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: Astrophysicists on hot juptiers and sprouting extrasolar planets

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Posted on 2nd January 2008 by Judy Breck in astronomy

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This learn node points to a video lecture from Yale online: Discovering Exoplanets: Hot Jupiters. In the image above the shadow is from the hand of Yale Professor Charles Bailyn, Director of Undergraduate Studies in the Department of Astronomy who delivers this and other lecture videos that are part of the Yale University open courseware for the course: Frontiers and Controversies in Astrophysics (Spring 2007). The course description says that:

Professor Bailyn explains how the outlook of our Solar System can predict what other star systems may look like. It is demonstrated how momentum equations are applied in astronomers’ search for exoplanets. Planet velocities are discussed and compared in relation to a planet’s mass. Finally, the Doppler shift is introduced and students learn how it is used to measure the velocity of distant objects, such as galaxies and planets.

A video titled Searching for Extrasolar Planets on the website of the American Museum of Natural History describes work begun there in 2003. The video’s webpage explains that:

Astrophysicists are discovering new extrasolar planets—those outside our Solar System—almost daily. NASA’s Spitzer Space Telescope (originally called SIRTF, or the Space Infrared Telescope Facility) and AMNH’s Lyot Project Coronograph are two of the many technologies uncovering the attributes and evolution of these faraway worlds. The techniques employed by these instruments may one day help answer one of astronomy’s reigning mysteries: do any extrasolar planets host life?

A sample of the discoveries is a Spitzer Mission News report dated November 22, 2007: Youthful Star Sprouts Planets Early.

More learn nodes at: learnodes.com

Learn node: Happy Birthday Sputnik – first orbiting satellite launch was fifty years ago

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Posted on 28th September 2007 by Judy Breck in general science | sciences

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satellite orbit speed

This learn node notes the fiftieth anniversary of satellites. On October 4, 1957, the Soviet Union launched a 23-inch diameter satellite. It was the first object ever launched into Earth orbit by humankind, as a post I wrote for iCommons.org describes in a birthday salute to this object named Sputnik 1.

Although the image above suggests Sputnik satellite in orbit, it is more general. It is from a Connexions tutorial � an open educational resource where you can learn how artificial satellites are the backbone of modern communications system. A lot has happened in the past 50 years as orbiting objects have diversified and become common. The open learning website How Stuff Works’ section on How Satellites Work begins:

Not so long ago, satellites were exotic, top-secret devices. They were used primarily in a military capacity, for activities such as navigation and espionage. Now they are an essential part of our daily lives. We see and recognize their use in weather reports, television transmission by DIRECTV and the DISH Network, and everyday telephone calls. In many other instances, satellites play a background role that escapes our notice.

An interesting place to move out into the online clusters of the adventures and ramifications of the Sputniks is from this Astronomy Picture of the Day salute to Traveling Companion (which is what “sputnik” means). You can even meet Laika, the first dog in space.

More learn nodes at: learnodes.com