Posted in Science & Nature

Honeybee Dance

How do honeybees share the location of a food source, such as a flower, to other bees of their colony? An Austrian biologist named Karl Von Frisch devised an experiment to learn how the honeybees communicated with each other. He set up two different food sources and tagged every bee that came to pot A green and bees that came to pot B red. He then studied the behaviour of these bees back at the hive. What he discovered was fascinating.

For millennia, beekeepers have noticed that some honeybees have a tendency of moving in a peculiar yet methodical way once they returned to their hive after foraging for flowers. The bees would move in a straight line while waggling their bottom (moving side-to-side), then walk in a semicircle back to where they started. They would then waggle in the same direction, then move in a semicircle on the opposite side, completing a figure-eight path. This is called a waggle dance.

image

Frisch noticed that bees with green spots and the bees with red spots both did the waggle dance once they returned to the hive, but in different directions. All bees with green spots danced so that the straight line pointed a certain direction, while the bees with red spots danced the same dance except pointing another direction. Amazingly, the angle between these two directions was exactly the same as the angle separating pot A and B (with the hive as a point of origin). Frisch deduced that the waggle dance was the language of honeybees.

Through further experimentation, Frisch was able to tease out the details of this “language”.

  • Honeybees’ eyes can see ultraviolet and polarised light, which allows them to see where the sun is in the sky at all times. This is because sunlight polarises so that it points towards the sun and honeybees can see this direction. Therefore, the bee’s eyes act as a solar compass that tracks the exact location of the sun in real-time.
  • Bees have a finely-tuned internal clock that allows them to predict exactly where the sun should be depending on time, season and latitude, as the sun moves through the sky.
  • Another point of reference that is used in the bees’ language is gravity. Gravity is a constant that does not change, meaning all bees know which direction is “up” and which is “down”. This also means they can use a vertical, perpendicular line as a standard zero-point.

By pairing the two global constants, gravity and the location of the sun, the bees can accurately signal to other bees the direction they should fly in to find the food source. If a bee does a waggle dance that points 60° right from the vertical “up” direction (as defined by gravity), it signals that the bees should fly 60° right from the direction of the sun. If the angle is 0°, the bees should fly directly towards the sun, and if the angle is 180°, the bees should fly directly away from the sun. The bees use their internal clock to calibrate the direction depending on the time of the day.

The straight line “waggle” part of the dance gives the information of distance. The longer the duration of the straight line, the further away the flower is. As a general rule of thumb, the duration of the straight line increases by 1 second for every 1 kilometre. When the food is within about 60m of the hive, the 8-shape waggle dance turns into an O-shape round dance. The bee deduces the distance by the energy required to fly to the location.

By encoding the two variables “direction” and “distance”, a bee can effectively use the waggle dance to accurately pinpoint the location of a food source. It is amazing to see that animals that we consider “primitive” such as bees have such an intricate method of communication.

image

(Image source: http://aireona93.deviantart.com/art/YAY-Waggle-Dance-146361214?q=boost%3Apopular%20waggle%20dance&qo=1)

Posted in Science & Nature

Cryptography: Frequency Analysis

A cipher is a message that has been encoded using a certain key. The most common and basic type of ciphers are encrypted using letter substitution, where each letter represents a different, respective letter. For example, the message may be encoded in a way so that each letter represents a letter three values before it on the alphabet (e.g. if a=0, b=1… “a” becomes “d”, “b” becomes “e” etc.). This creates a jumble of letters that appears to be indecipherable.

However, the characteristics of substitution ciphers make them the most decipherable type of encryptions. As each letter can only represent one other letter, as long as the key is cracked (i.e. what letter is what), the message and any future messages can be cracked. The most important tool in decrypting substitution ciphers is pattern recognition and frequency analysis.

Frequency analysis relies on the fact that every language has certain letters that are more used than others. In the English language, the letters that are most used, in order, are: E, T, A, O, I, N, S, H, R, D, L, U (realistically, only E, T, A, O are significant and the rest are neither reliable nor useful in frequency analysis).

For example, if Eve intercepted a long, encrypted message that she suspects to be a simple substitution cipher, she will first analyse the text for the most common letter, bigram (two letter sequence) and trigram. If she found that I is the most common single letter, XL the most common bigram and XLI the most common trigram, she can ascertain with considerable accuracy that I=e, X=t and L=h (“th” and “the” are the most common bigram and trigram respectively). Once she substitutes these letters into the cipher, she will soon discover that certain patterns arise. Eve may notice words such as “thCt” and deduce that C=a, or find familiar words and fill in the blanks in the key. The discovery of each letter leads to more patterns and the vicious cycle easily breaks the code.

Frequency analysis is extremely useful as it can be used to attack any simple substitution ciphers, even if they do not use letters. For example, in Sir Arthur Conan Doyle’s Sherlock Holmes tale The Adventure of the Dancing Men, Sherlock Holmes uses frequency analysis to interpret a cryptogram showing a string of hieroglyphs depicting dancing men.

To reinforce this weakness in substitution ciphers, many cryptographers have devised better encryption methods such as polyalphabetic substitution, where several alphabets are used (e.g. a grid of two alphabets – also called a tabula recta).

