Category: Science & Nature

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Atrophy

Posted on by Jinavie

With exercise, muscles get bigger and bigger to generate enough power to meet the demand. This is called hypertrophy, where the cells in tissue divide faster to increase their numbers and build mass. When you do not use the muscles as much, the body decides to recycle the precious resources by breaking down the extra muscle. This is called atrophy – also known as wasting.

Muscles are not the only things that atrophy. The less you think deeply and explore your curiosities, the more your intelligence and wisdom atrophies. As you care less, your heart and ability to love atrophies. As you smile and laugh less, your happiness atrophies.

Like much of nature, the human body dislikes the status quo and strives to avoid stagnation. It continuously breaks down old, unnecessary things to make way for new, different things that will help you better adapt to your environment.

Unfortunately for us, that means to maintain the parts of us that we like, we must train and use the relevant “muscles” – whether it be lifting weights, reading books or laughing heartily for no reason.

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Mandrake

Posted on by Jinavie

The plant Mandragora officinarum, more commonly known as mandrake, is a plant that has interested people in various fields throughout history. Firstly, the root is split into two at the end, giving the uprooted plant the appearance of a human being. Secondly, it belongs to the nightshade family, containing plants such as the infamous deadly nightshade (belladonna), tobacco, Datura, petunia, tomatoes and potatoes. Like its relatives the belladonna and Datura, mandrakes contain alkaloids such as atropine, scopolamine and hyoscyamine. These substances are potent (and toxic) hallucinogenics and sedatives, which is why they have had various uses ranging from witchcraft to anaesthesia to murder through poisonings.

The shape of the mandrake and its hallucinogenic effects have given it notoriety. Legend goes that when a mandrake root is dug up, it shrieks with such terror that anyone who hears it will die – possibly referring to the toxicity of the alkaloids. Historical texts give detailed instructions on digging up mandrakes by tying a hungry dog to the root and making it pull the plant out of the ground when the owner is out of earshot and he lures the dog with food.

Other folklore suggest that mandrake only grow when the ground is inseminated by semen dripping from a hanged man. This folklore is likely fuelled by the mandrake’s human-like appearance. Ancient and medieval literature associates mandrake being used to make fertility agents and love potions(again, likely related to the hallucinatory, sedative effects). Mandrake is a common ingredient in magic rituals of various kinds, such as in Wiccan rituals.

Alkaloids extracted from mandrake have been used in medicine since the Middle Ages, where extracts were used to anaesthetise patients before surgery, as it has a sedating, hypnotic effect. Eye drops made from mandrake extract were used for hallucinations and mandrake syrups were used to aide sleep. In modern medicine, scopolamine is used in motion sickness patches and atropine is used to speed up the heart rate when it slows too much.

The extensive list of supposed and actual properties of mandrake has made it a popular plant in fiction as well and it can be found in countless works throughout time, such as works of Shakespeare, Sir Arthur Conan Doyle and J.K. Rowling.

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Interesting Numbers

Posted on by Jinavie

One of the more humorous sides to numbers is mathematicians’ attempts to categorise numbers as “interesting” or “dull”. For example, 1 is interesting because it is the first positive integer. 73 is interesting because it is the 21st prime number and 21 is a multiple of 7 and 3. The number 1729 is a good example of how a number can seem dull but later found to be interesting. When the British mathematician G. H. Hardy visited Indian mathematician Srinivasa Ramanujan, he commented that the number of the taxicab he rode in on was 1729 – a number he found to be rather dull. Ramanujan objected and stated it is very interesting as it is the smallest number expressible as the sum of two cubes in two different ways (1729 = 1³ + 12³ = 9³ + 10³). Such numbers are now referred to as taxicab numbers and 1729 is called the Hardy-Ramanujan number.

A way to discover the smallest most uninteresting number is through the Online Encyclopaedia of Integer Sequences, which documents every integer worth noting as it is in some sort of arithmetic sequence. The smallest integer that does not appear in this encyclopaedia as part of a sequence could be considered as objectively the smallest “uninteresting” number. In 2009, this number was 11630, but has since changed to 12407, then 13794 and now 14228 (22 April 2014).

