Risultati letto da "Edwin Newman" in Tutte le categorie

Einstein overthrew Newtonian physics but like Newton he still believed that physical events have definite causes. Then Niels Bohr, a Danish physicist, joined others in describing a strange new world of uncertainty and mystery. Quantum mechanics has intrigued and confounded many by joining keen insights with apparent contradictions and indeterminacy. Quantum theory also was later used to create semiconductors, the technology of the computer revolution.

Isaac Newton's world had operated in a fixed, rigid, "absolute" framework of space and time. Yet discoveries about electromagnetism in the late 19th century created new and troubling inconsistencies. In 1905, Einstein's name became synonymous with "genius" when his Special Theory of Relativity challenged old concepts in physics. Hertz, Lorentz, Mach, Poincare, and others illustrated the ideas that so captivated Albert Einstein and shook our conventional ideas about space and time.

Alexander Von Humboldt and others sparked a centuries-long debate about natural history and geological destiny by discussing what today we call the environment. Some now believe the earth cannot safely accommodate its growing burdens; others say longer life spans and more people are signs of progress. Are humans destroying the earth, or building a better world? Will the future bring despair and destruction, or hope and improvement?

Though medical science began with the ancient Greek physician Hippocrates, dissection and the study of the human body was prohibited for religious reasons until the Renaissance. Only in 1628 did William Harvey theorize that blood circulates in the body; germs weren't discovered until the 19th century. Since then, surgery and drugs have greatly reduced deaths and pain from accident and disease. Genetic research and biotechnology hold the promise of even greater advances in the 21st century.

Newton was a natural philosopher (the word "scientist" had not yet been coined) who described a planetary system held together by gravitational forces. His "Principia" changed science forever; gravity not only explained the orbits of stars, it explained common earthly events as well. Newton established a way of thinking that still shapes our everyday understanding of how the world works.

As optics improved, man began to see the solar system. Tycho Brahe in Denmark, Nicolaus Copernicus of Poland, Johannes Kepler of Germany, and Italy's Galileo Galilei all began to see a new relationship between the world and the stars. Their questions, and their non-religious answers, toppled the idea that man and the Church are at the center of the universe.

While astronomers charted the heavens, geographers and cartographers mapped the earth's exotic land and seas. Commerce and navigation exploded as mapmakers and bold explorers built on each other's achievements; in the process, our very concept of the earth changed from a flat surface to a sphere.

Many believe the "Middle Ages" lacked progress, yet during this time algebra was developed, and Islamic scholars preserved and extended Greek thought (which otherwise was lost). Metallurgy (and its speculative counterpart, alchemy) led to a deeper understanding of materials. These advances set the stage for the Renaissance and a scientific revolution.

The scientific impulse can be said to have existed forever. But only with the written word did there emerge a record of speculations about how and why things happen. Middle Eastern civilizations developed ways to measure and describe (e.g., math and the alphabet); Greek philosophers classified natural objects and studied cause and effect. This is the story of ancient science from Asia to the Mediterranean Basin.

In the 19th century, scientists working with chemistry and magnetism began discovering a rich variety of electrical phenomena. These were to be applied later in inventions including motors, alternating current, radio, batteries, the telephone, and much more. This is the story of a new branch of science that changed the way the world does physical work and the way it controls information, spurring the Industrial Revolution, followed by the Information Age.

In 1859, Charles Darwin published a vastly important work, On the Origin of Species by Means of Natural Selection. For centuries, man had been seen as a created species, distinct from any other animal. Then, Darwin persuasively argued that mankind and other species are descended from common ancestors. His theory of "natural selection", also known as "survival of the fittest", explains how life evolved through natural processes.

The story of the cosmos, its beginning and its changes through time, has been a topic of much speculation and myth. It also has attracted intense attention from scientists. There are many questions about the universe's size, stability, growth, and its ultimate cause. This presentation also addresses such colorful cosmic topics as red shifts, white dwarfs, black holes, super strings, and the "big bang".

In the 17th and 18th centuries, scientists went beyond Aristotle's four elements (Earth, Wind, Fire, and Water) to catalogue nature's many basic elements. New materials and potions stimulated visions of wealth and healing; soon, new theories of atomic structure and combustion laid the foundation for practical applications that blossomed into the Industrial Revolution.

We think of science as a way of discovering certainty in an unpredictable world; experiments are designed to objectively measure cause and effect. Yet science often produces more new questions than answers, and all scientific theories can change with new and better observations. Scientific philosophers say that "objective" observations actually depend heavily on the observer's intuition and point of view.

Newtonian physics described a regular, clock-like world of forces and reaction; randomness was equated with incomplete knowledge. But scientists in the late 20th century have found patterns in things formerly thought to be "chaotic"; their theories help explain the unstable, irregular, yet highly structured features of everyday experience. It now seems likely that randomness and chaos play an essential role in the evolution of the living world and in intelligence itself.