Iron is one of the most important elements on earth. It plays a vital role in the development of the civilization, and it is also important for the transportation of oxygen for most organism.
The changing gravity on earth.
Iron composes approximately 35% of the total mass of the earth, and removing iron will make the earth lighter, and the gravity will be smaller (We have to hypothesize that the size, the formation and the orbit of the earth remain unchanged, or the earth will be no longer livable for carbon-based life.), approximately 65% when comparing to modern earth.
Surprisingly, nothing will change besides the gravity. The length of a day or a year doesn’t change much. Still, a smaller gravity will lead to various changes among plants, animals and our civilization, which we are going to discuss about them later.
- The collapsing ecosystem.
I would better describe the ecosystem using “reforming” or “changing” instead of the word “collapsing”, that the ecosystem would be greatly changed but not destroyed. Most vertebrates transport oxygen through their body, and if iron disappears, organisms have to develop another system during the evolution to survive. A perfect substitute for iron is copper, that cuprous ions are available in carrying oxygen. The nature provided us with the perfect example: octopus and snails are powered by copper. They have transparent venous blood and blue arterial blood, and if their blood is exposed in the air, it would turn blue in seconds. Therefore, human will look alike the creatures in the film Avatar, having blue skins, blue eyes and blue bodies.
The only difference which is likely to change the society is that copper blood is not capable of heat, and it will be hard for people to live around the equator before the invention of air conditioner, and the equator will be covered by plants and inferior organisms like insects.
Another difference among plants and animals is that they will be larger. A lower gravity means that without changing the structures of the xylem of trees or the bones of animals, they could support more mass. Still, this also will not affect the world too much since if everything is scaled up to equal proportions, their relationship is not likely to change.
- The difference in civilization.
There were differences between eastern and western civilization, and we have to discuss them separately. What’s more, to understand the change, we have to know about the metal activity sequence. This sequence determines the sequence that human utilize different elements.
Eastern civilization
Iron was the second element to be applied to mass production, in around 500BC. Chinese people gave up the heavy and relatively undurable bronze and began to apply iron into agriculture (cultivation) and wars (weapons). This greatly improved the productivity, providing excessive supplies for people to fight, and potentially speed up the Warring State in China.
However, there was only little record for Chinese people to utilize elements more active than iron. People utilized steel, mingling carbon in iron, but iron is also needed to manufacture steel. Therefore, if removing iron from the universe, Chinese people were likely to live in the bronze age until 1840, when the western civilization invaded their country and at the same time, brought the technologies in using other metallic elements.
Thus, China would, unsurprisingly, remain in the Bronze Age. It is difficult to estimate how more efficient is iron than bronze, but we could discuss the change in agriculture, and war based on the discussion.
Agriculture and Food:
Bronze tools were not durable and efficient when comparing to the iron counterparts, therefore they could only feed a limited population. Farmers had to frequently replace their tools to cultivate crops, and since bronze is slightly heavier than iron, it was more tiring and this would further limit the efficiency of cultivation. Copper reserves were relatively small compared to iron, but given the lower temperature requirements for copper smelting, there may not be a significant cost difference between the two.
Based on the previous discussion, the population and proficiency of Eastern civilization before 1840 (especially for China) would be limited to that in the end of Xizhou (a period in Chinese history when Zhou lost its ability to control its barons), when iron was not applied to agriculture and war. Although the southern part of the country would no longer be suitable for people to grow crops, the center of economy was still in the northern part of the country, and therefore would not affect the accuracy of the estimation.
The population of Xizhou was about 20 million, but considering the absent of iron, the would be some uncultured land, the population would still experience a smooth growth and finally settled at about 30 million people. Most of the population would settle in the north of Yangtze River since copper blood made people maladjust the hot weather in the south.
People’s eating habits also changed with the change of their resident: rice cultivation would no longer be a reasonable option because of the reduction in the amount of arable land and the lack of adaptation to hot weather. Wheaten food including bread and mantou (traditional Chinese paste made from wheat) would be the most popular dish among Chinese people.
War (and probably politic):
The disappearing iron would directly shape the pattern of war and eventually changed the development of history. War was a very time-consuming event in times of low productivity. Wars between countries usually lasted for as long as a hundred years, as can be seen through the wars of the Spring and Autumn Period and Warring State periods. Hundreds of bannermen fought for about five hundred years before they were finally reunited and continued the course of history. Therefore, it was reasonable to assume that the change of dynasties would also be more time consuming (300 years on average), and this would apparently lag the history of the country behind.
China would be divided for an additional 1000 years (the end of the Qin dynasty would take an additional 200 years, the Three Kingdoms period an additional 200 years, the Northern and Southern dynasties an additional 300 years, and the Five Dynasties and Ten Kingdoms period an additional 300 years). We could therefore hypothesized that around the time of the Song Dynasty, that the first Opium War would break out, opening China towards the whole world.
The Song dynasty was open to new foreign technologies, as well as the smelting of aluminum (which I’ll mention later). There was no doubt that China will become a capitalist, monarchy country, just like Spanish or Britain in the 20th and 21st century.
Western Civilization
It is easier to speculate what’s happening on western history with the absent of iron. The lack of iron did not affect European civilization much, as a significant part of the Western economy was not supported by farming. Trade and colonization supported the population of Europe to a considerable extent. Therefore, Europe’s productivity up to the Renaissance would not have changed much, and a reasonable estimation of population among Europe before the first industrial revolution was about 50 million to 60 million.
I would describe a world without iron as a world built up by aluminum, magnesium and titanium. With the absent of iron, the center of the industrial revolution would also change. People would build furnaces on a large scale, except that these furnaces would be used to melt metals like copper, aluminum, and magnesium instead of iron. I’m sure this wasn’t terribly difficult for 18th century humans. Still, steam engines would be polularized, changing the way people travelled; in addition, more changes would revolve around aluminum. With only a little bit more active than iron, people would try to separate them with technologies from the industrial revolution.
Technology developed, except that everything that should have been iron was replaced by aluminum or its alloys. The widespread use of aluminum may even benefit our civilization: oxidation of aluminum results in the formation of a dense aluminum trioxide surface, which prevents further oxidation of the aluminum. This also undoubtedly increases the durability of aluminum products. Only that they will darken over time.
But in any case, an aluminum boat still sounds strange; after all, aluminum is not as strong as iron alloys.