Sunday, November 25, 2012

My first online course, and my take on MOOCs

Marshall Street Starbucks - Syracuse, NY

I finally did a whole online course (a Massive Open Online Course, or MOOC) starting this summer into the fall - a 7-week course on Listening to World Music offered on Coursera by Prof. Carol Muller of the University of Pennsylvania. I did this course for many reasons.

One was a quick introduction to different kinds of music - pretty likely that I'd never have heard of many of these. Having learnt some percussion music myself, having constantly interacted with musicians, and having attended many different concerts while I was growing up, I believe I have been exposed to many mainstream kinds of music, but would certainly have not come across many not-so-popular ones.

Second, I also thought I wanted to check out how the MOOCs work out, through a complete course. The lectures, homeworks, tests, grading, online discussions, etc. - the whole deal. Checking out the logistics also interested me.

Finally, I wanted to see if I had it in me to finish the course "successfully" when there was no compelling reason to. I mean, the certificate itself was not the motivation at all. It was a course just to learn. I'm happy to report that I did - I did not need a "do it or else" to finish the homeworks and tests :)

This course did not disappoint. It was definitely a fun course. I highly recommend it. A review article on the NY Times prompted me to blog about this course as well - my take on it.

I did enjoy the different kinds of music introduced by Prof.Muller and some stories surrounding them. Many forms of music remain indigenous to the place of origin and must be shared by experts so that we can learn about such cultures. I got introduced to very interesting kinds of music - Tuvan throat singing, Aboriginal traditional music, South African Isicathamiya, and many others. And since they were all YouTube links, you know how it goes - keep following links and suddenly it would have been many hours of browsing.

Some interesting comments that were raised during the course included concerns about plagiarism(!) such as googling for answers during tests, etc. Well, if such courses is purely to learn, what is the real point behind this? So, I'll not really analyse this further, except that perhaps they just wanted the certificate. Now, if as there are discussions going around to offer college credit for such courses, this will be an issue to ponder over. There will be the additional overheads of supervised online exams, expert reviews on essays, etc. I'm curious to see how this works out, esp. if there are so many thousands in hundreds of courses. It will be a huge step in the format of education if this happens. And no, by way of credit it will not affect me, though. I will remain a bystander with regards to college credit - since I would have graduated by then! :)

I will admit, however, that I did skip or skim through many parts of the slides since I was not very keen on the details about the political scenes at the time. I just wanted the music and a brief story or two. But, of course, there were about 30-40,000 other students registered, and so, the course is tailored for students with varied interests, but the benefit of it being open and online is that you participate to whatever degree you wish to; pick and learn whatever you want to. I think this in itself is a very strong message.

Slightly off-topic, but my personal opinion on many of the "well-rounded education" theories after undergraduate degrees are somewhat overrated and it is perhaps not necessary. Most people I know just end up going through the motions and doing what needs to be done, not really with interest. And for a Masters or a PhD, it should not be essential. For high school and bachelors degrees, yes, it is essential - since students are still unsure about what they want to pursue and specialize in. But not later than that. Anyway, that is my two pennies worth on "core courses".

That said, back to the main subject. I did suffer through the final exam because I had skipped through many slides and did poorly enough that I did not complete this course with distinction (>80%), but just received a certificate of completion (>70%). That's fair though, I did just pick and choose whatever interested me most! My scores and the material skipping reminded me of my undergrad days :) However, as I mentioned before, the certificate was never the motivation, so that's that on the certificate's role in the course.

The grading was done by peers, and averaged out - the average of 5 anonymous reviews. Seems OK (students were generous and, in general, gave me high scores, and so did I), but perhaps multiple choice questions would have been more fun (I like MCQs), easier to have automated grading, and it is objective, not subjective. However, I understand that is perhaps hard to incorporate HWs as MCQs for all courses. This one, for example, had essays to write, so I don't know how this would have worked out as MCQs.

Online discussions were pretty awesome, actually. (Although, I was kind of lazy, mostly used it as read-only.) There were so many interesting ideas put forth. If I had to pick out just one really fantastic feature of MOOCs, it would be this - online discussions by fellow students. You can see social networking, crowd sourcing, etc. at its best - a treasure chest of ideas pinged back and forth, very original opinions, hard to find in any textbook. This course had a few Teaching Assistants as well, and they did a fantastic job in their contributions to the discussion forums.

There have also been discussions about whether MOOCs will replace traditional college educations completely in the future. I can see it being a powerful factor, but I don't know about complete replacement, since a college education is much more than just doing a bunch of courses. However, this does bring about the issue of how much people will be willing to pay for "traditional" a college education and degree now that there are a growing number of such courses available for free online; and that too, all by leading experts. Well, I guess I'll wait and see it play itself out - I'm curious about this as well, i.e. to see where the equilibrium lies.

One thing I'm sure of, this will not be my last MOOC. And neither will it be my last explorations of the exciting kinds of music that I was exposed to through this course - I sense many more hours of YouTube-link-following coming up!

Saturday, November 10, 2012

Fahrenheit Scale - what's the basis?

Marshall Street Starbucks - Syracuse, NY

Curiosity made me look up the logic recently. It was surprising!

What I mean by the title is that I know what the Celsius scale is based upon. Water freezes at 0C, boils at 100C, and using these two round values as base points, the scale is calibrated. Sounds reasonable.

