Incomplete - Gravity to create motion

function movePoint($current_point, $other_points, $mass, $time_interval){
    //Given the above information, this function will return the resulting point after it has been affected by the gravity of the other points.
    /* Basically the method is:
        -Find the distance between the given point, and another of the rest of the points
        -Find the net force experienced by the point
        -Separate net force into the X, Y and Z planes.
        -Repeat steps 1-3, summing up the separated forces.
        -Then, a = G*((m1*m2)/(r^2))/m1
        -I guess that the period is going to affect the velocity, and then displacement... how does it go again. :S
        -s = ut+1/2at^2
        -...I'm going to need more information from the $current_point, I believe. Going to need velocity aswell.
        -shit...
    */
    $net['x'] = 0;
    $net['y'] = 0;
    $net['z'] = 0;

    $dif['x'] = 0;
    $dif['y'] = 0;
    $dif['z'] = 0;
    foreach($other_points as $other){
        //I suck at creating variable names
        //And I didn't really think this through
        if($current_point['x'] != $other['x'] && $current_point['y'] != $other['y'] && $current_point['z'] != $other['x']){
            $dif['x'] = $current_point['x']-$other['x'];
            $dif['y'] = $current_point['y']-$other['y'];
            $dif['z'] = $current_point['z']-$other['z'];
            $distance = sqrt(pow($dif['x'], 2)+pow($dif['y'], 2)+pow($dif['z'], 2)); //Pretty much the radius
            $acceleration = ((6.67300*pow(10, -11)*pow($mass, 2))/pow($distance, 2))/$mass; //I guess that's right
            //now to divide this into the 3 planes - x, y and z
            //Fuck... I'll come back to this tomorrow... Needs more trig.
        }
    }
}