Universe & Multiverse
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SIMBAD on the Web is the WWW interface to the SIMBAD database.
by John Walker Welcome to Your Sky , the interactive planetarium of the Web. You can produce maps in the forms described below for any time and date, viewpoint, and observing location.
The universe can be a very strange place. While groundbreaking ideas such as quantum theory, relativity and even the Earth going around the Sun might be commonly accepted now, science still continues to show that the universe contains things you might find it difficult to believe, and even more difficult to get your head around.
space-time AND time-space
Pioneers 10 and 11, which preceded Voyager, both carried small metal plaques identifying their time and place of origin for the benefit of any other spacefarers that might find them in the distant future.
Among the unsolved mysteries confronting 21st century physics from gravitational waves to dark energy, neutrinos -the "ghosts of the cosmos"- are near the top of the list.
Spinning black hole: Scientists measure supermassive black hole rotating at nearly the speed of light.Artist's illustration of matter falling into a black hole, with X-rays blasting out from the very center. Click to chandrasekharenate. Image credit: NASA/JPL-Caltech
Several million stars are vying for attention in this NASA/ESA Hubble Space Telescope image of a raucous stellar breeding ground in 30 Doradus, located in the heart of the Tarantula nebula. 30 Doradus is the brightest star-forming region in our galactic neighbourhood and home to the most massive stars ever seen. The nebula resides 170 000 light-years away in the Large Magellanic Cloud, a small, satellite galaxy of our Milky Way.
Visual thinking: Spacetime
Universe Sandbox is an interactive space simulator for Windows based PCs. Unlike most astronomy software that just shows you what the sky looks like or where the planets are, Universe Sandbox is a powerful gravity simulator. You can add another star to our solar system and watch it rip the planets from their orbits.
A man sits down before a gun , which is pointed at his head.
quantum fluctuations of the vacuum
Our pursuit of naught provides profound insights into the nature of reality
Théorie Des Cordes
Quantum - String Theory
Jusque là, la relativité générale d'Einstein et la mécanique quantique se sont partagées les 4 forces fondamentales auxquelles sont liés tous les phénomènes de la nature.
Avant de poursuivre cette initiation à la relativité, il est indispensable d'introduire quelques rudiments de mathématiques afin de fourbir votre esprit avec la meilleure arme intellectuelle qui soit pour comprendre la suite du récit. Il faut en effet à présent définir quelques notions fondamentales, quitte à devoir faire usage d’un peu de symbolique mathématique. Mais n'ayez pas d'inquiétudes, le sujet retiendra votre attention.
What is Time?
“Time” is the most used noun in the English language , yet it remains a mystery. We’ve just completed an amazingly intense and rewarding multidisciplinary conference on the nature of time , and my brain is swimming with ideas and new questions. Rather than trying a summary (the talks will be online soon), here’s my stab at a top ten list partly inspired by our discussions: the things everyone should know about time. [Update: all of these are things I think are true, after quite a bit of deliberation. Not everyone agrees, although of course they should.] 1.