Function example_2

physics/n_body_simulation.py:277–300

Example 2: Moon's orbit around the earth This example can be seen as a test of the implementation: given the right initial conditions, the moon should orbit around the earth as it actually does. (mass, velocity and distance taken from https://en.wikipedia.org/wiki/Earth and

()

def example_2() -> BodySystem:
    """
    Example 2: Moon's orbit around the earth
    This example can be seen as a test of the implementation: given the right
    initial conditions, the moon should orbit around the earth as it actually does.
    (mass, velocity and distance taken from https://en.wikipedia.org/wiki/Earth
    and https://en.wikipedia.org/wiki/Moon)
    No doctest provided since this function does not have a return value.
    """

    moon_mass = 7.3476e22
    earth_mass = 5.972e24
    velocity_dif = 1022
    earth_moon_distance = 384399000
    gravitation_constant = 6.674e-11

    # Calculation of the respective velocities so that total impulse is zero,
    # i.e. the two bodies together don't move
    moon_velocity = earth_mass * velocity_dif / (earth_mass + moon_mass)
    earth_velocity = moon_velocity - velocity_dif

    moon = Body(-earth_moon_distance, 0, 0, moon_velocity, moon_mass, 10000000, "grey")
    earth = Body(0, 0, 0, earth_velocity, earth_mass, 50000000, "blue")
    return BodySystem([earth, moon], gravitation_constant, time_factor=1000000)


def example_3() -> BodySystem: