History

Alfalfa Leaf Diseases Alfalfa Leaf Diseases- Photographs and information on a number of diseases that affect this crop. Alfalfa Plant Diseases and Damage Alfalfa Plant Diseases and Damage- Photographs of plants infected by various pathogens and pests, with links to articles on integrated crop management. Michigan Asparagus Advisory Board Michigan Asparagus Advisory Board- Promotes the production and sale of the vegetable, and assists in research. Also includes recipes, nutritional information and details on the as… The Potato Then and Now: History The Potato Then and Now: History- The history of potato cultivation and its role in society, including the Irish potato famine. Particular focus on Prince Edward Island, Canada. Agriculture and Horticulture in Ancient Egypt Agriculture and Horticulture in Ancient Egypt- Article describing agricultural practices of the ancient Egyptians including irrigation, ploughing and planting, harvesting, the cro… Agricultural History Society Agricultural History Society- This society aims to promote interest in, and the study of, the history of agriculture. Provides information on membership, the journal, meetings and… History of Farming History of Farming- Illustrated overview of the origins and development of agriculture, with bibiliography, notes from early cultures, and pictures of early farm implements and tr… History of Farming and Cities History of Farming and Cities- Links to pages which give research on the development of farming and cities by culture. Module Truck Systems Inc. Module Truck Systems Inc.- History and pictures of cotton modules and cotton module trucks. (Lubbock, Texas, USA) British Agricultural History Society British Agricultural History Society- Promotes the study of agricultural history and the history of the rural economy and society. Organization information, upcoming conferences, … Agropolis-Museum Agropolis-Museum- A Science Center dealing with topics such as food, nutrition, agriculture, with a historical approach on a worldwide scale. Website has virtual exhibitions on th… How Stuff Works: Special Relativity How Stuff Works: Special Relativity- The major principles of special relativity (SR) are discussed in an accessible way, via 5 segments, to help you understand the lingo and theor… The Structure of Space-Time Transformations The Structure of Space-Time Transformations- This theorem by H. J. Borchers and G. C. Hegerfeldt proves that the constancy of light velocity alone implies the Lorentz group (up to… Special Relativity Special Relativity- Download Christoph Schiller's 1612 page walk through the whole of physics, from classical mechanics to relativity, electrodynamics, thermodynamics, quantum the… Relativity (Kinematics) Relativity (Kinematics)- Chapter of a classical mechanics text describes spatiotemporal effects. Includes problems and solutions. Uniform Acceleration Uniform Acceleration- This paper analyzes several simple uniform acceleration problems, including the paradox of John Bell. Simple Derivation of the Special Theory of Relativity Without the Speed of Light Axiom Simple Derivation of the Special Theory of Relativity Without the Speed of Light Axiom- Special relativity may be derived just from assuming isotropy, homogeneity and a principle … The Doppler Shift Equation For An Accelerating Frame of Reference The Doppler Shift Equation For An Accelerating Frame of Reference- The exact equation for the Doppler shift in a uniformly accelerating rocket is derived in two different ways. Th… A Special Relativity Paradox: The Barn and the Pole A Special Relativity Paradox: The Barn and the Pole- The answer to the famous barn and the pole paradox is that the two doors are never closed at the same time in the runner's fra… Derivation of the Lorentz Transformation Derivation of the Lorentz Transformation- This derivation uses the group property of the Lorentz transformations, which means that a combination of two Lorentz transformations als… Understanding Special Relativity Understanding Special Relativity- Brief explanation of special relativity, using no more than high-school level mathematics; includes an account of the twin paradox, some remarks … Wikipedia: Introduction to Special Relativity Wikipedia: Introduction to Special Relativity- Encyclopedia article giving a brief outline of the basic concepts of special relativity (including simple formulas). The Special Theory of Relativity The Special Theory of Relativity- Self-tutorial with short essays, questions and answers. Imaginary In All Directions Imaginary In All Directions- There is a preferred algebra of quaternions and complex numbers that is ideally suited to express the equations of special relativity and classical el… Space Measurements on a Rotating Platform Space Measurements on a Rotating Platform- The age-old puzzling problem of Lorentz contraction on a rotating platform, i.e., Ehrenfest's paradox, is explained in its proper mathem… Sagnac Effect, Twin Paradox and Space-Time Topology Sagnac Effect, Twin Paradox and Space-Time Topology- When viewed with an alternative synchronization convention, the Sagnac effect on a rotating disk is purely topological and the… The Twin Paradox in a Spatially Closed and Bounded Universe The Twin Paradox in a Spatially Closed and Bounded Universe- Spatially compact spacetimes break global Lorentz invariance and define absolute inertial frames of reference. Nothing but Relativity Nothing but Relativity- There are many ways to derive the Lorentz transformation without invoking Einstein's constancy of light postulate. The path preferred in this paper restate… Deriving Relativistic Momentum and Energy. II. Deriving Relativistic Momentum and Energy. II.- The usual relativistic expressions for momentum and kinetic energy are generalized from the one-dimensional to the three-dimensiona… Deriving Relativistic Momentum and Energy Deriving Relativistic Momentum and Energy- Expressions for momentum and energy of a relativistic particle may be derived from the composition law for velocities along one spatial …