Walk Overtaking and why we kick stones

Walk Overtaking and why we kick stones…

Walking is the means of reaching our destination by foot. While walking, some people tend to walk faster than others. Different people walk at different speeds at different times of the day.

Overtaking is the phenomenon by which, a person walking behind another is found to be ahead of him at a different instance of time ahead of the current. In a more geekish sense, the position of the two people is swapped over time and distance. We are very familiar with the  way vehicles overtake one another on the road. A lot of this overtaking pattern is seen to be similar with the way humans overtake during walking.

Some people find it in-acceptable to suppress their walking speed just to adjust to the people ahead of them. Some find it thrilling to be ahead of another person. While overtaking a pedestrian, the “left-to-right ratio” calculated by the distance available to overtake from the left divided by the distance available to overtake from the right, is a very important factor. In most situations, this factor alone decides which side a person gets overtaked while walking.

To prevent a person from overtaking you, make sure you try to block him on the side of you whichever is of larger distance.

There generally is a lot of hesitation when it comes to overtaking a handicapped person, because, even if you are successfully able to overtake him, there lays a sense of pity and un-satisfaction. Most people prefer to walk side by side or take an alternative path if feasible.

People don’t care if small children overtake them. However, older people don’t like it when adolescents overtake them, due to the mixture of helplessness and envy.

Overtaking a pedestrian by running past him is viewed in a totally different way. Firstly you make it very clear that you are going to overtake so a path is made clear. Since walking and running are considered different activities, nobody cares if you get ahead, because it can’t technically be a competition.

We are born with this instinct to overtake. Even if we don’t have anybody to overtake while walking, we tend to kick stones on the pavement, observe the path taken by the stone, try to catch up with the stones motion and tend to repeatedly kick the stone over and over till one of the following may happen:

·         We reach the destination

·         We have someone else to overtake

·         The stone gets kicked off into some un-retrievable region.

I remember a day when I had kicked a stone all the way from my school to my home. Most people discover kicking the stone as an activity by themselves. It is fascinating how an extremely irregular stone can take seemingly predictable trajectory.

Though the habit of kicking stones as we walk lasts only for a short time, every once in a while, if we find a large stone in the middle of a road, we tend to not be able to resist the idea of slowly kicking the stone over to one side of the road.

Like I had mentioned in the blog on ‘Advice Proximity Effect’, gender, age difference, posture and height play a very important in overtaking mechanism. However, additionally facial expressions, mood of a person, choice of arena, level of urgency we can determine the success of overtaking.

Mood is perhaps the biggest influential factor and can cause a person to participate or give up in this overtaking activity:

Case 1: Consider the scenario, where you have had a good night’s sleep, had a great breakfast and have left home early-enough to reach the destination. This is when you feel that no force on earth can stop you, and you find yourself overtaking the most number of people.

Case 2: On the contrary, suppose you had a very bad day for reasons that can be due to one or more of the following incidents however several others not mentioned in the list can also be a reason for having a bad day:

·         You have been working all day and are very tired.

·         You got you test results and are not happy.

·         You broke up.

·         You did not get a certain expected output.

·         Your dog died.

·         Your best friend has left school.

                                                            …

In such scenarios, you feel like you don’t need one more competition to judge your talent and seem to give up on an opportunity to overtake a person while walking.

If the mood has been bad, due to a combination of the above mentioned reasons. Then you may even lack the concentration to walk, let alone overtaking or kicking a stone along… We can see this beautifully illustrated in the movie ‘Jab We Met’.


Anger is one more serious factor influencing kicking stones... If you are angry on one more person, each time you kick you sometimes can see the the persons face on the stone just before your feet touch the stone (^_~). It does depend on the level of the anger. If you are in some kind or irrational wrath, then you tend to look at the world around you just as i have described in the sad mood part.

Pen Dynamics

Pen dynamics:

Dynamics is the study of motion of bodies. Well what has that got to do with a pen??? In our every day occasion we can see people twirling pen between their fingers. The motion of the pen around the pen and landing in an exact position which makes it appear as if he intended to hold it as we do when writing is studied in pen dynamics.

Origin: Pen dynamics originally began when students who were bored by a teachers continuous nagging in a class started thinking of productive ways to use the time.

It might have begun in any part of the world. But there are several points of origin to this art and there are newer and newer versions of the twirling seen in everyday lives.

Some learn the art to show that they are skilful. Others use it to show-off in a class. Some attempt to reverse the direction of the motion and find success. But at this point we must see that what began as a means to utilize time productively has just ended up in entertainment.

Some do it so often, that they don’t even realize doing it at times. Some people have developed the skill so well that they can do it continuously without ever stopping (^_^).

There are parameters that guide the motion of the pen which can be proved by solutions to newtons laws of dynamics, but let not get into that right now. Because these are passive skills that were achieved without doing those tedious calculations.

