Recent content by Chetic

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    Undergrad Approximating Ellipse Orbits with Newton's Law

    Okay, forget what I said. I've managed to calculate the eccentricity vector, which now always points towards apoapsis (with the length of the eccentricity of the orbit). How do I calculate the semi major axis? Or something else that gives me the rest of the information I need to draw the...
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    Undergrad Approximating Ellipse Orbits with Newton's Law

    I'm going to try running the simulation 5 steps ahead, collecting positions, and solve for a conic section.
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    Undergrad Approximating Ellipse Orbits with Newton's Law

    Sorry, I didn't realize. I'm simulating the orbit of bodies based on position and velocity vectors. The only orbit that's really interesting is the player's. The player will want to have an idea of where he is going. All I really need is how to calculate the ellipse of a two-body system. The...
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    Undergrad Approximating Ellipse Orbits with Newton's Law

    How do you approximate the ellipse of an object's orbit using Newton's law of universal gravitation? I'm working on a 2D space game and that's pretty much the only physics I use, so no other forces to consider.
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    Undergrad Calculating the position of the 'other' focus point of an orbit

    Actually, I think the best way might be to solve for vectors representing periapsis and apoapsis (the highest and the lowest points of orbit). I have wiki'd myself crazy trying to find some formula for this. Can anybody give me a hint? Edit: Forgot to mention my problem; I can only find...
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    Undergrad Calculating the position of the 'other' focus point of an orbit

    You know how orbits are made of ellipses and ellipses are made out of two foci? I'm trying to find a formula where I can extract the position of the other focus point, relative to (0,0). By the other focus point I mean the one that's generally out in space. Very much like how the...
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    Undergrad Calculating Orbit Velocity Around a Star

    Hah! It works! Now the problem turned out to be that my vectors were rotated incorrectly, but your answer helped me realize what wasn't wrong so thank you very much! Here's a li'l pic of it at the moment: http://img814.imageshack.us/img814/3983/gasim.png"
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    Undergrad Calculating Orbit Velocity Around a Star

    I'm toying with the idea of making a little 2D space orbiter game so I've implemented Newton's universal gravity law into this little app. It works really well, even. The problem I'm having is when I want to create an asteroid-belt. I spawn little asteroids randomly around an area around the...