Knot theory A knot diagram of the trefoil knot Knots can be described in various ways. Given a method of description, however, there may be more than one description that represents the same knot. For example, a common method of describing a knot is a planar diagram called a knot diagram. Any given knot can be drawn in many different ways using a knot diagram. A complete algorithmic solution to this problem exists, which has unknown complexity. History[edit] Archaeologists have discovered that knot tying dates back to prehistoric times. A mathematical theory of knots was first developed in 1771 by Alexandre-Théophile Vandermonde who explicitly noted the importance of topological features when discussing the properties of knots related to the geometry of position. In the late 1970s, William Thurston introduced hyperbolic geometry into the study of knots with the hyperbolization theorem. Knot equivalence[edit] On the left, the unknot, and a knot equivalent to it. Knot diagrams[edit] or ) + z C(
Gel Body Armor 19Google + 28StumbleUpon Xion Protective Gear: Silly Putty that Protects Xion PG was originally founded by a stunt performer and a military police officer from the Netherlands. After years of prototyping, testing and developing, the Xion PG brand (formerly known as Xion Stuntpadding) became known within the underground scenes of various early adaptors. Although Xion PG initially started to design universal body protection for stunt applications, it soon became evident that the products were suitable for a much greater audience. Everyone, confronted with the risk of getting injured, either professional or leisure wise, will highly benefit from our protective product line. Examples of applications are: -Extreme sports athletes -Stunt performers -Costume departments / Actors -Motorcycling -Skating / rollerblading -Parcour / freerunning -Winter sports -American football -Governmental units Featured by Bilgidrom Featured by user 19googleplus 28stumbleupon
Digital Drawing Board Creates Objects in Stunning 3D Detail ETOS, or Electronical Tool for Object Sketching, is a tool for designers and architects that lets them see their creations in three dimensions without the need for 3D glasses. The tool uses the familiar shape of a pen and the intuitive function of a touch interface to bring sketches into the real world. The drawing board takes the form of a tablet computer with a built-in stand formed from its folded cover. It displays objects in 3D using lenticular lens technology and motion tracking, which also allows users to move the shapes around with their hands. The pen-shaped input tool performs basic editing functions that are selected by simply turning it along the horizontal or vertical axis.
Simple animation to explain complex principles - Electronics 1, aircraft radial engine 2, oval Regulation 3, sewing machines 4, Malta Cross movement - second hand movement used to control the clock 5, auto change file mechanism 6, auto constant velocity universal joint 6.gif 7, gun ammunition loading system 8 rotary engine - an internal combustion engine, the heat rather than the piston movement into rotary movement # Via World Of Technology. 1, inline engine - it's cylinders lined up side by side 2, V-type engine - cylinder arranged at an angle of two plane 3, boxer engine - cylinder engine arranged in two planes relative Eat, Drink and Live Forever: Immortality is 20 Years Away It seems that we’ve been edging toward becoming a race of cyborgs for a number of years. Medical advances like replacement limbs and joints, cochlear implants, and artificial organs are already being used. Improving medical technology and our understanding of anatomy will continue to drive the human race toward immortality, according to scientist Ray Kurzweil. He believes that within 20 years, there will be no need for humans to face death at all. Kurzweil and other scientists believe that by using nanotechnology, we can reprogram our bodies’ “stone-age software” to halt the aging process, then do away with death altogether. In Kurzweil’s perception of the future, we’ll all sport cybernetic limbs and organs, and rely on nanobots to keep us alive through traumatic injuries and illnesses.
Stone Island Heat Reactive Jacket *notcot in wearable , 07:18 Thermochromatic goods seem to come and go and never quite disappear… remember when American Apparel brought it back and AZFN did their version too? Well latest to run into is Stone Island’s Heat Reactive Jacket “A hooded bomber jacket in cotton nylon canvas with thermosensitive liquid crystals, the garment changes colour according to the temperature. The fabric of the heat reactive jacket is treated with a thermo-sensitive coating that changes colour at high temperatures. Beginning at 27 degrees the molecules within the micro- capsules of the external strata undergo a rotation modifying the light course. See the video of it dramatically changing colors Tags: fashion - gifts - outdoors - shopping - technology
Appendicitis? Human Appendix Maybe Not Useless After All For a long time, we’ve believed that the human appendix was more or less good for nothing. Darwin postulated that the appendix was a remnant of evolution that was no longer needed. But for the first time, researchers are actually taking a close look at the appendix and its function. And they’ve come to believe that it is, after all, good for something: it may help to restock the stomach with good bacteria after an illness, like a bout of diarrhea. (image via: ashe-villain) Scientists and researchers from Duke University Medical Center, the University of Arizona and Arizona State University collaborated on the study, which concluded that not only is the appendix not useless – it’s also been around far longer than anyone previously thought.
- Simple Harmonic (and non-harmonic) Motion § Harvard Natural Sciences Lecture Demonstrations [S | t | ★★★★] keywords: simple harmonic motion, periodic motion, quantum revival, aliasing What it shows: Fifteen uncoupled simple pendulums of monotonically increasing lengths dance together to produce visual traveling waves, standing waves, beating, and random motion. One might call this kinetic art and the choreography of the dance of the pendulums is stunning! Aliasing and quantum revival can also be shown. How it works: The period of one complete cycle of the dance is 60 seconds. The length of the longest pendulum has been adjusted so that it executes 51 oscillations in this 60 second period. Setting it up: The pendulum waves are best viewed from above or down the length of the apparatus. Comments: Our apparatus was built from a design published by Richard Berg 1 at the University of Maryland. James Flaten and Kevin Parendo2 have mathematically modeled the collective motions of the pendula with a continuous function.
Think ..."Some time ago I received a call from a colleague. He was about to give a student a zero for his answer to a physics question, while the student claimed a perfect score. The instructor and the student agreed to an impartial arbiter, and I was selected. I read the examination question: The student had answered, "Take the barometer to the top of the building, attach a long rope to it, lower it to the street, and then bring the rope up, measuring the length of the rope. The student really had a strong case for full credit since he had really answered the question completely and correctly! I suggested that the student have another try. In the next minute, he dashed off his answer which read: "Take the barometer to the top of the building and lean over the edge of the roof. At this point, I asked my colleague if he would give up. "Well," said the student, "there are many ways of getting the height of a tall building with the aid of a barometer. "Fine," I said, "and others?" "Of course.