Tag: encyclopaedia

Posted in Science & Nature

Hammer And Feather

Posted on by Jinavie

What would happen if you dropped a 1kg ball and a 10kg ball at the same time from a high building? Most people would think that the 10kg ball would obviously fall faster and thus hit the ground faster, but the truth is they would fall at exactly the same time. The reason for this is that the force that accelerates a falling object is gravity, which on Earth is constant at 9.81ms-2. This means that no matter how heavy the object is, they will always accelerate by 9.81 metres per second per second. This was hypothesised by Galileo Galilei, who came up with the thought experiment of dropping two balls of different mass from the Leaning Tower of Pisa (there is debate as to whether he actually performed the experiment). The theory was later solidified by a certain Isaac Newton, who devised the laws of universal gravitation and the three laws of motion.

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However, if the two balls were dropped from an extremely high place, they may land at different times as mass affects the terminal velocity – when the force of gravity equals the force of drag caused by air resistance, leading to a constant velocity. A heavier object will keep accelerating to a greater velocity than a lighter object, which would have reached terminal velocity before the heavier object.

One place where this will not happen is in a vacuum where there is no drag force. To prove that the hypothesis that two objects of different masses will fall at the same time in the absence of air resistance, Commander David Scott of the Apollo 15 moon mission took a hammer and a feather with him. Once he landed on the moon, he dropped the hammer and feather in front of a live camera, showing that the two landed at exactly the same time. He thus proved that Galileo’s conclusion from two hundred years ago was in fact correct.

Posted in Science & Nature

Alligator

Posted on by Jinavie

What is the best or easiest way to protect yourself from an alligator attack? Obvious answers aside (such as avoiding them), it is to use something like an elastic band or a rope to tie their snout shut. Alligators have the strongest bite in the natural world – clocking in at about 2125 pounds of force (about 966kg). The sheer force of the bite is enough to crush the victim and kill them instantly. Even if the victim survives, there is a serious risk of being left with a permanent disability or die from an infected wound.

Although the force of the bite is incredible thanks to its extremely strong jaw muscles, alligators do not have nearly enough the same strength when opening their jaws. This means that a simple elastic band is enough to keep their jaws shut, leaving the alligator helpless and giving you a chance to run before its friends come to find you.

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Posted in Psychology & Medicine

Empty Nest Syndrome

Posted on by Jinavie

When children grow up and learn to become independent, parents must let go of their children and allow them to fly free. However, it is the inevitable human condition that the parents will be saddened by this change. For many parents, the moving out of their children can lead to depression and a loss in purpose. This phenomenon has been named empty nest syndrome as it happens as the children leave the metaphorical nest that is home.

As obvious as it sounds, empty nest syndrome can have a serious effect on the parent’s well-being. Common symptoms include depression, loss of purpose, anxiety, stress and a feeling of rejection. The suffering parent continues to obsess whether they brought up their child in a way to prepare them for the big world. At the same time, they feel that they are losing their identity as a “parent” – something they may have defined themselves as while they were bringing up the child. They may also feel rejected as they may believe that the child “does not need them anymore”. It has been observed that mothers are more likely to suffer empty nest syndrome (occasionally, menopause may be a confounding factor). Other factors that contribute are parents who find change difficult, have an unstable relationship with their spouse or those with an unhealthy obsession with their children or with the idea of being a parent.

Empty nest syndrome is a natural part of parenthood, but it is important to know how to prevent it from becoming too severe. The best way to cope with this syndrome is to keep in touch with the children and accept that they are young adults who are moving on with their life. Not only that, but the parents must also recognise that a new era has begun for them as well. This is important as failure to do so will lead to the identity crisis mentioned above. A good way to remedy this is through discovering hobbies and interests while maintaining healthy social networks with other people. Essentially, the parents have to “begin a new life”, just like their children. It is also worth noting that it helps if the children recognise this as well and try to keep in touch with their parents to make sure they are coping well without them.

Posted in History & Literature

Rod Of Asclepius

Posted on by Jinavie

There are many symbols that represent the field of medicine such as a red cross or a stethoscope. However, one of the most famous symbols representing medicine and healthcare is the rod of Asclepius. This symbol is used in the logos of numerous medical associations and army medical corps. Those who do know of the rod may describe it as a staff with two wings and two snakes intertwining on it, but this is a common misconception. That symbol is called the caduceus and is actually the symbol of Hermes – the Greek god of messengers, merchants, markets, the high roads, gamblers and thieves. The misconception is very common and many medical associations use the caduceus as their symbol instead of the correct Rod of Asclepius.

