 27,000 light-years away from the Galactic Center, on the inner edge of one of the spiral-shaped concentrations of gas and dust called the Orion Arm.