Signals and Systems is very different from the five other theory courses we have this semester. First of all, our class of 90 was split into two batches, and have classes from 5.30 to 7 in the evening on two days every week. Besides, all the exams except for the final test, consist of questions for more marks than the maximum. For instance, if the test is out of 15, there may be questions for 20 marks, and one can score 20 out of 15 if he answers all the questions! And then we have these open book tests, which together account for 20% of the total marks, in which you are free to refer to your text books, note books, discuss with your friends and even the professor. Today was the first experience of that.

As soon as the students got the question paper, many of them began to flip through the pages of their text books! Abhilash sir laughed, and told us that wouldn’t help in any way. True enough, all the questions were highly indirect and intellectual. There was a question which goes like “Define convolution in plain English”. When I asked him whether he needed the answer in the context of systems, he replied in his trademark joyful and mystical way that he needed the “inner meaning” of convolution and that I’d have to meditate, to find it! I thouroughly enjoyed the exam, because he had cautioned us not to give undue concern for the evaluation, but advised us to take it as a delightful experience. It was certainly different from all other exams I’ve taken at NIT!

Signals and Systems is indeed a beautiful subject, and I like the intuitive approach of Abhilash sir. Though it’s very involved, I’ve occasionally been able to appreciate glimpses of beauty here and there during his classes. The problem is that we have rarely if ever, come across the need for such involvement, in our education hitherto, to appreciate and understand and participate intellectually. So only a small percent of the class actually follow, and even then, I doubt whether they appreciate the beauty. As for me, I often find it unable to follow all the equations, but somehow the purely intuitive approach affords a sense of beauty even then.