Today's soundtrack is Zae da Blacksmith and Average Joe: The Mosaic Mixtape.
This evening, I am reading the first chapter of National Geographic Picture Atlas of Our Universe, by Roy Gallant. The first chapter is "Sun Gods to Gamma Rays: Beginnings."
The ancient Egyptians believed that the sun's journey across the sky each day was Ra traveling in his boat. The Norse believed that the earth was flat, with a tree of life in the centre. Many civilizations learned to recognize patterns in the seasons and constellations and the phases of the moon. Before agriculture became important, necessitating a calendar that followed the right number of days in a year, some civilizations followed twelve "moonths, adding up to about 354 days" (p. 13); however, the Egyptians eventually learned that the seasons depend not on the moon's phases, but on the "movement" of the sun and stars; thus, they developed the first solar calendar, which had 365 days in a year. Some people used stones or other markers to determine the time of year; aboriginal people in Wyoming used a circle of stones to identify the summer solstice; on the day of the summer solstice, the sun would rise in line with a pile of rocks within the circle. Stonehenge may have been used similarly; the sun rises directly over one of its stones on the morning of Summer Solstice.
Eventually, people began to be more aware of the stars. They believed the stars were fixed, and that planets were "wanderers" (p. 14).
Eudoxus, an early astronomer, believed that the Earth was static, suspended in the centre of a universe made up of transparent spheres.
Ariststotle was one of the first to argue that the earth is round, not flat. Aristarchus was one of the first to theorize that the earth is a planet revolving around the sun, with the reason for the stars' movement not being attachment to a transparent sphere, but due to the rotation of the earth.
Eratosthenes came close to estimating the earth's circumference by using a logical experiment involving shadows and extrapolation.
Ptolemy was the first person to predict planetary motion.
Julius Caesar implemented the leap year once every four years; Pope Gregory XIII improved on this by ordering that three leap years be skipped once every 400 years, creating the still-used Gregorian calendar.
The Arabians collected and protected many important works of scientific discover.
Copernicus perfected the heliocentric system.
Tycho Brahe built the first observatory and observed comets further than the moon, and thereby disproved the transparent spheres that had been hitherto believed to hold the universe's layers; he also proved Aristotle, who believed that the heavens were unchanging, wrong.
Johann Kepler, the student of Tycho, discovered the laws of planetary motion.
Galileo Galilei proved that air has weight, that the weight of an object doesn't affect gravity's pull on it, used a telescope to observe the night sky, and wrote a book about mechanics and motion, Two New Sciences.
Isaac Newton invented calculus to prove his idea that a force held the objects in the universe together, then formulated the three laws of motion, publishing his works in the book Principia; he also invented the reflecting telescope.
William Herschel discovered Uranus lol and discovered that the Sun is not at the centre of the universe.
Harlow Shapley discovered that we are at the edge of the Milky Way.
Edwin Hubble discovered that we are not the only galaxy in the universe.
There are many kinds of energy radiated by the bodies in the universe - all of the colours of the visibule spectrum, the electromagnetic spectrum, ultraviolet radiation, infrared energy, and radio energy.
