So as it turns out, religious flamebait is only fun for about 5 minutes. What else can I do to ease my boredom? Well, how about talking about things that are actually fun! Like what, you ask? Like astronomy! Each day, excluding days when I'm studying or doing projects, I will come back to this thread and post on a different topic as it relates to astronomy. Disclaimer: I am not an actual astronomer. All the information I will be posting comes directly from what I've learned in the astronomy classes I've taken in university (don't worry, I've gotten all A's in those classes amazingly enough), as well as various textbooks and scholarly articles. If you believe anything I post is factually wrong, please feel free to let me know! But please make sure to cite your sources. I actually like talking about this shit, and would be happy to further my knowledge. Today we'll be talking about stars! No, I'm not talking about the kind you see in Hollywood blockbusters. I'm talking about the kind you find on the Hertzsprung-Russell Diagram! First up: Parallax! Is Parallax related to Snorlax, you ask? No! Simply put, measuring the parallax of stars can reveal their distance from our own sun! But what IS parallax? Parallax is the apparent displacement of an object because of a change in a observer's point of view. Huh? Okay, let's put it like this. Hold your arm out in front of you. Now, close your left or right eye and look at your arm. Now, switch eyes. You should notice that your arm looks like it is shifting back and forth against the background of other objects. The closer the object you're looking at, the greater the parallax shift. The human brain analyzes parallax shifts constantly as it compares images from your left and right eye. Yay depth perception! To measure the distance of stars, astronomers will measure the parallax shift of a star from two points of view that are as far away as possible, such as the opposite sides of Earth's orbit. The direction from Earth to nearby stars changes as the Earth orbits the sun, and nearby stars appear to move back and forth against the background of more distant stars. This is called Stellar Parallax. The parallax of a star (let's use P) is equal to HALF the angle through which the star's apparent position shifts as Earth moves from one side of it's orbit to the other. The larger the parallax, the smaller the distance to that star (let's use D). Let's measure D in parsecs. A parsec (pc) is equal to 3.26 light-years. A star with a parallax of 1 second of arc is at a distance of 1 parsec. PARallax and arcSECond gives us parsec. If the angle P is measured in arcseconds, the the distance D to the star in parsecs is given by THIS equation: D = 1/P where D is equal to the distance to a star in parsecs and P is equal to the parallax angle of that star, in arcseconds. Let's use Barnard's star as an example. Barnard's Star has a parallax of 0.547 arcseconds. So , the distance can be calculated as thus: D = 1/P = 1/0.547 = 1.83 parsecs (pc) Since a parsec is equal to 3.26LY, we can also express the distance as: D=1.83 pc X 3.26ly/1pc = 5.97 LY. Barnard's Star is 5.97 LY away from Earth. Isn't that neat? Next time I'll talk more about the HR-diagram and the luminosity and apparent/actual magnitudes of stars! Stay tuned. Also, feel free to discuss space-stuff.