Tag Archives: Science

The KnotPlot Site – trefoil

Trefoil Knot“Here you will find a [browsable] collection of knots and links, viewed from a (mostly) mathematical perspective. Nearly all of the images here were created with KnotPlot, a fairly elaborate program to visualize and manipulate mathematical knots in three and four dimensions.” The diagrams are in color and are exceptionally clear.

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Kepler’s Three Laws of Planetary Motion

keplerThe laws were formulated between 1609 to 16l9, and are (as usually stated):

  • Planets move around the Sun in ellipses, with the Sun at one focus
  • The line connecting the Sun to a planet sweeps equal areas in equal times.
  • The square of the orbital period of a planet is proportional to the cube (3rd power) of the mean distance from the Sun in (or in other words–of the"semi-major axis" of the ellipse, half the sum of smallest and greatest distance from the Sun)

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From Stargazers to Starships

This high-school level tutorial focuses on three topics: Astronomy of the Earth's motion in space, which includes information, and some experiments and projects that teach concepts about the calendar, seasons, Kepler's laws, building a sundial, and more; Newtonian mechanics, which ha understanding Newton's laws and discussion of mass and motion; and Spaceflight and Spacecraft. Includes a timeline, a list of concepts covered, and a glossary.

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