26 April 2011

Do We Have Differest Taste Zones on Tongue?

We all are familiar with the 'tongue map' concept which says we have got different areas of tongue that senses different tastes. It also says that there are four primary tastes namely sourness, sweetness, saltiness and bitterness. See the figure. It shows the areas on our tongue which are supposed to receive these primary tastes.
But how many of us know that it is utterly a false idea? Yes, of course it is. This century old misconception comes from the research paper of a German scientist D. P. Hanig published in 1901. Probably, it is the most popular false idea ever presented and Hanig owns the credit of misguiding generations for a century! It was only in 1974, Virginia Collins re-examined Hanig's findings. She does agree to Hanig in one concept; there are variations in sensitivity to the four basic tastes. But it is too small to have any practical significance. Collings found that all tastes can be detected anywhere there are taste receptors—around the tongue, on the soft palate at back roof of the mouth, and even in the epiglottis, the flap that blocks food from the windpipe. 
Another fact is, other than sweet, sour, salty and bitter, there is another fifth distinct taste. It can be called 'meaty' which is the taste associated with meats. It is the taste of glutamate.
It is a mystery why scientists didn't bother about this seemingly simple idea until 1974 and why on earth the text books print this idea even today. [Read more]

25 April 2011

Why Do Watches Always Show 10:10 in Ads?

Most of you must have noticed that the picture of watches in advertisements always show 10:10 on their dials. But do you know why is it so? There are so many rumors regarding this question. Some say, it is the time Abraham Lincoln was shot, some others say it is the time the inventor of wrist watch Patek Philip died. But none of these is true.
According to what Timex says, the answer is quite simple. When the time is fixed at 10:10, it gives the look of a 'smile' and the manufacturers want their products to be smiling at the customers. Another advantage is that in that position, the manufacturers' trademark or logo on the top of the dial is fully visible. Timex clocks always show exactly 10:09:36 in their ads. Later this became a custom to show 10:10 on all watches, and even digital watches show this time.
But it should be noted that there do are some companies whose watches show other times such as 08:20.

19 April 2011

How Many Senses We Got, Just Five?

Sometime when we say something from our intelligent guess work, we say for fun "You know, I've got sixth sense". What make us say so is the assumption that man has only six senses and extra sense is surely superhuman. But how many of us knows that we have got far more number of senses. I'm not talking about any para psychological concepts. Although definitions vary, physiologically number of senses we got varies from at least 9 to more than 20!
The five senses we always talk about are sight, smell, taste, touch and hearing. These five senses were identified and listed by Aristotle in the 300 BC's. But modern science has identified many more senses. I'll tell you a few examples I know:
1. Equilibrioception- It is the sense that prevents us from falling while walking and standing.i.e., the sense of balance and equilibrium[Read more]
2. Nociception- This is nothing but the sense of pain. When you touch a hot iron box, you are not sensing 'touch', are you? Pain is a different perception than touch.[Read more]
3. Proprioception- It is the sense that helps you know the position of your own body parts. Have you ever thought a 'sixth sense' is working when you take food directly to your mouth without mistake even if it is perfectly dark?[Read more]
4. Thermoception- This you might have guessed. Yes, it is the sense that helps us know the relative temperature.When you say, 'Oh the climate is too hot', your thermoceptive sense is working. The exact mechanism behind this sense is yet to be known.

Some other senses that I don't know the names are the senses of time, itching, pressure, hunger thirst, fullness of stomach, need for urination and defecation( Number 1 and number 2!) and blood carbon dioxide level. So next time when you joke about your sixth sense, remember, six is too small a number!