But paradoxically, the smallest uninteresting number is interesting in itself by being the smallest most uninteresting number. This is known as the interesting number paradox. By this paradox, every natural number is unique and ergo, “interesting”.

Number Line

(Image source: http://www.xkcd.com/899/, and here’s an explanation of some of the numbers on it)

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Chocolate Overdose

Posted on by Jinavie

It is common knowledge that you should not feed dogs and cats chocolate as it is poisonous to them. This is because chocolate contains a substance called theobromine. The name theobromine comes from the Greek words theo (“god”) and broma (“food”), thus meaning “food of the gods”.

Cats and dogs metabolise this chemical very slowly, so they can easily overdose on it. Theobromine poisoning causes vomiting and diarrhoea initially, then progresses to cause hyperactivity, cardiac arrhythmias (irregular heartbeats), seizures, internal bleeding, cardiac arrest, respiratory failure and eventually death. Although cats and dogs have the same metabolism rate of theobromine, there are far less cases of cats overdosing on it as they do not have sweet taste receptors and do not particularly like the taste of chocolate.

Luckily for us, the human body can metabolise theobromine much more efficiently and we are much less likely to get theobromine poisoning (although it is still possible if you eat too much of it). Although it is weaker, theobromine behaves similarly to caffeine in the human body. It stimulates the heart to beat faster, relaxes the blood vessels, reduces blood pressure and stimulates your nervous system to decrease your tiredness and give you a “buzz”.

The effects are potent enough that there is some evidence that eating dark chocolate (which has a higher theobromine content) regularly can reduce your risk of heart disease. However, this is counterbalanced by the negative health effects of sugar and fat found in chocolate. That being said, a small amount of chocolate every now and then not only has a positive effect on your heart, but is a great medicine for your exhausted mind and soul.

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Milk Tea

Posted on by Jinavie

In many cultures, it is normal to drink black tea with milk (and sugar, depending on preference). The milk neutralises the acidity of tea and softens the bitterness of tannins, making the tea more palatable and easier on the stomach. This is especially for strong teas such as Assam tea. However, the downside is that there is some evidence that adding milk to tea reduces the beneficial effects from drinking tea, such as relaxing blood vessels and reducing risk of heart disease.

One of the timeless debates is whether to pour the tea or milk first when mixing the two. It is such a bitter topic that there are even recordings in literature of people using the phrase “rather milk in first” as an insult to another person.

George Orwell once published an article on making a perfect cup of tea and he claimed that adding milk to tea allowed you to regulate the amount of milk as you stir. Tea-first advocates also insist that pouring the tea first allows for more brewing time and increases the flavour of the tea.

The reason for milk-first is more scientific. In the early days of tea-drinking, most households did not own high-quality porcelain teacups. Cheap porcelain teacups were too thin to withstand the hot temperature of fresh tea and would crack. Pouring milk first cooled the tea and stopped this from happening. Therefore, pouring tea first was seen as a show of social status as you could afford high-quality teacups. The other main rationale for adding milk first is that the hot tea denatures proteins in milk, which can reduce the flavour and creamy texture of the milk.

To settle this old argument, British chemist Dr Andrew Stapley of the Royal Society of Chemistry undertook experiments to determine which is better from a scientific point of view. He concluded that it is indeed better to pour milk first then add tea. The reasoning is that when you add milk to tea, individual drops contact the tea and increases the surface area exposed to hot tea, denaturing more proteins. Ergo, adding tea to milk reduces this process and provides for a richer, creamier flavour.

At the end of the day, it really is just a cup of tea and you should drink it in whatever way you desire.

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Space Pen

Posted on by Jinavie

According to a popular legend, it is said that during the height of the Space Race, NASA was hard at work trying to develop a pen that could be used in space. The standard ball-point pen relies on gravity to pull the ink to towards the ball, allowing it to write. Obviously, this design does not work in space. NASA reportedly spent $1.5 million (some sources say $12 billion) and finally developed a space pen. This pen could write upside-down or in zero-gravity, on almost any surface and would work even at temperatures below freezing or over 300°C.
The Russians were faced with the same dilemma – they used a pencil.

