About Me

When not at work with students, I spend my time in my room either reading, calculating something using pen and paper, or using a computer. I read almost anything: from the pornographic to the profound, although my main interests are mathematics and physics. "When I get a little money I buy books; and if any is left I buy food and clothes." -Erasmus

Friday, December 30, 2011

Do We Really Know Rizal?

It's Rizal day, and one of the things I read while looking at the news is the article Do We Really Know Rizal? Rizal Law Ineffective.by  Mona Lisa H. Quizon.

I guess it's irritation that makes me write this, because I have talked before about how the purpose of the Rizal law was subverted, not just in private schools but in public schools as well. And the ones most at fault are the Catholic Church and the translators.

You don't actually need to read about Rizal. Let him be hidden, so long as his unexpurgated novels be read. I recently bought two copies of Noli Me Tangere, the first one an English translation by Ma. Soledad Lacson-Locin, and the second one being the most popular translation for high school use, the Tagalog translation by the trio Guzman-Laksamana-Guzman.

And here, in the second translation, you can see where the Rizal law has gone wrong. In an effort to get the bill passed, our lawmakers gave in to Church lobbying to allow them to use abridged (read: censored) versions of  Noli Me Tangere and El Filibusterismo. I've talked about it before in the blog post Bowdler, Rizal and Scripture, but the examples I gave were based on memory. Meantime, I lost my old copies of these translations, and so decided to get replacements.

I've been rereading these two translations, and making a line-by-line comparison. It's worse than I remembered. And I see the trio's fell hand. Page-after-page of censored passages, all of them aimed at the Catholic church. I've browsed through other translations, and I see the same thing. The Guzman-Laksamana-Guzman translation seems to act like a strange attractor to other translations meant for high schools-- with all its faults duplicated by other texts meant for high schools.

Have you ever wondered why the Catholic church persecuted Rizal? A reading of the expurgated Noli will give you no answer. Even worse, the deleted passages contain the best of Rizal. It's here that you find him at his drollest. In an effort to please the Catholic Church, the translators made a mockery of what Rizal actually stood for. And because this translation is what we make our students read, it's no wonder they get the wrong impression.

So you don't know Rizal? Maybe it's because you've read the bowdlerized translations or worse, relied on the comics versions. Read him uncensored.

New printer

I bought a new printer two days ago, an HP LaserJet P1102. It set me back by PhP 5K. I got fed up with having to go to school just to get some documents printed. I decided to get a monochrome laser printer because I rarely print in color, and  was familiar with this printer. It's similar to the one I use at school, an HP LaserJet 1020.

I had almost no problems getting it to run with my netbook, both in ubuntu and in windows 7. It turned out that I didn't even need the CD, because the drivers were easily fetched by Ubuntu, and seems to be built-into windows 7 as well. I did make a silly mistake when I first tried printing. I tried printing a pdf (an article from Physical Review by Ronald Gautreau) and got two blank pages. To fix it, I did a google search and one of the first things I found is the question "Did you remove the tab at the left end of the toner?". Turned out there was a plastic protector attached to the toner so that it won't leak while in storage. I removed it and got it working.

Although I'm satisfied with the performance of the printer, there are a few things I dislike. It's HP's business model. Take the practice of including a starter toner (that supposedly prints 700 pages) instead of a regular toner (which, if you believe the product claims, can be used for 1600 pages)  when they could have easily done so. This seems to be a common gripe, not just with HP. Samsung also does the same thing.

Another issue is how much the toner costs: approximately three-fifths the price of the printer. I'm not surprised. It's like how Gillette markets its products. You pay a low teaser price for the shaver, and then they gouge you on the replacement razor blades. I understand that it's how HP makes money on printers; I've read somewhere that printers are one of HP's cash cows. But it sure alienates their customers. The printing, if you rely on HP's cartridges, will cost about PhP 2 per page.

Before I bought this printer, the home printer I used was my brother's HP  inkjet. The ink cartridges cost about PhP 500, and it was expensive, and so and my brother decided to get a refill kit. CDRking, for example, has a refill kit that allows you to recycle spent cartridges. Where a new ink cartridge costs PhP 500, for about PhP 200 you can get a refill kit that allows your cartridge to be used for printing about five times (this is a figure drawn out from air, I'm guessing it's an understatement since we've used such refill kits on my brother's printer, and they last for a long long time) what you'd get from the original cartridge. Could something similar be done for a LaserJet printer?  A quick search gave me a Youtube video (it's actually an advert for a toner refill kit) showing how you can refill an HP 85A toner.

One way to reduce cost is to buy replacement toners from CDRKing. If you look at CDRKing's online catalogue, you'll also find a toner cartridge that's compatible with my printer and costs only a third of the price of HP's. But if I could find a reasonably priced refiller, I'd rather go for the refill because of two things: it's a lot cheaper than getting a new cartridge, and also because it's  environmentally saner to do so. If HP had such a service here, with reasonable pricing, I'd go for it. But because they aren't doing the right thing by their customers, they'll have to live with customers who don't get their toners from them.

Friday, December 2, 2011

From Windows 7 to a dual-boot with ubuntu 11.10

Since it was a holiday yesterday, I decided to convert my Windows 7 netbook into a dual-boot, with ubuntu 11.10 as the alternate operating system. I've read about how linux distributions use less system resources, and I wanted to try it. Since my computer does have 320 Gb of hard disk space, all I had to do was use Gparted to repartition my hard disk, and then run the ubuntu 11.10 liveCD.

Of course it wasn't that simple. I had to get the partitions right, and make sure that my windows installation would be unaffected. When I originally set up my netbook on win 7, I created three partitions, one for Windows, the second one for an alternate OS, and the third one for a place that both can access.

I spent 5 hours getting it done (swearing all the way!) for the following reasons:
(1) I am a Linux newbie, especially when it comes to administrator tasks such as installations, and system administration. In order to get things  working, I had to  hop between Google searches and the installation process.

(2) I had to learn about the difference between ordinary partitions and logical partitions, since only four partitions were allowed. Since Windows had to have two of these, only two were left for ubuntu. I'd read about the root needing a separate partition, and another one for the swap space ( the linux analog of the windows pagefile), and then the last one for the other files. It took me a while to realize that I could set it up using logical partitions.

(3) The installation stopped somewhere in the middle. Turns out the Live CD has a bug: if you run it first as a Live CD, and then go back and install, the installation will stop somewhere. To get it running, you should restart your computer and then choose the install now option without going through the LiveCD's "try it first" option.  Once I did that, everything went smoothly.

After the install, I decided to use ubuntu and see if I could do my usual tasks: edit MS Office documents, browse the web, listen to music and watch movies. While doing all that, and downloading the necessary program components, I inadvertently unplugged my laptop. Which led me to another bug. Although I knew that the battery was full, and that while on Windows I could get it to run continuously for four hours, the ubuntu power-manager informed me that I only had a few minutes of power left and it was asking me if I wanted to shut down or hibernate. Naturally, I replugged my power cord and then started searching for a fix.

One workaround involved turning off one of the settings of the power manager. After using the workaround, I decided to see if updates for ubuntu were available. I found around 240 Mb of updates waiting for permission to be downloaded and installed.  So I let my computer to download the updates overnight, and slept. The next morning, I tried going back and restoring the settings back, and see if the update fixed the power manager. It did the trick. 

I've been using ubuntu since yesterday to do all of my regular work, and plan to use windows only when necessary. It feels good, especially when I compare how my netbook performs while running GIMP. On windows, I usually use about 600 to 800 MB of RAM, while the same tasks on ubuntu usually take about half as much RAM. GIMP doesn't feel choppy in ubuntu, compared to how it works wile running windows 7. Since I use GIMP or photoshop for making figures for exams and presentations, it's nice to see GIMP running smoothly even when I have other things running side-by-side. 

Other things I did to see if ubuntu and its component programs worked properly: I opened a powerpoint presentation using LibreOffice Impress, and hook up my computer to a projector. While using windows I had to download a driver to get it working properly; In contrast, in ubuntu, it worked automatically.

I also spent time recording student quizzes using LibreOffice Calc (that's the LibreOffice spreadsheet program, an alternative to MS Excel), and it worked fine.

So most of the things I need to do that's office related, such as manipulate spreadsheets, edit documents, and present powerpoint presentations I could easily do with ubuntu. The only other thing I haven't tried yet is printing documents. I'll see how it goes tomorrow.

