Although the evidence in favor of this model is scientifically plausible, the evidence against it is substantial. For instance, a cursorial flight model would be energetically less favorable when compared to the alternative hypotheses. In order to achieve liftoff, "Archaeopteryx" would have to run faster than modern birds by a factor of three, due to its weight. Furthermore, the mass of "Archaeopteryx" versus the distance needed for minimum velocity to obtain liftoff speed is proportional, therefore, as mass increases, the energy required for takeoff increases. Other research has shown that the physics involved in cursorial flight would not make this a likely answer to the origin of avian flight. Once flight speed is obtained and "Archaeopteryx" is in the air, drag would cause the velocity to instantaneously decrease; balance could not be maintained due to this immediate reduction in velocity. Hence, "Archaeopteryx" would have a very short and ineffective flight. In contrast to Ostrom's theory regarding flight as a hunting mechanism, physics again does not support this model. In order to effectively trap insects with the wings, "Archaeopteryx" would require a mechanism such as holes in the wings to reduce air resistance. Without this mechanism, the cost/benefit ratio would not be feasible.