As entertaining the story of overthinking Americans is, it is a complete urban myth. Both US and Russian astronauts used pencils in the early stages of the Space Race, but there were many flaws with pencils. Firstly, it was deemed unsafe to write important official documents using an erasable writing tool. Secondly, wood is combustible and fire is potentially disastrous on a space mission. Lastly and most importantly, pencil lead is made of graphite and broken tips and graphite dust are commonly released when using a pencil. Graphite is an extremely conductive material and if the dust were to go into an electrical circuit, it could easily cause a short-circuit and spark a fire.

To solve this solution, Paul C. Fisher – founder of Fisher Pen Co. – invested his own funds (not the US government’s) to create a pen that used pressure-loaded ink cartridges, making it perfect for zero-gravity use. NASA approved of the pen’s effectiveness and not long after, even Russia imported about a hundred of these space pens for their own use.

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Sonic Boom

Posted on by Jinavie

When something moves through the air, it pushes the air in front and creates a sound. This sound spreads as a wave at the speed of 340m/s (1225km/h). As the object moves, it makes a series of pressure waves, which is why the Doppler effect happens. These pressure waves look like rings that are squashed to the side the object is moving towards. As the object moves faster, the more compressed these rings become. When the object moves at the speed of sound (340m/s), the pressure waves all overlap as the object makes a pressure wave on the same place as where the last wave reached. This is the sound barrier.

At this point, there is so much overlap of the waves that a shockwave is formed. This shockwave – made of compressed air – travels at the speed of sound (Mach 1) and originates from the front tip of the object (e.g. nose of the plane). If the object moves any faster than the speed of sound, the new wave is made even before the old wave has propagated that far. The rings are now no longer in a nice concentric pattern, but instead form a shockwave cone. Sometimes this can be seen physically if there is enough condensation in the air to create a vapour cone. The sudden change of pressure from the shockwave creates a large booming sound, which we call a sonic boom (in fact, there are two booms due to the pressure difference at the tail too).

Sound, like other waves, is a form of energy. Hence, the shockwave formed by breaking the sound barrier can cause physical damage. If a fighter jet were to fly over a building at low altitude at supersonic speeds, it may cause windows to shatter and people’s eardrums to rupture. The shockwave creates a significant problem in aircraft design, for if a plane’s wingspan is wider than the width of the shockwave cone, its wings will snap off. This is why fighter jets and the Concorde have a characteristic sleek, triangular shape. The faster the plane travels, the narrower the shockwave cone becomes and the thinner the plane’s wingspan has to be.

Then what was the first manmade object to break the sound barrier? The answer is surprisingly old and simple – a bullwhip. The crack from a whip is actually a small sonic boom made by the tip of the whip travelling beyond the speed of sound.

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Pigeonhole Principle

Posted on by Jinavie

If I have three gloves, there must be at least either two left gloves or two right gloves. It is impossible to have one left glove, one right glove and a third glove that is neither left nor right (usually). This logic is called the pigeonhole principle. It is named because of the logic that if you have n pigeons and m pigeonholes where n > m (e.g. 10 pigeons in 9 holes), then at least one pigeonhole must contain more than one pigeon. This is because the biggest spread of the pigeons is putting at least one in each box, but as n > m, there is a pigeon left over and it must go in a box with another pigeon. The pigeonhole principle seems like a basic counting principle, but its implications are quite interesting.

For example, let’s say that your sock drawer is very unorganised and has a mix of black and white socks. What is the minimum number of socks you need to pick out before you get two of the same colour? The pigeonhole principle dictates that when n > m, each “slot” must be filled with more than one item. Here, the slot is colour. As there are two colours (m = 2), you only have to pick three socks out to have a matching pair (n = 3, 3 > 2).

The pigeonhole principle allows us to make seemingly impossible conjectures, such as the fact that a person living in London will have the exact number of hairs on their head as at least one other person living in London. An average human head has about 150,000 hairs and it would be a safe assumption to say that no one would have more than a million hairs on their head (m = 1,000,000). The population of London far exceeds a million (n > 1,000,000), therefore, there must at least two people living in London with the exact same amount of hair on their head. Similarly, if you are in a room with 366 other people, you are guaranteed to share a birthday with at least one person.

