How students can benefit from simulations

Just before leaving the planetarium(mentioned in my previous post), I also asked Madhusudan Sir if he would like me to be involved in anything to do with simulation. He seemed reluctant. I understand his skepticism. We need to touch and feel things. He was talking about the delight on his daughter's face when an evacuated bottle, crumpled under atmospheric pressure. I can fully relate to that.

I believe that a simulation is half way between a formula and an experiment. So someone who can enjoy a formula as well as conducting an experiments should definitely enjoy the stuff in the middle. But I would like to someday actually show delightful faces after a simulation and then and only then would I have convinced myself that yeah simulations really have really good pedagogical value. I was really impressed by some simulators such as the following one from MIT



I have been bowled over by this. At least I find it to be an awfully interesting toy for kids to play with. Unfortunately u need a tablet PC or the fundu Whitebord being shown... Otherwise I could have checked it out myself.

Madhusudan Sir is of the opinion that one should preferably use real objects and use simulations only if the experimental objects are exotic. Of course he admits that it is his personal choice. And he can like apples and I can like oranges. But maybe who knows... his opinions were formed by some rotten oranges ;-). But, I think he will change his mind after seeing that video. But I also understand that it is long way before I can figure out how to use it in teaching students. But I am confident that there are a lot of places that this forms a perfect solution even when the objects are not exotic.

I have always missed good simulators when I needed them.

As kid, I was obsessed with inventing perpetual motion machines just like any other physics geek would love to ;-). I had noticed an interesting anomaly. Inertia says, that something that moves will keep on moving... blah blah... and that a coil moving in a magnetic field would induce an EMF. But the friction would bring it to a halt over time. So I thought that you could trivially create an infinite source of energy by moving a magnet in a coil of wire in free space. I wrote to Prof. Yashpal who used to come on Turning Point and got a reply after a long long time. In a bizzare way, I had rediscovered Lenz Law. But no one around me could tell me what was wrong with my argument. Lenz's law was an anticlimax. But if I could run to my comp and create a coil and magnet and get it to spin and see it slow down... it would have been a Eureka moment at that instant. I would have happily gone and told my teacher that if I drew power from my generator, it would slow down. If I did not it would not. If my simulator was too good, I might have noticed that some energy was being radiated out as electromagnetic radiation... Maybe even gravity waves ;-). I can run a fast forward and see what would be the state of my generator after 1 billion years. And still I don't need to think about the core getting rusted ;-).

Here is another instance. Very early in my education, I had figured out that chemical rockets are a real disgrace and mock at human ingenuity. Going to orbit on a chemical rocket is like driving a petrol tanker filled with petrol half way to the destination and then leaving it there when the petrol gets over and then skating to your destination until all the food you have eaten gets used up. A space shuttle is incapable of even getting you to the moon and now they need a new bunch of reinventions to take man to the moon again. Summary of the story is that you need to something about it.

I had noticed that, a tape recorder motor placed on the table with something heavy and asymmetric connected to the shaft and powered up would start walking on the table though no moving parts touched the table. This looked like magic. I was in my first PU and concepts like the real cause of centrifugal force were still fuzzy... I was aware of the law of conservation of momentum but was not even fully aware that newton's 3rd law was telling me the same thing. Law of conservation of angular momentum seemed to apply to some other parallel universe.

My logic was simple... The sun provided more than one kilowatt of power on each square meter. Silly calculations showed that if I converted that to kinetic energy, I could do some insane accelerations. And I did not need to break the law of conservation of energy. I thought that all I needed to do was create some bizarre bending twisting thing that could use the power from the sun and move forward. It took a long time for me to figure out that the creator of this universe has created a huge book of rules and each law in that book holds true in tooooo many places. Following law of conservation of energy was not enough.

I wanted to see whether my ideas would work... But how do I get rid of the "unwanted behaviour" of the world?? Suspend things from strings? Move things on water? My math was not strong enough to face this at that time, not even now to conduct those experiments on a sheet of paper. The real world just introduces reaction and friction according to its own whims and fancies. In fact I got a glimpse of the meaning of "reaction" only after I skimmed thru Feynmann about a year ago and realized the coulumbian repulsion is at the core of the world's stability... so that it does not collapse into itself... and also supplies interesting forces on demand!!! How did anyone dare to tell me that there are only 4 known forces in this world when this funny force called "reaction" can rear its head wherever it chooses to ;-)... Anyway, I digress...

It was impossible for me to setup an experiment to check out my ideas nor the theoretical muscle power to face the challenge. I don't have the theoretical muscle power to model those systems even today. Of course I realize that, I need to bow my head to many more laws and this was a wild goose chase. But if I had a good simulator, I might have been a master at mechanics by now... Maybe I might even have developed the theoretical muscle power to understand the nitty gritties of why my solution would not work. But hey that is what learning is all about... Making wrong predictions and figuring out why they were wrong.

I am sure each one of those reap boys has the audacity to think up such mutant thoughts like me. Whenever such mutant thoughts occur at least a subset of those thoughts can be tackled by simulation.

Here are a few more thing I thought of... The lens in my eyes were removed during dislocated lens surgery when I was a child. So my eye has no lens. But I can see fairly well even without spectacles(especially at medium distances). These days they put an artificial lens in place. But those days they did not do it or it was optional. So I have always wondered whether my eye works like a pin hole camera... the pupil seems too large for a "pin hole" to be able to focus enough... does the curvature of other transparent objects like the cornea have a significant effect on the resolution of my eye? My mom and aunt underwent cateract surgery and they both got artificial lenses implanted. They seem to have a much poorer vision even with spectacles. The doctors blamed it on diabetes.

But the question that occurred to me was that "Were these doctors fleecing us?". The lens is just an optical device. If the rest of the system can't provide the needed resolving power, then a good lens is of no use. I wanted to be able to pull out a virtual eye... delete the lens and see how it would work. I would like to check the resolving power of this new system. Of course that is just a daydream... but hey who knows... Now that I think of this... the question is even more profound. The creationists insist that human eye is too complex a device to be created by evolution... i.e. by accident ;-)... In the book "The Selfish Gene" by Richard Dawkins, the situation is explained beautifully... lenses without eyes and so on... I have nothing much to say beyond the fact that I realize in practice how well an eye without a lens and without spectacles can work.

Another interesting simulation experiment rolling in my head is Spherical Aberration. My First PU textbook had some interesting gobledegook about it. If I look into a camera I can see many lenses... I guess they are there for chromatic and spherical aberration. How about asking the student to use POV ray to design any damn system of lenses and minimize spherical aberration or chromatic aberration. The student can even choose a non spherical lens... He can virtually cut out lenses according any equation he chooses... parabola,hyperbola,centenary... or some bizarre eqn he himself wrote... Refractive indices can be changed according to whims and fancies and so on... If he did that by grinding glass, he could spend for ever... Simulations are extremely good if you have a hunch and want to see if you are getting closer to your solution or you are moving farther...

Madhusudan sir was talking about some real world probability experiment which seemed to show some crazy behavior producing a gauzzian when I felt it was absurd. He too found it odd. Maybe it was bad data or too little data. But I want to know if this is physics related or mechanics related or probability related. It is extremely unlikely that two very different systems will show the same loophole unless there is some profound connection among them. After conducting an experiment in the real world, you can come back to a simulation and see how different the two behaviors are. In the real world you cannot switch laws off. To do that you need to do a lot of work. In simulation you can simply delete a law that troubles you.

Ultimately, the objective of Open Education is to give the student the maximum number of eureka moments and other satisfying experience and maximizing the grasp of the subject per unit time spent. I guess simulations can play a huge role in this.