For thousands of years, people pictured the sky as a giant dome surrounding the Earth. The stars were thought to be fixed to this dome, which slowly turned above us, much like the motion of the Sun, the Moon and the planets. This book tells the story of the scientific revolution that changed that picture forever—the moment humanity realized that the motions we see in the sky are only apparent motions, created by the Earth spinning on its axis and traveling around the Sun. The “celestial dome,” it turned out, was an illusion. It is the Earth—and the heavens—that move. This revolution began with Nicolaus Copernicus’s book On the Revolutions of the Heavenly Spheres , published in 1543, just as the author was nearing the end of his life. The bold ideas in that book sent shockwaves through the scientific world and helped lay the foundations of modern physics. They also transformed the way people thought about nature—and about humanity’s place in the universe. This book follows the dramatic story of the Copernican Revolution and the long struggle to convince the world of its truth, from Galileo’s telescopic discoveries—made with a telescope he built himself—to the fierce scientific and religious debates that followed. The Copernican Revolution opened the door to an even bigger idea: The universe is vast, stretching far beyond our solar system. The “fixed stars,” we learned, are actually distant suns, so far away that they appear as tiny points of light. From there, it was only natural to wonder whether some of those stars might have planets of their own. At the end of the twentieth century—more than 400 years after Copernicus—astronomers finally discovered that planets are everywhere, orbiting stars across the galaxy. And who knows—perhaps some of those distant worlds may even host life.

Over the past two decades, advanced technologies and space missions have completely transformed our understanding of potential life beyond Earth. The resulting field, astrobiology, has become a multidisciplinary scientific discipline, encompassing many of the natural sciences and having implications for many areas of research. This book presents an introduction and overview of astrobiology. It deals with a wide range of fields, from the search for signs of life on planets in our solar system, to the discovery of exoplanets in distant solar systems and assessing the potential for life there. The book is based on the course of the same name that the author taught for more than two decades at the Hebrew University, and the course recorded on YouTube in the Cornerstones program , which has accumulated tens of thousands of views. The book is accessible not only to students of natural sciences, but to any reader who wants to learn about and understand the fascinating possibilities of life on other worlds.

Prof. Heinrich Mendelssohn was a young student of medicine and zoology in Berlin, where he was born in 1910. When the Nazis came to power, he immigrated to Israel with his family, completed his studies at the Hebrew University in Jerusalem, where he also wrote his doctoral thesis in zoology. Mendelssohn invested great efforts to expand zoological knowledge in Israel, and later became the director of the Zoological Institute, one of the cornerstones of Tel Aviv University. He served as vice president of the university and dean of the Faculty of Natural Sciences. His extensive research earned him the title of "the father of zoology" in Israel and one of the founding fathers of the field of nature conservation. From the beginning of his studies at the Hebrew University of Jerusalem, Mendelssohn kept a journal in which he recorded his observations of flora and fauna throughout the country and neighboring countries. The Journal was recorded in many notebooks from the year of his immigration, 1933, until 1958. He made many drawings of birds and other animals. In his wonderful drawings, he "captured" the character of the subjects and their behavior in a unique way. Many of them accompany the pages of this book. The journals are a document of enormous importance for the study of nature in our country, a basis and source of information that provides contemporary researchers with the possibility of understanding and researching many processes that have occurred since then and to the present day. Those who peruse the book will learn a lot about Mendelssohn's path and will be able to learn firsthand about the character of our rich animal world in the first half of the twentieth century.

Few texts have left a mark on history as profound as The Communist Manifesto . First ‎published in 1848, this brief yet explosive work by Karl Marx and Friedrich Engels became ‎one of the most influential texts in the formation of modern society and the modern self. It ‎ignited revolutions, inspired political movements, and provoked fear, resistance, and ‎enduring controversy, while offering a powerful framework for understanding the economic ‎and social forces that continue to shape our world.‎ But The Communist Manifesto is more than a political program. It is a striking work of ‎philosophical and moral reflection, grappling with the human condition in a world defined ‎by perpetual change—a world of capitalism, restless desire, and the drive toward ceaseless ‎innovation. Read anew, the Manifesto emerges as a mirror of our present moment, ‎challenging us to rethink freedom, justice, and the transformative power of ideas.‎ This book offers a fresh introduction to The Communist Manifesto and its place in the ‎history of ideas. Through close reading and conceptual analysis, it seeks to restore the ‎text’s vitality—not as a document of the past, but as a living invitation to reflect on the ‎present and imagine our collective future.‎

If a large rock had collapsed in a desert or a tree had fallen in the heart of a distant forest several hundred miles away from living beings, would it have made a sound upon its fall? Different people will give different answers to this ancient question. Objectively, some will say that a sound would have been heard because sound does not exist only in the mind of the listener. Subjectively, some would say that a sound requires someone to listen to it. What is correct? Is this complex answer related to the essence of sound? It's All in the Sound investigates the phenomenon of sound and tries to understand it and answer, among other things, the above questions. It was written to meet the needs of students and teachers, with a desire to update the teaching of physics and fill the shortage of textbooks in this field, which is associated with teaching the subject of sound waves. The gradual development of the concept of sound is discussed in the book by building structured experimental illustrations, as well as mathematical expressions describing this miraculous phenomenon. The illustrations were chosen so that a curious reader could repeat most of the experiments in a home environment without the need for special laboratory equipment. Even for readers unfamiliar with the basics of physical mathematics that describe sound, this book may provide a unique experience and open up a new window to understanding physics.

