The Secrets of the Terracotta Warriors

• In 221 BC, craftsmen in China began creating an 8,000-strong army of clay warriors, a feat that had never been attempted before.

• The Terracotta Warriors were discovered in 1974 by farmers digging a well near the Chinese city of Xi'an, and archaeologists uncovered three pits containing the life-size clay soldiers.

• The warriors were created for the tomb of China's first emperor, Qin Shi Huang, who unified seven warring kingdoms into a single empire.

• The Terracotta Warriors were made to be life-size, nearly two meters tall, and weighed up to 300 kilograms each, making them a massive achievement.

• The creation of the warriors required years of work, endless ingenuity, and a massive labor force.

• Facial recognition expert Glenn Cameron analyzed the faces of about 100 Terracotta Warriors using Neoface software, concluding that each warrior has a unique face, with no duplicates.

• The warriors' faces show a range of emotions, from sadness to frowning, and their eyebrows and noses are distinct.

• Archaeologists believe that the warriors were not mass-produced using molds, but rather made individually using a clay coiling technique.

• The coiling technique involved pounding the clay until it became soft, rolling it into strips, and then coiling the strips upward to create the body.

• The ancient craftsmen used a simple method to create the statues, but it was an incredibly laborious process.

• Making 8,000 statues in just over 10 years would have required a massive labor force, with experts estimating that 87 master craftsmen and nearly 1,000 workers were involved.

• The ancient warrior makers faced a challenge in maintaining a consistent temperature in their workshops, as extreme cold and heat would ruin the clay statues.

• Replica maker Chiang Bin Rou believes that the ancient craftsmen may have worked in cave houses, which would have provided a stable temperature year-round.

• The Terracotta Warriors were originally painted in bright colors, but the pigments have largely faded over time.

• Conservation experts have been working to restore the colors, but it's a challenging task, as the pigments can easily fall off after excavation.

• The ancient Chinese used a syrup-like substance called lacquer to coat the warriors, which was a highly valued and expensive material at the time.

• Lacquer was used to protect the warriors from decay and provided a glossy black finish, making it a highly sought-after material in ancient China.- The lacquer trees used to create the lacquer for the Terracotta Warriors are six years old, and only produce sap from June to September when the weather is warm.

• It's estimated that the sap of 25 trees would be needed to lacquer just one Terracotta Warrior, and as many as 200,000 trees to finish all of them.
• Lacquer harvesters can only take about 10 grams of sap from each tree, just enough to fill an egg cup, because taking too much can kill the tree.
• The lacquer trees are related to poison ivy and poison sumac, and touching or breathing in the fumes can cause a severe rash.
• The lacquer layer on the Terracotta Warriors is embedded in the wet soil and begins to shrink and separate from the clay as it dries out, taking the paint with it.
• Researchers are trying to find a way to preserve the lacquer layers by replacing its water with something that won't evaporate, such as a plastic coating.
• One group of German scientists has tried coating warrior fragments with a plastic used to seal underground water pipes and then bombarding it with electron beams to bond the plastic to the lacquer.
• Archaeologists are hoping to find a simple and cheap method to preserve the lacquer layers during excavation.
• Visitors to a Munich museum can see replicas of the Terracotta Warriors painted as they believed they looked on the day they were finished, over 2,000 years ago.
• The original colors of the Terracotta Warriors were faded and fragmented, but researchers have made an unexpected discovery - one of the ancient colors wasn't like all the rest, called Chinese Purple.
• Chinese Purple is one of only two entirely man-made colors produced anywhere in the world before the birth of Jesus, the other being Egyptian Blue.
• Scientists at Stanford University have used the world's most powerful X-ray machine to analyze Chinese Purple and found that it shares the same ingredients as Egyptian Blue, but with two exceptions: Chinese Purple contains barium and lead oxide.
• The discovery suggests that the Chinese invented Chinese Purple independently from the Egyptians, without any technology transfer.
• The team believes that Chinese Purple was invented by alchemists searching for a formula for making jade, which was believed to make them immortal.
• Chinese Purple and Chinese Glass had nearly identical compositions, and their apparent connection doesn't end there - both disappeared at the same time, around 250 AD.
• Scientists at the National High Magnetic Field Laboratory have discovered that the Terracotta Warriors' purple paint is much more than just a beautiful color, it has unique properties that could make a better world.
• The 45 T Hybrid magnet has revealed that Chinese Purple becomes a single magnetic wave when cooled down to hundreds of degrees below zero, and separates into individual two-dimensional planes when cooled further.
• Studying shifts from three to two dimensions could help make better superconductors, leading to more efficient magnetic trains, lower electricity bills, and faster computers.