Now, the Kelvin scale. The scale is the same as Celsius, but with an offset. That is, each difference of 1K is equal to 1C, but the base is not the freezing point of water, but absolute zero. In other words, any temperature in this universe, however cold, would be non-negative on this scale. Zero Kelvin is when all motion ceases (not yet attained experimentally but about 1E-9K has been reached). Very clear reasoning.

There's other scales but they do not appear to be very frequently used, so I won't comment on them for now.

This brings us to Fahrenheit. Water freezes at 32F. Water boils at 212F. Normal body temperature is 98.6F. Absolute zero is -459.67F. So what really is the basis for this scale? There should be some "round" number that means something. Why choose seemingly arbitrary numbers? We know what zero is in Celsius and Kelvin. What really is "Zero degrees F", in  other words, what is the basis for this scale?

The only thing I could think of was that perhaps 100F is a likely threshold for a (serious) fever. 98.6-100F may not be a cause for much concern, likely a simple cold/flu. Although I must admit, this was not strong enough a reason, and I couldn't think of any other round number, in order to calibrate.

It so happens that this scale is still popular partly because of the following "intuitive" sense of these numbers, that were easy to remember. 50F is a pleasant day. 100F is on the threshold of being too hot. 0F is borderline very cold. And so on.

But none of all this explained the logic behind creating the scale. I mean 99F is very hot as well. 1F is chilly too. 55F is even more pleasant. 100.4F is also a reasonable fever.

As it turns out, the scale just happens to produce values this way. The reason behind creating the scale as it is was very different. Fahrenheit, in 1724, determined the zero as the freezing point of a mixture of ice, water and ammonium chloride (in equal rations), essentially a kind of brine. At the time, this temperature was considered widely as the coldest possible.

32F was the freezing point of ice and water (also mixed in equal ratios). The number 32 came about as Romer's scale (proposed in 1701) was modified by Fahrenheit to avoid fractions (he multiplied all values from Romer's scale by 4). This new scale underwent further minor refinements by scientists which led to the scale being the way it is today.

OK, now the next (obvious) questions - 1. Why ammonium chloride and not other salts? 2. Why was Romer's scale set to 7.5 for water/ice freezing mixture?

1. Ammonium chloride is a commonly available salt used in forming Frigorific mixtures, i.e. a mixture where the final equilibrium temperature reached by the mixture is fixed, no matter what the temperature of the constituents were, initially. I assume this particular salt was used (and not some other salts which also produced such mixtures) since it was commonly available, but I'm unsure.

2. Romer set 0 in the same way as above, the freezing point of brine. The boiling point was set at 60 degrees. Why 60? I tried searching on the net, but found no convincing answer. Well, it's a round number. And the freezing point of water on this scale was 1/8 of the way, at 7.5 degrees.

So there's my understanding of the scale. The availability of ammonium chloride abundantly, its contribution towards forming frigorific mixtures, a misunderstanding of what the coldest possible temperature was, and an (arbitrarily?) chosen boiling point of 60 degrees by Romer led to the scale that is still so popular today!

In my opinion, metric systems are the way to go!

Friday, November 2, 2012

Lava Simulation!

Lab - Syracuse, NY

When I say I ran into this project, I actually did. Last Friday, I was on my way back to the parking lot in a shuttle, and one stop before mine, I saw a demo in progress. I hopped off, curious. From a distance it appeared to be a glass making demo.

It turned out to be a really cool project. Well, a really hot project - simulating lava flow!

Researchers from the Geology Department and sculptors from the Department of Art were collaborating on this. I met a geology student and he was kind enough to explain what was happening and he also sent a few links across for me to read.

Now, I have hardly any knowledge on this, so I'm going to try to describe briefly only what I learnt (and not make up stuff!) as accurately as I can. I'd never seen such a simulation before. I imagine it must take quite some planning to keep that kind of unharnessed energy under control. I learnt that the temperatures generated were about 1200 degrees C plus! It occurred to me that this was about a fifth of the sun's surface. In a parking lot next to a building!

The material was basalt, and it flowed through molten and re-solidified. It was apparently part of a 1.1 billion year old basalt bed from Wisconsin. So, this was already molten and solidified at least once before (long before humans existed!), and it went through the same process in the simulation. Check out the project webpage. There are many more details, and links to lots of great pictures and videos in the site.

Now the sculpting department will create some artistic creations using this molten lava, making it flow on certain molds or surfaces and allowing it to solidify.

I got to take a small piece with a little wavy design on it as a souvenir. From the site I gather this pattern arose as a result of pahoehoe flow.

This will now be on my desk for a while, a paperweight with a story!

Note to future species (Time capsule note)

If you are a bot or some other highly evolved super-intelligent species reading this (perhaps using your fiftieth sense? We primitive beings had a mere five senses in our time) 1.1 billion years from when I write this (I'm guessing it's around 1,100,002,012 C.E. now), this piece of rock has melted and solidified at least twice before - in Wisconsin (It was the Proterozoic eon then - this rock was probably the home continent of a colony of cyanobacteria) and in Syracuse (man's experiments described above). According to current human simulations and predictions around the time this picture was taken, this will melt at least once more - four billion years further ahead in time, when the sun engulfs the earth. If you have figured out the mysteries of life and death, and are able to communicate with past and future beings, I'd be interested to learn where this little piece of rock landed up, let me know!