Wednesday, November 30, 2011

Red Night Sky

I usually leave my office at around 8 or 9 pm. My  habit is to listen to music while taking a bicycle ride home. Home is an hour away, so that gives me plenty of time to listen and let my mind wander. Even though I shouldn't have, I happened to look up at the sky and could only see the moon and a star or two. The rest of the sky was reddish from the street lights and pollution.

This is actually an old problem connected with urbanization-- as cities get larger, city lights eventually obscure the night sky so that only the brightest stars are the only ones visible at night. And if we want the stars and the Milky Way back in the sky, the solution is simple: make sure that the outdoor lighting you use is appropriate. There is a movement called the Dark Sky Initiative, and it is all about making sure that future generations can enjoy a starry night sky.

One of the things I miss in my home town is the night sky. For example, the sight of the Milky Way has given me much pleasure. Here in Metro Manila, you can see only the brightest stars, and you can't even see the Milky Way because of light pollution. And that would be too bad, especially for children who grow up seeing nothing else. If you have never seen the starry sky, in some ways you are made less human, since you will not be able to fully appreciate poetry that evokes the feeling of being under the stars. (Such as, for example, Neruda's Puedo escribir los versos más tristes esta noche.)

Which makes me wonder: how will future poets describe walking with their beloved under the moonlight?  "Under the red night sky, we walked, my beloved and I"?

Sunday, November 6, 2011

Apple as the New Big Bad Guy?

I recently read an article (reposted on Facebook by a friend) entitled "Apple to Make Billions on Google's Android" and I'm troubled at the way Apple is vigorously pursuing litigation all over the planet.

Consider what Apple is doing to other smartphone makers (such as Samsung),  and developers of smartphone operating systems (such as Google). What it ultimately amounts to, I think, is the stifling of competition and innovation. Although swipe to unlock is a clever solution, does it really make sense to patent it? Or proximity detectors, so that the phone doesn't get mixed instructions when your face is near the touchscreen?

Probably my biggest gripe is the Apple patent on the use of a touchscreen.  When you look at how the patent is written, it covers almost everything we want to do on a smartphone or tablet with a touchscreen display. It looks like Apple wants to be the only one to make touchscreen devices, or get all the royalties for touchscreens. (Remember the way Apple fans have been painting IBM and Microsoft in the past? Ironic, isn't it?)

At issue, of course, is what exactly is patentable, and how long patent protection should last.

The idea behind patents is to give inventors some time to get some return on their effort, and not to give a permanent monopoly. For example, medicine is patented and the discoverer has the right to restrict who can manufacture a drug so that the money spent on research and clinical trials will be recovered, and some profit is made as a reward for taking the risk of developing new technology.

The years of protection allotted to inventors (20 years) reflect a different age, when there weren't that many people, and the rate of advancement of technology was slow. When consumer devices last only for two to three years, the number of consumers much much larger (7 Billion?) , and product development cycles much shorter, the old twenty year lifespan doesn't seem to make much sense anymore. I think copyright and patent law during our times needs an overhaul.

Given the stakes, I'll be keeping an eye on how the patent battles play out. And I do plan not to buy Apple.

Friday, November 4, 2011

All Saints Day

Although I was planning to spend the day at home on November 1, I ended up visiting Daranak falls with my brothers and their families. A visit to google maps and a keyword search for "Daranak Falls" should provide you with directions. To show how lovely it was, I took a photograph using my phone:

I've been to Hinulugang Taktak (another waterfall in Rizal) and was struck by how polluted the water there was. The water was bubbly with detergent, and there was a lot of litter lying around. Not so here. The water was clean, and even though I had no plans to go swimming, the water looked so inviting that I borrowed a pair of shorts from my brother so that I could swim as well. To show how clean the water was, I took this photo downstream:
The entrance fee was reasonable (my understatement of the day) : PhP 20 or about 0.50 USD. We were able to get one of the picnic huts for PhP 200. Although there was a store there, it's better to bring your own food since the choices are limited. But it was alright since a more extensive store would also be accompanied by litter. Since we went there on All Saints Day, when most people are found at memorial parks visiting their dead, I can't gauge how crowded it would have been on other holidays. 

Ironically, my younger brother (the one who organized the trip) got sick on the day itself. Although he was able to drive us there, he spent most of the time asleep, and wasn't able to swim at all. He did, however, walk around and take a few photos of his own. His wife was the one who drove us to Dimple Star terminal to pick up some stuff my father sent us. After that, I switched cars, and my youngest brother drove me home.

Sunday, October 30, 2011

Steve Jobs, Talks, and the Reality Distortion Field

I've recently been on a Steve Jobsfest. I've read Young and Simon's iCon: Steve Jobs: The Greatest Second Act in the History of Business, and Walter Isaacson's Steve Jobs, and watched some of his talks on youtube.  It all began when I serendipitously read Carmine Gallo's book, The Presentation Secrets of Steve Jobs; I got interested because I wanted to learn how Apple convinced people that they actually needed an Ipod, Iphone, Ipad and a Mac. The book was a lot of fun, and thanks to youtube, Steve Jobs's  talks are available online.

Although I've heard the term "Reality Distortion Field" when my thesis adviser was describing his thesis adviser, I didn't know that it was first used to describe Steve Jobs. The videos were the first time I saw Steve's RDF in action. I've met people who had such RDF's, and I've always maintained an interest in how they maintain such fields, both as a means of protecting myself and to use during my own teaching and talks. I supposes some reality distortion can be good if it makes people do insanely great stuff. And one of the sources of RDF's is good communication skills.

Of his talks, the two I liked best were his Iphone keynote, and the Ipod introduction. I've had mixed results with my own talks, and I watch all sorts of talks, from TED talks to Steve Jobs to help me learn fantastic ways of doing presentations. Gallo's book provides a peek at what makes a Steve Jobs talk work. As usual, when I find something interesting, I usually walk around and drag my kohai to the source of my entertainment, so I had undergrads and PhD students sit with me as I watched the talks repeatedly.

I like the way Steve Jobs makes the talk look effortless and informal. The secret--- which is really no secret --- is preparation. Because it looks so effortless and informal, people think it means no preparation and just speaking your thoughts aloud. (I've seen examples of TEDx talks where the speaker tries to do things that way, and I've scratched my head and said, hey, I can do better than that!) I've read that Jobs spends days on each keynote, and he pays attention to such things as lighting and timing.

I think that what makes his talks effective is clarity-- people think that putting more features makes the talk better, when it's the other way around. The talk should make people zoom in on the speaker (and his message!), not on the slides.

Steve Jobs avoids death by powerpoint by having minimal content on slideshows. Anyone who attends seminars and conferences has experienced powerpoint horror shows: put too much information into the slide and you put people to sleep.. The best talks, I've found, use the least amount of material on the slide. In a way, it's like writing a crib sheet. If the crib sheet contains too much, you're in trouble.

It doesn't mean having no crib sheet. Powerpoint and keynote has a presenter view so that the slides you see contain marginal notes that you can use to prompt yourself. It's silly how underutilized presenter view is. You can tell by looking at the desktop onscreen. If the computer that's hooked up to the projector shows a clone of desktop, instead of an extended view, you'll know that presenter view is not being used.

Even Steve Jobs has notes, but cleverly hidden from view. Since your computer screen usually points away from the audience, you can use presenter view so that you won't have to look at the projection screen. Instead, you can maintain eye contact with your audience. You should always look at your audience.

Speaking of talks, even a poster presentation can be structured as a talk. Instead of letting the visitor just read the poster, one should instead have a prepared conversation so that you can motivate the viewer of the poster to read the paper itself. Most poster presentations are ruined because the poster has not made the effort to prepare himself to  engage the viewer. I've sadly seen some posters during the recent National Physics Conference that were under-appreciated because the necessary preparation was not done.

I could go on--- I do have a lot of rants that I could make about powerpoint horrors and posters-- but won't go into them here. Maybe on another post?

Saturday, October 22, 2011

Einstein and the Atheist Professor

One of the things that irritate me is a shared wall post that's making the rounds in facebook. The post is a variation of the "atheist professor is humiliated by the Christian student" meme. The last one I've seen on my wall adds the line "The student was Albert Einstein.".

A good biography of Einstein ought to dispel the myth that Einstein was a Christian. There are a lot of quotations from Einstein showing that he did not believe in a personal god. In any case, belief or unbelief in god should not be supported by arguments from authority.

