Why is it that babies like being rocked to sleep yet as we get older rocking can be uncomfortable such as on a boat?
Humans sense of balance is largely derived from bubbles of fluid by our ears. The fluid moves around as we move like a bubble in a carpenter’s level. But the fluid gets thicker as we age and is less accurate for tracking movement. So while children like merry go rounds and usually don’t get carsick, as humans age they find such things to be less pleasant and get car sick more easily
Being rocked in someone’s arms is generally a fixed rhythm and gentle. Being rocked on a boat is generally more violent and random.
I don’t think that rocking becomes uncomfortable as we get older. Many people like rocking chairs, for example.
Boat rocking or airplane turbulence is uncomfortable because it’s not steady, it’s uncontrollable, and can be dangerous (like in a storm).
But slow and gentle rocking at a steady pace that you’re in control of? That shit is the tits.
Motion sickness on cars and boats is also influenced by a conflict between what you are seeing and what your inner ear is feeling. That’s why some people feel motion sick in Imax movies or other situations where they see a moving view but their body isn’t actually moving at all.
And it’s why, if you are carsick, it helps to look ahead at a distant object rather than looking at something inside the car (like reading). It helps your brain recognize “yes, I am moving in relation to my surroundings.”
Babies don’t have any conflict like that, just like you don’t have a visual conflict if you sleep on a waterbed or lie in a hammock.
The womb is a fluid-filled sac, and when a mother moves about the baby is very slightly rocked thanks to that fluid. The baby becomes used to this feeling before birth, so rocking helps to calm them afterward for a time.
Adult humans don’t live in fluid-filled sacs. We’re not used to being moved or rocked outside of our own willpower.