Sharp lines, shapes with lots of corners, etc., leave a viewer on edge. They can be used to represent harsh emotions such as anger or hate because those are sharp feelings.
Steady patterns of lines, such as waves like an ocean, create a sense of calm because patterns mean order, and order is commonly associated with calm.
7.8 Billion (2020)
The current world population is 7.8 billion as of March 2020 according to the most recent United Nations estimates elaborated by Worldometer.
