Category: Science & Nature

Posted in Science & Nature

Folding Paper

Posted on by Jinavie

Take any piece of paper and fold it in half. Then fold it in half again. Chances are, you will not be able to fold the paper more than seven times. Try it. No matter how thin the piece of paper is, it is extremely difficult to fold a piece of paper in half more than seven times. The reason? Mathematics.

A standard sheet of office paper is less than 0.1mm thick. By folding it in half, the thickness doubles and becomes 0.2mm. Another fold increases it to 0.4mm. Already, the problem can be seen. Folding a paper in half doubles the thickness, meaning every fold increases the thickness exponentially (2ⁿ). By seven folds, the thickness is 2 x 2 x 2 x 2 x 2 x 2 x 2 = 128 times the original thickness. This makes the piece of paper so thick that it is “unfoldable”.

Another limitation is that folding the paper using the traditional method means the area also halves, decreasing exponentially. With a standard piece of paper, the area of the paper is so small after seven folds that it is mechanically impossible to fold it. Furthermore, the distortion caused by the folds is too great for you to apply enough leverage for folding the paper.

Could these limitations be overcome by using a larger piece of paper? Sadly, no matter how large the piece of paper, it is impossible (or at least extremely difficult) to fold a piece of paper over seven times. This has been a mathematical conundrum for ages, until it was solved in 2002 by a high school student named Britney Gallivan. Gallivan demonstrated that using maths, she could fold a piece of paper 12 times. The solution was not simple though. To fold the paper 12 times, she had to use a special, single piece of toilet paper 1200m in length. She calculated that instead of folding in half every other direction (the traditional way), the least volume of paper to get 12 folds would be to fold in the same direction using a very long sheet of paper.

Mathematics, along with science, is what makes something that seems so simple, impossible.

Posted in Science & Nature

Metal

Posted on by Jinavie

Next to the discovery of fire and the wheel, the discovery of metals and the mastery of metalworking was arguably one of the most important advances for prehistoric humanity. Metal was far superior to rock, clay, wood or any other natural resource known to man in terms of strength and sharpness. Because of these properties, metal soon became a valuable commodity. It can be seen how much impact metal had on humanity’s history, considering that the stages of human prehistory were named after the type of metal (or lack thereof) that was mastered then: Stone Age, Bronze Age and Iron Age.

The discovery of metal came in two ways.

One was through mining, where prehistoric people discovered that shiny, hard objects were buried in the ground. They later discovered that with enough heat, they could melt the metal out of ores (copper and tin were the first metals to be gathered this way) and mould them into any shape. After smelting technologies developed, our ancestors found that mixing copper and tin produced bronze – a much stiffer and more durable metal than either of its components. A mixture of metals is called an alloy. This was the start of the Bronze Age. Bronze was extremely useful and people quickly came up with innovative ways of using it, such as farming equipment and weapons.

Some other metals used during this age were: gold, silver, lead and mercury. It is likely that gold was one of the earliest metals used as it comes in pure nuggets and is easily workable thanks to its chemistry. However, given that gold is rather soft and was treated more as jewellery than a practical metal, it was not used as much to advance technology.

The second way mankind came upon metals was in the form of “gifts from the gods”. A prime example is iron. Although the Iron Age began around 1200BC at the earliest, there are iron objects (mainly jewelleries) that have been dated back to 5000BC. How could this be? This was before mankind had the technology to smelt iron ores (which is more difficult and needs much higher temperatures than copper or tin ores), so the iron could not have been gathered through mining. The answer to this conundrum lies in meteorites. About 6% of meteorites contain iron and nickel, which prehistoric civilisations may have stumbled onto and taken the shiny pieces back to their tribe. The people would have considered the gathered iron a “gift from the gods”, as it had crashed down from the “heavens”. Because of this reason, iron was considered more valuable than gold or silver and was frequently used for jewellery. This is reflected in Arthur C. Clarke’s science fiction short story, The Songs of Distant Earth, where sentient sea scorpions hoard metal objects stolen from the humans and wear it proudly as a badge of honour.

The history of iron and how it was believed to be a gift from the heavens relates to a common superstition of how finding a penny (or any coin) represents good luck. As “metal” (mainly iron) was considered a holy gift bestowed unto mankind, finding a piece of metal was believed to be a blessing and some form of protection against evil. This is also represented in various traditions such as hanging horseshoes over doorways and wearing charm bracelets with metal on it.

Although it sounds like a silly superstition, it clearly shows how metals have been an integral part of the development of civilisation.

