Between the 6th and 5th centuries BC, civilizations that had no idea the others existed threw up world-changing thinkers at almost the same moment: Laozi and Confucius in China, the Buddha in India, Pythagoras and Socrates in Greece. Follow this thread and you will see "meanwhile" with your own eyes — across the same span of time, people in several corners of the earth began, unprompted, to ask the same great questions.
This trail ends here — keep exploring in any universe.