A good link on the post that got my ire is here. To my Christian friends, please: before you post anything like that, get the facts right.

Wednesday, October 19, 2011

New phone

I bought a new phone yesterday, and then spent the next few hours practicing how to use it. My older phone is a Nokia clone, and I've had a number of complaints. Since it's a cheap knockoff of the Nokia phone, I found it easy to use--- when everything is working perfectly.

The main problems of my old phone were:
(1) I could only use it for text. When I try to use it for calls, I cannot hear what the person calling me is saying. Although I could use it to play music, the phone was accidentally set so that it was usable only with earphones. There is a way to fix it,  but I couldn't find it in the settings, because of....

(2) The lack of technical support or documentation. The box that came with the phone had no user manuals, the phone had no warranties, and no websites existed supporting my old phone. To use the phone, I had to learn by trial and error.

(3) Cannot recharge using a travelling charger. The terminal connecting the charger to the phone seems to be busted. The only way I could recharge the battery was to open the cover, and place the battery in an external charger.

(4) Lack of USB connectivity. To transfer MP3's to my older phone, I had to remove the micro SD card from the phone and then connect it via adapter to my computer. I could not use a USB cable to connect my phone to my computer.

I don't usually spend much on consumer electronics, but this time, I wanted a well-known brand name so that I wouldn't have to suffer through the same pain again. When I checked my bank account, I was pleasantly surprised yesterday that I had more cash than I expected. Since getting a new phone was on my task list (as soon as I had the money-- my plan was to use my thirteenth month pay), I decided to look for a new phone.

One boundary condition was price.  It should cost no more than PhP 6K or around 140 USD (I'd feel guilty buying a more expensive phone, and I knew that the Nokia phone with the same capabilities as my clone was priced that much.).

Although the Samsung Galaxy Y was designed to be a low-end smartphone, it still set me back by (for me) a large amount. So I'm going on a consumer electronics hiatus; the next time I'll be buying anything as expensive will be next year, since the new phone comes out of my Christmas shopping list.

My main use for my phone (both old and new) was for phone calls, text, and music. Of course, if that was all I wanted, the phone I ended up getting was an example of overkill. I bought a Samsung Galaxy Y smartphone mainly because I liked the look of it, and also because the Nokia model that I wanted was priced the same but had fewer capabilities.

I had some trouble adjusting to the virtual keyboard, and couldn't find some of the options I wanted. The accompanying documentation gave basic instructions, so I had to go online to find out how to use the Android based operating system. I had difficulty updating my phone book-- I just used a manual method, although if I had saved my phone list in my google account, I would have had less difficulty since my phone had the ability to use my google contact list as soon as I went online.

One mistake I made at the start was to create contacts and then accidentally save them without including phone numbers. I couldn't find the an edit contacts button or link, so I had to search online on how exactly one does it on Android. It turns out that a short press of the contact name allows you to send a message or call,  while pressing the contact name for a longer period gives you the option to delete or edit your contact's information. After finding out that a short press and a long press is interpreted by the phone as two different commands, I was able to navigate through the menu.

Another minor headache I had to overcome was using the internet at work. Since my work network uses a proxy with an appropriately designated port. To change the proxy settings on the Galaxy Y: start from the Main Menu Screen and press the Settings button. Next press "Wireless and Networks". Press "Wi-Fi Settings". Assuming you've connected to the local wireless network, press the Menu button on the lower left-hand of your phone, and the "Scan" and "Advanced" buttons should pop up from the bottom of the screen. Press "Advanced", and the Proxy and Port Settings should now be on the list of things you can change. After changing the assigning the proxy and port settings, I was able to use the net at work.

My older phone had no wifi capability, so I was unable to use it for going online. I've tried using the new phone to go online on our home network; it does the job but it's slower than my laptop. I suspect I'll be using the internet connectivity only for checking on my email and twitter.

Sunday, October 16, 2011


It's a habit of mine to bring something to read when I travel. The travel time from my home to my brother's home is approximately an hour and a half  by train.  So today's companion was A. S. Byatt's Possession. One passage, deliciously indirect,  made me laugh:

" He opened his locked case, putting away Randolph Ash's letters to his godchild, or anyway the stolen images, and drew out those other photographs of which he had a large and varied collection-- as far as it was possible to vary, in flesh or tone or angle or close detail, so essentially simple an activity, a preoccupation. He had his own ways of sublimation."

Tuesday, September 27, 2011

Population, Sewage and Flood

I slept all day today. We're in the middle of typhoon Pedring, and Metro Manila was under Public Storm Warning Signal #2. With this kind of weather, schools from elementary to secondary are suspended, while tertiary schools (my university, for example) leave it to the school officials to decide on suspensions.

I stayed awake until 2 am reading manga, with twitter on another tab to keep track of the suspension status of our school. I think it's silly to let university officials decide on suspensions when they always do suspend classes when it's Signal #2. They should just make a rule that it's automatically suspended, and then have make-up classes on weekends. 

Public storm warning signals in the Philippines are based not on the amount of rain but on wind speeds. So it's possible to have heavy rain and flooding with no storm warnings. Exactly two years ago, Metro Manila was inundated by tropical storm Ondoy. The wind speeds, in Metro Manila at least, were within the maximum of 60 km/hr. These wind speeds were not high enough to cause damage to roofs here. The government weather bureau actually did all right with its prediction of wind speeds. Although people faulted the government for being unprepared, I don't know if you can actually predict the amount of rainfall from a given storm.

The lack of a sewerage system, and haphazard garbage collection exacerbates the problem of flooding. Sewage disposal is through septic tanks that are later drained by independent contractors (for people with means, at least), and dumped who knows where, or if you happen to be poor and living near a creek or river, it gets dumped directly into nearby waterways. As a result, our floodways are too clogged with  garbage to be useful in preventing floods. 

One sign of the problem is the population density of Metro Manila (18,000/sq km); Singapore, in contrast, has 7,000 per sq km. In fact, Manila (43,000/sq km) is the city with the largest population density in the world, and of the top fifty cities ranked by population density, we have 10 cities, all in Metro Manila, in the list. So people who claim we have no population problems here are talking through their hats. (Or their mitres). Now, translate these numbers into volume of garbage and sewage per square meter everyday, and you can say, that's a lot of shit!

Monday, September 26, 2011

Coffee, Tea, and the Global Financial Crisis

There are a lot of inexpensive pleasures-- one just needs to consciously savor them when they come. One of my more recent pleasures is doughnuts and tea; a feeling of luxury can be achieved by buying doughnuts at Dunkin' Donuts and then having two or three doughnuts with Earl Gray tea.

I suppose that pleasures must be contemplated to be enjoyed; it's no use to rush through the ritual of drinking tea. I've read about the  tea ceremony in Kakuzo Okakura's The Book of Tea, but it's not the kind of tea I drink. There's no formality nor ritual; just a teabag, a mug of hot water, milk and sugar. Reading it did give me a greater appreciation of tea. Alas, although it is somewhere here in my house, the number of books and papers, and the lack of a classification system means I will probably take a day or two to search for it. It's faster to download it here.  

Along with Earl Gray, I bought English Breakfast Tea, and Peach flavored  tea. I was pleasantly surprised by how inexpensive it actually is. A teabag costs about PhP 8 to 10 (about 20 US cents) compared to a cup of coffee from Starbucks (around PhP 80 or USD 2.50).

Although I do have a French press at work, I'm also thinking of buying a teapot, and getting an infuser as well. On the other hand, I'd probably have to look for a shop that sells loose-leaf tea, since it's not available in most supermarkets here. Even Rustan's ran out of tea-bags of Earl Gray tea, so it'll probably be difficult to find loose-leaf tea. Most Filipinos prefer coffee to tea, so there's not much to be found here, except in specialty shops (which I do not know). Maybe I ought to ask the friend who got me to drink tea.

This doesn't mean that I dislike coffee. When I was an undergraduate, there was a time when my coffee consumption was 6 to 8 mugs a day. I don't do that now-- I've limited my coffee consumption to just two mugs a day.  I used to drink instant coffee but after trying brewed coffee, you really don't want to go back to instant. Nescafe, for example, has an acidic aftertaste that I won't miss. When I do drink instant, it's mainly for the caffeine; I use creamer and sugar to mask the taste.