Posted in Science & Nature

Caesarean Section

Posted on by Jinavie

(To read about how babies are made and born, read the From Cell to Birth miniseries! https://jineralknowledge.com/tag/arkrepro/?order=asc)

Most animals give birth through a female’s vagina. Of course humans are the same when it comes to natural birth, but nowadays, it is not uncommon to find women wanting a caesarean instead of the traditional method. A caesarean (also called C-section) is a surgical procedure where the fetus is taken out by cutting through the lower abdomen into the uterus. The history of caesareans is quite dark. Back in the old days when medicine was not advanced, caesareans were mostly used to rescue fetuses from mothers who had died during childbirth. The first record of a successful caesarean where the mother survived dates back to the 1500s. Many people believe the word “caesarean” came from the Roman emperor Julius Caesar, who was allegedly born via a caesarean. However, it was rare for caesareans to be performed in Roman times and even if they were, the mothers almost certainly died in the process. Given that his mother was alive and healthy well into his adulthood, it is highly unlikely that Caesar was born by caesarean (there are no concrete records of it either).

There is much debate to whether a caesarean is better or worse than natural birth (except in emergency situations where a caesarean is required). According to research (in cases without known risks to the fetus), the mortality rate is definitely higher in babies born by caesarean compared to those born naturally. This is most likely due to a caesarean bypassing some of the physiological changes that occur during vaginal birth.

Another debate is about the use of general versus regional anaesthesia (spinal block) when doing a caesarean. A fascinating fact about childbirth is that when a baby is born, it cries to expand its lungs but then quietens down for about an hour (unless it is in pain or there is some stimuli). This is possibly a mechanism to allow bonding between the mother and baby. New mothers often remember the moments following the birth of the child as extremely emotional and blissful. Contrastingly, mothers who are under general anaesthesia and not awake when their child is born bond less with the baby initially (some mothers do not even recognise the baby as their own). Thus, unless it is an emergency caesarean, a spinal block (which allows the mother to be awake and painless) is preferable over general anaesthesia.

Lastly, it is common tradition to cut the umbilical cord straight after the child is born. But is this okay? When the fetus is in the uterus, it shares its cardiovascular system with the placenta. The umbilical cord connects the two and carries blood to and fro. At any given point, the placenta contains 30~50% of the fetal blood. If the umbilical cord is suddenly cut, the fetus essentially loses this blood, being born in a state of low blood volume. If you look at the umbilical cord, you can see that it is about 1m in length, which is enough for the baby to be put next to the mother’s breasts for breastfeeding and bonding. Perhaps we are cutting the cord too soon, not letting the blood flow back from the placenta to the fetus.

If you think about it, humanity has been giving birth without too many problems to survive generation after generation for 200,000 years (otherwise we would not exist). Although the mortality rate was high, Mother Nature has optimised childbirth over time through evolution. Ergo, it is possible that modern medicine is intervening too much in a natural process. We must always consider whether medical advances are helpful or harmful to us.

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Verneshot

Posted on by Jinavie

If there is one thing we learn about dinosaurs, it is that they were wiped off the face of the Earth by an asteroid impact. Another feasible theory is that a supervolcano eruption completely destroyed the ecosystem, wiping out all life on Earth by either directly destroying them via a massive shockwave (if they were within range), or by slowly starving them as the resultant plumes of smoke would have blotted out the sun for years. But interestingly, scientists looking back over some extinction-level events of the past, discovered signs of both an asteroid strike and a volcanic eruption. This sounds to be extremely implausible, as the odds of both happening in the same era are near impossible (unless there is some extremely vengeful deity that hated the dinosaurs).

One theory that tries to explain all of this is the verneshot theory. To better understand the concept of a verneshot, imagine a cartoon character such as Yosemite Sam (the beloved red-bearded, gunslinging cowboy character on Looney Toons) shooting his gun wildly into the sky. Cartoon logic dictates that his bullets will eventually fall back on some unwary bystander. Now imagine if the Earth did the same thing, but instead of a bullet it shoots a giant piece of rock capable of causing mass extinction into the sky.

A verneshot occurs in a similar way a supervolcano erupts, where there is an incredible build-up of super hot molten rock. A supervolcano would be when this molten rock erupts as lava. In the case of a verneshot, massive amounts of carbon dioxide build up instead, leading to a pressure build-up under the crust. When the pressure becomes too much, the crust explodes, with the piece (of indeterminate size) being rocketed into space. However, the giant rock does not end up in space. Instead, it is only launched to a sub-orbital altitude, meaning it will come crashing back down to Earth due to gravity. Thus, a verneshot is when a volcanic eruption acts as a giant cannon to launch a piece of the Earth into the sky, which falls back to Earth as an asteroid-like object.

