Category: Science & Nature

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Complementary Colours

Posted on by Jinavie

Red, green, blue, white… There are many colours that we can see and there are even more different combinations of colours possible. It is common knowledge that some colours clash with each other while some synergise very well. A common example of a “good combination” is when you use complementary colours. Complementary colours are two colours that oppose each other on the colour wheel, creating an effect where they brighten each other. This makes it very eye-catching and attracts people’s attention. For example, blue and orange make a bright contrast making them a popular colour choice for movie posters. Red and green, and yellow and purple are also examples of complementary colours. Complementary colours are an important concept in art and design as it helps the product stand out.

Complementary colours have an interesting relationship with our sense of sight. If you stare at a colour for a while then quickly look at a blank, white surface, you will see an afterimage of the complementary colour. A good example is when you have your eyes closed under bright sunshine and upon opening your eyes the world seems a blue hue (the blood vessels in your eyelid make the light appear orange as it reaches your eyes). This is because the retinas try to negate the intense colour by downregulating the nervous signals corresponding to that colour, which makes the complementary colour stand out. Furthermore, the photoreceptors in the retina become fatigued after stimulation, causing a reduction in the signals sent for that colour.

Knowing about complementary colours is very useful when designing a sign or poster that easily attracts people.

(Image source: http://bonka-chan.deviantart.com/art/Color-Wheel-136855103?q=boost%3Apopular%20color%20wheel&qo=3)

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Lemming

Posted on by Jinavie

When you think of lemmings, you are bound to think of two things: a small, round rodent and mass suicide. The reason being, we have been taught as children that lemmings often commit mass suicide. This theory originates from the late 19th century when scientists could not figure out why lemming populations seemed to spike rapidly and then fall just as fast. In 1908, a man named Arthur Mee proposed that they kill themselves, writing so in the Children’s Encyclopaedia. He posited that as an overpopulation of lemmings could devastate the European ecosystem, the lemmings were naturally controlling their own population count. His theory was backed by a documentary made in 1958 called White Wilderness that showed a footage of a herd of lemmings leaping off a cliff to their death.

However, this “fact” has a severe flaw. Lemmings do not commit mass suicide. If you think about it for even a second, the thought of an animal that commits mass suicide (other than human beings) is preposterous as the species would die out. The reason why the lemming population spikes is the same as for mice and rabbits: they pride themselves in extreme reproductive abilities. A female lemming can have up to 80 babies in one year. If the population grows at such an alarming rate, then as explained above, the environment would not be able to support it. This causes the lemming population to plateau, not rising or falling, as there is not enough food to feed all the lemmings. However, due to the shortage of food, the lemmings become desperate and hungry. To find more food, the lemmings begin a migration, but the combination of hunger and being in heat causes them to act irrationally and wild. The result is a massive herd of hungry, stupid lemmings frantically running around all over the place. This leads to some lemmings accidentally slipping off cliffs and drowning in the river while swimming. This is not suicide.

Then what was the strange phenomenon of mass suicide depicted in White Wilderness? The answer is simple: it was staged. The producers tried to replicate Mee’s theory by importing a dozen lemmings and filming them running around the place. Then why did these lemmings commit suicide? Because the producers launched them off a cliff from a turntable.

Posted in Science & Nature

Umami

Posted on by Jinavie

Normally when people think of “tastes”, they think of sweet, salty, sour and bitter (“spicy”, or piquance is not a taste). However, in 1985 the family of four basic tastes were introduced to a new member: umami. Umami, commonly known as “savouriness” is a taste that has had its own word in Asian countries (e.g. 감칠맛, or gamchilmaht in Korean) for thousands of years but has not had a proper English word until very recently (much like piquance). Umami is a portmanteau of two Japanese words: うまい(umai) and 味(mi), which means “delicious” and “taste” respectively.

Sweetness comes from glucose, saltiness from sodium and sourness from acids. Then where does umami come from? Umami is the taste born from glutamates, which is found in high concentrations in meat products, thus leading to the association between umami and the taste of meat. For example, bacon is known to have six different types of umami flavours, creating a unique and addictive taste. Another product high in glutamate is monosodium glutamate, or MSG. MSG is essentially glutamate plus a sodium ion and thus brings out the full taste of umami when added to food. As umami has a powerful effect of boosting appetite and having a slightly addictive property means that chefs like putting MSG in foods to boost sales. Contrary to popular belief that MSG is detrimental to your health, recent researches have shown that unless you have an allergy to it, MSG is safe to consume even in high concentrations.

