Learn Node: Clustering hadron colliders and neutrino factories

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Posted on 22nd January 2009 by Judy Breck in general science | physics

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This learn node about the future of particle physics is a webpage on the Interactions.org Particle Physics News and Resources website. The introduction to the page explains:

The Future
Particle physics has reached an extraordinary moment in the quest to understand the universe and its physical laws. Profound new questions have emerged to capture the human imagination. To address these questions, scientists all over the world are collaborating to imagine, design and build the particle physics of the future.

The page offers links to hadron colliders, linear colliders, neutrino factories and other key places where the where the work is being done to on the particle physics quest. The result is a learn node in an online open cluster that you can explore to learn about particle physics from the scientists and institutions who are participating in this extraordinary moment in the quest they leading.

Learn node: Light echoes Tycho’s supernova that Brahe saw in 1572

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Posted on 4th December 2008 by Judy Breck in astronomy | biography | general science | history | sciences

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This learn node is about Tycho’s supernova that Brahe saw Nov. 11, 1572. As Yahoo! News reports, Brahe was astonished to see what he thought was a brilliant new star in the constellation Cassiopeia. The light eventually became as bright as Venus and could be seen for two weeks in broad daylight. After 16 months, it disappeared.

BBC reports the 2008 discovery by Max Planck Institute scientists, using telescopes in Hawaii and Spain to capture faint light echoes of the original explosion — in effect capturing a fossil imprint of Tycho’s famous supernova. Wikipedia’s excellent article on Tycho’s Supernova for more background. NASA’s dictionary defines supernova and other relevant terms. The Galileo Project has a fine biography of Tycho Brahe. MIT’s open courseware offers instruction on the Plasma Physics that is a major focus for Tycho’s supernova.

Animated learn node: new technology explains dolphin kick power

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Posted on 1st December 2008 by Judy Breck in about learn nodes | animals | biography | biology | engineering | general science | math | mechanics | sciences

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This learn node is centered in the 2008 discovery at Rensselaer Polytechnic Institute of how the dolphin kicks with huge power — something that has been a mystery called Gray’s Paradox. Six nodes emerge from the open internet in this animation, providing connected places to learn about dolphins and their power kick.

The center node takes you to the work of Timothy Wei, professor and acting dean of Rensselaer’s School of Engineering, to see how he has solved Gray’s Paradox using his new state-of-the-art water flow diagnostic technology — Digital Particle Image Velocimetry DPIV — that measures the force a dolphin generates with its tail. Other nodes are about DPIV, how the US Navy trains dolphins (a retired Navy dolphin stars in the Rensselear video), general dolphin information (from the San Diego Zoo), and open courseware from Tufts University School of Veterinary Medicine on marine mammal medicine including care of dolphins, who are cetaceans.

Learn node: dinosaur teeth and the reptile mouth

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Posted on 18th November 2008 by Judy Breck in biology | general science | paleontology | sciences

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This learn node features a tiny dinosaur with big canine teeth that the Natural History Museum reports shows for the first time how one of the earliest dinosaurs grew into an adult. The webpage explains:

The turkey-sized reptile called Heterodontosaurus lived around 190 million years ago in the Early Jurassic period and had an unusual combination of molar-like and canine teeth.

Reptiles usually have small same-sized teeth along the length of their mouth but Heterodontosaurus had 2 fang-like canines at the front.

The image posted here is from a video narrated by Dr. Richard Butler, a dinosaur expert at the museum and featured on the page linked above.

For nodes of related learning: An excellent overview article about Anatomy and Physiology of the Reptile Mouth is provided at PetEducation.com. For time frames for the dinosaurs, the big picture can be seen in the Chart of Geological Ages at Connexions.

Learn Node: How Fish Muscles Work

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Posted on 14th October 2008 by Judy Breck in biology | general science | sciences

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How fish muscles work from the molecular to the whole organ level is a lecture from the University of Southern Maine that gives focus to this learn node. A basic concept for the subject is that:

Two contrasting behaviors: The first is steady swimming at slow and intermediate speeds using low amplitude axial undulations (i.e. the side to side displacement of the body is small). The second is burst swimming and escape responses using high amplitude axial undulation. In the escape response, a fish bends into a C-like posture then whips its tail in the opposite direction, accelerating a mass of water behind the fish, which causes the fish to accelerate forward. The key is that body bending is small in steady swimming and large in bursts and escapes. Also, the escape response can be very fast, that is less than 1/10th of a second.

The toadfish is an important fish muscle specimen because it has been found that its swim bladder muscles are the fastest twitching muscles in the vertebrate world. The image by Robert Golder shown here is from an article at the Marine Biological Laboratory on this talented but ugly fish. Several articles at the St. Andrews University website of its Fish Muscle Research Group provide the latest ideas and theories in this important subject for mechanics, anatomy, genetics, and aquaculture.

