Posted in Science & Nature

Metal

Next to the discovery of fire and the wheel, the discovery of metals and the mastery of metalworking was arguably one of the most important advances for prehistoric humanity. Metal was far superior to rock, clay, wood or any other natural resource known to man in terms of strength and sharpness. Because of these properties, metal soon became a valuable commodity. It can be seen how much impact metal had on humanity’s history, considering that the stages of human prehistory were named after the type of metal (or lack thereof) that was mastered then: Stone Age, Bronze Age and Iron Age.

The discovery of metal came in two ways.

One was through mining, where prehistoric people discovered that shiny, hard objects were buried in the ground. They later discovered that with enough heat, they could melt the metal out of ores (copper and tin were the first metals to be gathered this way) and mould them into any shape. After smelting technologies developed, our ancestors found that mixing copper and tin produced bronze – a much stiffer and more durable metal than either of its components. A mixture of metals is called an alloy. This was the start of the Bronze Age. Bronze was extremely useful and people quickly came up with innovative ways of using it, such as farming equipment and weapons.

Some other metals used during this age were: gold, silver, lead and mercury. It is likely that gold was one of the earliest metals used as it comes in pure nuggets and is easily workable thanks to its chemistry. However, given that gold is rather soft and was treated more as jewellery than a practical metal, it was not used as much to advance technology.

The second way mankind came upon metals was in the form of “gifts from the gods”. A prime example is iron. Although the Iron Age began around 1200BC at the earliest, there are iron objects (mainly jewelleries) that have been dated back to 5000BC. How could this be? This was before mankind had the technology to smelt iron ores (which is more difficult and needs much higher temperatures than copper or tin ores), so the iron could not have been gathered through mining. The answer to this conundrum lies in meteorites. About 6% of meteorites contain iron and nickel, which prehistoric civilisations may have stumbled onto and taken the shiny pieces back to their tribe. The people would have considered the gathered iron a “gift from the gods”, as it had crashed down from the “heavens”. Because of this reason, iron was considered more valuable than gold or silver and was frequently used for jewellery. This is reflected in Arthur C. Clarke’s science fiction short story, The Songs of Distant Earth, where sentient sea scorpions hoard metal objects stolen from the humans and wear it proudly as a badge of honour.

The history of iron and how it was believed to be a gift from the heavens relates to a common superstition of how finding a penny (or any coin) represents good luck. As “metal” (mainly iron) was considered a holy gift bestowed unto mankind, finding a piece of metal was believed to be a blessing and some form of protection against evil. This is also represented in various traditions such as hanging horseshoes over doorways and wearing charm bracelets with metal on it.

Although it sounds like a silly superstition, it clearly shows how metals have been an integral part of the development of civilisation.

Posted in Science & Nature

History Of The Earth

The Earth has been around for a good 4.6 billion years. Let us compress the long time from the Earth’s birth to today (2012) into one year to put everything in perspective.

The Earth’s history starts on January 1, 00:00:00. The Earth is a hard sphere, barren as any other planet. Incessant wind and rain erode away the barren mountains and tectonic forces create new ones. Nothing much happens for the next three months. Then, around the start of April, life begins in the form of bacteria. Over the course of the next few months, the bacteria divide and mutate, slowly forming new life forms that are multicellular. However, all life on Earth are still in the oceans.

Life on land only starts in the end of November, when plants begin to settle on land. Plants expertly take the abundant carbon dioxide in the atmosphere and convert it into oxygen. By early December, the oceans are teeming with fish, some of which adapt to living on land by developing lungs. These become the first amphibians. Insects also populate the land and become one of the most diverse types of life.

In December 12, reptiles evolve and the land is ruled by dinosaurs, but only for 9 days until they are wiped off the face of the Earth by a meteorite on December 20. Mammals quickly take the niche left by dinosaurs, populating the entire world. Even at this late time, there are no signs of humans.

December 31, humans have still not arrived on Earth. They only appear around 8pm, where the first hominids venture on to the plains of Africa. At 10pm, the Ice Age begins and the Earth is covered by a thick white sheet of ice. The ice comes and goes three more times. At 11:59pm, human civilisation begins as cities begin to rise. 22 seconds before the end of the year, the Egyptians build their pyramids. More monuments arise within seconds. At 11:59:47pm, Jesus teaches the people to love one another, until he is killed a millisecond later. In the last second of the year (about 150 years), humanity: has two major world wars, take to the skies, create the nuclear bomb that can wipe out all life on Earth and even step foot on the Moon.

We may like to think that we have made a significant impact in the history of the Earth, but we have only existed for an infinitesimally small fraction of the history. We are but a dot on the grand scheme of natural history.

Posted in Science & Nature

Mitochondrial Eve

We were all born from our parents. Our parents were all born from our grandparents. Everyone has a family tree and a root. If so, is it possible to find the beginning of mankind – our true “root”?

Our cells have an organelle (a part of the cell) called mitochondria. Mitochondria act as the cell’s engine and allow the cell to generate energy through respiration. An interesting fact about them is that they are not originally “ours”. About 1.5 billion years ago, there was an event where a prokaryote (cells without a nucleus, like a bacteria) invaded (or was eaten by) a eukaryote (cells with nuclei, like our cells). The prokaryote and the cell began a symbiosis and the prokaryote became a part of the cell.

Due to the external origin of mitochondria, they have a different genome to us. This is called mitochondrial DNA, shortened to mtDNA, which allows mitochondria to divide and synthesise proteins without the help of the host cell. It used to be a completely independent organism, but it has lost some of its functions to the cell.

mtDNA is inherited in a different way to normal DNA. Normally we receive half of our mother’s and half of our father’s genes, but we only inherit our mother’s mtDNA. This is because sperm keeps mitochondria in the tail which is lost during fertilisation, meaning our father’s mitochondria cannot be inherited. The only way to gain mitochondria is from those in the cytoplasm (the material that fills cells) of our mother’s egg. This is known as maternal inheritance.

Using this information, scientists compared a large sample of people’s mtDNA to turn back the clock. Knowing that a child and its mother share the same mtDNA and the mother and grandmother share the same mtDNA, we can analyse mtDNA to find the origin of mankind, or our first common female ancestor – also called Mitochondrial Eve.

Mitochondrial Eve is estimated to have lived 200,000 years ago in Africa, thus she is also known as African Eve. Her mtDNA is an ancient heirloom passed along generation after generation to us, as evidence of evolution. Every living person on the face of the Earth is a descendant of her. So in some ways, it could be said that we truly are one big family.

Posted in History & Literature

Economics

Early economists believed that a growing economy was a sound economy. Growth was used as a ruler to measure the health of the nation, corporations, markets and all social constructs. But it is impossible to always move forwards. In reality, a growing economy goes through cycles of growth and depression, showing a waveform on a graph. An economy without depression forms a bubble that will burst in the future, bringing a greater economic crisis. Simply put, “sound economic growth” is only achieved by the concept of two steps forward, one step back.

We have reached a point where we cannot grow despite having the potential to. Perhaps there will be no further economic growth. Only a continuous state of balancing powers will remain. A sound society, a sound nation, a sound worker… those are things that do not damage the surrounding environment or become damaged by it. We should no longer try to conquer nature and space. Instead, we must integrate with nature and the universe. Our only slogan is harmony. There should be an entwining of the external and internal world and we must live with modesty not violence. Human beings will become one with the universe. Mankind will meet an age of stability where we do not strive for the future or reach for faraway goals. Mankind will live a simple life in the present. Only then will mankind finally attain happiness.

1 + 1 = 3

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(from The Encyclopaedia of Relative and Absolute Knowledge by Bernard Werber)