Why "3rd Space"?

The "third place" is sociologist Ray Oldenburg's name (1989) for the spot between home and work where people gather.

Long before the name, China's teahouses were that place, busy gathering spots by the Song dynasty (960 to 1279).

And three runs deep. The Daodejing, credited to Laozi (traditionally 6th century BCE; scholars date the text to about the 3rd century BCE), says:

“The Tâo produced One; One produced Two; Two produced Three; Three produced All things.”

Daodejing, ch. 42, tr. James Legge (1891)

There's no ancient Chinese idea literally called "the third space." These are the roots the name draws on.