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Niven’s Laws

Posted on by Jinavie

Larry Niven is a science fiction author. Like many other science fiction authors, he is responsible for citing many rules regarding the world, humorous or not. Niven took to this another level by publishing a series of laws on “how the universe works” as far as he can tell. The following is the revised list as of January 29, 2002.

  1. Never throw shit at an armed man.
  2. Corollary to #1: Never stand next to someone throwing shit at an armed man. 
  3. Never fire a laser at a mirror.
  4. Mother Nature doesn’t care if you’re having fun.
  5. Giving up freedom for security is beginning to look naive. (or “F x S = k”, meaning that the product of freedom and security is a constant.)
  6. Psi and/or magical powers, if real, are nearly useless.
  7. It is easier to destroy than to create.
  8. Any damn fool can predict the past.
  9. History never repeats itself.
  10. Ethics change with technology.
  11. Anarchy is the least stable of political structures.
  12. There is a time and a place for tact.
  13. The ways of being human are bounded but infinite.
  14. When your life starts to look like a soap opera, it’s time to change the channel.
  15. The only universal message in science fiction: There exist minds that think as well as you do, but differently.
  16. Corollary to #15: The gene-tampered turkey you’re talking to isn’t necessarily one of them.
  17. Never waste calories.
  18. There is no cause so right that one cannot find a fool following it.
  19. No technique works if it isn’t used.
  20. Not responsible for advice not taken.
  21. Think before you make the coward’s choice. Old age is not for sissies.
  22. Never let a waiter escape.

Posted in Science & Nature

Seven Bridges Of Konigsberg

Posted on by Jinavie

The city of Königsberg (capital of Prussia, now Kaliningrad, Russia) has the Pregel River running through the middle, with islands at the centre of the river connected by seven bridges. Is it possible to cross all of these bridges while only crossing them only once each?

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If you try to solve this problem, you soon discover that it is incredibly difficult not to cross the same bridge twice. But it is difficult to tackle this problem in a brute force manner. To calculate all of the permutations in the order of bridges, you use 7! = 7 x 6 x 5 x 4 x 3 x 2 x 1 = 5040, meaning that there are 5040 possible arrangements of bridges. Then how can you prove if the problem is solvable or not?

The great mathematician Leonhard Euler, upon being asked to solve the problem, is reported to have said that the problem is impossible to solve on the spot. In 1735, he proved his answer by modelling the seven bridges of Königsberg in a diagram of four dots connected by lines (representing the bridges).

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By using this model, the problem is converted into a “draw in one stroke” problem, which is also called a Euler walk to honour Euler’s contributions. Euler discovered many properties and laws regarding such problems. If a certain point is the starting point, then the line must first leave the point, then even if it comes back to the point, it must leave again. Ergo, the starting point must have an odd number of lines connected to it. The opposite applies to the ending point, where a line must enter the point, and if it leaves the point it must come back to it. Ergo, the ending point must also have an odd number of lines connected to it. In the case of a Euler walk, the starting and ending points are identical, so the number of lines is the sum of two odd numbers, making it an even number. Thus, to find out whether a picture can be drawn using one line, use the following laws:

  1. If there are no points of odd degree (odd number of lines), the starting and ending points are identical.
  2. If there are two points of odd degree, the starting and ending points are different.
  3. If there are one of more than two points of odd degree, it is impossible to draw using one stroke.

Thus, a Euler walk is only possible if there are 0 or 2 points of odd degree. Looking at the seven bridges of Königsberg problem, we can see that A is connected to 5 lines and B, C and D are connected to 3 lines each. As there are four points of odd degree, we have thus proved that it is impossible to draw a path that crosses all the bridges while not crossing any bridge more than once.

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Posted in Science & Nature

Mother Horse

Posted on by Jinavie

Female horses (mares) exhibit a very strange behaviour after they mate with a male. A mare will mate with every other male in the stable, almost immediately after mating with the first one. This strange post-coital promiscuity does not appear to make any sense from an evolutionary perspective, as one would think that pregnancy would lead to a decrease in libido so the mother can focus on caring for her embryo. However, this promiscuity is part of a strategy that helps protect the baby horses.

It is common behaviour in the animal kingdom for a male to kill a female’s young so that he can mate with her and produce babies with his own genetic material. This also happens in horses, where stallions engage in infanticide, kicking a foal to death if it is not his. For a mother horse, this is not only heartbreaking, but also a tremendous waste of the energy she put into pregnancy. So to protect her offspring and conserve energy, she ensures that no male knows who the father of her baby is. It has been shown that males who mated with a female who gave birth will not attack the foal, as there is a chance that it is his. Thus, a mother horse guarantees the protection of her child by prostituting herself to all of the males around.

