A tetrahedron can be placed in 12 distinct positions by rotation alone. These are illustrated above in the cycle graph format, along with the 180° edge (blue arrows) and 120° vertex (reddish arrows) rotations that permute the tetrahedron through the positions. The 12 rotations form the rotation (symmetry) group of the figure.
Quantum ManMolecular diffusion/Diffusion is an example of the law of large numbers, applied to chemistry. Initially, there are solute molecules on the left side of a barrier (purple line) and none on the right. The barrier is removed, and the solute diffuses to fill the whole container. Top: With a single molecule, the motion appears to be quite random. Middle: With more molecules, there is clearly a trend where the solute fills the container more and more uniformly, but there are also random fluctuations. Bottom: With an enormous number of solute molecules (too many to see), the randomness is essentially gone: The solute appears to move smoothly and systematically from high-concentration areas to low-concentration areas.
Racetrack in Conway's Game of Life. Legend: * Green structure : Gun * Yellow structure : Glider * Red structure : Spaceship * Violet structure : Reflector * Blue structure : Eaters (both as still lives and oscillators) and others still lives.
Sun posterA more complete and sophisticated moon diagramPoster showing the structure and features of europa.Diagram of the internal structure of Ganymede.C4 photosynthesis is really complicated. Microscope picture is my own work.
Cantino planisphere (or Cantino World Map) is the earliest surviving map showing Portuguese geographic discoveries in the east and west.
Stylized world map in the shape of a clover-leaf (the three classical continents of Europe, Asia, Africa), with Jerusalem at the center, with additional indication of Great Britain, Scandinavia and America / the New World.
Abraham Ortelius (Ortels, Orthellius, Wortels; 1527.04.4 or 14 – 1598.06.28): Brabantian cartographer, geographer, and cosmographer, conventionally recognized as the creator of the first modern atlas, the Theatrum Orbis Terrarum (Theatre of the World).