Posted in Science & Nature

Alex The Parrot

Alex (Avian Language EXperiment) was the name of an animal psychology experiment that ran for 30 years starting from 1977. The experiment was designed to see if birds could undertake complex problem solving and learn languages like primates. For this, Dr Irene Pepperberg bough an African grey parrot, named him Alex and started teaching him how to speak. Before Alex, scientists believed that animals needed a large enough brain like a primate to handle the complex problems related to language. But Alex proved otherwise.

Before Dr Pepperberg, scientists failed to establish any two-way communication with parrots. She used a new training technique called the model/rival technique, where two trainers act in front of the parrot to teach it things. The method is as follows. One trainer (the rival) shows the other trainer the desired student behaviour they want the parrot to learn. The other trainer then compliments the trainer and shows attention. The parrot sees that the behaviour gets the trainer’s attention and learns it to compete with the rival. This technique was extremely successful and Alex began picking up words at a very fast rate (technically it was more of a two-way communications code than “language”).

Once communication was possible, Dr Pepperberg taught Alex many different concepts. Over the course of his life, Alex learnt 150 words, how to differentiate between seven colours and five shapes and also understood the concept of numbers and sizes. If you showed Alex two objects, he could answer many questions regarding one object (thus showing that his response was not a conditioned one). For example, if you showed him a small blue key and a large green key, he could answer what colour the larger key was, or which one was the green key. Furthermore, if a plate full of objects of different colours and shapes was presented to him, he could correctly count how many green blocks (or any other shape or colour) there was among the objects. The important point here is that he could pick out just the green blocks, excluding green balls or blue blocks from his answers (showing he fully understood the question and could attribute more than one characteristic to one object). He knew how to express himself, such as saying “Wanna go back” when he was tired, and would give playful, incorrect answers when bored of the repetitious experiments. According to Dr Pepperberg, Alex had the intelligence equal to a dolphin, a great ape or a five year-old child. He also knew how to attain knowledge by asking questions, such as when he asked what colour he was to learn the word “grey”.

Alex, who told us so much about the intelligence of a parrot, unfortunately died in 2007. The night before he died, he said the following last words to Dr Pepperberg: “You be good. I love you”.

Posted in History & Literature

Language

If one was, for some twisted and malicious reason, wished to systematically destroy a culture, what would the first step be? Genocide? Brainwashing? The answer is destroying the native language.

Language is the skeleton that supports the culture of the people. It is an integral part of every culture that allows for effective communication of ideas and thoughts. Each language is tailor-made for a certain culture and best exhibits the culture’s character and ways. Language is one of the greatest inventions of mankind as it allowed for the preservation of thought. If you do not record thought into words, it may be distorted, warped or worse – be forgotten. Using words, one can pass on knowledge to others, even in the future. This is essentially what culture is: a collection of ideas and knowledge that we inherit from our predecessors.

As these thoughts were recorded in one language, there is bound to be some distortion during translation. We can often see examples of barriers in communication due to the inability to properly translate a word from one language to another. If you cannot describe an idea with words, it is extremely difficult to preserve the idea. Ergo, by destroying the language of the people and enforcing your own on them, you can mutilate or eradicate their culture over time. Of course, since language is a major part of the endemic culture, you have gotten off to a great start already. When the people lose their language, they become susceptible to being assimilated into another culture. Slowly, they talk and think like the oppressors until they lose all identity of their roots.

During the early 20th century when Imperial Japan was invading neighbouring countries, they used the exact same method to try and eliminate other cultures. They outlawed the native language and enforced the use of Japanese. To protect their cultural identity, Koreans (and other countries invaded by Japan) had to teach children in underground schools at the risk of torture or death. The preservation of the Korean language allowed the people to unite with strong patriotism, fuelling the resistance against the oppressors. Without the dedication of the people, who knows how much precious cultural heritage would have been lost forever.

When the people lose their language, they lose their voice. When people lose their voice, they lose their identity. When they lose their identity, they lose the fight.

Posted in History & Literature

Flower Language

Roses are the most common flowers used in modern society to profess one’s love. However, many people do not know the true meaning behind each flower. For example, every colour has a different meaning for roses.

  • Red rose: true love, passion
  • White rose: eternal love, innocence
  • Black rose: death, farewell
  • Yellow rose: friendship, jealousy, betrayal
  • Pink rose: grace, gratitude, youth
  • Mix of red and white roses: unity

As seen from above, a rose can mean love, friendship or even separation. It is also important to note that roses are traditionally given as a bouquet of one, six, dozen or any multiple of six. 
The following is a list of common flowers and what they symbolise:

  • Acacia: secret love
  • Bellflower: thinking of you
  • Cherry blossoms: beautiful mind, purity
  • Chrysanthemum: peace, love, mourning (used in funerals)
  • Cosmos: forever, devotion
  • Daffodil: Chivalry, respect, unrequited love
  • Daisies: innocence, modesty, beauty
  • Edelweiss: memories of an important person
  • Hibiscus: rare beauty
  • Lavender: silence, devotion
  • Lilac: memories of youth, first love
  • Lily: innocence, chastity, purity
  • Magnolia: unrequited love
  • Pansies: memories of love
  • Sunflower: happiness
  • Tulip: declaration of love (red), hopeless love (yellow), broken heart (white)
  • Violet: faithfulness