2.0 Unit 2 Overview: Networks of Exchange
Welcome to the second unit of AP World History! This unit covers the same time period as Unit 1 (1200-1450). However, where unit 1 discussed the political structures in the world during this time, this unit, called “Networks of Exchange,” discusses the major worldwide economic changes. The increase in global trade networks is what will mark the post-classical era. This unit covers the ways that these trade networks facilitated economic and cultural exchanges and how trade changed between the classical and post-classical eras. The curriculum focuses on the Silk Roads, Indian Ocean Trade Routes, and Trans-Saharan Trade Routes, along with their effects on culture, the environment, technology, and the global economy.
Contextualizing The Unit
Before we look at the new changes in global trade in the period 1200-1450, let’s take a quick look at the big picture. Major trade routes grew during the classical period between 600 BCE and 600 CE. These included the Silk Roads and Indian Ocean Routes. These trade routes connected empires such as the Roman Empire, Han China, and the Mauryan and Gupta Empires in India, which allowed goods and ideas to transfer between empires. After the fall of Rome and Han China, the post-classical era began and ushered in a new era of expanded trade. As empires like the Byzantine Empire, Abbasid Caliphate, and the Majapahit grew, so did trade. This unit can be contextualized by understanding the basic idea that during the post-classical era, new human connections began, and the existing connections expanded. Take a look at these two maps from the classical era and post-classical era showing this change:
Effects of Growth in Trade
Economic Impacts
As an economic activity, the expansion of trade fundamentally changed the way the global economy functioned. More than ever, empires relied on trade to grow and consolidate power along with spreading influence. In China, people began to use new financial tools, such as paper money, as a medium of exchange for goods. Many empires grew explicitly because of the increase in trade, such as the trade empires along the Swahili Coast in Africa or Southeast Asian empires. New technology such as the saddle and new boats such as Islamic dhows and Chinese junks also sped up the rate at which trade continues. Groups of traders known as caravans increased the supply of trade goods and trade cities such as Timbuktu and Samarkand grew as trade centers. These economic impacts will continue into future units as the growth of trade becomes a global trend that doesn’t stop. This time period marks the beginning of expanded connections between humans which through the years does not end. We’ll see the growth of global trade and then globalization in the 20th century, which all starts with the economic growth during the post-classical period.
Cultural Impacts
Trade is not just about goods but also about ideas. As travelers moved from empire to empire, they spread cultural ideas such as religion. During this time period, trade was the primary way religions such as Islam, Hinduism, and Buddhism spread. The main way this occurred was through proselytization: attempts at active conversion. Some religions, such as Judaism, do not proselytize, but many like Islam and Christianity do. Trade also facilitated the spread of technology from empires, such as the Abbasid Caliphate and Song China, renowned for their scientific and mathematical knowledge, to other areas of the world, notably Europe. The Abbasids invented trade technologies such as the astrolabe that allowed for navigation. The Chinese invented the compass and, most importantly, gunpowder, which will greatly impact militaries in the following periods. You’ll also learn about interregional travelers such as Ibn Battuta and Marco Polo and the significance of their journeys.
Environmental Impacts
The environmental impacts of growing trade break down into two major categories: food and disease. Food was essential, and therefore one of the primary trade goods during this time. Specifically, bananas and citrus fruits are notable examples of foods that traveled west. Another food, Champa rice, is crucial to agricultural and population growth in China. Similarly, disease traveled along trade routes across the world. The best example of this is the Bubonic Plague, also known as the Black Death, which killed upwards of a third of the population of Europe, but originated in rats in the Yuan Dynasty. History recognizes the Bubonic Plague not only as an important event to the world’s population at that time but leading to what would become the rise of Europe near the end of this time period. Humans also used animals like camels to aid in trade along routes, especially in Africa.
Conclusion
Unit 2 is incredibly useful in AP World, explaining many political, economic, and social changes that accompany the time period between 1200 and 1450. Trade is essential to everything in AP World, which is especially true for period 1. There’s a common phrase in AP World: “when in doubt, trade.” Remember this because trade is usually an answer to pretty much any question! In period 1, the cause and/or context for most developments often links to the growth in trade that we see in unit 2. Good luck!