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Monty Hall Problem

Posted on by Jinavie

Imagine that you are on a game show and you are given the choice of three doors, where you will win what is behind the chosen door. Behind one door is a car; behind the others are goats, which you do not want. The car and the goats were placed randomly behind the doors before the show.

The rules of the game show are as follows: 

  • After you have chosen a door, the door remains closed for the time being. 
  • The game show host, Monty Hall, who knows what is behind the doors, opens one of the two remaining doors and the door he opens must have a goat behind it. 
  • If both remaining doors have goats behind them, he chooses one at random. 
  • After Monty Hall opens a door with a goat, he will ask you to decide whether you want to stay with your first choice or to switch to the last remaining door. 

Imagine that you chose Door 1 and the host opens Door 3, which has a goat. He then asks you: “Do you want to switch to Door 2?”

Is it to your advantage to change your choice?

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Most people believe that as an incorrect option (goat) is ruled out, their odds of winning the car go up from 1/3 to ½ even by staying on the same Door 1 and there is no benefit to switching. However, it is better to switch doors as this will double your odds of winning the car. To illustrate this point, the following three scenarios (with the car being behind Door 1, 2 or 3) can be imagined, using the above rules of the game:

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In Scenario 1, you have already chosen the car (Door 1) so Monty Hall will randomly open Door 2 or 3. Switching will obviously lead you to losing the car. The chance of you losing after switching, therefore, is 1/6 + 1/6 = 1/3 (as either Door 2 or 3 could be opened)

In Scenario 2 and 3, because you chose the wrong door (goat) and Monty Hall will open the door with the goat behind it, switching will lead you to choosing the car (no other choices). As the odd of either scenario happening is 1/3 each, your odds of winning after a switch is 2/3 – double the odds of winning after not switching (1/3, the odd of your first guess being right).

Of course, this is only under the assumption that the rules of the game were followed and that Monty Hall will always open a door with a goat behind it. This problem and the answer suggested was extremely controversial as tens of thousands of readers refused to believe that switching could be a better choice. However, as the above illustration shows, the Monty Hall problem is a veridical paradox – a problem with a solution that appears ludicrous but is actually proven true by induction.

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Cordyceps sinensis

Posted on by Jinavie

Cordyceps sinensis is a fungus known as dongchoong-hacho(동충하초, 冬蟲夏草) in Korea, with the same characters used in China and Japan. It literally translates to “worm in the winter, herb in the summer”. It is a peculiar fungus with an interesting life cycle. In the summer when the weather is warm, the fungus infects its host (usually ghost moth larvae) through spores. The infected caterpillar is slowly filled with mycelium (thready part of fungi), until it becomes mummified with only the shell remaining. The fungus keeps replicating until it bursts out of the caterpillar’s head with a club-like fruit body (which holds the fungus’ spores). This makes it look as if the caterpillar, which was an insect in the winter, turned into a fungus in the summer (technically it is at this stage, but the caterpillar is long dead). In English, it is also called caterpillar fungus or vegetable worm (which is a misnomer as fungi are not vegetables).

Cordyceps sinensis is an important ingredient in traditional Eastern medicine as it is believed to be a perfect balance between yin and yang due to it possessing both animal and plant (actually a fungus) properties. It is used to treat many diseases from fatigue to cancer.

Although Western medicine usually looks down on and ignores Eastern medicine, research shows that Cordyceps sinensis actually has medicinal properties. Cordycepin, a chemical extracted from the fungus, has been shown to inhibit the growth of viruses, fungi and tumours through its inhibitory actions on a certain protein. There is also research that suggests it can protect the body against radiation poisoning.

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Fermat’s Last Theorem

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In the 17th century, a lawyer called Pierre de Fermat conjectured many theorems while reading a mathematics textbook called Arithmetica, written by an ancient Greek mathematician called Diophantus. He wrote his theorems on the margins of the books. After his death, a version of the Arithmetica with Fermat’s theorems was published and many mathematicians checked over Fermat’s proofs. However, there was one theorem that could not be solved. Fermat wrote on the theorem: “I found an amazing proof but it is too large to fit in this margin”.

