Dr. Nicole Morgan explained how the 19th century saw a change in perceptions of space. She believed the 20th century and the early 21st century are seeing a change in the perception of time, the 4th dimension.
By the end of the 19th century, humans had occupied virtually the entire land surface of Earth, thus completing the space enclosure. [In the 20th century we started exploring the rest of the solar system, though the costs of doing so are, well, astronomical. Ed.]
By the end of the 20th century, jet engines, rockets, and computer chips were beginning to define our time enclosure.
It had become the time and place to confront the limits of humanity’s growth.