Professor Says He Found Equation That Makes Time Travel Possible
In 1895, author H.G. Wells captured the imagination of his readers by having his protagonist, a Victorian English scientist, bravely climb into a time machine and set off into uncharted territory. Wells is credited with coining the phrase “time travel,” although the idea of exiting one timeframe and entering into another has intrigued humankind far into the misty past.
To this day, many still feel that it’s entirely possible to traverse time if we could only discover how. But now, the time may have finally come: A prominent astrophysicist recently claimed that he now has the mathematics to make time travel a reality.
Here we are, a hundred years since the introduction of Einstein’s Theory of General Relativity, and science is closing in on time travel. Astrophysicist Ron Mallett, professor emeritus of physics, has been studying time travel long before embarking on his professional career.
Now in his 70s, he has at long last — at least theoretically — discovered a way to travel into the past. Putting his mathematical equation to work, he has come up with a prototype device with functionality that seems plausible, although he has yet to wow his contemporaries who are standing in the wings to see what comes next.
Ingenuity Sparked by Tragedy
Although Mallett’s work is tantalizing from a scientific perspective, his yearning to rekindle the past has been driven by a strong desire to reunite with his father who died from a heart attack when Mallett was only 10 years old. Regarding his father’s passing, Mallett said , “For me, the sun rose and set on him, he was just the center of things…Even today, after all of these years, there’s still an unreality about it for me.” This tragic event changed the course of his life, and maybe even the lives of humankind, especially if his invention bears fruit.
Shortly after his father’s death, the young Mallett came across a copy of H.G. Well’s novel The Time Machine , and after he read the book he was imbued with hope and a desire to conquer time through science.
Twisting Natural Forces of Light and Space
In 2015, Dr. Mallett said that “time travel could, in fact, become a reality, though perhaps on a very limited scale…My breakthrough was to realize that if gravity can alter time, and light can create gravity, then light can alter time. This leads to the possibility of a time machine based on laser light.”
Mallett’s prototype is based on his research of a circulating laser light device that’s capable of twisting space and time, enabling travel into the past or future. His success hinges on Einstein’s theory of relativity, as well as Einstein’s general theory of relativity. Einstein showed that time can be altered by speed. An example of this would be realized when traveling through space in a rocket that’s almost as fast as the speed of light. Time would considerably slow down in space, though while on Earth, many more years would have passed. Therefore, the faster you travel, the more time changes. This has much to do with gravity, as well, because time slows down when gravity becomes stronger.
The force of gravity, according to Einstein’s general theory of relativity is the bending of space by a massive object. “If you can bend space, there’s a possibility of you twisting space,” said Mallett. In the simplest terms, whatever affects space also affects time. The professor’s theory proposes that by twisting time into a loop it should be possible to travel from the future into the past, and then back to the future.
Mallett Sees the Light
We can add yet another factor into Mallett’s theory that time travel is possible: Light can also affect time by using a ring laser. In a CNN interview, he said that a certain type of gravitational field produced by a ring laser could possibly comprise a time machine based on a circulating beam of light. “Eventually a circulating beam of laser lights could act as a sort of a time machine and cause a twisting of time that would allow you to go back into the past,” he says.
While Ron Mallett has come up with the mathematics to back up his theory of time travel, he does admit to one huge problem. While it may be possible to send information back in time, (as of this writing) it’s only theoretically possible to send it back to the point at which the time machine is turned on.
Doubtlessly, a great deal of science fiction eventually manifests into reality — including travel through space, walking on the moon and landing on Mars, laser beams that cut through metal like a knife through butter, and so much more. Perhaps Ron Mallett — an astrophysicist with a lifelong dream of traveling through time — has come up with an equation that is sure to stand the test of time.
