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A General Relativistic Stationary Universe. General relativity - Gravity and spacetime bending. Al-Tusi. Epicycloïde. ÉPICYCLOÏDEEpicycloid, Epizykloide.

Epicycloïde

SDSS

CMB. Linksammlung. Simulation. Einstein: Guest 3 Q2 - jeu - A Science Odyssey: That's My Theory: How do you define gravity?

Einstein: Guest 3 Q2 - jeu - A Science Odyssey: That's My Theory:

Gravity is nothing more than the curvature of the space-time continuum. Perhaps you are intimidated by the term space-time continuum. You needn't be. All it describes is our familiar three-dimensional world, plus a fourth dimension: time. In our four-dimensional universe, space "curves" around objects, such as the Sun. The Cepheids.

Spectro

Atomic Hydrogen Spectra: Tools for probing galaxies. The Stars, La vie des etoiles. Parmi les grandeurs physiques des étoiles, deux d'entre elles allaient se révéler très fécondes pour classer les étoiles : leur luminosité et leur couleur.

The Stars, La vie des etoiles

Luminosité Les étoiles dans le ciel brillent avec des éclats différents. Photos Dans le champ des étoiles. Physics, Astrophysics and Cosmology with Gravitational Waves. School of Physics and Astronomy. Welcome to the Cardiff Gravitational Physics tutorial pages.

School of Physics and Astronomy

We have put together a few pages describing our research into black holes and gravitational waves. We hope you enjoy them. Also, why not try searching for gravitational waves with our game black hole hunter. Two Minute Introduction A brief introduction to black holes and gravitational waves, with a discussion of the effects of gravitational waves as well as the Hulse-Taylor pulsar - the most famous source of gravitational waves. 1.

Classroom Activities. Tempsideral. Explorations in survey cosmology, theoretical physics, signal processing, and Bayesian inference. Mullard Space Science Laboratory Astronomy Blog. Hello, I am Dr Myrto Symeonidis a postdoctoral researcher at UCL’s Mullard Space Science Laboratory (MSSL), and this week I will be telling you about some of my research here at MSSL […] Read Article → Welcome to our first science blog post.

Mullard Space Science Laboratory Astronomy Blog

I am Dr Samantha Oates, a postdoctoral researcher at MSSL, investigating what we can learn about Gamma-ray Bursts (GRBs) from their X-ray and […] Read Article → Welcome to the MSSL Astrophysics Blog! IYA 2009. Experience Join the international celebration with these easy-to-use monthly guides.

IYA 2009

Each IYA Discovery Guide includes:  A Journey of Science, Technology and Thought. This topic can be a little frightening for younger children, and may be better left for the older students.

 A Journey of Science, Technology and Thought

In recent years, astronomers have begun to understand that asteroids (chunks of rock left over from the formation of our solar system) are not just collected in a belt between Mars and Jupiter. A number of them have orbits that carry them into the neighborhoods of other planets, including Earth. The ones that can come near the Earth are called NEO's (Near Earth Objects) or Earth-crossing Asteroids. Astronomers and geologists have accumulated evidence that many asteroids of various sizes have struck the Earth in the past. La vue la plus détaillée à ce jour de l'Univers lointain. Une campagne d'observations effectuée par le réseau ALMA en configuration étendue a permis d'obtenir une image spectaculaire et détaillée à la fois d'une galaxie lointaine subissant un effet de lentille gravitationnelle.

La vue la plus détaillée à ce jour de l'Univers lointain

Sur cette image figure une vue magnifiée des régions de formation d'étoiles au sein de la galaxie distante. Le degré de résolution qui caractérise ces nouvelles observations est inédit. Il surpasse nettement le niveau de détail qu'offre le Télescope Spatial Hubble du consortium NASA / ESA, et révèle l'existence, au sein même de cette galaxie, de régions de formation d'étoiles semblables à la Nébuleuse d'Orion, quoique de dimensions nettement supérieures. Ce travail est le fruit d'une collaboration internationale impliquant en France des chercheurs1 des laboratoires du CNRS et des Universités françaises et de l'Institut de Radioastronomie Millimétrique (IRAM).

ALMA fonctionne à la manière d'un interféromètre. Trous noirs -SXS - Simulating eXtreme Spacetimes. Brief History of Cosmology. Some selected highlights of the dramatic advances in observational cosmology this century.

Brief History of Cosmology

Early 20th century - flattened `island' or Kapetyn universe At the beginning of the twentieth century, it was generally accepted that our galaxy was disk-shaped and isolated. A New View of Light. During the late 1800s and early 1900s, scientists struggled to understand the nature of light.

A New View of Light

Most physicists of the time believed that light traveled through what they called the "luminiferous ether. " In 1887, two American scientists, Albert Michelson and Edward Morley, built a device known as an interferometer, which they hoped would enable them to prove the existence of the ether. Michelson and Morley ran their interferometer experiment numerous times but never saw any evidence of the ether. Other scientists, sure that the ether theory was correct, continued searching for it. It wasn't until 1905, when Einstein published his Special Theory of Relativity, that the physics community began to accept that the ether does not exist. The Michelson-Morley interferometer worked by splitting a single beam of light in two. Einstein's Messengers. Hubble Law - NRAO: Revealing the Hidden Universe. Most scientists agree that the universe began some 14 billion years ago in an event known as the Big Bang. Though the Big Bang suggests a colossal explosion, the universe didn’t explode into anything.

Space itself was created in this explosive expansion. Since the Big Bang, the universe has continued to expand. The “Big Bang” is a scientific theory about the origin and evolution of the universe. A scientific theory is more than “just a theory”. Q. Edwin Hubble first noticed this relationship before 1920. Using this line of evidence, and the spiral galaxies listed below, you can measure the age of the universe. The galaxy images are available as FITS data files or as Jpegs. Power Point ( In this presentation, I used just four galaxies - I have used this presentation with groups as large as 200 students!

Excel worksheet ( If you download this worksheet into the same location as the Powerpoint, you can access the numbers during the presentation. Galaxy HI Spectra Fits Images of Galaxies. Qu'est-ce qu'un jour ? HongKong. FQXi Community. Heavens-Above. Space Scoop (French)

Variations sur un même ciel

Denis Puy Concept d'univers aube 21°siècle domaine - validité modèles. Charlotte Bigg - Mesures de la science - légitimations du savoir. Qu’y-a-t-il dans les trous noirs ? - Le Vaisseau - La science en s’amusant. Mais au fait, d’abord, qu’est-ce qu’un trou noir ? Le concept de trou noir a émergé dès la fin du 18ème siècle, mais la première observation d’un tel objet astrophysique ne date que de 1971. Le terme « trou » est inapproprié, on devrait plutôt parler de « boule noire » pour donner une idée plus juste de sa forme réelle.

Un peu comme un aimant géant, son pouvoir d’attraction est si intense qu’il empêche toute forme de matière ou de rayonnement de s’en échapper (à l’exception notable de l’un d’entre eux appelé « radiation de Hawking »). De tels objets n’émettent donc pas de lumière et sont alors perçus comme étant noirs. Ils ne sont pas directement observables mais plusieurs techniques d’observation indirecte ont été mises au point et permettent d’étudier les phénomènes qu’ils induisent sur leur environnement. Un pas en avant, un pas en arrière. L'Univers a-t-il des limites. Cosmology/big bang models/topology of the universe.

Lentilles gravitationnelles