Running in circles, riding in a merry-go-round, or whirling on a seat – you most likely tried all that at some point in your life. You also would have probably noticed the dizziness it provides after, even if you have already halted the circular motion. Regardless of the method that you use to spin, your body reacts the same way, and you would surely see the sky wheeling. But why?
When you spin too swiftly, your eyes process a vast amount of information in a short period, which leads to sudden disorientation. Your body is not equipped for instant changes like, and it strives hard to maintain a normal visual field. Without that attempt, what you will see would be pretty perplexing, and it would be challenging to function properly.
But, truth to be told, the process which tries to keep you oriented does not initially start with your eyes. It all begins in your ears instead. Deep inside the inner ear lies the semi-circular canals that are placed at an angle of 90º of each other. Incredibly tiny strands of hair are situated on each of these canals. Then, two layers of gelatinous fluid brim each of each canal and provide you with a sense of balance.
They are regarded as endolymph and cupula. With every movement of your body, these two fluids splash inside the ear canals. These splashes then hit the tiny strands of hard, allowing them to move in a particular direction, like water plants moving in a river current. What the ear does is detect to which direction are these hair cells are moving. It then utilizes roughly 20,000 nerve cells to transmit signals or data to the brain.
When you stay still, the splashing motion of the fluids also stops, halting the tiny strands of hair from detecting movement and pausing the transmission of any information to the brain. However, when you run in circles, ride a merry-go-round, or whirl on a seat, your body moves to fast, causing quick movement on these ear fluids. Thus, it provides the feeling that you are still wheeling rapidly.
While muscles won’t have any issues stopping or starting any movement at your will, the fluids in our ears don’t function as fast as we’d like. Imagine stirring water on glass using a spoon. Even if you stopped stirring, the water would still continue to whirl for some time. This scenario goes the same way with the ear fluids. It would also take a certain period for it to halt moving eventually. However, during the given time, the hair cells are still detecting the motion, and continually transmits signals to the brain. The latter processes the data, although the body is already still. Your mind thinks that you’re moving, but you’re actually not. Thus, it causes a disconnection, producing the extreme of dizziness that you feel. Fortunately, it’s only temporary and will normalize one the fluids starts to settle.
Astronauts who are constantly in orbit also become dizzy due to the absence of Earth’s intense gravity. With the lack of inertia, the ears do not work well as much, causing disorientation and difficulty in determining which way is up or down. The same experience happens with scuba divers as buoyancy affects the ears the same way the absence of gravity does. Thus, it also easy for divers to experience disorientation underwater, which they combat using visual cues.
- Dizziness (Wikipedia)