text: "use strict";
  
  !function (CBTravel) {
      let module = {};
  
      const G = 6.67e-11;
      function distancePow2(pd) {
          return pd.x ** 2 + pd.y ** 2;
      }
  
      function FGravity(tb1, tb2) {
          /*
          *       m1 * m2
          * Fg = --------- * G
          *         r^2
          * */
          return (
              (tb1.weight * tb2.weight)
              /
              distancePow2(tb1.pos.sub(tb2.pos))
              * G
          );
      }
  
      module.G = G;
      module.FGravity = FGravity;
  
      CBTravel.Physical = module;
  }(CBTravel);