Giancarlo Varnier: 27 books

Galaxies are huge clusters of stars held together by mutual attraction, so as to constitute a system self-gravitating.The discovery of clusters of galaxies is very important from the cosmological point of view, because it helps you learn more about the value of the density of matter in the cosmos. From this value we can determine the curvature of the Universe and its destiny.

The name derives from the greek Galaxias, meaning "milky", used to designate the Greek goddess Era. According to the most recent studies, it seems that the Galaxy is, from a morphological point of view, a barred spiral galaxy, or a galaxy composed of a core crossed by a bar-shaped structure, from which depart the spiral arms , following a logarithmic.

The Mesozoic or Secondary Era, extends for a period ranging from 251 to 65 million years ago. Also called as the Age of Reptiles, derives its name from the greek mesos, "middle", because it was placed in between the ancient (Paleozoic) and recent (Cenozoic) where he witnessed a veritable explosion in the number of living species and formed the majority of sedimentary rocks.

The Neozoic or Quaternary Era owes its name to the emergence and spread of man and comes from the greek "new life" should be from 1.8 million years ago until today.In this book we will explore the trails along the path leading to Homo sapiens, we will see what have been, until now, the most important scientific discoveries about the origin of our species with related issues, and much more.

The Precambrian is the oldest era of Earth's history, and, of its origins (4 billion and 500 million years ago), the appearance of the first invertebrates with exoskeletons (542 million years ago). In this long period of time, the planet, newly formed, was affected by cosmic events and geological shocking that border on the limits of imagination.

The Palaeozoic or Primary Era spans a period of time ranging from 542 million to 251 million years ago. The name Paleozoic, derives from the fact that, in the past, it was considered the first geological age. The Paleozoic covers a range of about 300 million years, giving rise to many forms of life, until the appearance of thecodonts, commonly believed to be the ancestors of dinosaurs.

The Cenozoic or Tertiary Era, derives its name from the greek and means "recent life". It covers the long period of time ranging from 65 to 1.8 million years ago. For the great success of the Mammals, the Cenozoic is also called the Age of Mammals.Birds conquer the heavens, no longer dominated by the flying reptiles. Toward the end of this Age will come out early hominids.

About five billion years ago the solar system was born and then the star we call the Sun The Sun, with all the bodies that revolve around it, is a system of which only a few years know other examples, but none of these is within the reach of our direct observation. For this reason, the problem of its origin, the evolution and prediction of its future is far more complex and difficult.

Nature teaches that when a species takes precedence over the other, becoming dominant, unchallenged, does nothing but start slowly, toward its decline. Extinction, in other words, serves as a balancing event, from a biological standpoint: that the dominant species to make room for new, more sophisticated expressions of the concept of life.

Some scientists have questioned the existence of the blacks holes as they are currently defined and speculated that the heavenly bodies currently identified as holes blacks but only indirectly observed are actually "black stars" without an event horizon. "We have shown that some quantum effects can prevent blacks holes to form, producing instead an object called" Black Star ".

In this text, after a brief description of the general characteristics of our planet, we focus on its dynamic training through the various geologic eras to arrive, then, the emergence and evolution of life in its many forms, with particular reference to the human species. Finally may try to understand the great events that could lead to the end of life on Earth.

Try to penetrate the mystery of the Universe is the greatest challenge to the limits of human thought. The progress of scientific knowledge in the field of cosmology and astronomy, puts today available to the reader the basic tools for self-reflection to reach a new awareness of the profound meaning of existence and life.

The Wonderful immensity of the Universe has always fascinated the human mind. The progress of knowledge around the bodies that fill the sky has marked the key stages of its evolution. We will look at theories of origin of the universe and the celestial bodies that comprise it,including Earth and development of life,from beginning to end, as part of our universal Cycle.

Le galassie sono enormi ammassi di stelle tenute insieme per attrazione reciproca, così da costituire un sistema autogravitante, Il nome deriva dal greco γαλαξίας (galaxìas), che significa "latteo". Sono corpi dalle vastissime dimensioni, che variano dalle più piccole galassie...