Fermat’s last theorem is as follows:

No three positive integers x, y, and z can satisfy the equation
xⁿ + yⁿ = zⁿ for any integer value of n greater than two.

For example, x² + y² = z² can be solved using Pythaogorean triplets (e.g. 3, 4, 5) but there are no values for x, y and z that solves x³ + y³ = z³. This theorem remained unsolved for 357 years until Andrew Wiles finally found the proof in 1995.

There are many stories surrounding Fermat’s last theorem, but by far the most interesting is related to suicide. In 1908, a German mathematician called Paul Wolfskehl decided to kill himself after being cold-heartedly rejected by the woman he loved so much. He decided to shoot himself at midnight and in the remaining time started reading some mathematics texts until he found a flaw in Kummer’s theory, which disproved Cauchy and Lamé’s solution (the leading solution at the time. After Kummer’s essay, most mathematicians of the time gave up on Fermat’s last theorem). After researching Kummer’s essay, Wolfskehl found that it was far past midnight and he felt great pride in reinforcing Kummer’s solution. His depression was gone and through mathematics he found new meaning in his life. Wolfskehl, who believed that the theorem saved his life, made a resolution to donate his wealth to whoever solved Fermat’s last theorem, putting up 100,000 marks as a prize. This prize was claimed by Wiles in 1996 (then worth $50,000).

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Duel

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Three gunslingers called Good, Bad and Ugly duel to the death. They each stand an equal distance from each other and shoot at the same time. Good’s accuracy is 30%, Ugly’s accuracy is 70% and Bad’s accuracy is 100%. Who has the highest chance of survival?

Common sense dictates that Bad, with the highest accuracy, will have the highest survival rate. However, when the duel begins, the following scenario will occur.

Good’s most rational decision is to shoot Bad rather than Ugly. Reason being, shooting the person with the higher accuracy improves your survival rate in the next round. Ugly also chooses to shoot Bad instead of Good as it is the best choice. Lastly, Bad shoots Ugly instead of Good. This scenario can be explained by the following diagram:

Thus, the probability of Bad being alive after the first round is (1-0.3)(1-0.7)=0.21, or 21%. This is because Ugly is killed by Bad on the first shot. On the second round, the probability of Good dying is the same as Bad’s survival rate of the first round, which is 21%. Therefore, Good’s survival rate is 79%. On the other hand, Bad’s survival rate becomes 0.21(1-0.3)=0.147, or 14.7%. 

Ultimately, the survival rate of each shooter is: Ugly 0%, Bad 14.7%, Good 21%, making Good the most likely winner. This illustrates the fundamental principles of game theory – an extremely useful theory that helps predict the many choices we make in life.

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Nuclear Explosion

Posted on by Jinavie

Nuclear weapons are quite possibly the most dangerous weapons mankind has ever developed. Through the use of nuclear fission, atoms are split to release the massive amounts of energy contained within, causing a gargantuan explosion. When a typical nuclear bomb detonates, energy is released in various forms: blast energy (40~50%), heat (30~50%), radiation (5%) and fallout (5~10%). The distribution of the energy varies according to the type of bomb (e.g. neutron bombs produce significantly more radiation than heat and blast energy).

The initial damage that follows a nuclear explosion is from the blast energy, much like a conventional weapon. The sheer amount of kinetic energy creates a shockwave that pulverises everything in its path, travelling at speeds over 1000km/h. In addition, the heat from the explosion, over ten million degrees celsius at one point, causes vaporisation of all matter within a certain radius, causing a massive release of gases, fuelling the shockwave from the expansion. In the case of the bomb that destroyed Hiroshima, all structures within 1.6km were vaporised and those within a 3.2km radius suffered moderate to severe damage. A modern nuclear weapon is at least tens of times more destructive and will affect a significantly larger area.

At the same time, thermal radiation spreads out in all directions much like sunlight. Thermal radiation travels far further than shockwaves and can cause severe burns and eye injuries (flash blindness) to people in the vicinity (if they are close enough, they will spontaneously combust or melt). Near ground zero (point of explosion), a firestorm may erupt from the sheer amount of heat energy, as observed as a fireball. 

