Who invented the wheel?
November 2016 - Because people in Central Asia often talked to people from West Asia, Europe, and China, they were able to bring together inventions from all of these places and put them to new uses, or combine them in new ways. But people in Central Asia also invented a lot of new things on their own.
About 4000 BC, people in Central Asia domesticated the horse and put wheels on sledges to make carts for the horses to pull, about 3700 BC. The wheel reduced friction and made it possible for the horses to pull heavier loads. People took the idea of wheels from early pottery wheels in West Asia. The first wheels were made of solid wood, and may have seemed more obvious in the north where there were more trees, and on the flat grasslands where a cart could move more easily. Soon people in West Asia and China began to use wheeled carts too.
When people in Central Asia began to ride horses, about 2500 BC, they also invented the composite bow, a kind of bow and arrow that was shorter, so you could shoot it while you were riding your horse. Around the same time, they also domesticated camels to ride.
By 2000 BC, the people of Central Asia had improved on the wheel by also inventing the spoked wheel. Wheels with spokes were stronger and lighter and used less wood than solid wheels. Again, this new invention spread quickly south to China and to the Indo-Europeans, and then with them to Greece and Italy and even further south to Egypt, West Asia, and India.
Around 1500 BC, people in Central Asia - possibly the Sogdians - started to burn coal to keep their houses warm, and probably as a way to melt copper and tin together into bronze, too. Tin was common in what is now Afghanistan, and so it was a good center for metal-working.
Sometime around 1000 BC, Central Asian archers invented the recurve bow, which was shaped like a W, and could shoot further with a shorter bow, which was also easier to use while you were riding your horse. Then around 200 BC, people in Central Asia invented saddles and stirrups for their horse equipment, making it much easier to ride and fight from horses. Around 800 AD, Central Asian farmers may also have invented the horse collar, which made it possible to use horses to plow fields.
With the creation of the Silk Road connecting Central Asian traders with China and West Asia (and Europe), Central Asians became much richer than before, and they could afford to pay for great libraries and universities. The scholars there invented many new things. The most important was crucible steel, a better kind of steel, harder and more flexible. They also made many medical advances. As early as the 400s BC, a doctor did surgery on a man's throat at Subashi in what is now western China and stitched the wound shut with horsehair. A thousand years later, Ibn Sina understood that diseases like smallpox were contagious, and al Razi showed that fever was not a sickness, but the body's reaction to sickness. The Armenian doctor Mkhitar Heratsi advocated quarantine to keep diseases from spreading, and discouraged bleeding patients. Like Maimonides at the same time, Mkhitar thought clean air, good food, and exercise were the foundations of health. Central Asians also began manufacturing glass at Kuva (Uzbekistan).
Although many Central Asian inventions have to do with horses, by the year 1000 AD Central Asian people were also using boats, and Russian boat-builders invented an early ice-breaker boat, the koch. The koch had a rounded body under the water so it wouldn't be wrecked if it hit ice, and also had ice-resistant wood planking at the waterline.
Ulugh Beg's observatory (thanks to Michel Benoist)
In the later Middle Ages, under Mongol rule, Central Asian scientists did a lot of good astronomical observations. In 1256 AD, Nasir al-Tusi convinced Hulegu Khan (a grandson of Genghis Khan) to build him a big observatory in Azerbaijan, where al-Tusi first saw that the Milky Way was made up of thousands of stars. In 1420, the Mongol astronomer Ulugh Beg, a grandson of Timur, built a great astronomical observatory in Samarkand, in order to take more accurate measurements of the movements of the planets and stars. He got more accurate measurements by building a really huge sextant with a radius of about 36 meters. With this sextant, Ulugh Beg made a list of 994 visible stars, more than anyone else had ever seen, and with more precise locations than ever before. Ulugh Beg was also able to figure out how long it took the earth to go around the sun, with an accuracy to within 58 seconds, and he measured the tilt of the Earth's axis at 23.52 degrees, which was more accurate than anybody else had ever done. To make these calculations, Ulugh Beg also calculated trigonometric sine and tangent tables accurate to eight decimal places.