Let us calculate, in fact, according to the usual kinematics, the duration of each of the double paths. In view of simplifying the exposition, we will admit that the direction SA of the luminous ray has been chosen so as … Read More
A comprehensive guide of bridge game: online games, variants, suits, hand evaluation, bidding systems, techniques, strategy, tactics. Contract bridge, usually known simply as bridge, is a trick-taking card game of skill for four players, usually sitting around a table, who … Read More
This book is an anthology of essays dedicated to the relations between the two states, as well as to analyses regarding the evolution of the United States of America – a hegemonic power having many competitors among which shines the People’s Republic of China.
The detection of asteroids is an essential aspect of planetary defense and understanding the potential risks they pose to Earth. Astronomers use various methods to detect and track asteroids. Astronomers use telescopes on Earth to scan the night sky for … Read More
Autarchy is an economic system in which the state refuses any commercial connection with the outside, solely relying on its own resources. In an autarchic economy, the state does not participate in the international economic life, is not part of … Read More
Birds are among the most extensively studied of all animal groups. Hundreds of academic journals and thousands of scientists are devoted to bird research, while amateur enthusiasts (called birdwatchers or, more commonly, birders) probably number in the millions. Birds are … Read More
The moon in August 2023 will be a spectacular sight for skywatchers, as it will feature a rare blue moon, 2 full moons, 2 supermoons, and a partial lunar eclipse. A Blue Moon is a term used to describe a … Read More
The contemporary security environment has increasingly unpredictable mutations and the international scene seems to be gripped by a conflict that threatens to erupt at any moment, becoming an open conflict, violent and able to spread quickly everywhere; although for decades … Read More
In common usage, the terms “electronic book” and “ebook” designate both the content (the text itself) and, by metonymy, the container (the medium allowing the content to be viewed). These two expressions are therefore also synonymous with “reader”. However, this … Read More
The theory of relativity, even “restricted”, is not precisely based on the Michelson-Morley experiment, since it expresses, in a general way, the need to preserve the laws of electromagnetism in an invariable form when passing from one system of reference … Read More
The singularities from the general relativity resulting by solving Einstein’s equations were and still are the subject of many scientific debates: Are there singularities in spacetime, or not? Big Bang was an initial singularity? If singularities exist, what is their … Read More
Suppose that we propose to find a function F which satisfies Laplace’s equation inside the sphere S and which, at the different points M of the surface of this sphere, take given values V°. The value of this function V … Read More