Pen-dynamics just like any other area of study has its own restrictions. For one, it is found to be very effective with dot pens. But when tried on fountain pen, the results turn out to be really messy. However because of the underlying principle the pen manages to followed the expected trajectory in both the scenarios.

Men are familiar with the arts of pen dynamics more than woman, there are very few woman who can perform this skill. Pen dynamics enthusiasm generally develops right at the time we reach the dynamics section of physics in our schools. But very few people manage to cultivate this as an active hobby and take it all the way up to college.

However on entering corporate world, the kind of skill is no longer appreciated, also costlier pens tend to lose ink from the back (a phenomenon I can’t currently comprehend). Thus many of the cultivated art forms are lost in time.

In many of the occasions, elders often as a teacher or parents tend to tell us not to perform pen rotation in the open. This is causing a lot of harm to the survival of pen dynamics, and as students its our right to fight against such acts of silliness.

While looking over the net I have recently found links that help educate the people around the world to learn the art of pen rotation. The art is scientifically called as sonic(http://www.upsb.info/wiki/index.php?title=Sonic) and inverse sonic (http://www.upsb.info/wiki/index.php?title=Inverse_Sonic) for more details yoube it...

This art has many benefits which are overlooked most of the time. For one, it is a remedy for repetitive strain injury. It increases the dexterity of the user. Also it takes so much of the attention that it prevents us from yawning even in conditions of really boring lectures.

For all you know, this method might be one day used to generate energy needed for small electronic devices (ha ha ha ha ha... {(~_^)})

For all you know it might have a shorter solutions of gyration and other circular rotation problems.


Some people can even rotate pens around their fingers on both hands and simultaneously. Such accomplishments deserve awards!!!

I mean look at this beautiful phenomenon, an axis is formed around the finger that the pen rotates and the pen rotates due to centrifugal/centripetal force cancellation. The effect is also favoured by gravity because of which the two end states:Start and Stop are specific.

Pen Fights:

One of the more interesting extension of the pen dynamics lies with the traditional 'pen-fights'.

Unlike street fights, a pen fight is literally fought between pens. To begin with, the two pens are laid on a table or a bench. Traditionally a guy begins a pen fight with the toss of a coin. The objective of the game is to knock the other pen out of the arena.

Here, unlike in the previous case, there is no fixed axis of rotation. The pens traverse as they rotate and the mathematics can be quite complicated. However, a player can sometimes make startlingly accurate predictions about the trajectory that his pen is likely to take.

Pen fights are friendly games; however, a user must understand the risks before entering into a penfight!!! The pen might get damaged when it falls off the table. The pen might start leaking from the back. The pen might hit some other person in the vicinity.

Also Mutated version of this game are found in many schools where a pen is substituted by a marker. General dynamics can solve problems arising in those.

Sometimes, when pen fights are played in the midst of an ongoing lecture, there is also the added risk of exposure. It is still a mystery to me on how the two pens during a pen fight can land one on top of another. Especially when the two travel in the same plane collide and land up in strange positions. It is as if these objects can move from 2D(the surface on which the pen fights are played) to 3D because of some underlying mechanism....


Various unreported experiments have been conducted on pen fights, such as adding rubberband to a pen, combining 2 pens to check the trajectory, adding a cap from a spare pen to make it more stiff. However there is no clear documentation on any of the experiments because it is not taken seriously enough!!!!

Bus - seat acquisition via Aufbau principle.

Bus - seat acquisition via Aufbou principle.

Generally when we enter a seemingly vacant bus, we try to fill each seat in the order of one person per seat, and those who enter later on, fill the rest of the seats.

We have all studied in chemistry, that this behaviour is very much evident in electons when trying to fill a vacant shell. An electron fills a completely vacant seat first, and all the electrons that arrive later form pairs as per the Afbau Principle.

It is remarkable how the results seen in electrons are also visible in real life scenarios.

If the bus is completely vacant then the first arriving person takes a considerable amount of time to decide where to sit, this is because he tends to rely on his past experiences and need to sit in a particular seat such as a window seat. Other factors affecting the sitting could be the proximity of the bus tyres to the seat, relative distance from the entry to the bus, etc...

However when almost all seats have been occupied by at least one individual, the oncoming visitors, tend to occupy a seat in a hurry. Because he is concerned about Factors like:

• Destination distance
• Need for comfort
• The apparent demand for the seat
• In case there are lot of people boarding the bus at the same stop

The late arriving passenger does not mind the dimensions (body sizes) of the people occupying the seats which are vacant when he gets in. He tends to temporarily rely on instincts rather than thought process, and often gets denied of better available opportunities.

More-over, a late arriving passenger would have experienced a lot of waiting in the bus-stand and desperately sees the comforts offered by the sitting arrangement in the bus.

Another interesting phenomenon is the kind of orderliness that happens when an interested traveller sees an approaching bus from a busstand. It is as if, someone has ordered everyone to queue up in many situations, all the people waiting in the bus stand suddenly become extremely alert; It can be compared to the the way iron filings behave in the presence of a magnetic field. (^_^)

However this is not true if a lot of people are waiting in the bus stand, because in this situation, people tend to mass up and there is a lot of confusion while boarding the bus apart from the inherent competition.