In this book Yoram Yom-Tov summarizes sixty years of observations and research on animals around the world, and takes readers on a fascinating journey into the wonders of the animal world — a journey intertwined with the life story of a curious, nature-loving boy who became a renowned researcher. Through the eyes of the researcher, the beauty and complexity of nature are revealed, exposing three key insights: nature is dynamic and constantly changing; every living creature is in constant interaction with its biological and physical environment, which creates a complex web of interactions; and the adaptations that animals have developed to their environment during evolution are evidence of unparalleled refinement and sophistication. These insights emerge from research conducted by Prof. Yom-Tov around the world throughout his long academic career in collaboration with colleagues, students, and even family members. They illustrate how scientific research not only expands human knowledge, but also encourages inspiration, appreciation, and even admiration for the great wonder that is nature.

In 1905, Albert Einstein astounded the scientific world when he proposed a theory that would become known as the special theory of relativity. Einstein's theory revolutionized the fundamental concepts of time and space, demonstrated the equivalence between mass and energy, and completely changed the face of modern physics. Despite its enormous importance, the theory of special relativity has remained largely unknown to the public interested in the scientific revolutions of the twentieth century. This book presents the theory of special relativity in a way that any student of the natural sciences can understand the theory itself, the crisis that led to its emergence, and its dramatic impact on the world of science. The book takes the reader on a fascinating, yet entertaining, journey of discovery and understanding of the theory of special relativity.

Since its creation, the Babylonian Talmud has stood at the center of the Jewish intellectual canon and the heart of Torah study. Despite its wide circulation and enduring significance, it remains an elusive work to define. It is a religious text, yet contains little theology; it is deeply legal, yet it is hardly concerned with practical rulings; it is framed as a commentary on the Mishnah, yet frequently departs into independent expansive discussions. What, then, is this composition? How was it constructed? How did it come to occupy such a central place in Jewish tradition? And how has it been interpreted over the centuries? The first part of The Talmud: A History of Learning is devoted to analyzing the Talmud itself—dissecting its constituent parts and exploring their formation, purpose, and historical context. The second part turns to the reception of the Talmud: the ways in which it has been read, studied, and reinterpreted from its redaction through the present day. The title of the book reflects this dual focus: it addresses both the internal processes of learning that gave rise to the Talmudic text, and the external history of its study and the discourses it has generated from late antiquity to the present.

Einstein’s revolution traces back to his key papers of 1905 in which he questioned the classical understanding of our concepts of space, time, matter, gravitation, and radiation, shaking the foundations of classical physics. These papers challenged the idea of light as a wave, gave striking proof for the existence of atoms, led to a new understanding of space and time, which came to be known as the “special theory of relativity,” and identified mass as a form of energy. Ten years later, Einstein completed his relativity revolution with his masterpiece, the general theory of relativity, which became the source of modern cosmology. Albert Einstein : Creator of a Worldview deals with these developments, with the ideas which led to them and with their consequences. It also describes briefly Einstein’s activity outside the world of physics and his reaction to major issues on the agenda of mankind in his time.

A Ramble in the Hive is an eco-philosophical text that deals with the relationship between humans and honeybees from the dawn of humanity to the present day, interlinking mythology, folklore, literature, art and science from different historical periods. A Ramble in the Hive works as both popular science and philosophy, combining a study of the history of beekeeping and its multitude of inventions, with a philosophical and poetic view of the human encounter with honeybees as reflected in the imagination of our culture. It suggests approaching the hive as an archetype of living mythology that works on our collective imagination. A Ramble in the Hive presents the planetary honeybee crisis as a fascinating window through which to observe wide-ranging ecological issues. How did the honeybee get such a lofty and critical role – holding responsibility for both the future of humanity and the earth? What do the bees tell us in their current state? This book is an attempt to answer these questions.

In the 1940s, Erwin Schrödinger attempted to tackle the eternal question "What is Life?" from the perspective of the "naïve physicist." The result is this short book, which has influenced generations of scientists, sparked much controversy and become a classic. What Is Life? appears in Hebrew for the first time, accompanied by an epilogue by Prof. Avshalom Elitzur, who demonstrates to what extent Schrödinger's insights are relevant eighty years after the first publication of the essay.

Korot publishes original articles related to medical history covering medicine in Jewish and Hebrew sources, the history of Jewish physicians, medicine in Palestine and Israel and medicine during the Nazi era. There are shorter historical notes on these topics, book reviews and comments on important developments in medical history. Articles are mainly in English but with a significant Hebrew section.