Author: Ron Cowen File Type: pdf A sweeping account of the century of experimentation that confirmed Einstein s general theory of relativity, bringing to life the science and scientists at the origins of relativity, the development of radio telescopes, the discovery of black holes and quasars, and the still unresolved place of gravity in quantum theory. Albert Einstein did nothing of note on May 29, 1919, yet that is when he became immortal. On that day, astronomer Arthur Eddington and his team observed a solar eclipse and found something extraordinary gravity bends light, just as Einstein predicted. The finding confirmed the theory of general relativity, fundamentally changing our understanding of space and time. A century later, another group of astronomers is performing a similar experiment on a much larger scale. The Event Horizon Telescope, a globe- spanning array of radio dishes, is examining space surrounding Sagittarius A, the supermassive black hole at the center of the Milky Way. As Ron Cowen recounts, the foremost goal of the experiment is to determine whether Einstein was right on the details. Gravity lies at the heart of what we dont know about quantum mechanics, but tantalizing possibilities for deeper insight are offered by black holes. By observing starlight wrapping around Sagittarius A, the telescope will not only provide the first direct view of an event horizona black holes point of no returnbut will also enable scientists to test Einsteins theory under the most extreme conditions. Gravity s Century shows how we got from the pivotal observations of the 1919 eclipse to the Event Horizon Telescope, and what is at stake today. Breaking down the physics in clear and approachable language, Cowen makes vivid how the quest to understand gravity is really the quest to comprehend the universe.

Author: Adam Michnik File Type: pdf Polands relationship with its Jewish population has long been a subject of often agonizing debate. In September 1939, there were approximately 3.3 million Jews living in Poland, the largest population in Europe. In May 1945, between 40,000 and 60,000 remained. Most of the Nazi death camps had been located on Polish soil. The intertwined issues of wartime complicity and victimhood haunt Poland to this day, complicated by the unavoidable fact that anti-Semitism in Poland existed well before the outbreak of the Second World War, and has existed long after it. The deadly Kielce Pogrom in July 1946 appalled the world, since its victims were precisely those Jews who had miraculously survived annihilation. And while with the years physical violence against Jews diminished-if only because there were not many at whom to direct it-anti-Semitism has remained no less virulent, emerging as a force in Polish politics, religious life, and in society at large. A study undertaken in 2002 determined that one in nine Poles believed the Jews collectively responsible for the crucifixion of Christ. One in four claimed that Jews were secretly plotting to rule the world. Is anti-Semitism integral to Polish identity? Nowhere has this question been more the cause of soul-searching than in Poland itself. In this volume, Adam Michnik, one of Polands foremost writers and intellectuals, and Agnieszka Marczyk have brought together the most significant essays of the twentieth century written by prominent Poles on Polish anti-Semitism, including by such writers and intellectuals as Czeslaw Milosz, Leszek Kolakowski, Jerzy Andrzejewski, and Tadeusz Mazowiecki. Taken from a three-volume original Polish edition, 3,000 pages in length and containing 320 entries, the essays, most of which have been translated into English here for the first time by Marczyk, resonate with Michniks central argument-that anti-Semitism is not a given of Polish culture. It has been consistently challenged and rejected. Taken together, through their collective courage and wisdom, expressed even in moments when reason seemed lost, these essays and their authors remind readers not only of the destructive and self-destructive elements of anti-Semitism, but of the necessity of combatting it in all of its forms. Even some of the darkest parts of Polish history have produced moments of illumination. **