People in the olden days believed that Above is heaven Below is hell. With the human world in the middle Humans imagine that The world in which we live There is a circle around the sky. With the star stuck in that sphere Therefore, the ancients thought that Each star is an equal distance from the world because there are many stars in the sky. Humans then divide the stars into groups. And imagine drawing images of people, animals, and other things according to beliefs and lifestyles of each culture.
Constellations in the sky vary according to culture, for example that Europeans in the mountains have a hunting career. Can see the Orion constellation as a picture of the Orion But Thai people live on the waterfront Therefore can see this constellation as a turtle and plow. Ursa Major is also the Europeans who live in the mountains, seen as a big bear. But Thai people live by the water Therefore, it can be seen in the form of a crocodile. It can be seen that the constellations are just a matter of imagination. Which is different in each locality, ethnicity, language and culture. Therefore, in order to communicate the same meaning The International Astronomical Union therefore sets the same standard. By dividing the constellations on the celestial sphere into 88 groups with the same name By equaling to Europe, such as Orion And the big dipper The name of the constellation Turtle The Crocodile Considered as a local name within Thailand.
Starry sky Actually the size is not the same. And away from our world With different distances But because each star is very far away from us We therefore see only light. Just the difference in color and brightness. For example, the constellation Cassiopeia, which is near the North Pole (in Figure 3). Europeans imagine it as a “queen” but Thai people see it as “Bats” When looking at the naked eye, we see five stars arranged in an “M” or “W” shape upside down, with each star not very far apart. And have similar brightness in reality These five stars There are many different sizes. And the distance from Earth is very different. Beta stars ( β ) are small but near The star gamma ( γ) Large in size but far away We therefore see that both stars have similar brightness. We see like Both stars have the same angular distance. Both stars are not uniformly deep in space.
Each star does not stand still. But moving in space at different speeds and directions Because the stars are very far away We therefore saw them as though they were still. And imagine connecting the lines to the exact shape, as in Figure B. Because each star Moving in the Milky Way galaxy The constellations that we see It has a shape that changes with time, as shown in Figure A, a constellation of 50,000 years in the past, Figure B is an image of the current group of bats, and the image of a group of bats in another 50,000 years.