Teoretisk og matematisk astronomi

En moderne klassiker, som har slået alle udgivelsesrekorder med 237 uger på bestsellerlisten. ”Denne bog er en forening af et barns undren og et genis intellekt. Vi rejser med ind i Hawkings univers med dyb fascination.” Sunday Time ”En af de mest fremragende videnskabelige begavelser siden Einstein.” Daily Express ”Hawking forklarer kompleks kosmologisk fysik med en medrivende blanding af klarhed og humor … en hjerne af usædvanlig kraft.” Observer

Avi Loeb, ledende astrofysiker ved Harvard University, fremlægger sin kontroversielle teori om, at vores solsystem for nylig blev besøgt af avanceret og fremmed teknologi fra en fjern stjerne. I slutningen af 2017 fik nogle forskere på et observatorium i Hawaii øje på et objekt, der kom flyvende gennem vores indre solsystem og bevægede sig så hurtigt, at det nødvendigvis måtte stamme fra en anden stjerne. Avi Loeb påviste, at det ikke kunne være en asteroide. Objektet bevægede sig ganske enkelt for hurtigt og langs en underlig bane – og det forsvandt sporløst. Bogen er en tankevækkende rejse til videnskabens og den menneskelige forestillingsevnes yderste grænser.

Every night, above our heads, a drama of epic proportions is playing out. Diamond planets, zombie stars, black holes heavier than a billion Suns. The cast of characters is extraordinary, and each one has its own incredible story to tell.

For all those who wonder about our bizarre universe, and those who want to overthrow the big bang, this book gives you 'just the facts': the observations that have shaped established ideas and theories. The authors pull back the curtains, and show how cosmology really works.

Tiden er en gåde. For at løse den tager fysiker Troels Harmark os med på en rejse tilbage til antikkens græske filosoffer, videre op gennem naturvidenskabens historie til bl.a. Newton og Einstein og helt ud til forskningsfronten i moderne fysik og de største spørgsmål som, hvordan universet blev til. Tiden oprandt ved universets fødsel, og vi lever stadig i tiden her 13,8 milliarder år senere. Vi har en krop, der ældes, og kan ikke forestille os vores liv uden tid – vi indordner os under den, og tænker, at den bevæger sig regelmæssigt, som visernes præcise vandring over døgnets timer på uret. Men fysikken beretter en anden historie – om tidens relativitet: at den går langsommere tæt ved Jordens overflade end på toppen af et bjerg, at tiden står stille på kanten af sorte huller, og at universet udvider sig uendeligt. Tidens gang skal findes imellem de to modpoler: at alt er tilfældigt og at alt er uafvendeligt. På sporet af tidens gåde handler om, hvordan det hele hænger sammen, og hvordan det kan være, at man regner med, at tiden en dag vil stoppe med at gå. Hvordan skal vi forstå tiden?

Spectroscopic study of classical Be (Be) stars is important to better understand their disc physics. Recently, Banerjee et al. (2021) produced an atlas of all major emission lines found in a large sample of over 100 field Be stars using the 2-m Himalayan Chandra Telescope facility of the Indian Institute of Astrophysics (IIA) located at Ladakh, India. This study revealed several important aspects of Be star discs, such as the importance of considering the extinction parameter (AV) for studying Be star properties, their discs are generally optically thick in nature, probable existence of non-isothermal discs in some such stars which might be responsible for the production of Ca II triplet emission lines, etc. In another separate study (Banerjee et al. 2022), we focused in understanding the disc transient nature of Be stars through continuous monitoring of their H¿ line profile variations for 5 consecutive years using the 1-m telescope facility at the Vainu Bappu Observatory, Kavalur, India operated by IIA. Our work thus opens a broad scope to perform further dedicated studies of Be stars using larger samples to better understand their disc properties.

A professor of history considers 5 different subjects which he has thought, taught, and written about in his career as a historian. After decades of pondering and refining his ideas, these essays are fresh insights into his delvings.

The monograph explores space astronomy as a new scientific direction. Space astronomy complements classical astronomy and is its development. Space astronomy can be considered as the astronomy of points of observation of which observations are transferred from the Earth's surface and near-Earth space to space on space carriers. Space astronomy differs from classical astronomy not only by the transfer of observation points into outer space, but also by its methodological and organizational basis. Space astronomy, in addition to the basics of astronomy uses as components new sciences: space geodesy, space geoinformatics, geodesic astronomy, spatial analysis, spatial logic, systems analysis, informatics. The application of spatial logic is one of the features of space astronomy. The main means of observation in space astronomy is space monitoring. The application of the information field model is an important distinction of space astronomy/.

