Posted in Science & Nature

The Closest Planet

Which planet is closest to Earth? If we look at a typical model of the Solar System with each planet neatly lined up, we can see that Venus approaches Earth closer than any other planet. However, this is only one interpretation of the question.

Technically, Venus is the planet that comes closest to Earth. However, as they do not orbit in synchrony, this approximation happens about once a year. At other times, Venus will orbit away from Earth and can go on the other side of the Sun, making the distance between Earth and Venus vast. In those times, Mars may seem like the next obvious choice to be closest to Earth.

But then again, Mars has the same issue where it and Earth are often on opposite sides of the Sun. Because of the nature of circular orbits, the distances between the planets swing and fluctuate, meaning that the real question should be:

Which planet is closest to the Earth most of the time on average?

The answer to this question happens to be Mercury. If we look at a “top-down” model of the Solar System, we can see that Mercury – being closest to the Sun – orbits rapidly around the Sun and often lies between Earth and the two other planets, Venus and Mars. If we plot the distance between each of these three planets and Earth, we can see that on average, Mercury is closer to Earth because the distance fluctuates less.

Interestingly, if we take this question further, we find that Mercury is also Mars and Venus’ closest neighbour on average. This is a property of the Solar System being formed of concentric circles, meaning that Mercury’s smallest orbit makes it average a closer distance to all of these planets.

Fascinatingly, if we go even further than that, we find that the same pattern holds for every other planet in the Solar System, despite the vast distance between Mars and Jupiter due to the Asteroid Belt. Even Pluto (not formally a planet anymore) with its massive elliptical orbit has Mercury as its closest neighbour on average compared to the other planets, due to the unique property of concentric circles.

No matter the distance, if you are orbiting the Sun, Mercury is the closest planet to you.

This video from CGP Grey explains it in a concise and informative way, complete with clean diagrams and animations!
Posted in Science & Nature

Around The World

Imagine, if you will, a very long piece of ropethat loops around the Earth, fitting it tightly around the equator like a belt. If you wanted to raise this rope off the surface by one metre all around, how much more rope will you need?

The length of rope is the same as the circumference of the Earth which is 40,075km (24,901 miles). Ergo, it is easy to think that you would need kilometres of rope to extend it enough to float a metre off the Earth’s surface. However, in reality you need a mere 6.28m of extra rope to achieve this.

The reason is extremely simple, mathematically speaking. The circumference of any given circle is given by the equation 2πr, where r is the radius of the circle. Therefore, if you increase r by 1 unit (e.g. 1m), then the circumference increases by 2π x 1 = 2π = 6.28. No matter how large the circle may be, this rule does not change.

(This is a famous maths riddle, but here’s a much more interesting application of the concept in this What If? article. God I love that blog!

Posted in Science & Nature

Intelligent Life

One of the great questions in science is “could intelligent life develop on planets other than Earth?”. Even the general populace has heard of programmes such as SETI (Search for Extraterrestrial Intelligent Life) and mathematical models such as the Drake equation that attempt to predict the possibility of extraterrestrial intelligent civilisations. But an equally intriguing question we seem to neglect is: “could intelligent life develop on Earth?”.

The definition of “intelligent life” is hugely varying, but nonetheless attempts have been made to compare our intelligence level to other animals. From the pool of research throughout the decades, the most “intelligent” non-human animals appear to be chimpanzees, bonobos, great apes, dolphins, elephants, certain parrots, ravens and rats. There is much research on the intelligence of cephalopods (e.g. the octopus) that has shown promise. If we were to shift the focus from individual intelligence, we could also consider “civilised” animals such as ants, as they are capable of building vast cities with intricate societies. All of this shows that intelligence is not exclusive to our species. We have simply walked down the path of evolution where the trait of ever-increasing intelligence, knowledge and wisdom have allowed us to adapt to and survive our environment. Ergo, it is fair to consider the possibility that other animals are walking a similar path that may lead to the making of a species with intelligence comparable to us.

However, this only raises the theoretical possibility of intelligent life. What is the realistic, practical possibility of intelligent life developing on Earth in the near future? Put another way, could intelligent life develop in the presence of a higher intelligent life (e.g. humans)? The road that brought us to throne of “the most intelligent species on Earth” was not an easy one. We are but one of many other hominid (human-like) species that evolution produced while tinkering with the concept. For example, there was a time when we (Homo sapiens) shared the Earth with other intelligent hominids such as the Neanderthals. The Neanderthals are commonly pictured as simple, knuckle-dragging apes but in reality they were just as intelligent as Homo sapiens during that time. They had a culture similar to our own, developed stone tools just as complex and even made cave paintings in a display of art. The reason why we are not breaking bad with Neanderthal neighbours now is that (according to one theory) we successfully outcompeted them, driving them to extinction (there is debate whether genocide and cannibalism was involved).

