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 above image combines a map from the USGS Earthquake Hazards Program with a formula from a Connexions module by Sunil Kumar Singh that teaches forced oscillation. The map was captured as a screenshot from the USGS website 2 days after the Sichuan Earthquake began, and as the large squares on the map indicate, the aftershocks were continuing.
The resonance is an interesting feature of oscillation. This phenomenon attracts interest as it makes possible to achieve extra-ordinary result (material failure of large structure) with small force! Resonance also explains why earthquake causes differentiating result to different structures – most devastating where resonance occurs! The condition for maximum amplitude is obtained by differentiating amplitude function with respect to applied frequency as [the illustrated formula sets out.]
Thomas L. Pratt, who teaches research geophysicists at the University of Washington, provides a webpage that explains frequencies, periods, and resonance in which he includes this simple explanation: “Resonance is when motion at a given frequency is amplified by waves of that same frequency. For example, when a child is being pushed on a swing, the swinging is increased by a push being applied at the right time (at the correct frequency) during each swing.”
This learn node features a video called “The Arch Never Sleeps” in which professors explain the mechanics of the support arches provide for structures. One professor points out the limitations of laying a block of stone across two others. The professor whose foot is shown as he stands on an arch (that is not glued together) is demonstrating the strength of stone arches. The video is on a page from the Open University Mathematics and Statistics modeling problems open courseware.
The illustration below shows a learn node, which you can use as an educator to make webpages more findable. The top little circles illustrate links out to content nodes related to the subject of the large circle. Bottom left, experts connect to the node affirming its quality - giving it juice. Bottom right, a student connects to the node to learn the subject of its content.