Movimiento De Rotación Y Traslación (Estaciones Del Año) Las muchas formas de vida que viven en la Tierra son en gran parte dependientes del calor y la luz del sol, mediante la conversión de hidrógeno en helio, el Sol genera una enorme cantidad de energía cada segundo de cada día. Aunque hay pequeñas variaciones en la intensidad de esta energía, en su mayor parte, el calor y la luz generada por nuestra estrella madre son de la misma fuerza. Si la energía que llega a la Tierra cada día es de la misma intensidad y fuerza ¿Por qué algunas partes del año es caliente y otros muy frío? Si el Sol está produciendo de forma continua una cantidad constante e inmutable de calor, no deben ser las estaciones siempre las mismas? Los cambios de estación son causados por los movimientos de la Tierra. Las estaciones son creadas por dos acontecimientos muy importantes – la rotación de la Tierra que nos da el día y la noche, y la traslación de la Tierra alrededor del sol que nos da nuestro año.
Wikipédia, l'encyclopédie libre Elon Musk’s Mars project is the ultimate symbol of our throwaway culture | Life and style Elon Musk made some rather wild promises at the International Astronautical Congress last week: his SpaceX company is going to start sending people to Mars by 2024, and in 40 to 100 years, he will have a million of us living there. I have one big question about this. Why bother? Mars is a rotten place to live. You can’t breathe, eat, drink or go outdoors; the soil’s toxic, constant radiation streams in from space, and the average temperature is -60C. It looks rather bleak to me, but for some people I suppose the clincher would be that messages home would take 15 minutes, and “it would be hard to Skype with anybody”, according to Ashwin Vasavada of Nasa’s Mars Science Laboratory. But Musk is determined to plough on, make us a “multi-planet species” and turn Mars into “a really nice place to be”. There is being adventurous and curious, and then there is being overambitious, verging on potty.
cosmic dawn Astronomers have detected a signal from the first stars as they appeared and illuminated the universe, in observations that have been hailed as “revolutionary”. The faint radio signals suggest the universe was lifted out of total darkness 180m years after the big bang in a momentous transition known as the cosmic dawn. The faint imprint left by the glow of the earliest stars also appears to contain new and unexpected evidence about the existence and nature of dark matter which, if confirmed by independent observatories, would mark a second major breakthrough. “Finding this minuscule signal has opened a new window on the early universe,” said Judd Bowman of Arizona State University, whose team set out to make the detection more than a decade ago. “It’s unlikely we’ll be able to see any earlier into the history of stars in our lifetime.” In practice, detecting this signal has proved hugely challenging, however, and has eluded astronomers for more than a decade.
PlanetaMovil_Astronomía - Recurso fisico Hoy en día, por culpa de las luces y de la contaminación, los habitantes de las grandes ciudades hemos olvidado el espectáculo que puede ofrecernos el cielo nocturno. Por ello, los planetarios se han convertido, ahora más que nunca, en herramientas imprescindibles para enseñar astronomía básica y en ventanas abiertas al cosmos, que nos permiten maravillarnos con la contemplación del cielo y que, además, hacen posible que descubramos cuál es nuestro lugar y cuál nuestra relación con el universo que nos rodea. Los 4 programas que componen el Planeta Móvil "El cielo de las estaciones" muestran el firmamento, de cada una de las estaciones, visible a simple vista desde nuestras latitudes, tal como lo veríamos si no nos molestasen ni las luces ni la contaminación de la gran ciudad. Durante la proyección también se hace mención de las leyendas y mitos asociados a las principales constelaciones visibles a lo largo del año. Este recurso se puede pedir en préstamo por un periodo de dos semanas.
42 raccourcis clavier Windows indispensables Pour améliorer sa productivité lorsqu’on utilise un PC, les logiciels proposent de nombreux raccourcis clavier. De Microsoft Word à Microsoft Excel en passant par Gmail, Et comme la plupart des ordinateurs tournent sous Windows, beaucoup de raccourcis clavier communs permettent d’aller plus vite sur de nombreux services. Voici les 42 raccourcis clavier à connaître pour booster sa productivité sur ordinateur. Les 10 raccourcis clavier de base sur Windows Ces raccourcis mythiques fonctionnent sur toutes les versions de Windows. Ctrl+C : copierCtrl+X : couperCtrl+V : collerCtrl+Z : annulerCtrl+Y : rétablirCtrl+A : tout sélectionnerCtrl+P : imprimerF1 : afficher l’aideCtrl+Alt+Suppr : pour ouvrir le gestionnaire de tâche ou verrouiller l’ordinateurWindows ou Ctrl+Echap : ouvrir le menu démarrer/basculer sur le bureau (Windows 8) Les raccourcis Windows les plus utilisés par les professionnels Pour améliorer votre productivité au travail, vous pouvez utiliser ces raccourcis clavier.
Gravitational waves: breakthrough discovery after two centuries of expectation | Science Physicists have announced the discovery of gravitational waves, ripples in the fabric of spacetime that were first anticipated by Albert Einstein a century ago. “We have detected gravitational waves. We did it,” said David Reitze, executive director of the Laser Interferometer Gravitational-Wave Observatory (Ligo), at a press conference in Washington. The announcement is the climax of a century of speculation, 50 years of trial and error, and 25 years perfecting a set of instruments so sensitive they could identify a distortion in spacetime a thousandth the diameter of one atomic nucleus across a 4km strip of laserbeam and mirror. The phenomenon detected was the collision of two black holes. At the beginning of the signal, their calculations told them how stars perish: the two objects had begun by circling each other 30 times a second. The observation signals the opening of a new window on to the universe. Thursday’s announcement was the unequivocal first detection ever of gravity waves.
Astronomers discover mysterious pulsing object that may be new class of star | Astronomy Astronomers have discovered a mysterious object emitting a radio wave beam that pulsed every 20 minutes. The team behind the discovery believe the object could be a new class of slowly rotating neutron star with an ultra-powerful magnetic field. The repeating signals were detected during the first three months of 2018, but then disappeared, suggesting they were linked to a dramatic, one-off event, such as a starquake. “It was kind of spooky for an astronomer because there’s nothing known in the sky that does that,” said Natasha Hurley-Walker, from the Curtin University node of the International Centre for Radio Astronomy Research, who led the team that made the discovery. Despite the unusual nature of the signal, the team believe the source is likely to be a spinning object rather than a technologically advanced civilisation reaching out across the cosmos. “It’s definitely not aliens,” said Hurley-Walker. Over time, the neutron star would lose energy and slow down.