Evolutionarily speaking, it makes sense for an intelligent species to wipe out another species trying to compete with the ecological niche of intelligence. This has been discussed in many works of science fiction, such as Planet of the Apes where the emergence of intelligent apes leads to the destruction of human civilisation. Arthur C. Clarke discussed this as a side plot in his novel The Songs of Distant Earth. Upon discovering a species of sea scorpions that show signs of intelligence such as social hierarchy and metal collecting, the scientists suggest that they should allow it to develop, but ultimately the government decides to eradicate them as soon as they attempt to migrate to land.

Suffice to say, given our track record in history involving the countless times colonists wiped out other civilisations to serve their purpose, there is a good chance that any new intelligent life would immediately be removed by us if they had the misfortune of arising during our time.


Posted in History & Literature

Destroyer Of The Environment

In the history of mankind, who could be considered to have done the most damage to the environment? Although many names may pop up, no one comes close to the destruction that resulted from one man: Thomas Midgley Jr. While working for General Motors in 1916 as a chemist, Midgley discovered that adding iodine to kerosene reduced “knocking” in engines – where pockets of air/fuel mixture explode in the engine. The effects of knocking on engines range from negligible to destructive. However, he found that the iodine only reduced knocking slightly. To improve on this, he tried adding different elements to fuel until he found the magic solution – lead. And so, the leaded petroleum was born.

Leaded petrol was an instant commercial success and it became the most popular choice of fuel. This resulted in cars, buses, planes and almost all motor vehicles pumping out billions of tons of lead into the atmosphere for over seventy years. Unfortunately, lead is a highly toxic metal that causes symptoms such as muscular weakness, pain, nausea, vomiting, fatigue and madness. Lead poisoning is particularly dangerous to children as it can cause irreversible retardation of physical and mental development. Even though the effects of lead poisoning were recognised since the late 19th century (with many workers and even Midgley himself suffering from it), it was only after the 1970s when fuel companies stopped adding lead to their fuel. Thanks to Midgley’s idea of adding lead to petrol, who knows how many children would have suffered a crippling illness due to lead poisoning.

But Midgley’s “accomplishments” did not stop there. In the late 1920s, Midgley decided to tackle the problem of using sulfur dioxide, propane and ammonia as refrigerants (possibly out of guilt over the whole lead fiasco), which were effective but prone to combusting or exploding. Within three days, he developed an alternative – dichlorofluromethane. This amazing gas was inert, non-toxic and did not have the risk of exploding. It was the first of the chlorofluorocarbons (CFC), which was named “freons”. We now know that freons are responsible for destroying the ozone layer.

In 1940, Midgley contracted polio, causing him to be disabled. Poliomyelitis causes paralysis due to the destruction of motor neurons. Being an inventor, Midgley devised a clever device that would help him off the bed using pulleys and strings. Unfortunately, one day the invention twisted in a certain way, leading him to become entangled in the ropes and being killed of strangulation.

Such was the sad life of Thomas Midgley Jr, who environmental historian J. R. McNeill dubbed “[someone who] had more impact on the atmosphere than any other single organism in Earth’s history”.

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 History & Literature


The Taegeukgi is the official flag of the Republic of Korea. It was chosen as the official flag of Joseon by Emperor Gojong in 1883 and has been used as the flag for South Korea since 1948. The Taegeukgi is an extremely symbolic flag that expresses the values and ideals of the Korean people while also containing the sorrow caused by the great tragedies in modern Korean history: the 36 years of Japanese colonisation and the Korean War. Even before Korea was founded, the flag was used in protest of the Japanese Empire and for the independence of Korea (especially in the famous March 1st movement). Much like Hangul (the Korean alphabet), the Taegeukgi, designed by Park Young-hyo and commissioned by Gojong, is a very scientific and mathematical flag. Let us analyse each part of the Taegeukgi.

The Taegeukgi is composed of a red and blue taegeuk symbol (“yin(eum)-yang symbol” is technically a misnomer) on a white background, surrounded by four black trigrams (4괘, sa-gwe). The white background symbolises brilliance and purity and the Korean people’s traditional love for peace. The taegeuk symbol symbolises the harmony of eum (blue) and yang (red), an imagery of the interaction between the two extremes and the natural rule of continuous generation and progress seen in the universe.

The trigrams in each of the four corners is called geun gon ri gam (건곤리감, 乾坤離坎) in order and each trigram symbolises a certain characteristic of everything in the universe.

Geun (three lines) symbolises the sky, spring, metal (geum, 금, 金) and humanity (yin, 인, 仁). Gon (six lines) symbolises the earth, summer, earth (toh, 토, 土) and righteousness (eui, 의, 義). Ri (four lines) symbolises the sun, autumn, fire (hwa, 화, 火) and courtesy (ye, 예, 禮). Gam (five lines) symbolises the moon, winter, water (su, 수, 水) and intelligence (ji, 지, 智). The taegeuk lies in the centre of the four extremes in each each corner to establish an infinite harmony and balance.

As you can see, the taegeuk is far more scientific and deeply philosophical than simpler flags such as those symbolising the Sun God (Japan), the number of states (USA) or a composite of three different flags (UK). It is the ultimate flag that prides the Korean people’s wisdom and advanced culture.

