![]() ![]() And in particular, I agree with that third point. (iv) If the distance traveled is large enough to see the change in apparent position, then we can see parallax.Īnd I agree with these four points. (iii) If the distance traveled is large enough then we can see the change in apparent position of stars, (Again, it could be invisible if the distance is too small) (ii) If an observer travels a certain distance, then there will be different parallax for different stars. (This change can be invisible if the distance is too small) (i) If an observer travels a certain distance, then there will be a change in the apparent position of stars. Basically it's a logical problem that he seems to miss every time, but perhaps simplifying this will allow other people to explain it better.įirst we start with things that we all agree on : You wouldn't see parallax in a star trail photo, even if you were using the word right.Īfter 5 days of conversation, I can point the exact problem /u/danjo_mcnasty has. The distance you move in the single night of a star trail photo is fuck-all. That's about the apparent size of a coin a mile away and it's using the entire orbit of the earth as the baseline. One parsec is about the distance to our very closest stars, and the 'sec' bit means a second of an arc of a minute. The unit of distance, the parsec, that George Lucas famously mis-used in Star Wars, tells you how big this effect is. Six months from now I'm going to be 300 million km away, which is still so small a distance that it would take the aforementioned house-sized telescope and much more skill in astronomy than I possess to detect.ĭo you think the stars are so close that the earth's motion should make the stars dance about like they look when you're moving at warp speed in Star Trek? No. That's nothing, set against the scale of the distance to the stars. Now, 12 hours from now I'm going to be around 6000km away from where I am now, relative to the earth's axis. What everyone including me means when using the word 'parallax' is the particular effect where at least two stationary objects appear to move relative to each other because the observation point is moving linearly. If you want to make up your own special little definition of a word, that no-one else in the world uses, then I guess I can't stop you. You're not going to be able to measure that with just an 8000 mile baseline. It was done accurately with telescopes and photographic plates in 1915. Nothing you're ever going to see with your eyes but measurable with the right equipment. If you take two pictures that are six months apart then your baseline is the diameter of earth's orbit, 17 light minutes, the closest star is 4 light years away. You need to do the math in order to know if you can tell the difference between zero parallax or not zero but too small to be measured or measurable. The farther apart, the smaller the parallax that can be seen. The ability to observe parallax is determined by the angular resolution of your camera and the distance between the observations. In fact, you can cause the stars to rotate around any point in the sky you can point your camera at, from the point of view of the camera. You can generate your own star trails by pointing a camera up at night and rotating it 360 degree. Linking me Wikipedia articles about how Santa Claus can fit down a chimney does not debunk reality. The fact all the stars move in synchronicity and at the same rate proves the stars have no depth. It is what's causing the star trails to begin with. Saying they are too far away to notice parallax is asinine. ![]() It is impossible for both of these stars to appear to move the same distance. This means that within the star trail, there will be stars that are 100 light years away and stars that are 26,000 light years away. The fact we see star trails means they are close enough to measure Parallax. ![]() This is where you and your Wikipedia claim is proven false. Their apparent position is changing as my position changes. I am not moving but the earth is rotating moving me thousands of miles throughout the night creating the illusion that the stars above me are rotating. It's the entire reason we see star trails. Parallax affects an object's apparent position based on the distance and change of position from and of the observer. ![]()
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