Small world. By Ralph C. Merkle Xerox PARC 3333 Coyote Hill Road Palo Alto, CA 94304 merkle@xerox.com This is an extended web version of the article published in the Feb/Mar 1997 issue of MIT Technology Review. This version has greater technical detail and embedded links. Introduction Manufactured products are made from atoms. Since we first made stone tools and flint knives we have been arranging atoms in great thundering statistical heards by casting, milling, grinding, chipping and the like. That's changing. Build products with almost every atom in the right place. One warning: in contrast to the useage in this article some researchers use the word "nanotechnology" to refer to high resolution lithographic technology while others use it to refer to almost any research where some critical size is less than a micron (1,000 nanometers).
There are two main issues in nanotechnology: What might molecular manufacturing systems look like? The advantages ofnanotechnology The advantages of positional control. 25 Acts of Body Language to Avoid. Our body language exhibits far more information about how we feel than it is possible to articulate verbally. All of the physical gestures we make are subconsciously interpreted by others. This can work for or against us depending on the kind of body language we use. Some gestures project a very positive message, while others do nothing but set a negative tone. Most people are totally oblivious to their own body language, so the discipline of controlling these gestures can be quite challenging.
Most of them are reflexive in nature, automatically matching up to what our minds are thinking at any given moment. Nevertheless, with the right information and a little practice, we can train ourselves to overcome most of our negative body language habits. Practice avoiding these 25 negative gestures: “ I speak two languages, Body and English. ” — Mae West Holding Objects in Front of Your Body – a coffee cup, notebook, hand bag, etc. Want to know powerful, dominant, confident body language postures?
Motion Mountain - The Free Physics Textbook for Download. The Official String Theory Web Site. Wine on Superconductors. Misuse of statistics. A misuse of statistics occurs when a statistical argument asserts a falsehood. In some cases, the misuse may be accidental. In others, it is purposeful and for the gain of the perpetrator. When the statistical reason involved is false or misapplied, this constitutes a statistical fallacy. The false statistics trap can be quite damaging to the quest for knowledge.
For example, in medical science, correcting a falsehood may take decades and cost lives. Misuses can be easy to fall into. Professional scientists, even mathematicians and professional statisticians, can be fooled by even some simple methods, even if they are careful to check everything. Types of misuse[edit] Discarding unfavorable data[edit] All a company has to do to promote a neutral (useless) product is to find or conduct, for example, 40 studies with a confidence level of 95%. Another common technique is to perform a study that tests a large number of dependent (response) variables at the same time. Loaded questions[edit] ). Strike - To Do lists. Scientists See Advances in Deep Learning, a Part of Artificial Intelligence.
Pseudoreplication. Pseudoreplication, as originally defined[1] , is a special case of inadequate specification of random factors where both random and fixed factors are present.[2] The problem described by this term arises when treatments are assigned to units that are subsampled and the treatment F-ratio in an analysis of variance (ANOVA) table is formed with respect to the residual mean square rather than with respect to the among unit mean square.
The F-ratio relative to the within unit mean square is vulnerable to the confounding of treatment and unit effects, especially when unit number is small (e.g. four tank units, two tanks treated, two not treated, several subsamples per tank). The problem is eliminated by forming the F-ratio relative to the among unit mean square in the ANOVA table (tank MS in the example above). Replication[edit] Hypothesis testing[edit] Statistical tests (e.g. t-test and the related ANOVA family of tests) rely on appropriate replication to estimate statistical confidence. Problem Solving. Common statistical fallacies. I've been reading papers on how people learn statistics (and thoughts on teaching the subject) and came across the frequently-cited work of mathematical psychologists Amos Tversky and Daniel Kahneman.
In 1972, they studied statistical misconceptions. It doesn't seem much has changed. Joan Garfield (1995) summarizes in How to Learn Statistics [pdf]. Representativeness: People estimate the likelihood of a sample based on how closely it resembles the population. You can't always judge how likely or improbable a sample is based on how it compares to a known population. For example, let's say you flip a coin four times and get four tails in a row (TTTT). Similarly, a sequence of ten heads in a row isn't the same as getting a million heads in a row. Gambler's fallacy: Use of the representative heuristic leads to the view that chance is a self-correcting process. The history boards at roulette tables mean nothing. Base-rate fallacy: You have to consider the base population for comparison. Motion Mountain - The Adventure of Physics : The Free Physics Textbook. The Physical Science Virtual Lab. 4 Important Rare Earth Elements.
Sir William Crookes, a 19th century British chemist, once wrote that, "rare earth elements perplex us in our researches, baffle us in our speculations and haunt us in our very dreams. " These weren't easy elements to isolate or to understand, and so there was a very long lag time between the discovery of the rare earths, and the discovery of practical uses for them. It didn't help that individual rare earth elements don't occur by their lonesome—they travel in packs. To get one, you have to mine all of them. At first, industry didn't even bother to separate out individual rare earths, instead using them in a blended alloy called mischmetal. This provided the first commercial applications, says Karl Gschneidner, senior metallurgist at the Department of Energy's Ames Laboratory.
