In all images, the direction of gravity is downward.
Besides, the social climbing is so much easier when you're going in the direction of gravity.
Statoliths bend the hairs in the direction of gravity, providing a vertical reference direction.
Some function as rotation receptors or exteroceptors to detect the direction of gravity.
Tunicate larvae have visual organs sensitive to light and sense organs responsive to the direction of gravity.
Plants can sense the direction of gravity and change the growth orientation of their organs.
In vertebrates the utricular maculae in the inner ear contain an otolithic membrane and otoconia (particles of calcium carbonate) that bend hair cells in the direction of gravity.
In the inner ear of higher vertebrates there are three variants of this basic design, responsible for detecting the direction of gravity, angular rotation, and sound waves.
Suggestion: you can change the direction of gravity to be at an angle, or even be rotating to make the dynamics inside your box more interesting.
These specially designed layers allow the 2D layers to be transported across distances, regardless of the direction of gravity, for placement onto a 3D object.
Mahadevan and coauthor Raghunath Chelakkot describe plant shoots as 'sentient' meaning they can sense their own shape and the direction of gravity and light through mechanochemical pathways.
