What do Olympic gymnasts and star-forming clouds have in common?
Unravel the unexpected parallels between Olympic gymnasts' precision and the formation of celestial bodies. Discover how the laws of physics govern both the spectacular flips of athletes and the birth of stars in distant nebulae.
Olympic Gymnastics and the Conservation of Angular Momentum
Much of the beauty of gymnastics comes from the physics principle called the conservation of angular momentum
- When a spinning object changes how its matter is distributed, it changes its rate of spin
- Naturally, there are many Olympic events from which we could learn some basic principles of physics
- Swimming shows us hydrodynamic drag
The Conservation of Angular Momentum
Much of the structure and history of the universe comes down to the physics of rotating objects.
- Rotating objects obey a conservation law, but now it is not just the mass of an object that matters. The distribution of mass – that is, where the mass is located relative to the center of the rotation – is also a factor.
Gymnastics, a cosmic sport
When gymnasts perform flips, the only force acting on them is gravity
- Since gravity only affects their “center of mass,” it cannot apply forces in a way that changes the athlete’s spin
- But gymnasts can do that for themselves by using the conservation of angular momentum
- By changing how their mass is arranged, gymnastics can change how fast they spin