The Gold Rush, positive for California in so many ways, had a devastating effect on the state's environment. Many of these problems were directly related to gold-mining technology. The process of hydraulic mining, which became popular in the 1850s, caused irreparable environmental destruction. Two images show California's largest hydraulic mine ? Malakoff Diggings, in Nevada County ? in action. (Malakoff Diggings is now a state park and open to visitors.) Dams (such as the English Dam in Nevada
Excerpts from A Cambridge Mass
An early work by composer Ralph Vaughan Williams is to be performed for the first time after being spotted in an exhibition at Cambridge University Library. The score of A Cambridge Mass was written by Vaughan Williams for his doctoral examination and has never been heard. It has been in the safe-keeping of Cambridge University Library for more than 100 years. Vaughan Williams studied at Trinity College, Cambridge, in the 1890s. Here short excerpts of A Cambridge Mass are played at Trinity b
SAGP Guide to Clinical Medical Practice
Manual originating from personal notes made over many years of semi-rural private and hospital practice in South Africa. A useful resource based on many years of semi-rural private and hospital practice in South Africa involving major trauma, surgery and obstetrics, in addition to the common problems of general practice. I have always felt it very useful to be able to confirm facts and figures at the bedside if needed and this has been the motivation that has taken me over 40 years. This meant
Alsos Digital Library for Nuclear Issues
Nuclear weapons and nuclear power have greatly influenced history from 1945 to the present. This digital library provides an annotated bibliography of over 2,700 books, articles, films, CDs, and websites about a broad range of nuclear issues.
NASA KSNN Is flying a plane in a videogame like flying a real plane?
Learn more about simulators through this video newsbreak and demonstrate the purpose of using simulators. Explore the importance of water for living things and analyze and compare a variety of fruits and vegetables based upon the mass of water in these foods
NASA KSNN Is water important for all living things?
Explore the importance of water for living things and analyze and compare a variety of fruits and vegetables based upon the mass of water in these foods.
NASA KSNN What is gravity?
Gravity is one of the fundamental forces of nature. No one really understands exactly why, but gravity is a force that pulls objects toward each other. The mass of the objects and distance between the objects affects the strength of the force of gravity. Greater masses attract with more force and the force weakens as the objects get further apart.
25 - The "End" of Reconstruction: Disputed Election of 1876, and the "Compromise of 1877"
This lecture focuses on the role of white southern terrorist violence in brining about the end of Reconstruction. Professor Blight begins with an account the Colfax Massacre. Colfax, Louisiana was the sight of the largest mass murder in U.S. history, when a white mob killed dozens of African Americans in the April of 1873. Two Supreme Court decisions would do in the judicial realm what the Colfax Massacre had done in the political. On the same day as the Colfax Massacre, the Supreme Court offere
In some years back the craft upholstery was used to describe the making of carpets, curtains, wall hangings, mattresses and the covering of furniture with fabrics etc. However, with the upsurge of specialization during the industrial revolution, which now dominates the industrial world, the word upholstery is limited to the manufacture and repair of stuffed furniture. The making of curtains and wall hangings has now become a specialized area for interior decorators whilst the production of mattr
Zebrafish embryo development
Early development of Danio eggs note the internal structure and the cluster of eggs (note the large yolk attached to the two-cell egg). The cells all divide at the same time. Within two days this mass of dividing cells will take on the shape of a zebrafish larvae.
ABC's of Nuclear Science and Technology
Introduces the object that contains almost all of the mass in the universe, the atomic nucleus. Antimatter, beta rays, fission and fusion, the structure of the atomic nucleus, how elements on the earth were produced, how we use the nucleus in every day life, and the effects of radiation in the environment are among the topics. The site includes nearly a dozen experiments that can be done in chemistry and physics classes, along with A Teacher's Guide to the Nuclear Science and Technology Wall Cha
Applying Ohm's Law to Semiconductors
This project allows students to apply concepts of momentum conservation and energy conservation from classical physics. However, here they are not enough: they must be combined with modern physics, using concepts from relativity and particle physics as well as modern units that put energy, mass, and momentum in terms of MeV and GeV. Most important, students will learn about both fundamental and cutting-edge physics by actually doing what physicists do.
Students are asked how acceleration, mass, momentum and velocity are involved in mountain boarding.
Attack of the Raging River
In this lesson, the students will discover the relationship between an object's mass and the amount of space it takes up (its volume). The students will also learn about the concepts of displacement and density.
Taking the Boat to Manaus
In this activity, the students will apply the concepts they learned regarding mass, volume and density in the previous activities to design a boat.
Through ten lessons and numerous activities, students explore the natural universal rules engineers and physicists use to understand how things move and stay still. Together, these rules are called "mechanics." The study of mechanics is a way to improve our understanding of everyday movements, such as how gravity pulls things together, how objects balance, spin and twirl, and how things fly and fall. While studying Newton's three laws of motion, students gain hands-on experience with the concept
Mass Balance Model With a Leaky Bucket
In this JAVA based online interactive modeling activity, students are introduced to the concept of mass balance, flow rates, and equilibrium using a simple water bucket model. Students can vary flow rate into the bucket, initial water level in the bucket, and residence time of water in the bucket. After ...
Masses & Springs
A realistic mass and spring laboratory. Hang masses from springs and adjust the spring stiffness and damping. You can even slow time. Transport the lab to different planets. A chart shows the kinetic, potential, and thermal energy for each spring.
Blast a Buick out of a cannon! Learn about projectile motion by firing various objects. Set the angle, initial speed, and mass. Add air resistance. Make a game out of this simulation by trying to hit a target.
This animation illustrates Pair Production. In this interaction, the photon's energy creates an electron-positron pair. The minimum photon energy required for this is determined by Einstein's famous Energy-Mass relation.