Posted in Science & Nature

Hexapod

Dragons are fantastic creatures of our imaginations, so they do not follow many of the rigid laws of natural science. They breathe unlimited amounts of fire, can endure extreme heat and they can fly despite their massive size. But perhaps the most unrealistic feature of dragons is the fact that they have an unnatural number of limbs.

All vertebrate animals on Earth follow a simple rule: they are four-legged creatures, also called tetrapods. The limbs may have devolved away such as in whales and snakes, but they remain as vestigial structures or still encoded for in the genes. Birds and bats have adapted their upper limbs into wings to fly, but the total number of limbs is still four.

How many limbs does a dragon have? They have four legs that they stand on, but also two large membranous wings like a bat. This means that they have a total of six limbs. The only other animals that share this trait are insects and other mythical creatures such as the centaur and pegasus.

To be a vertebrate with six limbs, a dragon must have evolved from an ancestor separate to Tetrapodomorpha, an ancient fish-like creature with four limbs that is the common ancestor to all four-legged beasts. Alternatively, the wings may not be true “limbs” and be similar to flying lizards that evolved to have a rib jut out with a membrane attached to act as a glider.

Unlike the scientifically inaccurate dragon, a wyvern obeys nature’s four-leg rule. Furthermore, unlike the traditional Western dragon that we have been describing, dragons of the Far East have no wings and four limbs, also obeying the law.

As ridiculous as it may sound, applying scientific principles to our imagination allows us to learn more about how our world works.

Posted in Simple Pleasures of Life

Simple Pleasures of Life #29

Doing absolutely nothing.

I kinda mentioned this in a previous post, but that was more in the context of taking a break. Don’t get me wrong, I LOVE doing stuff. Especially right now where all I can think of is all the stuff I’m waiting to do as soon as exams are over. But there’s a real simple joy in doing absolutely nothing. Just…sitting there, you know?

Of course I don’t mean literally nothing where you switch off your brain. That’s what you do when you watch TV (which I heartily endorse). But I mean putting down the book you’re reading or pausing that video, sitting back and getting lost in your thoughts. Maybe you’ll ponder the deep philosophies of what it means to be alive, or create an imaginary world you can adventure in.

If you don’t feel like exploring the inner workings of your mind, then get lost in your surroundings. Have you ever really taken into account what you see, hear, smell, taste and touch? Bernard Werber talked about a relaxation technique called “Opening your senses” in his books, which involves you systematically saying out loud everything you experience in the moment with each sense. For example, close your eyes and say everything you hear, to the smallest detail. Then do the same with all your other senses, you’ll notice that you’ve been missing out a lot of things in this world.

Sherlock Holmes stated that there is a great difference between seeing and observing. Try this out sometime. Have a cup of coffee at a cafe by yourself and look around you. You might see a boy and a girl making idle chit chat, but you might observe the two showing various subtle body language signs of mutual attraction. See if you can figure out a person’s job or personality or health condition just from observation. People-watching can be very fun, as long as you’re not being…you know, creepy.

So go on, drop what you’re doing, go lie in a patch of grass or sit at a cafe or wherever and just do nothing.

image

Posted in Psychology & Medicine

Tetrachromacy

They say that human imagination is infinite and limitless. But consider this: can you imagine a colour outside of the visible spectrum? Most likely, you are incapable of thinking of a new colour that cannot be mapped on a standard colour chart. Interestingly, a small proportion of people can see and understand colours beyond the range that the majority of us can see.

The physiology of vision is rather complex, but essentially boils down to the retina (inside lining of the eyeball) acting as a film for the image that you see. Cells known as photoreceptors convert the visual image into electrical signals that are transmitted to the occipital lobe of the brain via the optic nerve. There are two types of photoreceptors: rod cells, which sense movement, and cone cells, which sense colour and provide sharp images (visual acuity). Human beings typically see colour by combining three primary colours: red, green and blue (known as the RGB system). There are cone cells for each primary colour. The brain processes the signals sent by each cone cells and figures out what “colour” you are seeing. Therefore, you can only perceive colours made from a combination of red, green and blue. It is easy to visualise this by playing with colour palettes on computer programs such as Photoshop.

In recent years, it has been speculated that a certain percentage of women have an extra type of cone cell that senses a different wavelength of light. Ergo, they can theoretically sense a greater range of colours compared to someone who has three types of cone cells. This condition is called tetrachromacy (“four colours”). Tetrachromacy is the opposite to colour blindness, which is caused by a deficiency or fault in one or two types of cone cells. To these people, the average person (a trichromat) will appear “colour blind”.

According to one estimate, as many as 12% of women are tetrachromats. Although there are many theoretical barriers to true tetrachromacy, there have been several documented cases of women who perceive colour in much more depth.

The ability to see an extra primary colour is more significant than just a 25% increase in the person’s colour range. An average person can see about 1 million different hues (shades of colours), while a true tetrachromat can see 100 million hues – a hundred-fold increase in the range of colours they can see. One can only wonder what kind of amazing sights a tetrachromat sees when she gazes upon a field of flowers or even a rainbow. Unfortunately, even if a tetrachromat tried to explain the colours she saw to us, we would not be able to grasp the colours as our minds would be incapable of visualising the colours, much like how describing the colour red to a blind person is impossible.

image
Posted in Philosophy

An Opinion On The Senses

There are five physical senses and five mental senses.

The physical senses are sight, hearing, touch, taste and smell.

The mental senses are emotions, imagination, intuition, understanding and inspiration.

If a person only uses their five physical senses to live, that is like using the five fingers on their left hand only.

(Die fünf Sinne (The Five Senses) by Hans Makart, 1840-1884)