Professor Says He Found Equation That Makes Time Travel Possible
In 1895, author H.G. Wells captured the imagination of his readers by having his protagonist, a Victorian English scientist, bravely climb into a time machine and set off into uncharted territory. Wells is credited with coining the phrase “time travel,” although the idea of exiting one timeframe and entering into another has intrigued humankind far into the misty past.
To this day, many still feel that it’s entirely possible to traverse time if we could only discover how. But now, the time may have finally come: A prominent astrophysicist recently claimed that he now has the mathematics to make time travel a reality.
Here we are, a hundred years since the introduction of Einstein’s Theory of General Relativity, and science is closing in on time travel. Astrophysicist Ron Mallett, professor emeritus of physics, has been studying time travel long before embarking on his professional career.
Now in his 70s, he has at long last — at least theoretically — discovered a way to travel into the past. Putting his mathematical equation to work, he has come up with a prototype device with functionality that seems plausible, although he has yet to wow his contemporaries who are standing in the wings to see what comes next.
Ingenuity Sparked by Tragedy
Although Mallett’s work is tantalizing from a scientific perspective, his yearning to rekindle the past has been driven by a strong desire to reunite with his father who died from a heart attack when Mallett was only 10 years old. Regarding his father’s passing, Mallett said , “For me, the sun rose and set on him, he was just the center of things…Even today, after all of these years, there’s still an unreality about it for me.” This tragic event changed the course of his life, and maybe even the lives of humankind, especially if his invention bears fruit.
Shortly after his father’s death, the young Mallett came across a copy of H.G. Well’s novel The Time Machine , and after he read the book he was imbued with hope and a desire to conquer time through science.
Twisting Natural Forces of Light and Space
In 2015, Dr. Mallett said that “time travel could, in fact, become a reality, though perhaps on a very limited scale…My breakthrough was to realize that if gravity can alter time, and light can create gravity, then light can alter time. This leads to the possibility of a time machine based on laser light.”
Mallett’s prototype is based on his research of a circulating laser light device that’s capable of twisting space and time, enabling travel into the past or future. His success hinges on Einstein’s theory of relativity, as well as Einstein’s general theory of relativity. Einstein showed that time can be altered by speed. An example of this would be realized when traveling through space in a rocket that’s almost as fast as the speed of light. Time would considerably slow down in space, though while on Earth, many more years would have passed. Therefore, the faster you travel, the more time changes. This has much to do with gravity, as well, because time slows down when gravity becomes stronger.
The force of gravity, according to Einstein’s general theory of relativity is the bending of space by a massive object. “If you can bend space, there’s a possibility of you twisting space,” said Mallett. In the simplest terms, whatever affects space also affects time. The professor’s theory proposes that by twisting time into a loop it should be possible to travel from the future into the past, and then back to the future.
Mallett Sees the Light
We can add yet another factor into Mallett’s theory that time travel is possible: Light can also affect time by using a ring laser. In a CNN interview, he said that a certain type of gravitational field produced by a ring laser could possibly comprise a time machine based on a circulating beam of light. “Eventually a circulating beam of laser lights could act as a sort of a time machine and cause a twisting of time that would allow you to go back into the past,” he says.
While Ron Mallett has come up with the mathematics to back up his theory of time travel, he does admit to one huge problem. While it may be possible to send information back in time, (as of this writing) it’s only theoretically possible to send it back to the point at which the time machine is turned on.
Doubtlessly, a great deal of science fiction eventually manifests into reality — including travel through space, walking on the moon and landing on Mars, laser beams that cut through metal like a knife through butter, and so much more. Perhaps Ron Mallett — an astrophysicist with a lifelong dream of traveling through time — has come up with an equation that is sure to stand the test of time.
Source https://library.fiveable.me/ap-world/unit-2/unit-2-overview-networks-exchange/study-guide/mxYpnxvHa7XfSTjQDZeZ
Source https://www.gaia.com/article/professor-says-he-found-equation-that-makes-time-travel-possible
Source https://www.gaia.com/article/professor-says-he-found-equation-that-makes-time-travel-possible
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