Simulating physics in video games

In the most modern video games, software engineers are doing a lot of work to simulate physics. This lets the games look and feel more and more realistic. You can see, for example, how physics makes this soft-body simulation look realistic:



Here, a physics simulation makes trucks look very realistic:



But right now there are limits, as this video shows us:



The description that comes with the video says that: "a rigid car frame sitting on wheels and ball bearings is shown in this example. A multittude of forces are constantly pushing on the ball bearings and the ball races. These forces are very small, and the physics engine has a hard time accurately simulating the forces and positions of the objects, which results in small, unnatural movements. These movements are not dampened, but instead compound together into violent shaking and finally a powerful explosion that blows the ball bearings and the entire car apart in a shower of force/position errors. Created using Fraps and the 3D environment Second Life, wich uses the Havok physics engine."