Moon and The Great China Wall

Many of you might have read somewhere that the only man-made thing that can be seen from Moon on Earth is the Great Wall of China. Didn't you? But did you know it is purely false? Yes it is. None of the Apollo travelers who were on moon reported such a thing. Other than the Apollo travelers, nobody has ever been to moon. Then who on earth did spread such a 'fact'? It was one Richard Halliburton. The funny thing is, first moon-landing happened on 1969 and Halliburton had died in 1939! Don't think that Halliburton was a lying silly crack. He is a legendary American adventurer and author.(Read more about him here) In his 'Second Book of Marvels' he says "Astronomers say that the Great Wall of China is the only man-made thing on our planet visible to the human eye from the moon". He doesn't say which astronomer told him so. Anyway that is the source of such a widely spread misconception.
The above picture is a satellite image of the Great Wall. Can you distinguish it from the surroundings? And when you know Moon is ten times farther than an artificial satellite from Earth, how is it possible to see The Great Wall from Moon? Should I talk more now?

15 April 2011

Vishu - The Astronomical New Year

First of all, very warm Vishu wishes to all...

I thought today I shall talk about the astronomical side of Vishu.
We all know that from Earth, Sun would appear to revolve around us. The ancient people believed Sun actually is revolving around Earth in a circular orbit. To locate sun in its orbit, they divided the 'solar orbit' around Earth, called the ecliptic, into twelve equal parts. To identify these parts in sky, they joined some of the stars in that portion of sky to make out a picture. Then they named each part according to the picture they made out in that portion. These twelve parts of sky on the sun's path around earth are called the twelve Raashi's(രാശികള്‍), named Medam, Idavam, Midhunam etc. The strip of sky around Earth that comprises of these twelve raashis is called the Zodiac(രാശിചക്രം). See the picture below:
As Sun takes 365 days to make a complete revolution, it is trivial to see that it spends around 30 days (365 days/12) in a particular Raashi. Our Malayalam calendar is based on this concept. That is, our Medamaasam(മേടമാസം) is that period of the year during which Sun is in Medam raashi. The day on which Sun moves from one raashi to another is called Sankraanthi(സംക്രാന്തി). Vishu is astronomically the Medasankraanthi(മേട സംക്രാന്തി), that is, the day on which Sun enters Medam raashi.
Historically, Medam 1 is the beginning of Malayalam calendar. But most of us consider Chingam 1 as New Year which is the beginning of Kollavarsham(കൊല്ലവര്‍ഷം). This is believed to be started by the King of Kollam (Venad Udaya Marthanda Varma) who thought Chingam, the season of harvest, can be the beginning of a new year. Chingam has no astronomical significance. In another post, I had talked about the equinoxes when sun rises exactly in the East. At the latitude where Kerala is, it is around Medam 1 sun rises exactly in the East. So Vishu in Kerala represents Vernal Equinox.('vishu' in Sanskrit means 'equal').
So Vishu is the astronomical new year in Kerala. Once again, Happy Vishu to all

14 April 2011

Sun Doesn't Rise Exactly in the East Always

We have been hearing from childhood that sun rises in the East. But how many of us know that sun doesn't always rise in the East?
Actually only twice in an year does sun rise in the East. On all other days, the position where it rises will be either Northward or Southward to the exact East. And what is the reason? It lies in the fact that the axis of earth's rotation is not perpendicular to the plane in which it revolves around Sun. It is inclined at an angle of 23.5 degrees to its orbital plane.

See the figure above.It shows the variation in the circle of illumination (the circular portion on earth illuminated by sunlight) at different positions of earth on its orbit. It can be seen that on march 21 and September 22, sunrays will fall vertically at the equator. These days are called Vernal equinox and Autumnal equinox respectively. On these days, day and night will be of equal duration in equatorial region, i.e. zero degree latitude. Similarly, in other latitudes, there will be two days(separated by six months) in an year having equal duration of day time and night time and on these days sun will be rising exactly in the East. That means, Sun doesn't rise exactly in the east on days other than equinoxes.
This can be understood more simply by considering the example of a vertical post and its shadow. If we observe the shadow of the post on morning, it will be along west. As time passes its length decreases and after noon it increses along east. But does its length become zero at noon? Not always. Only on equinoxes, we can see that. On noon of all other days, shadow will be seen along north or south directions, although small in length.