The Caduceus

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The actual rod of Asclepius is much simpler looking, as it is simply a stick with one serpent intertwining it. The reason that it is associated with medicine and healthcare is that it was wielded by the Greek god Asclepius – the god of medicine and healing. Asclepius was the son of Apollo and had a particular interest in the human body and the healing of ailments. The ancient Greeks often referred to Asclepius in the field of medicine. In fact, the famous Hippocratic Oath originally began with the line “I swear by Apollo the Physician and by Asclepius and by Hygieia and Panacea and by all the gods…” (Apollo was the god of many things and medicine was one of his minor domains).

The rod of Asclepius

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So why does the rod of Asclepius have a serpent wrapped around it? In Greek mythology, it is said that Asclepius commanded many non-venomous snakes which he used in healing rituals. The snakes would crawl around the temple, living freely among the physicians and patients. A certain species of snake called the Aesculapian snake is considered to be the model for this story. The reason why the Greeks chose the snake as the animal of healing may be because snakes shed their skin periodically – symbolising rebirth and fertility. 

Another possible root of the symbol may be the traditional treatment for a certain parasitic infection. The Guinea worm (Dracunculus medinensis) is a parasite that lives under the skin, digging itself out through a painful blister when mature. As the blisters burn, the patient immerses the area in cold water to soothe it. The worm detects the change in temperature and releases its larva, completing its life cycle. The traditional treatment was to slowly pull the worm out of the skin, entwine it around a stick and leave it for a period of hours to weeks until it would be completely removed. The Greeks may have taken this image (of the worm wrapped around a stick) and applied it to the rod of Asclepius.

Posted in Psychology & Medicine

Urine

Posted on by Jinavie

Despite the implied disgusting nature (especially smell) of urine, it is one of the most important types of “samples” used in medicine for diagnostic purposes. Like blood, urine can tell a lot about a person’s health and whether they have a certain disease or not.

One of the earliest recorded uses of urine as a medical test was for the detection of diabetes mellitus. People noticed that the urine of a diabetic would often smell quite sweet, and also taste sweet (it is uncertain how they came to test urine this way). This is because a diabetic has too much glucose (sugar) in their blood, causing it to spill over into the urine as the kidneys become saturated. In fact, the words diabetes mellitus stand for “passing through” (referring to the symptom of frequent urination) and “honey-sweet”. A completely unrelated disease called diabetes insipidus also causes frequent urination, but the urine does not taste sweet, hence “insipidus” (tasteless). This type of etymology is also seen in countries like Korea, China and Japan, where the word 당뇨(糖尿) literally stands for “sugar urine”. Although we no longer taste urine, it is still used to gauge the severity of diabetes by measuring the amount of protein in the urine (due to kidney damage).

There are many other tests one can do with urine to check for certain diseases. The chemical composition of urine tells us about the hydration status of a person, while giving away clues to diseases that cause electrolyte imbalance. It also gives some indication of how well the kidneys can do their job of concentrating urine. Certain markers such as white blood cells and bacteria in the urine can indicate a urinary tract infection. Antibodies in the urine can point towards a certain type of bacteria as the cause of a patient’s pneumonia, or whether a woman is pregnant (βhCG). Looking for proteins or sediments in the urine can be diagnostic of certain kidney diseases such as glomerulonephritis. Even rare diseases such as phaeochromocytomas can be diagnosed from the level of catecholamines in the urine (this is slightly too complex for our scopes).

A more interesting part of urinalysis is looking at the colour of the urine. Urine is usually a yellow colour, ranging in darkness depending on the concentration of urine. But when there are other things in the urine, the colour changes. Reddish urine suggests blood (which is not an indicator of kidney failure as TV shows say), which can be caused by trauma, UTIs, kidney stones or some other disease. Brown urine could be due to muscle breakdown somewhere in the body. Urine can appear very dark if the person has an illness called obstructive jaundice. Eating beetroots can cause your urine to turn bright red, while medications can change your urine colour from anywhere from red to orange to green. Murky or cloudy urine (with an offensive smell) may suggest a UTI.

Perhaps the most interesting urine colour known in medicine is purple. This unique colour is produced in a rare genetic disease called acute intermittent porphyria. If urine is collected from a patient suffering an attack of AIP (causes crippling abdominal pain) then left in the sun or under a UV light, it will turn purple due to certain proteins. Because of this, urine collected to test for AIP is wrapped in tinfoil before sending to the lab (where the chemicals are measured) to limit light exposure.

