What examples are there in the article to illustrate that science has no borders?

China's four great inventions include papermaking, compass, gunpowder and printing.

The four great inventions greatly promoted the development of politics, economy and culture in ancient China, spread to the west through various channels, and had a great impact on the history of world civilization.

The statement of "Four Great Inventions" originated from the British sinologist Ai Yue Se.

Extended data

Inventing gunpowder editor

A black or brown explosive is made of potassium nitrate, charcoal and sulfur by mechanical mixing. It is first made into powder and then generally made into particles of different sizes according to different uses. It was the only military propellant until smokeless powder was used. Gunpowder was invented by an ancient alchemist during the Sui and Tang Dynasties in China, and it has been 1000 years.

The study of gunpowder began with the ancient Taoist alchemy. The ancients refined Dan medicine to live forever. The purpose and motive of alchemy are advanced, but its experimental method still has some advantages, which eventually led to the invention of gunpowder.