Category: Science & Nature

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Parthenogenesis

Posted on by Jinavie

It is often believed that for complex organisms such as animals, sexual reproduction is a must to produce offspring. Asexual reproduction is common in bacteria and (some) plants, but even tiny beings such as insects use sexual reproduction to produce a mass of variable offspring. 

However, it has been found that despite having two clear sexes – male and female – there are cases where a certain species is able to reproduce without the need of sexual intercourse. In these cases, the female’s eggs spontaneously divides to form a new offspring without being fertilised by a sperm. Furthermore, sometimes the egg either fuses with another egg or undergo several genetic mixing and mutation to produce some variety in genetic pool, thus avoiding the issue of asexual reproduction (where the entire population can be wiped out by a single disease due to identical genetic makeup). This is known as parthenogenesis, and it has been documented in many insects, fish, reptiles and even birds. 

Obviously, as there is no donation of a Y chromosome, every offspring born from parthenogenesis is female. Because of this, some species such as the New Mexico whiptail, a lizard that is capable of both sexual reproduction and parthenogenesis, the population has completely rid itself of males, making it a completely female species. Curiously, they still engage in “mock sex”, giving them the nickname “lesbian lizards”.

Although parthenogenesis has never been documented in mammals in nature, it has been induced artificially in mice, rabbits and monkeys. However, they all developed severe developmental issues due to the numerous mutations in the egg required for parthenogenesis. 
But if in the future, human parthenogenesis is perfected, it is possible that humanity too could end up as an all-female society.

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Star Wars

Posted on by Jinavie

Star Wars is packed to the brim with epic scenes of starship dogfights. The many “pewpews” of laser cannons and massive explosions characterise this classic science fiction film series. However, this is an example of a classic “unscientific fiction”.

The great explosions of ships would never generate a loud sound as in space, there is no air or any medium to carry the sound waves. As the tagline for the movie Alien states: nobody can hear you scream in space.
In this regard, 2001: A Space Odyssey is most accurate in its portrayal of space. Not only does it have absolute silence during its scenes outside in space, but it also has accurate portrayals of space-science such as magnetic boots and rotating toilets to generate gravity.

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Peppered Moth

Posted on by Jinavie

The peppered moth are a species of night-flying moth that have been studied extensively for over 200 years by biologists. They are known to be prime examples of the power of natural selection.

In England, there are two variants of this moth: one that has a peppery white appearance and another that is much darker, almost black. Originally, the white variant was much more common, as they could easily camouflage themselves on trees covered in light-coloured lichen.

However, during the Industrial Revolution, the heavy pollution killed the sensitive lichen causing trees to expose their dark bark. This caused the white moth to be extremely visible, making them easy prey for birds and other predators. The change in environment resulted in black moths, that used to be disadvantaged, to have a better chance of survival, causing the black moth population to become superior.

As people became more aware of air pollution and England began cleaning up its environment, lichen returned to the tree and the table turned once more – the dark moths were now better targets and were heavily preyed on. Instead, the white moth retook the majority position, thus showing how the environment affects which traits survive in a population.

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Kangaroo Rat

Posted on by Jinavie

Kangaroo rats are a type of rodent found in North American deserts. They are known for their extremely long and strong hind legs which they can use to hop great heights (up to nine feet), just like a kangaroo. But the most interesting feature of the kangaroo rat is its kidneys.
This tiny animal is known to be so efficient in using its water that it literally never has to drink water. By having extremely efficient kidneys, kangaroo rats gain sufficient water from metabolism, as water is made from oxidation of food naturally. This gives them a strong advantage in such a dry habitat.

Kangaroo rats have many more adaptations that aide their survival in their desert environment. They exhibit food-hoarding behaviour and can be often seen with their cheek pouches full of grains. As there is no pools of water, they roll in the sand to have sand baths like some birds. Being rodents, they are social and live in underground community tunnels to avoid the heat during the day.

When in danger, kangaroo rats hop on the spot and stamp their feet on the ground to send signals to nearby friends using the vibrations. Amazingly, they have been observed to even fight snakes in times of need, using sand to their advantage. By leaping back with their strong hind legs, kangaroo rats are capable of spraying sand at their enemy, irritating them and sometimes even damaging them. Furthermore, they show exemplary teamwork by attacking a predator together, biting and leaping back to continuously inflict damage. Because their legs are so well-developed, they are able to jump away from harm even if it is a snake striking at rapid speed.

Such adaptations in anatomy, physiology and behaviour allow the kangaroo rat to survive in an environment that can swiftly kill even a person.