(Also read the article on how different colours of skin can be of diagnostic importance: http://jinavie.tumblr.com/post/32313894252/skin-colour)

Posted in History & Literature

Nude

Posted on by Jinavie

The concept of the female body being the ideal subject for nude art only became popular around the 16th century when the Renaissance was in full bloom. Art before this time mainly focussed on the male figure that could portray the perfection of gods, such as the young and beautiful Apollo or Jesus Christ on the cross. In ancient Greece, the naked male figure was associated with triumph and victory (possibly related to the Olympic games being played in nude). Thus, statues focussed on nude male figures, with female figures tending to be clothed.

The point in history when this perception of nudity changed was when an Italian artist called Giorgione painted the Sleeping Venus in 1510. This painting portrays a nude Venus (or Aphrodite) lying peacefully on white and red cloths upon the backdrop of Venetia. This new type of nude art where the naked female form was displayed – with the figure posed with grace and shyness – sparked a revolution, changing the concept that the female body evoked an “uncomfortable feeling” in the audience. Many art historians consider this painting one of the starting points of modern art.

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Posted in Science & Nature

Tea

Posted on by Jinavie

Among the many hot beverages the world enjoys, tea is probably the number one. No matter how many people drink coffee, no beverage has a history like tea. From the tea ceremony cultures of the East to the Boston Tea Party of the West, the history of tea is long and full of stories. As everyone knows, tea is a drink made by boiling down the leaves of a plant. There are many types of tea: black, oolong, green, yellow and white being the most common. Teas made from more aromatic plants such as jasmine and chamomile are typically put in a separate category known as herbal teas. One surprising fact about tea is that most of them are derived from the same plant.

The plant Camellia sinensis is the source of all teas, with the aforementioned black, oolong, green, yellow and white teas all coming from the leaves of this one plant. However, what makes each tea unique is the way the leaves are processed. For example, if you steam freshly picked leaves of the Camellia sinensis plant then dry them out, you make green tea. If you wither the leaves then lightly crush and bruise them to promote oxidisation, you make black tea. The different ways of processing tea leaves gives each type of tea a unique flavour due to a variety in the ratio of various chemicals. For example, black tea is rich in tannin because of oxidisation, whereas green and oolong teas are milder as they have higher levels of catechins than tannin (the oxidised product of catechin). As catechins act as antioxidants in the human body, green tea is effective in slowing the aging process.

Although the source of the leaves are the same, the different ways of processing makes each tea unique in their ways of preparation. The milder white, yellow and green teas are best prepared by steeping them in water heated to (or cooled from boiling) 70~80°C for 1~2 minutes, while oolong and black tea should be steeped for 2~3 minutes in near-boiling water (80~99°C) for the best taste.

Posted in History & Literature

Hitler

Posted on by Jinavie

There are millions of units for various things. Some are simple and standard like the metre and gram, while others are quirky and humorous like the Helen unit and the Banana Equivalent Dose. As long as you can justify it with logic and objective quantification, you can virtually create any unit. Using this logic, some historical knowledge and a cruel sense of humour, one can come up with an extremely disturbing unit called the Hitler unit.

As most people know, Adolf Hitler is one of the most notorious criminals against humanity in the history of mankind. He was responsible for the death of at least 17 million people, including the 6 million Jews and 5 million other ethnicities killed during the Holocaust, and victims of World War II. For simplicity’s sake, let us only consider the victims of the Holocaust as direct victims of Hitler’s ambitions.

Using this statistic, we can now create a new unit called the hitler – equivalent to 11 million human deaths. Ergo, killing a single human amounts to a crime of 91 nanohitlers. The “hitler level” of some of history’s worst notorious dictators are as follows:

  • Kim Il Sung: 1.6 million deaths = 145 millihitler
  • Pol Pot: 1.7 million deaths = 154 millihitler
  • Hideki Tojo: 5 million deaths = 455 millihitler
  • Adolf Hitler: 11 million deaths = 1 hitler
  • Jozef Stalin: 23 million deaths = 2.09 hitler
  • Mao Zedong: 78 million deaths = 7.09 hitler

The hitler unit gives us a clear picture of “how much worse” someone’s crimes are compared to those committed by Adolf Hitler. For example, Jozef Stalin could be considered twice more evil than Hitler.