I brew the Barako variety; I like it better than Arabica, and it's actually cheaper here since most of it is grown in Batangas, Benguet and other parts of the Philippines. It's slightly more expensive than instant-(I think it costs me about PhP 15 (or 40 cents US) for every mug I brew) but much less expensive than getting it from Starbucks. The reason it's not as well known as Arabica and Robusta was the coffee rust disease that devastated local coffee plantations during the 1880's. A local coffeeshop, Figaro's, is promoting barako so that this local variety won't die out.  

Steven Johnson claims that the switch from alcohol (with the population being effectively drunk all day) to tea and coffee was one of the sources of the Enlightenment. (His TED talk is here.) Drinking alcohol then was the healthy choice-- the water was bad, and alcohol was one way of making sure that you don't have bad bacteria in what you drink.

Coffeehouses (and tea houses) were first introduced to Europe in the 17th century; this was before Pasteur and the germ theory of disease, and they had no idea that boiling water was one way of making drinking water safe. Now here was a beverage people don't (literally) get sick of, and it changed the population from being drunk all day to one that was alert and ready to engage in more intellectual pursuits. The first coffee houses also served as the meeting places of traders, and were the equivalent of today's financial exchanges. One can therefore trace the rise of the modern sciences and the Financial system from the Enlightenment to the atomic bomb and the Global Financial crisis today back to a coffeehouse!

Friday, September 23, 2011

Tea, Earl Gray, Hot

One of  L. E. Modesitt's books, Flash, features a character who drinks Earl Gray tea. Intrigued, I searched for the difference between ordinary black tea and found out that Earl Gray tea is a blend of tea and oil of bergamot. I knew that it wasn't supposed to be expensive, and decided to get some from Rustan's.

I wanted a substitute for coffee that I could enjoy at work, and it was good. Thankfully, I was able to obtain the original blend by Twinings; I was worried that I would get the "new and improved" blend (who remembers New Coke?) but found out from the Twinings website that the new blend was only made available in the United Kingdom.

Judging from the reaction, it looks like the new blend was a disaster for Twinings; the resulting public outcry led them to reintroduce the old blend as Classic Earl Gray.  In the same way, Coca-cola also reintroduced the old formula as Classic Coke, and then later stopped production of New Coke.

I don't know what motivated the Twinings people to tinker with the Earl  Gray formula, but I do know that sip tests of Coke versus Pepsi misled the management into thinking that people wanted the sweeter Cola, and so they used a sweeter (among other things) version of the Coke formula. Malcolm Gladwell tells the story in his book Blink, and his conclusion was that the Coke people were using the wrong test of what people preferred.

While reading one of the rants of the people who disliked the New Earl Gray, I was amused to learn that Earl Gray was Captain Jean-Luc Picard's favorite drink. His usual line was "Tea, Earl Gray, Hot." (with Earl pronounced "Ehl") There's actually a youtube clip of all the instances Picard had Earl Gray. It can be found here.

Thursday, September 22, 2011

Washing machines

I'm usually not at home, even on weekends. I spend Saturdays at school tutoring my methods students (class-time is not enough!) and working with undergraduates in our research group. So I don't have much time to do the laundry.

People who never hand-washed probably don't appreciate what a miracle washing machines can be. I remember hand-washing clothes when I was much younger. We didn't have a washing machine then, so it was either hand-wash or pay someone else to do the hand-washing. It has never been my favorite work. I remember how much it hurt my back to sit down, and how stiff I felt after a say of doing the washing by hand. So it was a minor miracle when we got a washing machine.

The washing machine we had then was not automatic. You had to wait until the water reached a certain level, then close the tap manually. After letting our clothes spin in soap-water, we then had to transfer our clothes into clean water to rinse out the suds. The washing machine had no spin-dryer, so I had to squeeze the water out by hand, and then hang the clothes on the clothes-line to dry.   

It was only when I was working that my brother and I bought a fully-automatic washing machine. (It was a huge dent in our budget-- around PhP 15 K, or USD 360-- but worth it in the long run.) You put in your clothes, some soap, fabric softener, and bleach and then the washing machine will do everything. It controlled the water inflow and the drain cycles, so you only had to wait. It also has a spin-dryer, so that at the end, the clothes were partially dry.

When I do the laundry (about three times a week), I usually put my clothes in the washing machine just  before going to sleep, and then hang them out to dry as soon as I get up. Imagine what it must be like for the rest of the world. In fact, Hans Rosling has a TED talk on washing machines:

So I'm already just above the wash-line, but below the air-line.

Although I had an opportunity to see him live (he was in the Philippines a week ago, and was  scheduled  to give a talk at UP Diliman), I had to forego the opportunity in favor of doing some paperwork. I just hope that someone uploaded the talk.  

Monday, September 12, 2011

Waiting for a plane

I'm writing this while waiting for a plane bound for Tacloban. My younger brother is getting married and they (that is, he and his fiancee) will be having their wedding at the bride's hometown. We're having some bad weather here-- lots of rain, but no wind-- and they're also having a traffic jam in the air.

I'm a bit nervous about flying in this weather, given that I'm riding a plane whose crew has among the highest power-distance-indicators. Malcolm Gladwell talked about it in his book, Outliers. Among the things I learned was the likelihood of having a crash is higher when the crew has a high-power distance indicator.

Power-distance is tied to culture; a large power-distance indicator tells you that a given culture places great value on authorities. One sign of a large power-distance index is the use of honorifics and a well-developed notions of polite behaviour. For example, Filipinos use the words po and opo, kayo at ninyo to indicate respect. Po is almost meaningless; it's word added to a sentence just to signify that the person being spoken to has a higher rank in society. Kayo and ninyo are probably more like the word "thee".One uses the word kayo as a substitute for ikaw (you) to be polite.

One of the disadvantages of a high-power distance culture is the use of mitigation when a social inferior is talking to a social superior. Malcolm Gladwell takes the example of a pilot and a copilot. Pilots and coipilots take turns handling the plane, and one of the surprising statistics is the higher likelihood of a plane crash when the pilot is handling the plane, compared to when the copilot is steering.

If the copilot is seen to be doing something stupid, then the pilot can easily correct his copilot, without mitigation, because he's the boss. On the other hand, if the pilot is steering, and he's doing something stupid, the copilot will use the most mitigated statement-- he hints! Example: the pilot would say: "Turn this way!" while in the same situation, the copilot would say: "Uh, you might want to look at the weather radar."

A lot of plane crashes happened (according to Gladwell) with the plane being in good shape; the biggest factors were bad weather, and bad communication between pilot, copilot and ground control. Mitigation exacerbates miscommunication especially when the pilot is steering; the copilot can only hint-- because the copilot is talking to his boss.

And which countries have the highest power-distance indicators? The top five just happen to be: Malaysia, Guatemala, Panama, the Philippines,  and Mexico.

No wonder I'm worried.

Thursday, September 8, 2011

Library.nu has risen from the dead

For the last month or so, library.nu has not been allowing me (and my friends) to log-in or register. The website provided no explanation-- it allowed me to browse, but gave no links. After a month or so of visiting the site, I'm glad to know that everything's back to normal.

Tuesday, September 6, 2011

How textbooks shape researchers, and mislead students

I downloaded a copy of Kuhn's The Structure of Scientific Revolutions because I couldn't find my hard copy. Sometimes finding a particular book in my collection is a problem because of the number I actually own. I'm not even sure if it's in one of the boxes, or in one of the shelves, or hidden under the stairs.

I was looking for a statement he made on textbooks-- and how unusual a textbook  that discusses alternative theories is. Although I would like to discuss historical issues in the development of physics, I don't have enough time in the classroom to do so. I find such issues fascinating, and you can sometimes use the confusion of the ancients to understand how difficult some of the concepts can be.

One of the books that I like is Arnold Aron's The Development of Concepts in Physics, which is unfortunately out-of-print. (I have to rely on a photocopy so that I could read it.) It  actually owes a lot to Gerald Holton's book (in fact, large areas were taken from it and reprinted with permission), and it helps me understand why older scientific beliefs, such as Aristotelian physics and impetus took hold in medieval minds. Another example is its development of the Bohr model, which follows Bohr's seminal paper.

Textbooks mislead. Let's again take the Bohr model as an example. If you follow the development in Young and Freedman's University Physics, what will be given is quantization of angular momentum as a postulate. This is in fact a major reversal of Bohr's paper. What Bohr actually did was to argue, from the Rydberg formula, and then argues that energy must be quantized. After that, he derives as a consequence, the quantization of angular momentum.