Next comes the indirect effects.
Ionising radiation is produced when atoms are split and these have detrimental effects on living organisms. Not only are they responsible for mutations in the genome, leading to deformed offspring, sterility and cancer, but if there is sufficient radiation, a person will immediately die from acute radiation poisoning.
The same radiation, especially gamma rays, creates what is called an electromagnetic pulse (EMP). EMP is caught by metal objects and induces a high voltage surge, destroying unshielded electronic devices. Sometimes, nuclear bombs are detonated at very high altitudes so that only the EMP affects the ground, damaging enemy communications and destroying entire power grids.
Lastly, radioactive material rains from the sky for long periods of time, also known as fallout. Fallout causes continuous radiation damage in affected areas.

A nuclear bomb is truly a weapon of mass destruction as it utilises various forms of destruction to devastate all life forms within an area spanning several kilometres, even killing over the course of time in the form of radiation.

Posted in Science & Nature

Newton’s Apple

Posted on by Jinavie

Common belief is that Newton discovered gravity after an apple dropped on his head. Although there is no historical evidence to support this myth, it has become a popular story. There are two common responses to this story: the first is “Wow, Newton was a smart cookie” and the second is “Pfft, I could have discovered gravity without an apple, it is such an easy thing.”

The latter group of people are idiots. Newton did not “discover” gravity. Human beings have known that objects fall to the ground since the dawn of time and have utilised it in ways ranging from sports to killing other people by crushing them with giant rocks. Even animals know of the concept as seen by eagles dropping turtles on rocks to crack the shell. In fact, if you could not figure that out, then you would really be an idiot.

The reason why Newton is famous is not because he found that apples fall from trees, it is because he observed the phenomenon, noting that it was always perpendicular to the ground, which in combination with the knowledge that the Earth is round suggests that objects tend to fall towards the centre of the Earth. Again, Newton’s brilliance was not that he simply observed an apple falling, it was that he pondered it and spent years researching it until he discovered the way gravity behaves. He devised formulas to estimate how gravity functions, even applying it to predict how the moon orbits around the Earth. Thanks to Newton, we are able to model the world around us and send rockets to the moon without launching our astronauts in to the depth of space with no hope of recovery. 

Interestingly, physicists still do not know what causes gravity. There are many theories, such as particles called gravitrons attracting two objects to each other. Although the mathematics of two objects attracting each other has been accurately calculated, it is unknown what causes it. Only after you discover the truth behind how gravity functions can you say that “I could have discovered gravity in my sleep” (actually, even then you probably spent decades just trying to grasp the concept).

Before you criticise, know what you are criticising. 


Posted in Science & Nature

Fire

Posted on by Jinavie

Every creature on earth knows the fearful power of fire. Learning how to utilise it is possibly one of man’s greatest achievements, as it allowed science and technology to kickstart in every way. However, we still lose control over it sometimes and suffer the consequences. Fire can develop from a tiny ember to a full-blown firestorm that incinerates everything in its path. The following are the four stages of fire development:

  • Stage 1 – Incipient stage: No visible smoke and very little heat. Small fire.
  • Stage 2 – Build-up stage: More heat causes pyrolysis (decomposition of material due to heat), releasing combustible gases. May cause a flashover (every combustible surface in the room ignites all at once).
  • Stage 3 – Fully-developed stage: Visible flame, massive amounts of heat, smoke and toxic gases. Everything is burning.
  • Stage 4 – Decay stage: Fire is either contained or extinguished. If not, may spread to other areas (e.g. the next room).

After sufficient heat has built up, fire spreads almost explosively (sometimes literally) causing extensive damage. Thus, the most important part is preventing the fire in the first place or extinguishing a small fire still at the incipient stage. As powerful a tool it may be, it can also destroy everything you hold precious within a matter of hours.

An interesting phenomenon related to fire is backdrafts. This is similar to flashovers (described above) except it is triggered by oxygen rather than a build-up of heat. Both cause a sudden transition from a small fire to a full-scale inferno.
A backdraft occurs when a burning room is filled with pyrolysed, combustible gases but lack the oxygen needed to continue burning as it was used up while the fire was building up. When a firefighter or a broken window causes air to rush into the room, the pressure in the room spikes and every combustible material suddenly bursts into flames, exploding out in a ball of fire. Backdrafts are one of the most dangerous fire phenomena that claim the lives of countless firefighters.