A Penrose tiling has no translation symmetry. If you pick any part of the tiling, that part is not periodically repeated when translated.
One easy way to make a Penrose tiling is to use two rhombuses as tiles. It is easy to subdivide such a tiling into a new tiling with smaller tiles. When repeating this process, you get a self-similar structure.
Subdivision algorithm - Penrose Tiling Explained:
Roger Penrose - Forbidden crystal symmetry in mathematics and architecture:
OpenProcessing-example used for making the gif:
The max value of 1.4 solar masses is crucial to their stability, and it's known as the Chandrasekhar limit. Chandrasekhar reasoned that something must be holding up material in white dwarfs against gravity, something known as electron degeneracy. When star contracts, electrons get close together and there is a continued increase in their resistance to being pushed even closer.
This process is related to pressure. At great densities, pressure from the degenerate electrons is sufficiently great, it balances the force of gravity and the star stops contracting. So electron degeneracy stops the white dwarf from contracting and compresses the gas of the star.
Pressure from degenerate electrons doesn't depend on temperature, so stars are stable even though no more energy is ever generated within them. Because of electron degeneracy, they can’t contract further. However, they still have stored energy that will radiate for a few billion years. Once the star burns out completely, or stops radiating, the white dwarf has reached the final stage of evolution and it becomes a cold and inert stellar remnant sometimes called a black dwarf.
What this also means is that a white dwarf is incredibly dense. A mass the size of the sun is compressed into a volume only the size of the earth. This is so dense that a teaspoon of white dwarf weighs ten tons. That is, they have about a million times the density of water.
Reeve's actual life sounds even more exciting than the fictional TV show character. Reeves didn't have an Indian sidekick who talked like Tarzan, but he did live with the Cherokee for quite a while, and he learned from them to speak fluently the 5 most popular native languages of the territory, as well as all their fighting skills, and he was known to sometimes wear disguises to catch criminals.
Reeves had a towering 6'2" figure (when most of the American men then were about the size of Mexican men today, averaging 5'6"). When he retired at 69 after 32 years of non-stop dedicated service as a Deputy U.S. Marshal, Reeves had brought in a whopping 3000 felons, killing only 14 of them, and never having gotten shot himself. He deserves more than this small film, perhaps a high-quality HBO or Showtime series, with as many of the real arrests he made worked into episodes. For example:
Three men he was pursuing managed to get the drop on him and ordered him off his horse. The leader approached, gloating that the “Indomitable Marshal” was about to die. Showing no fear, Reeves calmly took out his warrants and asked the three men, “What is the date today?” The puzzled leader asked, “What difference does that make?” Reeves explained that he’d need to put the date of the arrest on the paperwork when he took the three of them in — dead or alive, their choice. The three men laughed at the absurdity of the thought, and Marshal Reeves used the distraction to grab the barrel of the leader’s gun. One of the men opened fire, but Reeves drew and shot him dead. He then killed the leader by bashing his skull with his pistol. The third man wisely submitted to the arrest.
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