Mon Jul 15, 2024 PRINCIPIA
On July 6, 1686, Principia Mathematica was published in England. Principia was Isaac Newton’s great book on gravity and motion, which became a major breakthrough for our understanding of how the Universe works. His three laws of motion – inertia; force equals mass times acceleration; and action-reaction, plus the relationship between gravity, mass and distance, are still in use today, showing us how we can send rockets to the moon and beyond. Edmond Halley paid for Principia’s publishing, because he wanted it to help him work out comet orbits. Halley asked the Royal Society to pay for it, but they’d tied up all their money in a beautiful book, the “History of Fishes”, which nobody bought. Years later, when Halley wanted payment for his duties as secretary, they just gave him a lot of the fish books and suggested he could sell them and make some money that way.
Tue Jul 16, 2024 APOLLO 11 LAUNCH
On July 16, 1969, three astronauts were launched into space. On July 20th they would reach the moon. Six other men had preceded them, beginning with Apollo 8’s Frank Borman, Jim Lovell and William Anders; but they simply orbited the moon, they did not land on it. Beginning with the first rockets into earth orbit in the late 1950’s, then in America the manned training and preparation flights: a single astronaut aboard the Mercury spacecraft; two astronauts who orbited the earth in each of the Gemini missions, learning how to dock with other spacecraft, figuring out the best ways to maneuver while in a spacesuit outside the capsule; the loss of good people – Gus Grissom, Roger Chaffee, Ed White – in the Apollo 1 fire. Then to fix what had gone wrong, and continue the struggle, until at last the moon was within our reach. We went to the moon not because it was easy, but because it was hard.
Wed Jul 17, 2024 ROBERT HOOKE
Robert Hooke, born on July 18, 1635, is best known for his pioneering work in analyzing insects, plants, all manner of things in nature, using a microscope. He made a lot of sketches, and first described the cell-like structure of living organisms. He was also a mortal enemy of Isaac Newton. In fiction, Sherlock Holmes had to combat Professor Moriarty; Superman had to fight Lex Luthor; and Batman had to deal with the Joker. For Isaac Newton, it was this guy – Robert Hooke. Newton had built a small reflecting telescope, the first of its kind, and he was persuaded to share his experiments on how the eye sees light. Hooke, who had done some work in this area, strongly criticized Newton, and Newton didn’t like it. Hooke also claimed to have worked out the laws of gravity long before Newton’s published work, Principia. Thus began a life-long battle between the two.
Thu Jul 18, 2024 FULL MOON HANGS LOW
All full moons rise at sunset and set at sunrise. So full moons are at their highest around the midnight hour (or 1 am, if you throw in daylight savings time.) But even though it’s at its highest then, July’s full moon isn’t very high. You see, full moons are directly opposite the sun. So they occupy the part of the sky where the sun will be found six months later. Half a year from now it will be winter, and the sun’s path in winter is very low; even at noon it’s not far off the south horizon. In summer the full moon is at the spot where the sun is in winter. So the summer’s full moon mimics the sun’s wintertime path. This also means that full moons in winter can reach the top of the sky at midnight, mimicking the sun’s path in summertime. So this month’s full moon won’t get very far above the horizon, and will be at a convenient altitude for us to admire it, just above the treetops, low in the southern sky at the midnight hour. Check out the full moon this weekend.
Fri Jul 19, 2024 JULY FULL MOON
The moon is full this weekend. Because thunderstorms are common in July, this full moon is often called the Thunder moon. According to the Sioux Indians, this is the Moon When the Wild Cherries Are Ripe. To the Winnebago, it is the Corn-Ripening Moon, and to the Kiowas, it is the Moon of Deer Horns Dropping Off. To the Omaha Indians, however, this is the Moon When the Buffalo Bellow. In ancient China, this was the Hungry Ghost Moon, named for departed souls who had left no descendants. In medieval times this was the Hay Moon or the Mead Moon, named for the elixir from the meadows of Briton and Europe. After this full moon came the first harvests from the fields and the pagan festival of Lughnasaid, which was later adopted by early Christians and became the celebration of Lammas, or “loaf mass,” in thanksgiving for the first fruits of the farmer’s labor.