There are more examples of such reversals, which I will not multiply. The point is that textbooks will not present the historical development because it is too confusing, and distracts from the purpose of the textbook-- to display the current paradigm, give examples or models that serve as pieces that the scientist builds on when doing what Kuhn calls normal science.

(An aside: if you read older textbooks in general relativity, and compare them to each other, you will see examples of how the paradigms changed within the study of general relativity. The main problems in relativity during the early days was the study of small effects-- the deflection of light being the main example. It was only in the 1960's when strong gravitational fields, in the sense of great distortions of spacetime geometry from global Minkowski space, replaced weak effects as the main application of general relativity, as found in textbooks. An example of a text where this transition was incompletely done is Weinberg's Gravitation and Cosmology. Bergmann's, Moller's and Pauli's texts would represent the older the generation of textbooks, while Misner, Thorne and Wheeler's Gravitation, Hawking and Ellis's The Large Scale Structure of Spacetime, would be representative of the post-1960's paradigm shift.  

Another shift that I see is in the textbooks of today, which emphasizes the physics-first approach. When I first learned general relativity, I used Schutz's A First Course in General Relativity, which follows the math-first approach. The way it was developed put black holes near the end of the book, and I suppose that it took much stamina to be able to reach that point.

I think that the ordering it uses shapes the research of the people who use it. For example, since it places black holes at the end, its discussion of alternative coordinate systems is brief. This means the technique of choosing appropriate coordinate systems is under-emphasized, and it seems unlikely that a terminal user of Schutz's book will develop that skill. Or the technique of using orthonormal basis vectors. Compare this with the recent textbooks, such as Hartle's Gravity, or Taylor and Wheeler's Exploring Black Holes where these techniques are much used to answer basic questions.

Textbooks shape the research of the people who read them. The questions researchers ask are based on their choice of textbook, and someone who learned relativity from Schutz will ask different questions compared to someone who learned relativity from Hartle. )  

Thursday, September 1, 2011

Of Nursing and Bubbles

The Philippines has an oversupply of nursing graduates; I've heard stories of nursing grads having to pay hospitals so that they can do "volunteer work" just so they can gain necessary experiences.

A few years ago, I had an idea that there would be a glut-- a simple count of hospitals and expected nursing graduates would have given the game away, and I didn't expect demand from abroad to leave salaries at high levels after the inflow of many new nurses. About six years ago, there was a shortage of nurses, and this shortage meant large salaries.

Parents who saw those salaries didn't think about supply and demand-- and given that a nursing degree takes about four to five years, this means that by the time nursing freshmen graduate, the marketplace would be  much changed from what initially led people to take up nursing.

This reminds me of bubbles in financial markets. A famous example of a bubble is the Dutch tulip mania. Charles Mackay gave an account in Extraordinary Popular Delusions and the Madness of Crowds. (A wikipedia article on Tulip Mania is here.)

A relatively recent example of a bubble was in the nineties, when people kept buying technology-related stocks (even when the underlying businesses were lousy-- no earnings, etc) because people convinced themselves that good times (an upward trend in the prices of stocks) will last forever. (They don't.)

Due to higher stipends and an increase in the number of DOST scholars, we've been getting wonderful students in our research group, and I now worry about their employment prospects.  I think that the openings for tenure track positions will be available only within the next three to five years. Given the increasing PhD graduation rates at NIP, there's probably a coming shortage of available academic tenure-track work.

The same thing can be said for geology and chemical engineering. Right now, the employment opportunities look good. For new geologists with a BS degree, the monthly take-home pay starts at around PhP 70 K.(USD 1.7 K, a decent amount if you spend it in the Philippines.) DOST has encouraged the inflow of new geologists by increasing stipends, and I can see that there are larger numbers of geology majors compared, say, to a few years ago. What this means in terms of salaries is an eventual decrease in take-home pay.

Thursday, August 25, 2011

Solutions Manuals to Arfken

I like teaching using Arfken's book; and the biggest reason why I like it is the non-existence of solutions manuals. Although there is an official solutions manual  (I downloaded it once just to find out if Arfken was ruined as a good source of problems; it can be found here.), it's useless for problems that ask you to prove things. What it does do is provide numerical answers, or give the final form, or give hints.

I worked through the problems in Arfken the hard way; I solved the problems one-by-one starting from chapter 5 until the chapter on integral equations. I still have a list of the problems I did not solve (I used the third edition,but teach using the 6th ed.), and as I teach, I revisit them, hoping that this time, I would be able to figure it out.

On the other hand, although I have not worked through some sections in Arfken (such as the chapter on matrices and group theory), my problem-solving in other areas of theoretical physics  does mean that I've actually solved them elsewhere. Sakurai's Modern Quantum Mechanics, chapters 1 to 3 was where I learned about Pauli matrices and the rotation group, for example. If you compare Sakurai and Arfken's group theory chapter, there will be a lot of overlap. So dedicated study elsewhere means being able to solve Arfken's problems even though, on my first pass, I skipped through the group theory.

Another example is Arfken's chapter on the calculus of variations. I've encountered the material elsewhere, in classical mechanics (Marion's and Goldstein's books), in general relativity (Hartle and Weinberg), Finkelstein's book (Nonrelativistic Mechanics, a parallel presentation of classical and quantum mechanics), and Jackson's Classical Electrodynamics.

I've collected stacks of folders with solutions, and I really have no plans of uploading them. When I do teach, I do not provide an answer key either; I do mark papers and when time permits, we solve the assigned problems on the blackboard. I usually get a student to solve it in front and then act as the hostile critic so as to root out  misunderstanding, and bad reasoning. When the student is stuck, I suggest possible lines of attack, or solve a related problem.

Why do I not provide fully-worked solutions? Providing worked solutions encourages memorization, rather than understanding. Also, the worked solutions sometimes end up being recycled by people who take the course later on. It's hard to think up good problems at that level; it's different with introductory physics where it is easier to invent easy problems.

On the other hand, people argue that without solutions manuals, they cannot be sure of their work. I think it's bosh. The problem sets of today are usually the research questions of yesterday. Cauchy's theorem and other things that we take for granted today did not come by divine revelation; these things were discovered by people who were willing to think for themselves.

Instead, what one needs is a method of eliminating self-deception. When I write my solutions, I do it in such a way that my solutions can serve as supplementary lecture notes. (This is actually an old idea, and I owe this statement to N. David Mermin. ) This means you have to express clearly, without any obscurities, how you actually reason from start to finish. You have to justify every step you make, by quoting previous theorems (that you've also proven for yourself!), etc. If the reasoning you present is tight, with no missing steps, then you can be pretty sure that your solution is correct. It does mean, however, that you have a good grasp of prerequisite material.

Solutions manuals pervert the learning process because being able to submit correct solutions to problem sets leads to self-deception. One learns by making mistakes and by being stuck in some areas, and trying various possible dead-end solutions paths. Learning the dead-ends is also important; if you do not learn the dead ends, then you will be compelled to learn them later on, when you actually have to use the methods in Arfken to solve your particular research problem. (And since it is a research problem, by definition, no solutions manuals exist!)

(addendum: one of my friends had this to say about solutions manuals: You want a solutions manual? Make one!)

Tuesday, August 23, 2011

Sign Seeker

Had a laugh while watching this. The advertising is subtle, and doesn't detract from the short film. I learned about these short films from my thesis adviser.

Sunday, August 14, 2011

The Upside (and Downside) of Irrationality

I recently read Dan Ariely's The Upside of Irrationality, and started thinking about the many irrational ways I behave. Contrary to the image of humans fostered by classical economists, Ariely claims that experiments demonstrate that humans often behave irrationally, often counter to profit maximization schemes that underlie economic models.

One example he used was on compensation schemes for executives (it's also discussed by Dan Pink in one of my favorite TED talk), and the counter-intuitive result was that although low and medium levels of compensation may improve performance, for tasks that require even rudimentary cognitive skills, extremely large rewards may actually lower performance.

