We always thought of ourselves as being at the center of the Universe and at rest. It was not until very recently that Copernicus explained how our Earth is orbiting the Sun and that the Sun, not the Earth, is at the center of our solar system. Today’s theories such as Einstein’s special and general relativity, still believe that we and our galaxy, are at the center of the Universe. In fact, relativity with its “cosmological principle” claims that any observer on any galaxy in the Universe can consider him or herself at the center and at rest.
This is a humourous and informal rendition of the story of gravitation theory from the early historic origins to the latest developments in astrophysics, focusing on Albert Einstein's theory of general relativity and black-hole physics. Through engaging conversations and napkin-scribbled diagrams come tumbling the rudiments of relativity, spacetime and much of modern physics, narrated with high didactic and literary talent, and each embedded in casual lessons given by a worldly astrophysicist to his friend.
Suitable for a one-semester course in general relativity for senior undergraduates or beginning graduate students, this text clarifies the mathematical aspects of Einstein's theory of relativity without sacrificing physical understanding. The text begins with an exposition of those aspects of tensor calculus and differential geometry needed for a proper treatment of the subject. The discussion then turns to the spacetime of general relativity and to geodesic motion
Cracking the Einstein Code: Relativity and the Birth of Black Hole Physics
Albert Einstein’s theory of general relativity describes the effect of gravitation on the shape of space and the flow of time. But for more than four decades after its publication, the theory remained largely a curiosity for scientists; however accurate it seemed, Einstein’s mathematical code—represented by six interlocking equations—was one of the most difficult to crack in all of science. That is, until 1963. Roy Kerr’s solution emerged coincidentally with the discovery of black holes ...
What is the significance of mankind in the Universe? Ever since Copernicus, scientists have been moving man further and further from his lofty position at the center of Creation. But in recent years a startling new concept has evolved that puts humans more firmly than ever in a special position. Known as the Anthropic Cosmological Principle, it holds that the fundamental structure of the Universe is determined by the existence of intelligent observers: the universe is as it is because if it were otherwise, observers could not exist. In its most radical version, the Anthropic Principle asserts: "Intelligent information-processing must come into existence in the Universe, and once it comes into existence, it will never die out."
What is the significance of mankind in the Universe? Ever since Copernicus, scientists have been moving man further and further from his lofty position at the center of Creation. But in recent years a startling new concept has evolved that puts humans more firmly than ever in a special position. Known as the Anthropic Cosmological Principle, it holds that the fundamental structure of the Universe is determined by the existence of intelligent observers: the universe is as it is because if it were otherwise, observers could not exist. In its most radical version, the Anthropic Principle asserts: "Intelligent information-processing must come into existence in the Universe, and once it comes into existence, it will never die out."
