Alhazen. In medieval Europe, he was honored as Ptolemaeus Secundus ("Ptolemy the Second")[10] or simply called "The Physicist".[11] He is also sometimes called al-Basri (Arabic: البصري) after Basra, his birthplace.[12] He spent most of his life close to the court of the Caliphate in Cairo and earned his living authoring various treatises and tutoring members of the nobilities.[13] Overview[edit] Biography[edit] Born c. 965 in Basra, which was then part of the Buyid emirate,[1] to an Arab family.[14][15] Legacy[edit] Front page of the Opticae Thesaurus, which included the first printed Latin translation of Alhazen's Book of Optics. The illustration incorporates many examples of optical phenomena including perspective effects, the rainbow, mirrors, and refraction.
Alhazen made significant contributions to optics, number theory, geometry, astronomy and natural philosophy. Book of Optics[edit] Main article: Book of Optics Theory of vision[edit] Alhazen on Iraqi 10 dinars Scientific method[edit] G. A. When It Comes to Photosynthesis, Plants Perform Quantum Computation. Plants soak up some of the 1017 joules of solar energy that bathe Earth each second, harvesting as much as 95 percent of it from the light they absorb. The transformation of sunlight into carbohydrates takes place in one million billionths of a second, preventing much of that energy from dissipating as heat. But exactly how plants manage this nearly instantaneous trick has remained elusive. Now biophysicists at the University of California, Berkeley, have shown that plants use the basic principle of quantum computing—the exploration of a multiplicity of different answers at the same time—to achieve near-perfect efficiency.
Biophysicist Gregory Engel and his colleagues cooled a green sulfur bacterium—Chlorobium tepidum, one of the oldest photosynthesizers on the planet—to 77 kelvins [–321 degrees Fahrenheit] and then pulsed it with extremely short bursts of laser light. It also remains unclear exactly how a plant's structure permits this quantum effect to take place. The Casimir Effect. [Physics FAQ] - [Copyright] Calculation by Don Koks, 2002 Original by Philip Gibbs, 1997 The Casimir effect is a small attractive force that acts between two close parallel uncharged conducting plates.
It is due to quantum vacuum fluctuations of the electromagnetic field. The effect was predicted by the Dutch physicist Hendrick Casimir in 1948. According to the quantum theory, the vacuum contains virtual particles which are in a continuous state of fluctuation (see physics FAQ article on virtual particles). Casimir realised that between two plates, only those virtual photons whose wavelengths fit a whole number of times into the gap should be counted when calculating the vacuum energy. The attractive Casimir force between two plates of area A separated by a distance L can be calculated to be, π h c F = ------- A 480 L4 where h is Planck's constant and c is the speed of light. The tiny force was measured in 1996 by Steven Lamoreaux. Some examples or 1.3 mN. References. Researchers explain why bicycles balance themselves. Ruina Lab/Provided An experimental bicycle designed to eliminate the gyroscopic effect of spinning wheels and the "trail" of the front wheel is still stable on its own, disproving conventional theory.
The 1949 movie "Jour de Fete" shows a postman frantically chasing his bicycle, which rides away on its own. It could happen. Many bicycles, even without a rider, naturally resist tipping over if they are going fast enough. Scientists and engineers have been trying to explain bicycle self-stability ever since the 19th century. The accepted view: Bicycles are stable because of the gyroscopic effect of the spinning front wheel or because the front wheel "trails" behind the steering axis, or both. If you try to tilt the axis of a gyroscope in one direction, it will turn in a different direction. Almost any bicycle will keep itself upright as long as it's rolling. "There are other ways to distribute the mass and get self-stability without gyro or trail," Ruina noted.
Astronomy.
Electromagnetism. Electricity. Fluids. Nuclear Physics. Optics. Particle Physics. Thermodynamics. How can parts of Canada be" For more than 40 years, scientists have tried to figure out what's causing large parts of Canada, particularly the Hudson Bay region, to be "missing" gravity. In other words, gravity in the Hudson Bay area and surrounding regions is lower than it is in other parts of the world, a phenomenon first identified in the 1960s when the Earth's global gravity fields were being charted.
Two theories have been proposed to account for this anomaly. But before we go over them, it's important to first consider what creates gravity. At a basic level, gravity is proportional to mass. So when the mass of an area is somehow made smaller, gravity is made smaller. One theory centers on a process known as convection occurring in the Earth's mantle. A new theory to account for the Hudson Bay area's missing gravity concerns the Laurentide Ice Sheet, which covered much of present-day Canada and the northern United States. So which theory is correct? Is the Universe a Holographic Reality? The Universe as a Hologram by Michael Talbot Does Objective Reality Exist, or is the Universe a Phantasm?
In 1982 a remarkable event took place. At the University of Paris a research team led by physicist Alain Aspect performed what may turn out to be one of the most important experiments of the 20th century. You did not hear about it on the evening news. In fact, unless you are in the habit of reading scientific journals you probably have never even heard Aspect's name, though there are some who believe his discovery may change the face of science. Aspect and his team discovered that under certain circumstances subatomic particles such as electrons are able to instantaneously communicate with each other regardless of the distance separating them. University of London physicist David Bohm, for example, believes Aspect's findings imply that objective reality does not exist, that despite its apparent solidity the universe is at heart a phantasm, a gigantic and splendidly detailed hologram.
Episode LXXX: Party time! : Pharyngula. How To Build A Fireball You Can Hold Video. Lectures.