I suppose that's one reason why I'm having trouble writing. The ideas are there, but if I do get it published (before I'm out of my university), I will end up with a PhD, and a USD 1000 award. Surprisingly, I find it demotivational, in the same way that Mark Twain describes in Tom Sawyer.:

"He had discovered a great law of human action, without knowing it––namely, that in order to make a man or a boy covet a thing, it is only necessary to make the thing difficult to attain. If he had been a great and wise philosopher, like the writer of this book, he would now have comprehended that Work consists of whatever a body is obliged to do, and that Play consists of whatever a body is not obliged to do. And this would help him to understand why constructing artificial flowers or performing on a treadmill is work, while rolling ten-pins or climbing Mont Blanc is only amusement. There are wealthy gentlemen in England who drive four-horse passenger-coaches twenty or thirty miles on a daily line, in the summer, because the privilege costs them considerable money; but if they were offered wages for the service, that would turn it into work and then they
would resign" 

In the Philippines, USD 1000 is a large amount of money. You can buy four netbooks with that money, and it would be about seven times the monthly minimum wage. I even know of people here whose monthly wage is  USD 70. 

Ariely's research involved paying Indians different rewards and comparing performance when the reward for completing tasks (in this case, a bunch of games) was worth a day's wage, a few week's worth of wages, and five months of wages. The most surprising finding was that those offered the biggest rewards did worse! 

Later in the book, Ariely speculates on the effects of astronomical bonuses on executives in the finance industry, and I believe, post-financial crisis, that the compensation scheme was to blame for a lot of the financial system's woes. Ariely also talks about many other things, and I plan to reread his book, as well as his other book, Predictably Irrational.

Sunday, August 7, 2011

Buying new speakers

I just bought new 2.1 channel speakers. I had an old set, but due to a problem with the power supply, I decided to scrap it and buy a new set. I missed listening to music during the mornings, and the built-in speakers of my laptops were unsatisfactory.

I knew that the usual two-speaker systems didn't give me the right sound-- I didn't get any bass. But I didn't know what I wanted exactly. My brother was the one who liked playing with speakers-- while I lived with him, his home theater system had surround sound, and he was the one who set it up. I did know that my speakers needed a subwoofer, so I decided to get the simplest cdrking system with a subwoofer.

Looking at the available products on the net was helpful, because I learned what was available. I also learned how much speakers cost. the cheapest I could find at cdrking costs PhP 200 or around USD 4.8. The more expensive ones (which I bought), with a subwoofer, costs about PhP 700 or  USD 17. I even found 5.1 channel speakers on their catalog!

Since I planned to use the speakers in my room (it's a small room!), and the input would be from my laptop, I didn't need an expensive set, so I settled for a 2.1 channel system. I brought my netbook along to test the speakers, and was disappointed with how it sounded while I was at the store. But then, we had a noisy background, so even though the speakers didn't sound good while I was at the store, I decided to get them anyway, since I knew that the components worked. I figured that as soon as I got home and tried it, I should be able to tune it so that it would sound right to me.

Once I got home, I set-up the speakers, and played some music by Sitti Navarro.  I played with the controls, just to see what the effect of eliminating the subwoofer would be like, and having the subwoofer really makes a difference. I'm quite content with the sound right now, although I do plan to get a 5.1 channel system later... Maybe when I move to another university? :-)

Thursday, July 7, 2011

Computational Physics, dirt-cheap

When I was an undergrad (ages ago), we had to take a course called computational physics. The thrust of the course was learning how to program, understanding algorithms, and then implementing the algorithm using self-made code written in Fortran.

I took the course four (or five?) times, because I kept on failing the course. Let me describe what it was like-- it was so long ago that if you had a laptop, you were considered to be divine; even having your own desktop was A Big Thing. Since I am not Kintaro Oe (if you don't know who he is, watch Goldenboy!), I was unable to pass the course because I had no computer and had limited access. I only passed the course when I got admitted to the theory group; we had a single computer that we took turns (ab)using.

The text that we used was DeVries' Computational Physics. It was a good text; I learned a lot about making readable code as well as understanding the algorithms that we use for solving differential equations. In fact, upon comparing the current offerings of the same subject to what we had then, I realized that what we had was quite demanding. Although I complained a lot about the workload, I did eventually develop an appreciation for the course, thanks to De Vries. The way it taught was by giving a series of problems-- you had to create a working program and then produce the needed output. There really is no way to learn programming and algorithms except by actually doing it.

At that time I had to rely on photocopies of the book, since I had no money to buy it. So imagine how happy I was when I dropped by C and E bookstore to find my friendly old textbook on sale. The price they were selling it for was ridiculous-- they were selling it for about  0.75 USD, so I bought all four remaining copies. I plan to use these books to teach a newer generation of undergraduates in the theory group the joys of programming in Fortran.

Saturday, July 2, 2011

teaching practicum

Parts of the following were written a month ago (sometime during the middle of May 2011): 

I handled the lecture teaching practicum of three graduate students. I chose to have them attend the relativity related lectures this term (five consecutive days of lecture classes), do the recitations along with my students, and to take the exams as well.

The reason I did so is their need to learn special relativity; it's badly taught (universally, it seems, in Philippine universities) in undergraduate courses that the typical physics major takes. Also, attending a week's worth of lectures means I can later discuss the choices I made with my mentees (is that the correct word?) while handling the lecture classes.

I gave them the usual first day orientation and had them answer the first set of recitation problems, to ensure that they've read Mazur's talk and the syllabus. We also talked about why I give out such questions when most of the course group doesn't do so.

After attending the first lecture, I gave them a diagnostic exam, just to get rid of any self-deception that they actually do understand special relativity, especially since one of my mentees was probably a student of a relativist from another university; I suspect that they were given "wonderful lectures" but had a dearth of problem-solving experience.

I ought to have given the diagnostic exam before they attended my lecture-- I suspect that they would have scored much lower that way. As it was, they were able to answer the questions related to my first lecture. Still, their scores were way lower than the average undergraduate engineering major who studied with me. I think that should have convinced them of the need to study relativity-- nothing beats appealing to self-respect.

The scores were 13, 21 and 23 out of a maximum of 44 items. An average student in my classes usually gets around 29 to 34 items right. Keep in mind that my mentees are physics majors; they should have encountered relativity in at  least 6 courses during their undergraduate days. Their most recent exposure was supposed to have been during a recently concluded graduate electromagnetism course.

After attending the lectures and taking the exam, I helped each of them teach an hour-long segment of my class.I asked them to prepare ten multiple questions each, according to some guidelines laid out in most education-related literature. All of the questions they were required to prepare were relativity-related, and it would be crazy to have them prepare such questions without ensuring they know relativity at the appropriate level. After all, as my adviser is fond of saying: "You cannot teach what you do not know."

Of course, their questions were not used during the exams. It would be too much to expect them to prepare good questions on the first try. One of them was a headache: of the tasks I gave, the only task he did right was to take the exams-- diagnostic and the relativity exam.

One of the tasks I gave was to have them meet me for a dry-run of their lecture. Although our appointment for the lecture dry-run was at 1pm of May 4, he showed up at around 4:00 pm. Based on the dry run, it also turned out that he had not read the assigned reading, nor was he prepared to discuss the topic I gave him, which was on de Broglie waves. I then gave him an additional two hours two prepare, and we started our dry-run at 6:30 pm. I had to walk him through the lecture to ensure that my students's time would not be wasted during his lecture. We ended the dry-run at around 8 pm.

His lecture was supposed to be from 8:30 am to 9:30 am of May 5, but he came late. I was forced to begin what ought to have been his lecture, and was nearly a third of the way through when he came in. With great reluctance, I gave up the floor to him because I did not wish him to give the lectures on a more difficult topic in the third exam. As it was, he did not finish the topics assigned on time.

As for the exam items that he was supposed to construct, although due on May 16 at 1 pm, he neither came to give a hard-copy nor emailed an electronic version.  I emailed him, and upon receipt of my email, instead of submitting the assigned items from the 2nd exam, he gave a partial set for the third exam. That didn't make sense at all; the reason I made them go through the 2nd exam lectures and then take the exam itself was to ensure that they would be able to construct sensible test items.

What annoys me is the fact that he was accepted by my adviser as a graduate advisee. After what he did during the teaching practicum, I ended that term with a very low opinion of that guy, and I plan never to work with him again.

As for the other two, I have no complaints. They did all that was asked of them, and I did not have any qualms about having them give an hour-long lecture to my students. So if it were up to me to give grades two would pass, while I would flunk the third.

