Astronauts who experience weightlessness frequently get motion sickness  The astronauts see their own motion relative to passing objects, but while the astronauts are weightless their inner ears indicate that their bodies are not moving
The astronauts' experience is best explained by the hypothesis that conflicting information received by the brain about the body' s motion causes motion sickness
During rough voyages ship passengers in cabins providing a view of the water are less likely to get motion sickness than are passengers in cabins providing no view.