It is also observed that when a completely filled bus approaches a bus stand, the situation is very different, but we can observe that the environment is usually unpleasant.

Bus Seat Reservation:

For the convenience of woman travelers, the government of Karnataka has enforced reservation of seats for Woman, the old aged people and the handicapped. How ever, despite the contention for these seats, normal seats are also most often reserved much earlier than they are occupied.


Like my friend Naresh points out, It is a common scenario to reserve a seat by marking the spot with your kerchief. This reservation extends to Bags, Lungies, Towels, books, Bags and several other commodities that people happen to carry with them when they travel. Though normal reservations like these are common i many parts of the country, I had once heard that in Bihar, they spit the pan that they chew to reserve the seat, later wipe the seat just before acquiring it. I was shocked and surprised for a very long time after hearing this...


To reserve a seat, the person reserving it has to be alert and ready to strike as soon as the bus arives. He should jump select the appropriate seat for reservation and throw the kerchief just as the bus stops, else the seat can get reserved by another person.


BUS overflow:
This phenomenon has been commonly observed in cities in India, where there is shortage of public transport during peak hours and people are forced to resort to standing on the foot-board, back ladders and the roof tops of the bus or any public transport. I have traveled like this many times, though there is a little amount of suffocation on the inside, hanging on the foot board could be a fascinating experience.

Bus overflow

Footboard travel

As you can observe in this figure, women enjoy a better facility when it comes to foot board travel and many prefer to take the next bus instead of trying to fit into the same bus.

Why don’t we see black light?

Q) Why don’t we see black light?

I had asked this question to my teacher and she had told me that black was the mere absence of light and not a light by itself. I appreciate all the effort the teacher had put into answering this question for me. 

I have seen a villain in Justice League, use black torch to engulf the heroes into a realm of eternal darkness, now don't tell me that he does it with the absence of light!!!! I demand  anexplanation!

Don’t we see crows in bright daylight? 

Seriously, I did not fall for this answer. I used to wonder if there can be red light, blue light, green light, then we might as well have a black light. Time after time, my teachers had given me the same answer and finally one day I got a reasonable answer.

If you have seen how a projector projects characters on the screen, you will notice that even though the screen itself is white, the projector can project all kinds of light combinations. Yes it can project black on a white screen. This was a major revelation to me.

Black light bulbs don’t exist because you don’t need to darken a place using a bulb, you are comfortable with reducing the light intensity and living in shadow, but like in a projector it is possible to project black onto a region. Or an entire room for that matter. Yeah, well think again!!! 


There are black light parties celebrated in various parts of the world, and we can see them in movies. Here's what, today we do have black lights. Its going on now and we are not aware of it ( go on, google black lights)

I am aware that black ink is made by saturating red or blue ink till it appears black. As per physics white light is combination of all colours and black is absence of all the colours. But look at my line of questioning. It is very evident that man can see only a very small part of the colour spectrum. If something is black to you, can you justify that it is black to a cow, or a dog, or an eagle, an elephant. No!! You can’t because they see colours in different spectrum. 

This subject is prone to discussions from a lot of considerations and I welcome you to comment against the discussion or in support of it. But seriously, look at the Electromagnetic spectrum, and look at what we call colours. Isn’t it justifiable to expect more from your teacher than all of that you can find in a text book or encyclopaedia for that matter?

I recently came across an article on how black lights work, interested readers are free to visit this site. 

Bicycle Incident - A Brake failure

One day I had borrowed my friend Vinay’s bicycle on the way back from school. He had informed me that the brakes were a little loose and asked me to ride carefully. 

I was just learning to ride a cycle that time and as we continued down the road, suddenly I noticed that a speeding auto-rickshaw was heading down the same path, so to make way, I increased my speed just a bit, to my misfortune, and the cycle wouldn’t stop no matter what and kept accelerating down the hill. My friends kept looking at me ride down the road as I went zooming downhill.

Fortunately, that day, the roads were dug up to correct the optical fibre cables in the ground. I sped into the ditch, landing on the other side of the ditch, with the cycle inside the ditch. Since the ditch as a wide mud barrier, it kind of shielded the bike from scratch, and me from severe wounds.

I still remember the kind of thrill and panic I had on that day. Though I regret now for being so careless with my life, I am happy that I got to experience this event.

I later analyzed most of the options I could have taken on the way down.

On that day, because of the ongoing construction work on the side road, there was a lot of sand, I could have decided to land on the sand, but as most of you might have experienced, Sand can be dam slippery and I might not have made it.

Suppose the roads were not dug up on that day, I would have no way to stop myself from riding into the drainage channel on the other side of the road. Lucky me and thank God (^_^).

However, by the end of the year I got my own bicycle and had plenty of special experience which I will share some other time.