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That CAN'T be true! / Re: What causes motion sickness?
« on: 16/03/2017 00:01:03 »The stuff in my sickbags depends on what the victim had for breakfast, not whether the aircraft has an engine.It was firstly proposed by a Chinese physicist of acoustics that motion sickness was caused by infrasound. After reflecting on this over and over again for years, I think this view is wrong. In my opinion, motion sickness is supposed to result from booming low-frequency noise. For instance, it is beyond doubt that extremely loud booming low-frequency noise is always heard inside vehicles which easily bring about motion sickness. Inside vehicles without such noise, motion sickness isn’t caused at all. In spite of loud noise of tractors, people don’t feel sick inside them because there is no booming low-frequency noise. The key reason consists in that the noise of tractors doesn’t distract people because they don’t impact their verbal communications due to differences between frequency of the noise and people’s voices.
Part of the problem with instrument flying, yacht navigation or rear-seat car sickness is the inability of the semicircular canals to distinguish between linear acceleration and circular motion. You can induce carsickness by stop-start driving on a straight road, and airsickness on scheduled flights or glider "dolphining" is caused by sudden changes of pitch attitude, not turning.
If it's all due to infrasound, why don't pilots and drivers suffer the same symptoms as their passengers? It isn't a matter of aptitude or experience - hardened drivers often throw up when navigating in rallies, and the most experienced pilots still need to swap duties with each other to avoid becoming incapacitated under competition conditions.
The one time I had an entirely incapacitated crew was on a fairly large yacht, reaching into an opposing tide. For about two hours, we made no progress over the ground but just pitched and rolled at random intervals in almost total silence, broken only by groans and the sound of eight experienced sailors donating their stomach contents to the sea. The only relief was to do something: taking the helm in turn, or tweaking the sheets, though the latter was completely unncessary as we had the boat pretty well trimmed anyway, but the feeling of being a bit in control or able to anticipate the next roll was very calming.
Early on in my sailing days I noticed an uncharacteristic craving for ginger biscuits. I later discovered that Chinese sailors have always used ginger as a prophylactic against seasickness, and it seems to work as well as modern molecules without inducing drowsiness. Any explanation would be welcome!
Some other evidences can prove that motion sickness just arises from the aforementioned noise: People with good hearing easily suffer from motion sickness, while the deaf and dumb who can’t hear don’t feel sick inside vehicles at all. The noise is louder inside fairly closed vehicles, so people easily get sick in highly closed luxury buses and cars. The noise is so penetrating that motion sickness can’t be avoided either even if ears are covered with something.
The cause of such amazing trick is medical experts’ lack of knowledge about acoustics. They have only noticed that the tractor doesn’t cause motion sickness although it is rather noisy, so they have wrongly concluded that motion sickness doesn’t result from noise. In fact, they haven’t discerned that the noise of a tractor differs from the low-frequency noise which brings about motion sickness. Although they couldn’t figure out the cause of motion sickness, they were too hasty to reach a conclusion. As a consequence, they have scientifically tricked people that motion sickness is associated with many factors such as shaking, movement and visual motion.