The last flight of the day is nearly empty, and you’re tempted to move to a better seat with a view. However, the flight attendant informs you that this could disrupt the weight distribution of the plane. This may seem like a small change, but it actually involves some fascinating physics. The concept of center of mass is often misunderstood as the point where all gravitational forces act, but it’s actually more accurately defined in terms of torque. Torque, the rotational cousin of forces, depends not only on the magnitude of the force, but also on where it is applied. This is why a door handle is placed on the far side of the door. In the case of the plane, even a small change in the distribution of weight can have a significant impact on the torque and ultimately the stability of the aircraft. So next time you’re on a flight, remember that even the smallest movements can have a big effect on the physics of the plane.
