Science uses math to model and explain what is observed. For a very long time the phases of the moon have been used to model a calendar.
The image on the right attempts to show the sun, earth, and moon as the earth orbits the sun and the moon orbits the earth. While not to scale, it does show how the sun's rays hit the moon and what that looks like from earth.
Coding this image is simply a few circles. Animating it is simply rotating the circles about the center of the image. The sun's rays and view from earth, however, requires some trigonometry, since the length of the sun's rays does not stay constant.
The image can display a specific station when a station identifier is appended to the URL of the image. For example, clicking this link outsideTemp.svg?stn=KNYC displays the temperature from New York, NY.
To find a station near you, go to the NWS site, then select a state and click find: http://w1.weather.gov/xml/current_obs
Click on the caption or this link to display the image.
The image on the left shows a simplified model for an atom. Atoms consist of protons, neutrons, and electrons. Protons and neutrons make up the nucleus of an atom while electrons spin around the nucleus. Protons have a positive charge, electrons have a negative charge, and neutrons have no charge.
Learn how to code this model of an atom on the lessons page.
This image displays an animated atom from one of the first 3 periods of the periodic table - Atomic Numbers 1-18. It displays a random atom everytime you refresh the page and hides the periodic table selection.
The full image includes a partial periodic table with the element's symbol, atomic number, and atomic weight. It allows selecting any of the first 18 atoms of the periodic table and shows the 1s, 2s, 2p, 3s, and 3p orbits.
Click on the caption or this link to select other atoms.