In 1891, mischmetal became an ingredient in lamp mantles—devices that were hung above open flames, where they burned and produced a bright, white light you could see and work by. The Science Behind Foldit. Foldit is a revolutionary new computer game enabling you to contribute to important scientific research. This page describes the science behind Foldit and how your playing can help. What is a protein? Proteins are the workhorses in every cell of every living thing. Your body is made up of trillions of cells, of all different kinds: muscle cells, brain cells, blood cells, and more. Inside those cells, proteins are allowing your body to do what it does: break down food to power your muscles, send signals through your brain that control the body, and transport nutrients through your blood. What are amino acids? What shape will a protein fold into? Why is shape important? What do proteins do?
Proteins are present in all living things, even plants, bacteria, and viruses. Photosystem I is a collection of proteins in plants that captures sunlight for photosynthesis.Luciferase catalyzes the chemical reaction that makes fireflies glow.Hemagglutinin helps the influenza virus invade our cells. The Energy Story.
Energy is one of the most fundamental parts of our universe. We use energy to do work. Energy lights our cities. Energy powers our vehicles, trains, planes and rockets. Energy warms our homes, cooks our food, plays our music, gives us pictures on television. Energy from the sun gives us light during the day. Everything we do is connected to energy in one form or another. Energy is defined as: "the ability to do work. " When we eat, our bodies transform the energy stored in the food into energy to do work. Cars, planes, light bulbs, boats and machinery also transform energy into work. Work means moving something, lifting something, warming something, lighting something. There are many sources of energy. The forms of energy we will look at include: Electricity Biomass Energy - energy from plants Geothermal Energy Fossil Fuels - Coal, Oil and Natural Gas Hydro Power and Ocean Energy Nuclear Energy Solar Energy Wind Energy Transportation Energy.
How Nanotechnology Works. There's an unprecedented multidisciplinary convergence of scientists dedicated to the study of a world so small, we can't see it -- even with a light microscope. That world is the field of nanotechnology, the realm of atoms and nanostructures. Nanotechnology is so new, no one is really sure what will come of it. Even so, predictions range from the ability to reproduce things like diamonds and food to the world being devoured by self-replicating nanorobots. In order to understand the unusual world of nanotechnology, we need to get an idea of the units of measure involved. A centimeter is one-hundredth of a meter, a millimeter is one-thousandth of a meter, and a micrometer is one-millionth of a meter, but all of these are still huge compared to the nanoscale.
As small as a nanometer is, it's still large compared to the atomic scale. In a lecture called "Small Wonders:The World of Nanoscience," Nobel Prize winner Dr. In the next section, we'll learn more about our world on the nanoscale. How the Mind Works. Open Source Physics. Computational Resources for Teaching The OSP Collection provides curriculum resources that engage students in physics, computation, and computer modeling. Computational physics and computer modeling provide students with new ways to understand, describe, explain, and predict physical phenomena. Browse the OSP simulations or learn more about our tools and curriculum pieces below. Tracker The Tracker tool extends traditional video analysis by enabling users to create particle models based on Newton's laws. Learn more about Tracker Curriculum Packages OSP curriculum packages combine computer simulations with tutorial materials and student worksheets.
Browse curriculum resources by topic and learn how to customize packages Featured Curriculum Package Ghostly Images JS Package The Ghostly Images Package contains Javascript models and worksheets for 1D kinematics to illustrate the connection between motion diagrams ("ghostly images") and position-time plots. EJS Modeling Learn more about EJS Tools. The Biomechanics of Good Running | Playbook. AUSTIN, Texas — If you’re a runner and you can’t extend your hip well behind you on your stride, Jay Dicharry has bad news: You’re never going to be a great runner. [bug id="sxsw2012"]This doesn’t mean you should hang up your shoes. You can still run, and run well, but not everyone can attain the ideal stride needed to be a truly great runner. Dicharry is the director of the Speed Performance Clinic and the Motion Analysis Lab Coordinator At The University Of Virginia. In discussing the biomechanics of running here at South by Southwest Interactive he recalled his Louisiana roots to emphasize his point.
“I’m from New Orleans, and there’s great food there,” he said, by way of understatement. “But if you have bad shrimp in a dish, you’re doing to have a bad dish. Most runners don’t extend their hips, Dicharry said. Along with a lack of hip extension, overstriding is one of the biggest sins. “Look at their gait,” he said. “There’s more to it than just running,” Dicharry said of winning. Research. Molecular Library. [ About the Database ] Links to Other Molecular Databases K-12 Resources EDinformatics- Contains a large number of information databases.
Also has an excellent Math and Science Section Physics 2000 Physics 2000, is an interactive journey through modern physics! For more info, email: mr23@nyu.edu. Atoms are mini black holes?