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Millions And Billions

Posted on by Jinavie

Have you ever stopped and pondered what a million actually is? Sure, you might easily pass it off as the number 1,000,000, or a thousand thousands, but have you really tried to get your head around how big a number that is? For example, you may be able to visualise a hundred people, a thousand people or even tens of thousands of people in your head, but it is very hard to visualise an image of a million people.

Now consider this. When was a million seconds ago? You know a second is very short and a million is a very large number. But it is difficult to put the two together. Make a guess. Last year? Two months ago? Surprisingly, the answer is only a week and a half ago (11.6 days).
Then what about a billion seconds? A billion is a thousand million so you might think it is easy to just add some zeroes, but a billion seconds is 31.7 years ago. Just by changing one syllable, or adding three zeroes, we went from a scale of weeks to years. If we go one step further to a trillion seconds, you leap back in time 31,700 years. You can probably remember what happened a million seconds ago, you might not have even been born a billion seconds ago and our ancestors were still hunter-gatherers roaming Europe a trillion seconds ago. That is how mind-blowing the scale of large numbers can be.

Now let’s look at some other things to really understand how big a million and a billion can be. A million dollars (USD) could buy you a luxury house, a manufacturing line, a 41-acre island in Belize or over 200 years’ worth of coffee (if you drank two cups a day). A million dollars in $1 bills would weigh 1000kg and stack to 30 stories high. A billion dollars – even if you were to convert it into $100 bills – would weigh 10 tonnes, almost as heavy as the truck that would carry it.

The pitter-patter of raindrops on your face feels nice, but a million drops of water weighs 50kg and would break your neck. A billion red helium balloons would have enough lift to carry 14,000 tonnes – enough to lift a hundred small, two-storey houses up into the air. A million grains of rice will feed a person for almost two months, while a billion ants would weigh twice a standard car (3 tonnes total).

Related image

(You should definitely check out Hank Green’s take on “a million seconds”, because everything is better if Hank Green is ranting about it! http://www.youtube.com/watch?v=cJ7A0yTDiqQ)

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HeLa

Posted on by Jinavie

In February 1951, a woman named Henrietta Lacks was diagnosed with cervical cancer. The cancer was aggressive and her health quickly deteriorated, until her ultimate demise in October 1951. Although Henrietta Lacks passed away on that day, not all of her was dead. A scientist named George Otto Gey succeeded in culturing (growing on a petri dish) the biopsied cervical cancer cells, provided by Lacks’ physician. He discovered that this lineage of cells could keep dividing and growing without stopping. In the human body, cells will eventually reach a limit of dividing and be destroyed. The cells from Henrietta Lacks, however, were immortal. Gey named this cell line HeLa, taking the first two letters of Lacks’ first and last names.

The HeLa cell line (and all other immortal cell lines since) have proven very useful in research as they give an infinite supply of identical cells, giving scientists a model template they can experiment on. The immortality of the HeLa cells is such that 60 years later, scientists are still using cells from that lineage – cells virtually identical to the cells taken from Henrietta Lacks (save for random mutations that happen in any cells). The cells are so well-adapted to unlimited growth that they are sometimes considered a laboratory “weed”, because it can easily invade another cell culture and completely take it over. One biologist even went as far as claiming that HeLa cells were no longer human, but instead a new species. He supported his claim with the fact that HeLa cells are self-sufficient and can reproduce on its own, and that it has a different genome (even chromosome numbers) to human cells due to the nature of cervical cancer.

The main issue with HeLa cells is the ethics behind it. At no point did Lacks or her family give permission to the doctor for him to donate her cells for research. Since her death, the cells were not only used for the purpose of pure research, but also commercialised. Unfortunately, medical ethics was not well-established at the time and asking the patient’s consent for such things was not common. The two major sides in this debate would be the unethical act of taking human tissue and using it without consent, versus the potential benefit it brings. For example, HeLa cells were used by Jonas Salk for his research that led to the development of the polio vaccine. It may be a stretch, but if those cells were not taken from Lacks, the development of the polio vaccine may have been delayed and countless more people would have suffered from a lifelong crippling illness. This is the great question in medical ethics: how much of an individual’s human rights can we afford to sacrifice for the needs of the many? Do the needs of the many really outweigh the needs of the few, or the one?