Learn node: Fossil reveals ancient arthropod species chain gang

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Posted on 14th October 2008 by Judy Breck in general science | paleontology | sciences

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Early Cambrian arthropod chain gangs this learn node describes are fossilized in chain formation that reveals community behavior. The chain gang 525-million-year-old fossils were found in southern China’s Chengjiang Lagerstatte fossil field. A Science News report of the discovery says that the discovery site is “a treasure trove of fossils often compared to Canada’s Burgess Shale.” The above image from Science News (credit Derek Siviter) shows the that newly discovered species of Early Cambrian arthropod formed sturdy chains of about 20 individuals. In the report:

Nigel Hughes, a paleobiologist from the University of California, Riverside comments that these types of finds provide snapshot scenes of “normal” life.

“Of the millions of fossils, the chances of getting an occurrence where we can determine collective behavior is quite rare,” says coauthor Derek Siveter of the University of Oxford in England. He and his colleagues found 22 complete or partial chains, but only one solitary specimen.

A Brief History of Life on Earth provided at Connexions sets the time frame for these fossils

Learn Node: Galileo Pendulum and Spacecraft

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Posted on 7th October 2008 by Judy Breck in biography | general science | sciences

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Galileo and the Pendulum is a node for learning that is part of a rich cluster and course, The Galileo Project at Connexions. Other sections of the Galileo Project are his biography, family life, the Inquisition, and descriptions of his work on motion, mechanical devices, and the telescope.

Surely the great Galileo Galilei of 14th century Italy would gaze in pride on the achievements of his namesake, the Galileo spacecraft that explored the solar system from 1989-2003.

Learn Node: Atmospheric Radiation and Hurricane Ike Image

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Posted on 24th September 2008 by Judy Breck in animals | biography | ecology | engineering | environment | general science | health | math | sciences

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The image above is the Hurricane Ike Interactive Map from NOAA. When you go to the page you can click into the boxes to locate and study satellite photos of damage. StormWatch is part of the work of the Johns Hopkins University/ Applied Physics Laboratory.

Remote sensing imagery and study materials abound on the internet. An excellent cluster of information can be found at the Atmospheric Radiation Measurement (ARM) Program which “is a multi-laboratory, interagency program, and is a key contributor to national and international research efforts related to global climate change. A primary objective of the program is improved scientific understanding of the fundamental physics related to interactions between clouds and radiative feedback processes in the atmosphere. ARM focuses on obtaining continuous field measurements and providing data products that promote the advancement of climate models.”

To learn scientific and technical background for the field MIT offers open couseware on Atmospheric Radiation that is “an introduction to the physics of atmospheric radiation and remote sensing including use of computer codes. Subjects covered include: radiative transfer equation including emission and scattering, spectroscopy, Mie theory, and numerical solutions. We examine the solution of inverse problems in remote sensing of atmospheric temperature and composition.”

A NASA- based Remote Sensing Tutorial provides further introduction to the field.

The perfect learn node APOD is 13 years old

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Posted on 25th July 2008 by Judy Breck in astronomy | general science | physics

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Astronomy Picture of the Day (APOD) began on June 16, 1995 with the computer generated image shown here of Earth as a hypothetical neutron star. Each day since, the two astronomers who create APOD have devised a learn node: a webpage that focuses on a small subject interfaced by an image, and that links out into the Internet to related topics. Pushing, as learnodes.com does, for something called “learn nodes” is not an effort to invent something new. A learn node captures content for learning by exploiting the natural powers of the open Internet. The robust, 13-year history of APOD illustrates the validity and educational power of basing learning content in nodes.

Using the network node is the first key to the effectiveness in creating superior knowledge content in the open Internet. The second key is the creation of the nodes by people who are experts in their subject. The About page of APOD explains:

Astronomy Picture of the Day (APOD) is originated, written, coordinated, and edited since 1995 by Robert Nemiroff and Jerry Bonnell. The APOD archive contains the largest collection of annotated astronomical images on the internet.

In real life, Bob and Jerry are two professional astronomers who spend most of their time researching the universe. Bob is a professor at Michigan Technological University in Houghton, Michigan, USA, while Jerry is a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland USA.

Learn node: micro and nanomechanics in supported lipid biolayers

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Posted on 5th June 2008 by Judy Breck in biology | general science | molecules, cells

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Looking at the little tiny world – at things like bilayer formation of cells, veins, and neurons in biological membranes – is becoming more an more sophisticated and productive. The image with this post from page 7of Lecture 6: AFM imaging II: Artifacts and Applications from the MIT lecture notes for a course on Nanomechanics of Materials and Biomaterials. The image originates in the LadyofHats collection of public domain images, which is a source of superb drawings of dinosaurs, biology, and other subjects.

A general article describing micro and nanomechanics is available on the IMES Institute of Mechanical Systems website. This is its introductory overview:

Micro- and nanomechanics are concerned with the modelling, design, fabrication and application of three-dimensional structures and systems with dimensions in the range of micrometers and below. These systems incorporate a number of interesting features: The classical fabrication methods of micromachining are extended by those developed in the semiconductor industry during the passed decades. Different quantities scale differently when moving from large to small structures demanding new models to describe the physical behaviour observed on a small scale.Devices used to perform a certain function and found to be optimal for the macroscopic scale are replaced by others exploiting various physical effects suited to the microscopic world.

Last but not least, the limits of classical continuum mechanics have to be explored and extended. New methods need to be developed in order to quantify bonding properties between different layers, residual stresses which are caused by manufacturing processes as well as the elastic constants itself, just to mention a few examples.