//------------------------------// // Chapter 7: Ursas, Major and Minor // Story: Bedtime Stories For The Mare In The Moon // by Needling Haystacks //------------------------------// This being the last chapter, it seems appropriate to begin with an analysis so that the book may end with a story. First, regarding the creatures known as Ursa Major and Ursa Minor, the Ursa Minor is simply the name for the juvenile of the species, the equivalent of a filly or colt. This aspect sometimes gets confused in the telling. Second, the Ursa Major is a real creature. Ponies that live near the Everfree Forest know this, but those who live far from it sometimes think it is a myth. Every decade or so, Ursa Majors will congregate near the edges of the Everfree Forest for their mating season. No concentrated effort has been made to determine their age, but there is a recorded instance of an orphaned Ursa Minor being found around 800 years ago. It took nearly 100 years to reach sufficient maturity that it could be released into the wild. Gatherings of them seem not to top two dozen, but since only 3-4 Ursa Minors are seen with their mothers at such gatherings, there may well be more [Preceding facts from Beary Nice, “Rare and Exotic Animals”]. Next, a matter I could not work in the first chapter without going over-long: the fixed stars. There are, as you may know, constellations called Ursa Major and Ursa Minor. The story to follow regards the relationship between these and the creatures. The story is now considered a work of fiction. While it was always somewhat suspect, as no one could point to any record of the event actually being witnessed, the invention of the telescope essentially eliminated any doubt: point a telescope at the stars in question, and you'll find that the apparent shape is, in fact, merely the brightest of an enormous, dense field of stars. Such shapes become meaningless with a good enough telescope. Furthermore, we are now reasonably certain that the fixed stars are, in fact, distant suns. The was proposed over a thousand years ago, but until the invention of the telescope and the sextant, there was way to tell if this was true. As was mentioned in chapter 1, when looked at through a telescope, the wandering stars become larger (and one displays a “ring”), but the fixed stars do not. The predecessor of the astronomical sextant can be found in observatories built during the Reign of the Two Sisters. There were, at the time, a few observatories with 'mural sextants'. Mural sextants are essentially giant protractors carved into and painted onto the room itself. These are, of necessity, fixed in place, and at the time they were popular they relied on visual observation. Later devices were developed that were movable and could be adjusted by means of gears and pulleys (or magic). They achieved better accuracy in this way, as one could 'sight' them as one might a bow-and-arrow, and were only slightly smaller than the mural sextants so that the arm made the angular change more noticeable. Eventually, an astronomer named Bradford Pear* developed a better way, using a finely-beveled screw with markings on the head and a plumb line. A plumb line is a weight attached to a string, which thus always points straight down. By starting with the plumb line aligned with a mark on the telescope and counting the turns of the screw (and portions thereof), the angle could be adjusted with very fine accuracy. Then it was only necessary for the telescope to magnify the star enough that it could be centered with reasonable accuracy. But why would astronomers needs to know what angle their telescope was at when pointed at the star? Let us start with the case of the Earth's motion around the sun. Debated for centuries, the development of the telescope finally put it to rest. Consider, if you will, a star located directly over the center of the system. There is no real star in this position, although Polaris in Ursa Minor is close, but assume there is one for the sake of argument. Now, if the system is geocentric (that is, the Earth is at the center), then the star will remain fixed in position as seen from the earth. If, however, the system is heliocentric (the sun at the center), then it will appear at a slightly different point in the sky if the Earth is on one side of the sun than on the other. Ignore the possibility of the sun's light rendering the star unseeable for now. It is important to note here that one must compare their position relative to the position of the sun at some fixed point in time. By convention, it is the Spring Equinox. Obviously, the stars 'rotate' about the Earth over the course of a year (or appear to anyway), but this is motion besides that. It is important to note that this apparent motion would also apply to all stars, but it would be north-south instead of east-west. Now, by examining the above model, if the stars were close by, they would all show significant deviation of this sort over the course of a year. They do not, because they are quite far away. Bradford discovered, though, that all stars do have a small yearly deviation, and from this he determined that the Earth orbits the Sun at a distance of about 93 million miles. Also from this model, you can hopefully see that the closer a star is, the greater this motion will be. If, then, the stars are at significantly different distances, some of them will show a greater motion. This motion, however, is smaller than that caused by Earth's orbit around the Sun, and is correspondingly more difficult to measure: only in the closest of stars can it be detected. It was not until a generation later, still around 150 years ago, that Astral Vessel** first definitively measured this motion, known by the rather discordant name of parallax. He found that a particular star was about 96 trillion miles away, or 1 million times farther away than the sun. The parallax of about 150 other stars has been measured, with the closest being Alpha Centauri (the brightest star in the Centaur constellation), at around 26 trillion miles: still a considerable distance! Once we know the distance to a star, the star's brightness, and the sun's brightness, we can determine how bright a star would appear if we were near it. From this, we have determined that the stars with known parallax are mostly around the brightness of the Sun (some more, some less). This indicates that our Sun is, in fact, a star, and distant stars are Suns, which may have other worlds with other ponies, griffons, dragons, etc, or even other creatures the likes of which we have never seen! This is all speculative. At the very least, we can say that a constellation like Ursa Major would look very different from another Sun, particularly one within the constellation. Thus, the patterns of the stars likely have no real meaning. There are so many stars in the sky that some groups of them are bound to look like something. Those who have seen Ursa Majors can attest that they look only vaguely like the constellation. This chapter is running a bit short, but I believe I have explained as best I can without boring many of my readers, so I shall move to the story. Of note: the dragon in this story was apparently very serpentine and could not fly. Such dragons are not unknown, though they are not the kind most often seen. With no further delays from me, then, here is the tale. Story: Once upon a time, there was a mother Ursa Major who was raising her cub, and Ursa Minor. One day, when the mother was out foraging for food, the cub wandered off on its own. While out, it was attacked by a dragon. Fleeing in terror, the cub fled up a high mountain, the highest in the world, pursued by the dragon. When the mother returned home and found her cub gone, she dropped her prey and followed the trail in panic. The cub reached the top of the mountain and collapsed from exhaustion, but the dragon was not far behind. As the dragon closed in on its prey, he heard the cry of the mother. Thinking quickly, the dragon grabbed the cub, knowing the mother would not risk harm to it. But, sadly, the mother was too distraught and did not see the cub. She swatted both dragon and cub with her might paws. The dragon released its grip, and it and the cub flew apart. Too late, the mother realized her mistake. Already, the two were flying up, up, up, far beyond her reach. They flew so high, that they broke through the sky and became the constellations of Ursa Minor and Draco. Wailing for her cub, the Ursa Major backed up and, with a running start, took a mighty leap off the mountain. Driven by her desire to reach her cub, the Ursa Major broke through the sky as well, becoming the constellation of Ursa Major. And so they stand, mother watching over cub while the dragon waits nearby.