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"Grazie ad avventurosi studi fu possibile dimostrare un secolo fa che parte della radiazione naturale che si osserva sulla Terra è di natura extraterrestre: era la scoperta dei cosiddetti “raggi cosmici”, particelle che arrivano da misteriosi acceleratori nell’universo, probabilmente buchi neri supermassicci e resti di supernova, a energie anche centinaia di milioni di volte di quelle a cui riusciamo a produrle con i più potenti acceleratori della Terra. A cent’anni dalle prime scoperte questo libro si propone, con l’aiuto di documenti scoperti recentemente, di raccontare la vera storia di questa appassionante avventura scientifica e le frontiere dell'esplorazione dei raggi cosmici."

"This book is revised and extended to include using a low-cost "go-to" telescope, there are various pitfalls to be avoided, and how this class of instrument can make amateur astronomy more accessible to those with limited time at their disposal. It also discusses the new breed of mid-range digital cameras that include powerful on-board processing and image enhancement software that used to be available only to people with advanced astronomical CCD cameras. Finally, there are detailed reviews and test reports on some of the budget telescopes that are available on main street and by mail order."

"This book explores the subject in the context of quantum gravity. A novel approach to uncover the dark faces of the standard model of cosmology. The possibility that dark energy and dark matter are manifestations of the inhomogeneous geometry of our universe. On the history of cosmological model building and the general architecture of cosmological modes. Illustrations on the large scale structure of the universe. A new perspective on the classical static Einstein cosmos. Global properties of world models including their topology. The arrow of time in a universe with a positive cosmological constant. Exploring the consequences of a fundamental cosmological constant for our universe. Exploring why the current observed acceleration of the universe may not be its final destiny. Demonstrating that nature forbids the existence of a pure cosmological constant. Our current understanding of the long term (in time scales that greatly exceed the current age of the universe) future of the universe. And the long term fate and eventual destruction of the astrophysical objects that populate the universe, including clusters, galaxies, stars, planets, and black holes."

"The book is organized by ease of observation, lunar phases and the brighter planets come first, while solar eclipses, the aurora, and comets come later. Celestial Delights also includes a hefty dose of sky lore, astronomical history, and clear overviews of current science. It provides a handy reference to upcoming naked-eye events, with information broken out in clear and simple diagrams and tables that are cross-referenced against a detailed almanac for each year covered. Most broad-ranging astronomy field guides focus on stars, constellations, and the deep sky, but tend to ignore planetary events, which are in by far the most widely observable aspects of the changing night sky."

"Telah diketahui dengan baik bahwa simetri azimut hilang untuk lubang hitam yang berotasi, orbit yang terbentuk tidak terbatas hanya pada bidang ekuator. Baru-baru ini ada penelitian tentang orbit sferis non-ekuatorial foton untuk lubang hitam Kerr. Orbit sferis non-ekuatorial merupakan jenis orbit non-ekuatorial yang mungkin dibedakan dengan jari-jari koordinat konstan, seperti yang dibedakan dalam kelas orbit ekuatorial. Orbit ini menandai ambang batas antara orbit non-ekuatorial yang terjun ke bagian dalam lubang hitam dan yang tidak. Ambang orbit memainkan peran penting dalam pemodelan penangkapan foton dan materi, oleh lubang hitam. Dalam tesis ini, kami menyelidiki orbit sferis non-ekuitorial foton di sekitar lubang hitam bermuatan yang berotasi (Kerr-Newman) dan melihat bagaimana distribusi muatan mengubah klasifikasi orbit. Solusi analitik dari persamaan geodesik diturunkan dan beberapa bentuk orbit ditampilkan.

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It is well-known that, since azimuthal symmetry is broken for rotating black hole, the corresponding orbit is not confined to an equatorial plane. Recently there have been studies on the spherical photon orbit for Kerr black hole. Amongst the different types of possible non-equatorial orbits, those with constant coordinate radii are distinguished, just as circular orbits are distinguished in the class of equatorial orbits. Such orbits are known as spherical orbits. This special class of geodesics is obviously simpler to analyse than more general ones. Yet spherical orbits remain astrophysically relevant. For example, they mark the threshold between nonequatorial orbits that plunge into the black hole, and those that do not. Such threshold orbits play an important role in modelling the capture of matter and light by the black hole. In this thesis, we investigate the spherical photon orbits around a rotating charged black hole (Kerr-Newman) and see how the charge alters the classifications of orbits. The analytic solutions of the geodesics equation are derived and several orbital paths are shown."

"Summary: Astronomer Carl Sagan's landmark 13 part science series takes you on an awe inspiring cosmic journey to the edge of the universe and back, aboard the spaceship of the imagination."