Rarely do I give a presentation without referencing some video clip on YouTube. In a TIE staff meeting earlier this week, I referenced the Learning to Change, Change to Learn video. In a presentation at BHSU recently I referenced Common Craft videos on social bookmarking, wikis and Google Docs. Some of the greatest speeches from [...]
NASA Image of the Day
A Chameleon Sky
The sands of time are running out for the central star of this the Hourglass Nebula. With its nuclear fuel exhausted, this brief, spectacular, closing phase of a sun-like star's life occurs as its outer layers are ejected and its core becomes a cooling, fading white dwarf. In 1995, astronomers used the Hubble Space Telescope to make a series of images of planetary nebulae, including the one above. Here, delicate rings of colorful glowing gas (nitrogen-red, hydrogen-green, and oxygen-blue) outline the tenuous walls of the 'hourglass.' The unprecedented sharpness of Hubble's images revealed surprising details of the nebula ejection process and may resolve the outstanding mystery of the variety of complex shapes and symmetries of planetary nebulae. Image Credit: NASA, WFPC2, HST, R. Sahai and J. Trauger (JPL)
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