Recent content by Rapidrain

  1. R

    One satellite, two planets and movement

    Very good DH. This helps much more than "go look it up". Question though : your equations show : x(t + del*t) = x(t) + del*t*v(t) shouldn't the right side also have the distance covered by acceleration : x(t) + del*t*v(t) + (1/2)*acc(t)*(del*t)**2 ?? I'll give your algorithm a try.
  2. R

    One satellite, two planets and movement

    Again Voko, what do you mean by 'loop that up'? Is this the designation of how one solves Euler's three bodies?
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    One satellite, two planets and movement

    Sorry voko, but I don't understand what you mean by "loop that up". And really need to do what I am doing? Please explain.
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    One satellite, two planets and movement

    I am trying to write a program to show the flight of a satellite in the neighbourhood of two large planets. In all of this the mass of the satellite is negligible. I have the potential energy from planet1 = pe1 and the potential energy from planet2 = pe2 and the kinetic energy of the...
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    Angular Momentum in a Kepler Orbit

    I got myself here a satellite rotating at a large distance around planet X. Distance from center of planet X = 100, mass of the satellite = 1 gram (really small), mass of planet X = 1.0 kg velocity of my satellite 10 m/sec and in this oddball universe the gravitational constant = 10**4...
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    Using iteration to orbit dual suns - losing energy

    >>1) reduce the number of iterations so that the TE is constant Reducing the number of iterations does not cause the TE to become constant. >>Also, one thing to do is to try to look at the energy with smaller time steps. Smaller times steps = increasing number of iterations...
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    Using iteration to orbit dual suns - losing energy

    >>Which method do you use to calculate your iterations? I found by way of another entry in this forum a link to a site where 'Euler Implicit' and 'Euler Explicit' and 'Euler Semi-Implici' were described...
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    Using iteration to orbit dual suns - losing energy

    Using iteration I've got a satellite flying around two gravity sources. (See picture) When using the iteration over a 100 times I see that TE, total energy slowly sinks so I need to make a correction after each iteration to insure that TE is constant. Trouble is I have several...
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    One planet, two suns, ellipse or hyperbola?

    Thank you all for your replies. Imagine taking each of the two gravity sources individually and for an increment of time add the two trajectories. Position and velocity vectors. Then attack the problem anew. I could do this using interations in computer program. Would that be...
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    One planet, two suns, ellipse or hyperbola?

    I've got a nifty java program done which calculates the orbit of a body around a gravity source. The math and physics are all done for a body around a single gravity source and how to figure whether it's an ellipse, parabola, hyperbola or straight line. But now I've got a new problem. If...
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    Is acceleration always positive

    accelleration ever negative? Think of accelleration as a vector. Is a vector ever negative? Robin Hood once said "I didn't shoot that arrow backwards. I shot it in a different direction!" If it seems to be negative it's just really positive but pointed in a different direction. But if you're...
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    Calculating orbits of moons, when both the planet and star are involved.

    Well said. This is what I've been thinking for the past 18 months. There is very much math involved in the orbit calculations. First and foremost : conservation of energy. KE + PE is always the same. KE = v*v/2 and PE = -GM/d So you have two equations but dx/dt (change of distance...
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    Calculating orbits of moons, when both the planet and star are involved.

    I've been working on a java app which shows the orbits of satellites around a gravity source. I might have the smallest of tips concerning the moon, planet and star problem. I was able to take a satellite flying at a certain velocity near a gravity source at a certain distance and moving a...
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    The tangent to an ellipse from polar coordinates

    Got it! dy/dx is the slope, not dr/r*dTheta, slope is (ecc*sin(Theta)**2/(1+Ecc*cos(Theta)) + cos(Theta)) / (ecc*sin(Theta)*cos(Theta)/(1+Ecc*cos(Theta)) - sin(Theta))
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