In the pursuit of exploring the cosmos beyond Earth's boundaries, the field of electrical engineering has emerged as a driving force in the quest to overcome the challenges of extraterrestrial environments. Among these, the enigmatic and captivating landscape of Mars has captured the attention of engineers and scientists alike. In the pages of this book, we embark on a journey through the uncharted territory of electrical engineering within the Martian domain, a frontier where innovation and ingenuity converge to shape the future of space exploration and habitation. The Martian landscape, with its lower gravity, thin atmosphere, and fluctuating climatic conditions, sets the stage for a captivating narrative in which electrical engineering plays a central role. As humanity sets its sights on potential human missions to the Red Planet, the need for ingenious solutions in energy provision, transmission, and resource management becomes apparent. This book unravels the intricate tapestry of challenges and opportunities that the Martian environment presents to electrical engineers, captivating both enthusiasts and experts.

'If you want to remember why you once fell in love with the idea of the cosmos, or want to fall in love with it for the first time, then this book is for you' ObserverFrom Carlo Rovelli, the bestselling author of Seven Brief Lessons on Physics, this is a story of wonder, new worlds and why the end is just the beginningLet us journey into the heart of a black hole. Let us slip beyond its boundary, the horizon, and tumble - on and on - down this crack in the universe. As we plunge, we'll see geometry fold, we'll feel the equations draw tight around us. Eventually, we'll pass it: the remains of a star, deep and dense and falling further far. And then - the bottom. Where time and space end, and the white hole is born . . .With lightness and magic, here Carlo Rovelli traces the ongoing adventure of his own cutting-edge research, of the uncertainty and joy of going where we've not yet been. Guiding us to the edge of theory and experiment, he invites us to go beyond, to experience the fever and the disquiet of science. Here is the extraordinary life of a white hole.A BOOK OF THE YEAR ACCORDING TO THE FINANCIAL TIMES * SUNDAY TELEGRAPH * NEW STATESMAN * NEW SCIENTIST

The universe is highly complex, with facets that will remain unknown for millennia and millennia to come. Understanding its overall vision, but also all the mechanisms of its dynamics, its past and its future, is a most fascinating task. Studying it reveals the very meaning of existence. Through the study of the nature of photons, time, glass holes, etc., this particular approach attempts to highlight in a condensed way the 3 main components of the universe:- the anteriority component of its structural equilibrium and architecture; - the component of primordial life-giving creative energy ;- the great cosmic wave.The photon is ultimately the basic building block of matter in the universe.

This book presents a thread of the author's research findings in the field of Astronomy, taking as its starting point his first book, The Theory of the Solar Zenith. The earlier work is summarized here in the first pages, with novelties such as the demonstration of the helical shape of the Sun's apparent motion and the suggestion of a new tropical zone. The next chapter brings the baffling Inverted Variation, which demonstrates, among other things, that the solar day varies contrary to the regime of the planet's orbital velocity on three occasions a year. This variation to be completely understood and explained, creates the need to suggest the New Heliometric Coordinates, which in turn allow the announcement of the Earth's Harmonic Velocities, which keep perfect harmony for all the other planets demonstrating that the inclination of the axis is preponderant in the demonstration of the New Planetary Harmony, which comes to be its own and quite original reinterpretation of Newtonean Gravitation.

One of the most unfathomable mysteries of quantum physics... could the answer be much closer than ever we thought?

Universal Shadow and Perpendicularity discloses here answers to the following questions: how our Universe comes to existence. How clouds thunder, lightning, and rains are created. How Night and Day are created. How the Earth, its mountains and oceans are created. How the Sun and the stars are created. How the Sun, the Moon, and the Earth are configured in the Solar system and how they motion and rotate. What causes the Earth and its mountains and the moon to motion and rotate? Why we witness volcanoes and what is the cause of volcanoes. What is the cause of Earth Quake and how it occurs? What are the layers of the Earth and mountains and how each layer is created?

This work establishes the independence of the Hindu scientific astronomy of any foreign source specifically the Greek The Present book is an reprint edition of the Calcutta University edition. This has been brought out for the benefit of the interested readers and meet the researchers demand.

This book tells about the main constellations and galaxies. It also contains a small systematization of the main galaxies and constellations. The book tells what a black hole is and its features. The celestial astronomy is an extensive branch of modern astronomical science that deals with the statistical analysis of observational data and the study of the collective properties of stellar and gaseous objects in our and other galaxies in order to understand the structure and development of galaxies and the stellar Universe as a whole. Unlike astrophysics, which studies the nature of various objects, stellar astronomy deals with large ensembles of these objects and operates with their average parameters. It prepares materials for the construction of theoretical models of the origin and evolution of stellar systems, and at the final stage it checks the fulfillment of the observable consequences of these theories. Stellar astronomy makes use of vast, ever-increasing observational material, in the analysis of which the methods of mathematical statistics are very widely used.

Black holes present one of the most fascinating predictions of Einstein's general relativity, with strong evidence of their existence through observations of many means. The book provides a wide background to the current research on all mathematical aspects of the geometry of black hole spacetimes.