I suppose the biggest problem with the practicum is the lack of a syllabus. Having expectations clearly written is a good way of ensuring that the work gets done, and if I do decide to give a failing grade, the decision would not be contested. So although I wanted to give a failing grade to that worm, because other practicum teachers asked for less than I did, I could not, if I wanted to be fair, give him a fail.

Sunday, June 26, 2011

reading guides and complex methods

I'm teaching complex (variable) methods this semester, and I'm using Arfken's book to teach it. It's a long list of topics; the detailed syllabus is shown below:

Meeting no.
After the discussion and lined up activities, you should be able to:


§                 Explain what is expected of you to get good marks in this class
§                 Explain the expected role of your teacher
§                 Explain the expected role of your book
§                 Explain the expected role of your lecture classes
§                 List the materials you will need for this course
§                 Explain why the rules of coherence are needed.


 Read:  Rules of Coherence

§                 Perform algebraic operations using complex numbers
§                 Use the geometric series to evaluate complex valued sums
§                 Use the natural logarithm function to calculate inverse trigonometric functions
§                 Use the natural logarithm function to calculate complex powers

Complex Algebra

Complex-valued Series

Complex Powers

Read: Sec 6.1
Exercises: 6.1.7;  6.1.8;  6.1.9;  6.1.10;  6.1.16, 6.1.17; 6.1.22

12June 18, 2011 (Sat) 1pm

Complex analysis i


§                 Use the definition of the derivative to evaluate the derivative of polynomials
§                 Use the definition of the derivative to obtain the Cauchy-Riemann conditions
§                 Use the Cauchy-Riemann conditions and continuity of partial derivatives to test a complex function for analyticity.
§                 Use the Cauchy-Riemann conditions to show that the real and imaginary parts of an analytic function must satisfy the Laplace equation

Cauchy-Riemann conditions

Laplace equation

Analytic functions

Read: Sec 6.2
Exercises: 6.2.1; 6.2.4; 6.2.5


§                 Define the Riemann contour integral on a complex contour and compare with the real Riemann integral
§                 Use the definition of the Riemann integral to prove the Darboux inequality
§                 Use the definition of the contour integral to show that, in general, the contour integral is path-dependent.
§                 Use the definition of the contour integral to calculate the contour integral of a given function along a given path.
§                 Prove the Cauchy-Integral Theorem using Stokes’ theorem

Contour Integral

Darboux inequality


Cauchy Integral Formula

Read:  Sec 6.3  
Exercises: 6.3.1; 6.1.2; 6.3.3


§                 Prove the Cauchy integral formula by using a deformation of contour and polar coordinates.
§                 Use the Cauchy integral formula to obtain an expression for the nth derivative of an analytic function.
§                 Use the Cauchy integral formula to relate Rodrigues formula representations of special functions to contour integral representations.

Cauchy Integral formula

Nth derivative of an analytic function

Contour integral representations

Read: Sec 6.4
Exercises:  6.4.1; 6.4.5; 6.4.6; 6.4.8


§                 Derive the Taylor series of given functions and give the domain of validity
§                 Derive the Laurent series of given functions about a given point on the complex plane and, using knowledge of singularities, give the domains of validity

Taylor series
Laurent series

Read Section 6.5
Exercises 6.5.1; 6.5.2; 6.5.3; 6.5.7; 6.5.8; 6.5.10; 6.5.11

§                 Obtain a formula for the coefficient a-1 in terms of derivatives
§                 Given a curve in the z-plane, and a mapping w(z), obtain the corresponding curve on the complex w-plane
§                 Given a simply connected-region A, and a given mapping w(z), obtain its image on the w-plane
Residue formula


Read Section 6.6, 6.7
Exercises: 6.6.1, 6.6.2, 6.7.6

First long exam
july 16, 2011 (sat) 1pm

(7-8 to 7-13)

§                 Identify the poles and other singularities of a given meromorphic function, and evaluate the residues at these singularities (if any)
§                 Use the residue theorem to evaluate a closed simply connected contour integral
§                 Use the residue theorem and Darboux’s inequality to calculate Fourier integrals
§                 Use the residue theorem to calculate other integrals.

Singularities and residues

Residue at infinity

Contour integration

Read Sec 7.1 (exclude Pole and product expansions, pp 461-462)
Exercises 7.1.1, 7.1.3, 7.1.6, 7.1.8, 7.1.10, 7.1.11, 7.1.14, 7.1.15, 7.1.17, 7.1.18, 7.1.21, 7.1.24


§                 Given a series for w(z) in powers of z, obtain the series for the inverse function of z(w) in powers of w.
§                 Give the conditions for expanding an analytic function as a pole expansion
§                 Obtain the pole expansion of selected functions
§                 Obtain the product expansions of sin(z) and cos(z)

Inversion of Series

Pole Expansions

Product Expansions

Summation of Series via Contour Integrals

Read Whittaker and Watson, pp 134 to 139, Arfken  pp 461-462, Morse and Feshbach pp 411-413,pp 413-414
Exercises Whittaker and Watson Section 7.4 Examples 4, 6 and Section 7.5 Example 1
Exercises for inversion of series will be handed out in class

11 to 12
(7-20 to 7-22)
§                 Find the zeroes of the derivative of an analytic function f(z), and draw contour plots of the real and imaginary parts of f(z)-f(z0) in the neighborhood of the zero z0 obtained.
§                 Use the method of steepest descent to approximate a class of integrals with parameter s, for large values of s.
§                 Obtain the asymptotic series using the method of steepest descent

Method of Steepest Descent

Read Sec 7.3, Morse and Feshbach pp 434-443
Exercises 7.3.1, 7.3.2, 7.3.3, exercises to be handed out

2nd Long Exam
July 30, 2011 (Sat) 1pm



§                 Show the equivalence of  the three definitions (Euler integral analytically continued; Weierstrass product, Euler product) of the Gamma function
§                 Use the Gamma function to evaluate negative factorials
§                 Use the Gamma function to obtain the Binomial series valid for non-integral powers, and give the domain of validity
§                 Derive the recursion relation of the gamma function
§                 Find the poles of the gamma function and evaluate the residues of the gamma function
§                 Prove the Gauss-Multiplication theorem and the Legendre duplication formula
§                 Evaluate Gaussian integrals

Gamma Function

Binomial series

Gaussian integrals

Multiplication Formula

Read Sec 8.1, and Whittaker and Watson pp 244-246
Exercises  8.1.1, 8.1.4, 8.1.5, 8.1.9, 8.1.14,  8.1.18, 8.1.24


§                 Derive Stirling’s series
§                 Use Stirling’s approximation to evaluate large factorials.
§                 Use the Beta function and the chain rule to evaluate a selected class of integrals
Stirling’s Approximation

Beta Function

Read sec 8.3 and 8.4, Whittaker and Watson pp 251 to 253
Exercises 8.3.1, 8.3.6, 8.3.8, 8.3.9,  8.4.2, 8.4.17, 8.4.18

(8-3 to 8-5)

§                 Prove the orthogonality of a given set of sines and cosines on a suitable interval
§                 Use orthogonality and completeness of a basis of sines and cosines to obtain the Fourier series of a function within an interval
§                 Use Fourier series to solve the wave equation of a vibrating string
Fourier Series


Read Sec 14.1 to 14.4
Exercises 14.1.5, 14.1.9, 14.2.1, 14.2.3, 14.3.2, 14.3.12, 14.3.14, 14.4.2, 14.4.10

3rd Long Exam
12August 13, 2011 (Sat) 1pm


§                 Expand given functions defined over the whole real line as a Fourier integral
§                 Obtain the Fourier transform of a given function
§                 Given the function in (Fourier) k-space, use the inverse Fourier transform to obtain the function in coordinate space
§                 Relate Mellin transforms to Fourier transforms
§                 Obtain the representation of the Dirac delta in terms of Fourier integrals

Fourier Transforms

Read Section 15.1 to 15.3
Exercises 15.1.3, 15.3.2, 15.3.4, 15.3.9, 15.3.17,

§                 Obtain the Fourier transform of derivatives
§                 Convert a linear differential equation in coordinate space into the corresponding integral equation in k-space
§                 Solve the diffusion equation using Fourier transforms

Fourier transform of derivatives

Read Sec 15.4
Exercises 15.4.1, 15.4.3, 15.4.4, 15.4.5


§                   Use the convolution theorem to evaluate some integrals
§                   Obtain the momentum space representation of a wavefunction