Although the story of a mother willing to sacrifice everything, even her dignity, for the safety of her offspring may be inspiring, it has also been observed that if a mare cannot mate with all of the males in the stable, she will instead abort the pregnancy. For example, if a new horse is brought into the herd after the mare becomes pregnant, the mare senses the danger to her eventual foal and proceeds to abort it. In a study involving zebras, it was found that bringing in a new male made the foal’s chances of survival fall to less than 5 percent.

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Three Little Pigs

Posted on by Jinavie

The story of the Three Little Pigs is a timeless tale of how important good planning and doing things right is. Also, it serves to remind us that good architecture and engineering is key to one’s survival. A key aspect of the story is how the wolf “huffs and puffs” to blow the straw house and the stick house away. However, he cannot blow the brick house away as it is too well-built. Out of scientific curiosity, how hard does the wolf have to blow to destroy the Little Pigs’ three houses?

An experiment was performed to scientifically test this tale. The researchers built a house out of straw, a house out of sticks and a house out of bricks, then set up a fan to test at what wind speed the house was destroyed. The straw house blew away when the wind speed was 11m/s. The stick house lasted a little longer, up to a wind speed of 21m/s. Then what about the brick house? The brick house withstood winds of 35m/s, whereupon the researchers had to stop as the strong wind nearly blew the people away.

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Belling The Cat

Posted on by Jinavie

There once lived a community of mice in the attic of a house. The mice would sneak into kitchens, gnaw holes in the walls and run about freely. The owners were so fed up that they brought in a cat, causing the mice to all hide in fear. The terrified mice eventually held a meeting to discuss how they would sneak around the house without getting caught by the cat. One mouse suggested: “What if we put a bell around the neck of the cat? Then we can hear it coming and run away.”. The mice unanimously agreed that it was a brilliant idea. However, when they came to decide who would bell the cat, no mouse was brave enough to step forward and the plan was never carried out.

What would actually happen if a cat was belled? Without a doubt, the cat would take it as a cruel, cruel punishment. Not because it cannot catch mice, but because the sound of the bell ringing every time it moves will be extremely loud for the cat. A cat’s hearing is six times better than a human’s. With this excellent hearing, the constant sound of bells attacking its eardrums would be physical torture for the cat.

Furthermore, a cat can hear frequencies as high as 40,000Hz. A person can only hear up to 20,000Hz, meaning a cat hears over twice the range of sounds we can. This combined with the boosted volume results in the cat living in a very noisy world. Ergo, putting a bell around a cat’s neck is an extremely atrocious thing to do.

Posted in Science & Nature

Cattle Mutilation

Posted on by Jinavie

For decades, there have been case reports by farmers who found mysteriously dead cattle with strange, surgically precise wounds. Strangely, these corpses were split open and most of their soft organs (e.g. eyes, tongues, intestine, genitals) had been removed. Even stranger, the corpses were completely drained of blood.

The mysterious, mutilated cattle corpses set off a diverse range of conspiracies of what could have caused such a bizarre phenomena. The most popular theories included: alien experimentation (explaining the surgical precision and lack of blood and organs), sacrifice by cults, vampires and the El Chupacabra (a mythological vampiric beast).

Cattle mutilation became so well-known that during the 70’s, it was properly investigated by the FBI. Of course, no evidence was found of aliens and vampires. As with most supernatural phenomena, cattle mutilation could be logically explained by science.

It was found that the cattle had simply died of natural causes, with no foul play involved (other than the occasional psychopaths attacking cattle). But how could natural death cause the surgical wounds, the missing organs and lack of blood? The answer is obvious when one thinks of what happens to animals after they die.

Scavengers such as foxes and buzzards often feast on decomposing corpses, cleanly removing the soft organs before they rot away (organs are the first to spoil). As scavengers usually bite into the corpses, this does not explain the clean wounds. This phenomena is due to insects also feasting on the corpse – a key part in putrefaction. Insects prefer softer tissue such as organs and ragged wounds, so after the insects are finished, wounds often look extremely clean. Also, putrefaction of tissue leads to massive gas production, causing bloating. Once this reaches a peak, the cattle corpse bursts like a balloon, causing clean tears in the abdomen. Lastly, the flies that were involved in cleaning away organs lay eggs, which hatch into maggots. Maggots immediately eat away the dead flesh and organs, even sucking up the blood that pooled at the bottom of the corpse. All of these factors combined results in what appears to be a mysterious alien bovine autopsy.

Although this may sound crazier than Chupacabras, the theory was actually tested in 1979 by a sheriff who kept receiving complaints about cattle mutilation. He took a dead cow, left it on a field and filmed it for 48 hours. The video clearly showed each step described above, proving that cattle mutilation was simply Mother Nature’s cruel, vicious way of returning a corpse back to the soil.