What is the principle of perception that supports the idea that your brain expects that the puff of white between the fingers is a cloud that is much farther away than the hand?

Gestalt Principles of Perception: Figure- ground relationship

figure-ground relationship  segmenting our visual world into figure and ground

while it was true that the cotton gin reduced the labor of removing seeds, it did not reduce the need for slaves to grow and pick the cotton.

explanation:

before eli whitney's invention of the cotton gin, picking and cleaning cotton was a slow, labor-intensive job. workers, usually slaves, had to pick the seeds from the cotton fibers by hand. this invention made it possible to grow large amounts of cotton on big farms and make money.