07 April 2011

The Caesarean Delivery

When you saw the heading, did you think I am talking about the birth of Julius Caesar? I think some of you might have doubted for a while, "Is this the spelling of the caesarean delivery we often hear?" Yes, it is.
I thought I might write about this because once I saw a friend of mine writing 'scissorian birth'. He wrote so because, he found out the logic that 'birth carried out by the aid of scissors is scissorian birth'. I don't think he is an exception in this misconception.
Technically, Caesarean birth is a surgical procedure in which one or more incisions are made on the  abdomen of a mother to take the baby out, in the case where natural delivery is harmful to the mother(or to the baby).
There are rumors that this procedure got this name because birth of the Roman dictator happened by this method and so the method got this name. But it is false. It is said that this method got its name from 'Lex Caesarea' which are the ancient Roman laws around 700 BC, which required that child of a mother dead in child birth be cut from her womb (Ref: Caesarean section?: Etymology and early history South African Journal of Obstetrics and Gynaecology, August, 2009 by Pieter W.J. van Dongen).This seems to have begun as a religious requirement that mothers not be buried pregnant. It means Caesarean sections were performed even in the times of ancient Romans, although none among them are reported to survive. The earliest recorded survival is around 1500AD.

05 April 2011

"Oh, I think I've already seen it!"

Most of us have at least once exclaimed in our life, 'Oh, I think I've already seen this!" When you are in a get-together with friends, at some moment you feel that you have already been in exactly similar a company some time before. Or when your teacher(usually a teacher you likes a lot) tells a particular thing in the class, you feel he/she had already told this in the class in exactly similar a context. You might have overlooked it as one among the plays of mind.(Of course it is). But did you know this phenomenon has got a name? Yes, that feel is called Deja Vu. It is a French phrase meaning 'already seen'. This term was coined by a French psychology researcher named Emile Boirac.
Although this Deja Vu has been extensively studied by many psychologists, no established theory is there to explain this phenomenon. No one has ever succeeded in reproducing this feeling in laboratory conditions either. The exponents of ESP(Extra Sensory Perception or അതീന്ദ്രിയ ജ്ഞാനം) working in parapsychology consider this as a strong evidence of extra sensory powers. Since ESP itself is something yet to be approved as areal thing, it doesn't make any difference. Many attempts have been there to link deja vu with abnormal psychology like schizophrenia, dissociative identity disorder etc and even with the anomalies of neural networks in the brain. But it has been experimentally proved that persons with some observable anomalies in the temporal lobe of cerebrum, feels deja vu very frequently.
Whatever, I have experienced this Deja Vu many times and don't know how this stuff works exactly.

04 April 2011

Murphy's rule

Haven't you noticed when you wait for bus at a bus stop, all the buses go in the direction opposite to that you want to go? When you wait in a queue in railway station, the queue next to yours will move faster and the person in front of your queue will always have a long transaction. A coin dropped from your hand will move towards the farthest corner of your room. When a particular part of your hand is injured, you will more often hit that particular part thereafter. When you try to learn cycle riding on a ground where there is a single tree nearby, your cycle will definitely go towards that tree.
You can find so many such examples and many of them are already put to your notice by rigorous sms senders! But how many of us know that there is a particular name for that phenomena? Yes, there is. And that rule is called Murphy's Law. The law is stated as follows,
"Anything that can go wrong, will go wrong"
The essence of this rule is that the universe is against you! If you do something which has so many possible outcomes, and one of them being a bad one, then that bad outcome will have more probability. There are so many researches going on in this topic. There is even a book titled 'A History of Murphy's Law' by Nick T Spark.
Such incidences often have statistical explanations too. E.g. When you wait at a bus stop, you see buses in the opposite direction because if you get bus in your direction soon, you will not notice those buses in the opposite direction. So statistically, the probability of seeing buses in the opposite direction increases as you spend more time in that bus stop.
I must tell you that the things I told you in the first paragraph is just a common loose interpretation of Murphy's law. Edward Murphy, who was an aerospace designer, coined this word as key principle in defensive design. The law is actually is somewhat too philosophical and I'm not sure all of you will bear it. Interested buddies who can stand philosophical jargon may go to http://en.wikipedia.org/wiki/Murphy%27s_law