Convolution Theorem
Parseval’s Relation
Momentum Space

Read Sections 15. 5 to 15. 6
Exercises 15.5.3, 15.5.5, 15.5.6, 15.5.8, 15.6.3, 15.6.8, 15.6.12


§                   Calculate the Laplace transform of some elementary functions
§                   Use tables of Laplace transforms and the linearity of Laplace transforms to evaluate inverse Laplace transforms
§                   Use partial fractions to evaluate inverse Laplace transforms

Laplace Transform

Partial fractions

Read Section15.8
Do Exercises 15.8.3, 15.8.4, 15.8.5, 15.8.9

§                   Evaluate the Laplace transform of derivatives
§                   Convert linear differential equations with constant coefficients to algebraic systems
§                   Solve linear ordinary differential equations with constant coefficients using Laplace transforms

Laplace Transform of Derivatives

Convolution Theorem

Read Section 15.9 to 15.11
Exercises 15.9.2, 15.9.3, 15.11.2, 15.11.3

§                   Evaluate inverse Laplace transform using Bromwich integrals
§                   Convert linear differential equations with constant coefficients to algebraic systems
Bromwich integral

Read Section 15.12
Exercises 15.12.1, 15.12.2, 15.12.3, 15.12.4

4th Long Exam
September 3, 2011 (Sat)

23 to 24
(9-2 to 9-7)

§          Identify the singularities of linear second order differential equations
§          Use the power-series method to obtain a solution of linear second order differential equations
§           Use Wronskians to obtain a linearly independent second solutions if a solution is known

Power-Series Solutions

Read: Section 9.4 to 9.6
Ex: 9.4.1,9.4.2, 9.4.3, 9.5.5, 9.5.6, 9.5.10, 9.5.11, 9.6.18, 9.6.19, 9.6.25

§          Use generating functions to obtain the recursion relations satisfied by Bessel Functions
§          Use power-series methods to solve Bessel’s differential equation for both integral and non-integral powers
§          Use the generalized Green’s theorem to verify the orthogonality properties of a set of Bessel functions
§          Use the completeness of a set of Bessel functions to expand a given function in the interval 0≤ x ≤ a
Bessel Functions of the First Kind

Generating Function

Read: Sec 11.1 to 11.2
Ex: 11.1.1, 11.1.3, 11.1.10, 11.1.16, 11.1.18, 11.2.2, 11.2.3, 11.2.6


§          Use the definition of Neumann functions and verify that it is a second linearly independent solution of Bessel’s equation
§          Use the definition of Hankel functions to derive its properties
§          Use the asymptotic formulae for Bessel functions to approximately evaluate Bessel functions for large values of its argument
Neumann and Hankel functions

Asymptotic formulae for Bessel functions

Read: Sec 11.3 to 11.4
Ex: 11.3.2,11.3.6, 11.4.7


§                 Use generating functions to obtain recursion relations and other properties of Legendre functions
§                 Use the generalized Green’s  theorem to prove orthogonality of Legendre functions
§                 Expand an arbitrary function within the interval -1≤ x ≤  in terms of Bessel functions and give an integral for the expansion coeffiecients
§                 Use Rodrigues formula to derive orthogonality of Legendre polynomials and calculate the normalization constant of Legendre polynomials

Legendre functions

Orthogonality and Completeness

Read: 12.1 to 12.4
Ex:  12.2.2, 12.2.3, 12.2.5, 12.3.2,12.3.6, 12.3.11, 12.4.2

§                 Prove orthogonality of associated Legendre functions
§                 Use completeness relations of Spherical Harmonics to express functions depending on θ and φ  as a sum over spherical harmonics
§                 Express 1/ │x1-x2│ in terms of spherical harmonics
Associated Legendre functions

Spherical Harmonics

Addition Theorem

Read sec 12.5 to 12.6, 12.8
Exercises 12.5.1, 12.5.11,12.6.4, 12.6.5,12.8.3, 12.8.8


5th Long Exam
September 24, 2011 (Sat)

§                 Prove orthogonality of Hermite functions
§                 Solve Hermite’s differential equation via power series
§                 Use completeness relations to express functions in the interval -∞ ≤ x  ≤∞ as a sum of Hermite polynomials
§                 Use generating function to obtain the Rodrigues formula for Hermite polynomials
§                 Use Rodrigues formula to obtain Hermite polynomials
Hermite functions

Completeness and Orthogonality

Rodrigues and Integral Representations

Read: Sec 13.1
Exercises 13.1.2, 13.1.14, 13.1.12, 13.1.13

§                 Prove orthogonality of Laguerre functions
§                 Use completeness relations to express functions in the interval 0≤ x  ≤∞ as a sum of Laguerre polynomials
§                 Use generating function to obtain the Rodrigues formula for Laguerre polynomials
§                  Use Rodrigues formula to obtain Laguerre polynomials
Laguerre polynomials

Associated Laguerre functions

Read: Sec 13.2
Exercises 13.2.1, 13.2.3, 13.2.6, 13.2.7

§                 Prove orthogonality of Chebyshev functions
§                 Use completeness relations to express functions in the interval -1≤ x  ≤1 as a sum of Chebyshev polynomials
§                 Use generating function to obtain the Rodrigues formula for Chebyshev polynomials
§                 Use Rodrigues formula to obtain Chebyshev polynomials

Chebyshev Polynomials

Read Sec 13.3
Exercises 13.3.1, 13.3.3, 13.3.5

§                 Reduce any linear second order differential equation with three regular singularities into the hypergeometric equation
§                 Express some orthogonal special functions in terms of hypergeometric fuctions

Hypergeometric Functions

Read Sec 13.4
Exercises 13.4.6, 13.4.7, 13.4.8

§                 Reduce any linear second order differential equation with one regular singularity and one irregular singularity into the confluent hypergeometric equation
§                 Express some special functions in terms of confluent hypergeometric functions

Confluent Hypergeometric Functions

Read Sec 13.5
Exercises 13.5.4,  13.5.6, 13.5.11, 13.5.13, 13.5.14

6th Long Exam
October 15, 2011 (Sat) 1pm

The pace is very fast. When I first learned these topics, it took me more than two years of work, mainly because I had no one to look over my work. I used Churchill's book, Complex Variables with Applications, but  it's not enough to give justice to the course description. And I need to follow the course description because of university rules.

If asked, I would be the first to agree that it's an unreasonable amount of material, especially for a course that meets three hours a week. Cambridge University, for example offers a Methods of Mathematical Physics Course. One set of notes I found includes all the complex variable material, and removes most of the special functions. The only special functions that do show up are the hypergeometric and confluent hypergeometric functions, and Gamma and Beta. No discussion of Fourier series or Fourier integrals!

I am, however, stuck with the course description. I think that there ought to be changes made, but it has to go up to the university council. The only reasonable way of covering this material is to give them lots of work to do at home, and make extensive use of consultation hours.

I find it difficult to prepare conventional lecture notes. My main objection to conventional lecture notes is that reading the lecture notes is a more passive activity compared to working with pen in hand to prove the theorems or solve the problems. So instead of lecture notes, I will prepare reading guides.

The reading guides are a series of tasks that one should do while reading the text. One of the objections to Arfken is how easy it is to get lost. The way to avoid it is to divide the section into parts, and as soon as one reads the subparts, one should work on a problem or two in Arfken. I've prepared the reading guide so that when my students actually follow the guide, they will be able to construct a decent set of notes, and at the same time, solve the problems I've listed on the syllabus.

I hope that the reading guide makes it easier to read Arfken's book. My own method of reading Arfken (since I had no guide before) was to attempt solving the problems at the end of the section before reading the section.  But that takes more time, since I could not separate the more important problems from the ones of secondary interest. Even if my students solve all of the problems I've listed, it's still a fraction of what I've actually done on my own.

I hand out the reading guides a week or so before the lecture class, and I expect my students to use the reading guide to prepare for the coming class. This means I will not need to discuss everything; instead, I could concentrate on the more difficult parts.

My students are graduate students with back subjects-- they had their undergraduate courses elsewhere, and are in need of remediation. They had no complex methods courses during their undergraduate days. Since they're graduate students, they have, at most, 9 hours of classwork every week. I hope that all of them are full-time students; the pace we set will be demanding. But if they do the necessary work, they should end the semester with an unfair advantage over their classmates in other physics courses.