"What art thou, beam of light?"
wrote the poet James Macpherson, likely unaware of the physics of refraction. Snell's Law concerns the bending, or refracting, of light and other waves, for example, as they travel through the air and pass into another material, such as glass. When the waves are refracted, they experience a change in the direction of propagation due to a change in their velocities.
A convex lens makes use of refraction to cause parallel light to converge. Without the refraction of light by the lenses in out eyes, we couldn't see properly. Seismic waves - for example, the waves of energy caused by the sudden breaking of subterranean rock - change speed within the earth and are bent with Snell's Law.
When a beam of light is transmitted from a material with high index of refraction to one of low index, the beam can, under some conditions, be totally reflected. THe optical phenomenon is often called total internal reflection, and it occurs when light is refracted at a medium boundary to such an extent that it is reflected back.
This phenomenon is observed in certain optical fibers in which the light enters at one end and remains trapped inside until it emerges from the other end. Cut diamonds often exhibit total internal reflection when the diamond sparkles and emits light in the direction of the observer's eye.
Physics Readings
Re: Physics Readings
The banker Mr. Dimon uses near total internal reflection of the financial system. A large potion of the money entering his bank is reflected back into his pocket.
Re: Physics Readings
"Consider a collection of electrons, or a pile of sand grains, a bucket of fluid, and elastic network of springs, an ecosystem, or the community of stock-market dealersPigeon wrote:The banker Mr. Dimon uses near total internal reflection of the financial system. A large potion of the money entering his bank is reflected back into his pocket.
,"writes mathematical physicist Henrik Jensen.
"Each of these systems consists of many components that interact through some kind of exchange of forces or information... Is there some simplifying mechanism that produces a typical behavior shared by large classes of systems...?"
In 1987, Bak, Tang, and Wiesenfel published their concept of self-organized criticality (SOC), partly in response to this kind of question. SOC is often illustrated with avalanches in a pile of grains.
SOC has been looked for in the fields ranging from geophysics to evolutionary biology, economics, and cosmology, and may link many complex phenomena in which small changes result in sudden chain-reactions through the system. One key element of SOC involves power-law distributions. For a sandpile, this would imply that there will be far fewer large avalanches than small avalanches. For example, we might expect one avalanche a day involving 1000 grains but 100 avalanches involving 10 grains, and so on. In a wide variety of contexts, apparently complex structures or behaviors emerge in systems that can be characterized by simple rules.
-Pickover, The Physics Book
Re: Physics Readings
The physicist Lorand Eotvos once wrote, "Poets can penetrate deeper into the realm of secrets than scientists," yet Eotvos used the tools of science to understand the intricacies of surface tension, which plays a role in numerous aspects of nature. At the surface of a liquid, the molecules are pulled inward by intermolecular forces. Eotvos determined an interesting relationship between the surface tension of a liquid and the temperature of a liquid.