I'm making an Earth simulator in Flash and still have several concepts to work out. I managed to plot stars in a sky looking from the Sun's position, and can make out constellations seen from our sky. Now if I virtually move to the Earth's position, and look at the sun, how will the galactic sphere of stars rotate?
Any thoughts on where to get started? I could probably do without the stars in this simulation toy, but since I already went through the trouble, I feel it would be a waste to do so. I appreciate any feedback you could give. I also much appreciate it if you could spell things out as much as you can stand as my mind is more artistically oriented then mathematically inclined. :P
> I'm making an Earth simulator in Flash and still have several concepts > to work out. I managed to plot stars in a sky looking from the Sun's > position, and can make out constellations seen from our sky. Now if I > virtually move to the Earth's position, and look at the sun, how will > the galactic sphere of stars rotate?
> Any thoughts on where to get started? I could probably do without the > stars in this simulation toy, but since I already went through the > trouble, I feel it would be a waste to do so. I appreciate any > feedback you could give. I also much appreciate it if you could spell > things out as much as you can stand as my mind is more artistically > oriented then mathematically inclined. :P
> Thank you much!
> Chris
The effects will be extremely small because the distance to the stars is much greater than the sun-earth distance. If one looks at the sky now and wait a half-year (we're now on the other side of the sun) one can't tell any difference without scientific instruments. I don't think there is any use in trying to be precise. Fake it. Have them move a small - barely perceptible amount in an direction opposite to the direction of motion.
> Fake it. Have them move a small - barely perceptible amount in an direction opposite to the direction of motion.
Raphanus, Good point and great idea! That will work well for this project. I guess the biggest issue on faking it right now is the current orientation around the sun. The big dipper (seen in orange in my project) looks upside down, where in our sky in the US it looks right side up. Of course everything looks different standing on the Earth's surface. I'm looking for ways to verify which way is up, down, etc. in the star sphere so that the stars are in the somewhat correct directions. It is very possible that my calculations may have inverted where things really should be, or rotated everything 90 or more degrees, etc.
On Oct 6, 11:41 am, Ultrus <ownthe...@gmail.com> wrote:
> > Fake it. Have them move a small - barely perceptible amount in an direction opposite to the direction of motion.
> Raphanus, > Good point and great idea! That will work well for this project. I > guess the biggest issue on faking it right now is the current > orientation around the sun. The big dipper (seen in orange in my > project) looks upside down, where in our sky in the US it looks right > side up.
Believe me - the big dipper doesn't move just because the observer moves from the sun to the earth. I have seen the big dipper appear to be upside down. It depends on the time of night and the season.
Of course everything looks different standing on the Earth's
> surface. I'm looking for ways to verify which way is up, down, etc. in > the star sphere so that the stars are in the somewhat correct > directions. It is very possible that my calculations may have inverted > where things really should be, or rotated everything 90 or more > degrees, etc.
Remember that a reference frame doesn't dictate in which direction the oberver is looking - only where the observer is located. The earth's surface is a moving reference frame.
My impression is that you may have more thinking to do about what you're trying to accomplish.
The star Polaris could be "the star" of your show.
> On Oct 6, 11:41 am, Ultrus <ownthe...@gmail.com> wrote:
> > > Fake it. Have them move a small - barely perceptible amount in an direction opposite to the direction of motion.
> > Raphanus, > > Good point and great idea! That will work well for this project. I > > guess the biggest issue on faking it right now is the current > > orientation around the sun. The big dipper (seen in orange in my > > project) looks upside down, where in our sky in the US it looks right > > side up.
> Believe me - the big dipper doesn't move just because the observer > moves from the sun to the earth. I have seen the big dipper appear to > be upside down. It depends on the time of night and the season.
> Of course everything looks different standing on the Earth's
> > surface. I'm looking for ways to verify which way is up, down, etc. in > > the star sphere so that the stars are in the somewhat correct > > directions. It is very possible that my calculations may have inverted > > where things really should be, or rotated everything 90 or more > > degrees, etc.
> Remember that a reference frame doesn't dictate in which direction the > oberver is looking - only where the observer is located. The earth's > surface is a moving reference frame.
> My impression is that you may have more thinking to do about what > you're trying to accomplish.
> The star Polaris could be "the star" of your show.
> Good luck.
Raphanus, Thanks again for your feedback. I understand what your saying and apologize if my words aren't making much sense. Let me show you a draft: http://www.christopherstevens.cc/fun/test2.htm
The stars don't "move" themselves, but they do move on the screen as I rotate about the Earth. The star locations will never physically change in this project. I hope that helps clarify. You can see the potential in the link I sent, but calculating or faking what direction the sun is in relation to the Earth (I can figure this part out), and galactic angle of the galactic star shpere in relation to this project scene, makes my left eye fall out of the socket.
One point that bugs me is Polaris. Polaris is highlighted in orange, just "south" of the Big Dipper. To me it seems to be an odd location for a "north star", even if the the Earth's surface is a moving reference frame. That's when I started seeking calculations that might put the sun and earth into perspective with the rest of the galaxy, rotating the star sphere to fit the scene anyway. After some sleep though it may come together. If you hold apple/ctrl+click and drag, you'll see the "star sphere" or backdrop I speak of.
Thanks much for your input. I look forward to any additional thoughts out there. :)
