sentences: transverse waves have objects moving in the opposite direction of longitudinal waves
docs: waves is cycles_of_density_of_physical_objects. waves is moving_water. wave_propagation is translocating. electron is wave_propagation. electromagnetic_radiation is wave_propagation. wave is motion. delta_waves is large_slow_brain_waves. sounds is longitudinal_waves. wave_front is propagation. bilateral_object is localized_spatial_thing.