The true utility of the hitler unit is that like other units, it allows for useful conversions to other units. For example, the EPA currently values a human life at $6.9 million (USD). A simple unit conversion thus tells us that 1 hitler is equivalent to the loss of $75,900,000,000,000 (-$75.9 teradollars). In 2008 when the US Congress failed to pass a stimulus bill following the subprime mortgage crisis, the market lost $1.2 trillion over one day – the equivalence to 15.8 millihitlers. Conversely, if a mugger took $200 from you, they have technically committed a crime of 2.64 picohitlers.

Although the crimes of Adolf Hitler were beyond tragic, this imaginary unit teaches us that almost anything can be quantified in the field of science and mathematics.

Posted in Psychology & Medicine

Phineas Gage

Posted on by Jinavie

On September 13, 1848, a 25-year-old foreman named Phineas P. Gage was working on a railroad with his work team. In an unfortunate turn of events, as he was using a tamping iron (large iron rod with a pointed end, measuring 3 feet 7 inches in length and 1.25 inches in diameter) to pack gunpowder into a hole, the powder detonated. The forceful explosion drove the metal pole skyward through Gage’s left cheek, ripped into his brain and exited through his skull, landing dozens of metres away. His workmates rushed to Gage’s assistance (who they presumed to be dead at the time of the accident), and to their surprise, found that he was still alive.

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In fact, Phineas Gage spoke within a few minutes of the incident, walked without assistance and returned to his lodging in town without much difficulty – albeit with two gaping holes in his head, oozing blood and brain everywhere. He was immediately seen by a physician who remarked at his survival. In fact, it is reported that he was well enough to say: “Here is business enough for you” to the doctor. Another physician named Dr John Harlow took over the case, tended to the wound, fixed up the hole and recorded that he had no immediate neurological, cognitive or life-threatening symptoms.

By November, he was stable and strong enough to return to his home, along with the rod that nearly killed him. His family and friends welcomed him back and did not notice anything other than the scar left by the rod and the fact that his left eye was closed. But this was when things started to get interesting.

Over the following few months, Gage’s friends found him “no longer Gage”, stating that he was behaving very differently to the man who he was before the accident. Dr Harlow wrote that the balance between his “intellectual faculties and animal propensities” had seemingly been destroyed. Gage became more aggressive, inattentive, unable to keep a job, verbally abusive and sexually disinhibited. He would frequently swear using the most offensive profanities and would be as sexually suggestive as a March hare. How did the iron rod cause such a dramatic change in Gage’s personality?

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Phineas Gage would go on to be one of the most famous patient case histories in the history of modern medicine. His case was the first to suggest some sort of link between the brain and personalities. Neurologists noted that the trauma and subsequent infection destroyed much of Gage’s left frontal lobe – the part of the brain that we now attribute to a person’s logical thinking, personality and executive functions. It is in essence the “seat of the mind”. Ergo, Gage’s loss of one of his frontal lobes meant that his control of bodily functions, movement and other important brain functions like memory were undisturbed, while his “higher thinking” was essentially destroyed (he was essentially lobotomised). This explains Dr Harlow’s observation of his “animal propensities”.

Thanks to this case, a great discussion was sparked and the idea that different parts of the brain govern different aspects of the mind was conceived. We are now able to localise almost exactly where the language area is, what part controls movement and how a certain piece of the brain converts short-term memory into long-term memory.

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Posted in Philosophy

Thief And Murderer

Posted on by Jinavie

Imagine that you have been incarcerated for committing a crime. You get to choose one of the prisoners as your roommate, but your choice is limited to a thief and a murderer. Who would you trust more?

Most people would consider the thief’s crimes to be lighter and choose him without a doubt. They would rather live with someone who stole some jewellery than some beast that killed another human being.

But if you think about it in depth, you may come to the opposite conclusion. Stealing is often a meticulous and calculated crime that involves logical planning, but murder is more often a crime of passion that is spontaneous (of course the person may be a psychopath). Ergo, statistically speaking thieves tend to be more predisposed to a criminal nature than murderers. A thief will easily repeat their crime, whereas those who have murdered often do not repeat it. Furthermore, thieves tend to target people they do not know, where as murderers often kill someone that they know. Statistically, you are more likely to die in the hands of someone you know well than a stranger.

Therefore, it just might be that sharing a room with a murderer is preferable to a thief (maybe the murderer will not steal all your secret food). This would definitely be the case if the “murderer” was actually framed like Andy Dufresne in The Shawshank Redemption. Of course, the wiser choice still is to not commit the crime in the first place so you do not end up in prison.