Tuesday, March 12, 2013

Relativity

Of the entire one and a half years I spent being a college student, there are only two (not listed as texts / references) books I studied which I still remember, now, years later.

The first was Abnormal Psychology. I had to write a term paper for my Psychology class and my topic was Obesity. I don't remember how I ended up looking into that title - obesity is abnormal? abnormal conditions that cause obesity? - but I borrowed it. I remember reading, with unparalleled fascination, case studies of patients with brain damage from either illness or injury, with their behaviour and/or speech and/or specific abilities greatly altered according to the location and extent of the damage. I distinctly remember the case of a man that, due to some sort of accident, had his trachea permanently fused, such that he was unable to even swallow his saliva. Doctors connected a feeding tube directly to his stomach, through his abdomen. The psychologists observed that the man chewed food before spitting them down his tube. He even "drank" beer by taking the liquid in his mouth, therefore, tasting it, before spitting it into the tube. This afforded them a study of the significance of satiation. So. Interesting.

Since I'm already digressing so much, let me share one other thing I remember from the term paper I wrote. *Ahem* A group of researchers designed an experiment where they had two groups of randomly selected volunteers. These volunteers were told that they were to taste a new snack product (potato or some other kind of chips) and to provide feedback on how well, tasty it is. Each subject was be provided a bowl of chips. Those in the control group were not told anything futher whereas those in the test group were given a limit of how many chips they were allowed to eat. In other words, they had a constraint. The researchers then quietly observed and noted the amount the subjects ate. In the second half of experiment, the whole setup was repeated with the test group subjects being told they can eat as many as they like - no more constraint. The control group subjects were not given any instructions as previously. With a constraint imposed, predictably, the test group subjects ate much less compared to the control group. However, when the constraint was lifted, they ate significantly more than the control group, which showed no increase or decrease in amount of chips consumed between the first and second half of the experiment. The researchers (or some others, I forgot...) also observed that subjects tend to eat more when they are alone, than when in company of others (maybe because we all grew up with judgemental friends?). So, in conclusion, if you are trying to lose weight, don't try to stop yourself from eating (you'll risk overeating the moment you stopped stopping yourself) and always eat with a condescending person who loves to judge and criticize. Kidding =P

Now, the second one (yea, I was talking about books I read in college that left lasting impression on me) was a Physics title. I don't remember what I was doing, reading a Physics book that was out of my league at the time. I guess I didn't have a life. I studied the entire chapter on Einstein's Special Relativity, math and all. Yes... I actually studied all the mathematics. Unfortunately, I'm not genius enough to remember any of it *sad* One of the concepts - that time slows down for one travelling at speeds approaching the speed of light - remained in my memory though. It was perhaps also around that time that I was first exposed to the idea of time being one of the dimensions we live in. For example, if one gives 3-d coordinates of a place one is to meet a friend, the two will most likely not meet, unless one specifies the time of meeting as well. There are at least 4 dimensions.

I had for some time intended to revisit the theories of relativity, but as always, I had other things to do (I'm full of excuses, aren't I?). Recently, I came across this title:


It's all about the theories of relativity without the math! Well, there are simple equations that anyone can handle, but not any of those that only mathematicians and physicists can stomach. (You know, Reader, when I was very young, I planned to either become a physicist or marry one... both didn't happen *consciously stops veering off-topic*) Russell Stannard unfolds the concepts clearly, a step at a time, with easy-to-understand examples, diagrams and analogies.

The first part of the book deals with Special Relativity. The time slowing down at speeds close to that of light phenomenon that I mentioned earlier is termed time dilation. Seems pretty simple, but the part that might be called non-intuitive about it is that one experiencing time dilation will not notice that anything is out of the ordinary (neural impulses, like everything else, are slowed accordingly), because time is not of its own, but a part of spacetime, the four-dimensional reality we live in. Like this: In some Chinese folklore involving deities, a day in the heavens equals ten years on earth - so if a mortal visits heaven and spends a day there, when he returns home, he would find that ten years had passed. That's how in some stories, a maiden-deity who "runs away" to earth to experience life as a mortal can marry a mortal and live happily for ten years before the heavenly guards come to "catch" her. They would've only realise she's gone when she didn't return at the end of the day (in heaven)! But I've digressed... again. Apart from the effect on time, there is length contraction as well. Prof Stannard also discusses the Twin Paradox, Simultaneity (whether two events happened simultaneously or not depends on who is looking), and the (arguably) most famous equation of all time,  E=mc2. Subsequently, the reader will be introduced to General Relativity, which is, as the name clearly states, the theory of relativity for general cases, taking gravity into account. The reader must be prepared to understand (seemingly unorthodox) concepts such as light is bent when passing through a gravitational field, and space is not nothing and it can assume contours - like being curved one way or the other. The book concludes by showing the reader how everything comes together to provide scientists the understanding of much of the universe that they currently know (about 5% of it only!).

Honestly, this is a book I feel everyone should read. It's beautifully written, with adequate simplification of the complex, but not so much as to compromise the knowledge presented. Happy reading =)

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