Posted in Psychology & Medicine


Occasionally, there are news stories about a man who eats steel or a girl who likes to eat plastic. Such a condition where the person develops an appetite for a non-food substance is called pica. Pica is more common than one would think. The most common cases are those of dirt, clay and chalk, with the disorder being much more prevalent in children or pregnant women. Although pica is officially a mental disorder (possibly related to OCD), it is possible that it is a neurological mechanism to cure a certain mineral deficiency. For example, patients with coeliac diseases or hookworm infections tend to be iron-deficient and the substances they eat tend to contain iron. It is unclear how the brain knows what “food” to eat to cure a disease, but there are many cases where people subconsciously consume foods that would improve their health. According to a study, between 8% and 65% of people have had a sudden urge for a very strange appetite. However, as substances commonly involved in pica (such as dirt and ice) are solids, they can damage the oesophagus and the digestive tract. Also, they may contain toxic chemicals which can cause poisonings, making pica a potentially dangerous condition.

Posted in Science & Nature

Typical Person

What is the typical look of a human being? The following is a character bio using data of the most common traits and average statistics from the world population.

The typical model of Earth is a 28 year old Han Chinese male called Mohammed Lee. His height is 1.75m, weight 80kg, he has black hair and brown eyes and he is right-handed. He speaks Mandarin Chinese and his religion is Christianity. He works in a factory earning less than USD$12,000. He owns a cellphone but not a bank account. The following is the most typical face constructed using a composite of 190,000 faces of people fitting the above description.

Posted in History & Literature

Elements: Wu Xing Of The East

In ancient China and Korea, there are five, not four, basic elements (Japan also has five but they are slightly different). In the East, these five elements are called “oh hang (오행, 五行)” in Korean and “wu xing” in China. These are (read in Korean): hwa (火, fire), su (水, water), mok (木, wood), geum (金, metal), and toh (土, earth). When you combined with the theory of Yin and Yang, the concept is known as the Yin-Yang and the Five Elements theory (eum yang oh hang sul, 음양오행설). Wu Xing is quite different from the Four Elements of ancient Greece in that it explains the changes in life and the universe rather than being the building blocks of matter (“wu xing” translates to “five ways”). To first understand Wu Xing, one must understand that each element is more of an abstract concept than the actual object. For example, “mok” does not mean wood per se, but rather a symbol for the life force of a growing tree.

There are two relationships between the elements in Wu Xing: Creation (상생, 相生) and Destruction (상극, 相剋). Creation refers to the cyclic principle of what generates what, and Destruction refers to what overcomes and represses what. The Creation and Destruction of Wu Xing are as follows:

  • 목생화(木生火): Wood creates Fire. Wood feeds Fire.
  • 화생토(火生土): Fire creates Earth. Fire makes ash which becomes Earth.
  • 토생금(土生金): Earth creates Metal. Earth bears Metal.
  • 금생수(金生水): Metal creates Water. Metal carries Water.
  • 수생목(水生木): Water creates Wood. Water nourishes Wood.
  • 목극토(木剋土): Wood beats Earth. Wood takes roots in Earth.
  • 토극수(土剋水): Earth beats Water. Earth absorbs Water.
  • 수극화(水剋火): Water beats Fire. Water quenches Fire.
  • 화극금(火剋金): Fire beats Metal.  Fire melts Metal.
  • 금극목(金剋木): Metal beats Wood. Metal chops Wood.

(Image source

Posted in History & Literature

Elements: Four Elements Of The West

Human beings have believed that all matter can be divided into basic elements for a very long time. Although we now know that the basic building block of the universe is atoms, what did ancient people believe matter was made of?

In ancient Greece, the seat of Western culture, it was believed that everything was made from the four elements: earth, fire, water and air. According to Aristotle, every element has a primary and secondary characteristic, with the four characteristics being hot, cold, dry and wet. Air is primarily wet and secondarily hot, fire is primarily hot and secondarily dry, earth is primarily dry and secondarily cold and water is primarily cold and secondarily wet. He also spoke of a fifth element (quintessence) beyond the four elements. The name of the fifth element is aether and it is a pure and heavenly element that cannot be corrupted like the earthly four elements. Furthermore, it was thought that aether was the element of the sky and stars were composed of it as they were heavenly, not earthly.

The four classic elements of ancient Greece had an impact not only on physics and chemistry, but also on philosophy and culture (the concept of the four elements is popular in modern games too). The most interesting example of these is a theory by Hippocrates, the father of Western medicine, that states that the human body is composed of four bodily fluids (humours) and an imbalance between the humours caused diseases. The four humours are yellow bile (fire), black bile (earth), blood (air) and phlegm (water). Furthermore, he believed that the four humours affected personalities too. For example, an excess of black bile (“melan chole” in Greek) would cause a person to become introspective and think negatively, leading to depression or “melancholy”. This is quite possibly the first medical records on clinical depression.

The four classic elements of ancient Greece can also be found in ancient Egypt and many other ancient civilisations. It also had a significant influence on alchemy in the Middle Ages.

(Image source