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Rule Of Threes

Posted on by Jinavie

This is how long you can survive for without certain things:

  • 3 minutes without air
  • 3 hours without shelter
  • 3 days without water
  • 3 weeks without food
  • 3 months without hope

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Kiss

Posted on by Jinavie

Kissing is an act of love seen in cultures across the globe, with its history spanning many thousands of years. There are many theories as to how this act – representing love, affection, friendship and even respect – came about. The two most popular theories are the ideas that early humans in the Stone Age licked each other’s faces to obtain salt from sweat, or that it originated from ancient Romans. Roman soldiers kissed their wives as soon as they returned from war, to check whether there was the smell of alcohol (which was banned for women) or another man.
Using historical evidence from ancient texts from India and old paintings from China, it can be deduced that even in Asia the history of kissing is over 2000~4000 years old.

The human lip contains many nerve endings, making it one of the most sensitive part of skin on the body. Also, kissing stimulates the secretion of dopamine and oxytocin, chemicals responsible for invoking the feeling of love and happiness, causing an electric sensation (research states that the brain interprets it in a similar way to using cocaine).
It has already been proven that kissing lowers perceived stress and frequent kissing between couples lowers cholesterol and strengthens the cardiovascular system. Furthermore, it has been discovered that over 295 colonies of bacteria can be transferred per kiss (95% of which are harmless, but diseases such as glandular fever or herpes can be transmitted this way).
Some believe that the act of kissing came about to simulate the feeling of breastfeeding, an act ingrained in the subconscious mind (the same point is made regarding cigarette use).

This romantic behaviour is also seen in nature. Many bird and mammal mothers transfer pre-masticated food to their young this way, and calves kiss each other after drinking milk to prolong the sensation of breastfeeding. Even insects are found to “kiss”, such as ants that bring up food from their second stomach, the “social stomach”, to feed fellow ants that need food.

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Parkinson’s Law

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Parkinson’s Law states that the bigger a company grows, the more inefficient workers it will hire while paying out more wages. The reason for this is simple: those in power like to stay in power, and the best way to ensure this is to eliminate competition.

Hiring skilled workers brings upon the chance of a strong competitor that can over throw the bureaucrats, which is undesirable. Therefore, by hiring useless people, the bureaucrats are able to keep their seat of power.

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

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Echo

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Because sound is a wave, it is reflected by a surface. An echo is when this reflection is sufficiently loud and is quite common in everyday life. It is heard especially in places such as a mountain top or in a canyon because the surface needs to be quite far for our ears to detect the echo. If it is too close, as in within 340m – the distance covered by sound within one second – the echo overlaps with the original sound and cannot be heard. However, if a room is lined by a smooth surface, such as a bathroom or opera house, an echo may be heard. In these cases the delay between the sound and its echo is so close that it merely sounds as if the sound is amplified, thus explaining why singing sounds better when in a bath.

An echo can be very powerful, an example being St Paul’s Cathedral in London, England. This building is built with a giant, hemispherical roof that can amplify a whisper from one corner and replay it audibly at a corner on the opposite side of the room.
It is also very useful as it is used in technologies such as sonar and ultrasound machines to see through objects.

The word “echo” originates from a nymph named Echo from Greek mythology. Echo was instructed by Zeus to distract Hera from noticing him having an affair by chatting to her constantly. Hera caught on to this and cursed Echo to only be able to repeat what others say. After that, Echo could not even say “I love you” to the man she loved, and eventually lived in the mountains where she repeated whatever travellers said in an attempt to speak.

An interesting fact about echoes is the common myth that a duck’s quack does not echo. This is incorrect in that it does in fact echo, but since a quack is soft and fades quickly, the echo is usually too faint to be audible.

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Egg

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To know whether an egg is raw or boiled, simply spin the egg on its side, put a finger on top of it gently to stop it, then let the finger go.

A raw egg continues to spin because of the inertia of the liquid yolk still spinning within the shell.

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Schroedinger’s Cat

Posted on by Jinavie

In 1935, Erwin Schrödinger, a famous quantum physicist, devised a thought experiment in an attempt to explain the Copenhagen interpretation of quantum physics (which posits that the state of every particle can be described by a wave function, and that the process of calculating its position determines it). It goes as follows:

A cat is placed in a box with a sealed vial of poison that is set to release when a radioactive material has decayed. As the time taken for the decay varies (roughly 50:50 chance), it is unknown whether the vial has broken after an hour if the box is closed. This also means that it is unknown whether the cat is alive or dead. To solidify this variable reality, one must open the box, whence the cat is determined as either alive or dead. 

This experiment may be hard to understand for a non-physicist, but it is still a fascinating thought experiment. This is because there are many times in life where one cannot know the outcome of something unless action is taken. Ergo, if you want a state of uncertainty, do nothing; if you want a set answer, take action. This is a particularly useful answer to someone questioning whether they should start a relationship with someone and are unsure of the outcome.

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