Graduate Elliptical orbit parameterized by time

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Expressing an elliptical orbit in terms of time is complex and does not yield a straightforward analytic solution like a circular orbit does. While circular orbits can be represented with simple parametric equations, elliptical orbits require a more intricate approach due to the limitations of Newton's laws, which describe the shape in terms of radius and angle but not time. The Kepler Equation is essential for understanding the relationship between time and position in elliptical orbits. This equation highlights the challenges in deriving a time-dependent position formula for elliptical motion. Overall, the discussion emphasizes the complexity of modeling elliptical orbits compared to circular ones.
DuckAmuck
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How to express an eliptical orbit in terms of time
It is fairly trivial to do this with a circular orbit: $$(x,y) = (cos(\omega t),sin(\omega t))$$
where t is time, and $$\omega = \sqrt{GM/r^3}$$
How this parametric equation look for an elliptical orbit?
 
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DuckAmuck said:
Summary:: How to express an eliptical orbit in terms of time

It is fairly trivial to do this with a circular orbit: $$(x,y) = (cos(\omega t),sin(\omega t))$$
where t is time, and $$\omega = \sqrt{GM/r^3}$$
How this parametric equation look for an elliptical orbit?

I don't think it works out very well. Have you tried?
 
Yes. I get something non-analytic.
 
DuckAmuck said:
Yes. I get something non-analytic.
I think that's what you get. The analysis from Newton's laws bails out at a certain point and describes the shape of an orbit in terms of ##r## and ##\theta##, but eliminates ##t##. You get the shape (ellipse) and the period, but not an analytic formula for position as a function of time.
 
Look up "The Kepler Equation". You're in for an interesting ride!
 
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gneill said:
Look up "The Kepler Equation". You're in for an interesting ride!
Thank you!
 
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