Science

Posted on June 30, 2005March 8, 2014 by 3 — Leave a comment

The KnotPlot Site – trefoil

“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.

Continue reading The KnotPlot Site – trefoil

Posted on June 30, 2005July 19, 2019 by 3 — Leave a comment

Lithium – Periodic Table – element 3

Lithium is a Group 1 (IA) element containing just a single valence electron (1s²2s¹). Group 1 elements are called "alkali metals". Lithium is a solid only about half as dense as water. A freshly cut chunk of lithium is silvery, but tarnishes in a minute or so in air to give a grey surface.

Continue reading Lithium – Periodic Table – element 3

Posted on June 30, 2005July 19, 2019 by 3 — Leave a comment

Kepler’s Three Laws of Planetary Motion

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

    <ul>   <li> Planets move around the Sun in <strong>ellipses</strong>, with the Sun at one focus    </li>   <li> The line connecting the Sun to a planet sweeps <strong>equal areas in equal times. </strong></li>   <li> The<strong> square</strong> of the orbital period of a planet is proportional to the                                                              <strong> cube</strong> (3rd power) of the mean distance from the Sun in     (or in other words--of the&quot;semi-major axis&quot; of the ellipse, half the sum of smallest      and greatest distance from the Sun)      </li> </ul>   <ol>  </ol> <!--more--> <a href="http://www-spof.gsfc.nasa.gov/stargaze/Kep3laws.htm" target="_blank" rel="noopener noreferrer">Read more . . .</a><br />