Wednesday, December 31, 2008

Why Trusting Wikipedia is a Bad Idea

So my thoughts the other day concerning wars and educational institutions led me to the Wikipedia article on the Korean War. Being an amateur war history buff I like to think I have a pretty good grasp on most major conflicts.

In any case, there on the Korean War wiki page was this synopsis of the early stages of the war, discussing the orignial layout of the troops and number of tanks and airplanes on either side. There were even a few citations liberally scattered about lending the entire paragraph credence.

The problem? The information was wrong and the citation led to articles which contradicted what was written on wikipedia.

My faith in the wiki has been shattered.

Tuesday, December 30, 2008

Are Universities Valid Military Targets?

As I was reading through the news about the latest on the Gaza crisis, something that might not interest many caught my eye. Specifically, the decision by Israeli warplanes to bomb a university in Gaza.

To many this may not seem like that significant a deal, and I am sure that there can be numerous reasons for deciding to bomb a university. It is likely a hotbed of support for the Hamas militants, it provides a reasonable shelter and can likely be used for the construction of rockets, bombs or other such things.

The materials available to a normal university in the western world are quite significant and many are quite dangerous so it wouldn't surprise me if in the Gaza strip sympathetic professors or university staff would use the normal requisitioning of materials to obtain chemicals or tools that could be useful in the construction of rockets. Of course, this assumes that the Israeli blockade hasn't starved the university of any useful materials whatsoever.

However, there's something about bombing a university that just doesn't feel right. A university is to be a place of learning and education, where ideas can be freely discussed and exchanged without fear or repercussion. In many ways it is also a 'way out' for many young people; earning a degree provides the hope for a better job with better wages, or even the opportunity to travel abroad and continue their studies elsewhere.

Now, not having been to the university in Gaza I can't tell you for sure that that is what it was. But destroying it would be akin to destroying the hopes of thousands of young people and in the long term would only perpetuate the despair felt by many in the Gaza strip.

Even if peace were to come to the area it would require the investment of millions of dollars just to begin to rebuild the university. And even if the university is rebuilt, few professors would willingly put their research in a place where it might be obliterated by a bomb either and have their graduate students killed or maimed.

The decision to destroy a university has long term impacts that should be considered, and I hope the Israelis have done so.

Separation of Science and Religion

Now this is a topic on which libraries of books (literally!) are written so I don't want to get into the details too much.

My reason for writing this post arises from a video I saw of an interview between Rick Warren, the pastor of Saddleback church and a reporter who's name escapes me at the moment. The question that interested me most was the question of whether there is a genetic source to homosexuality or not.

The reporter wondered if science found a 'gay gene' would it change his opinion on the topic. Warren, quite rightly in my opinion, wondered why it mattered. Fundamentally there is a disconnect between what the reporter believes and what the pastor believes beyond simply their disagreement on this topic.

Simply put, the reporter is looking to make a (poor) scientific argument whereas the pastor is making a moral/religious argument. The two are incompatible. It is like two people arguing in two different languages, of course both will come away feeling frustrated and feeling that the other person doesn't understand their viewpoint.

If someone is making a moral argument to you, don't respond by trying to scientifically disprove them because fundamentally you can't. You can't scientifically argue that polygamy is immoral, or that prostitution is not immoral. So don't bother.

An poor way to convince someone who believes that prostitution is immoral to favour legalization and regulation of prostitution would be something along the lines of this:

"Using prostitution is a way to allow people to release stress and pent up hormones. Regular sex has physical and emotional benefits and under the proper conditions we can eliminate STDs and harm to the participants."

Why is this a bad idea? Because someone who believes its immoral will say 'So what? Just because its biologically beneficial doesn't mean its moral. If you want to have sex, get a wife!'

A better argument to use would be something like:

"Regulating prostitution removes women from the typically abusive control of pimps and gangs and can get them into a position where they can receive proper medical attention. Legalization and regulation would make prostitution, which will occur anyways, more safe for prostitutes."

From a moral point of view this is much more difficult to refute than the previous argument.

The same works in reverse, people who think in terms of these issues as moral/religious arguments should tailor their arguments towards their audience and use scientific arguments rather than moral/religious arguments against or in favour of their causes.

This is a rather universal principle I would think, but I'm still surprised to see some people don't get it.

Friday, December 19, 2008

Why I Never Trust Studies (Part II)

In the previous posting I took quite the cynical look at how the results from studies can be manipulated by researchers or journalists. But in the previous post I did not question the results themselves, simply the methodology taken, so I left open the possibility that with better methodology one might obtain the correct result. Unfortunately, even with proper methodology an ethical researcher might still obtain an incorrect result.

Moreover, groups of independent researchers may collectively obtain inaccurate results. A professor once related to me the story about a series of groups of astrophysics researchers who were observing a certain astronomical phenomenon. I won’t go into details but after extensive observations each of these groups obtained certain data, and together the data collected indicated that a particular process was occurring. With this evidence the researchers obtained millions of dollars in grants to construct a more advanced observation device to observe the process. Once it was constructed and turned on the data this more accurate device obtained indicated that all of the groups were wrong.

How could this be possible? Some of the researchers hypothesized that while they were constructing the observation device that the process ‘turned off’. Maybe. Or maybe the way they obtained the data unintentionally biased their results since they were looking to obtain a certain result (this is one reason that double blind studies are done).

But again, this is a methodology problem right? If they changed the way they handle data then it would remove this problem right?

Well not necessarily. Lets take a look at an example. Suppose that a medical researcher wants to test a drug on a set of 100 human patients. For simplicity, say that the ailment has a 50% chance of killing any individual patient over a set time frame. Someone might think that if the drug works then more than 50 of the patients will live, if it doesn’t then only 50 will survive. But compare this to flipping a coin 100 times, will you always get 50 heads and 50 tails? Of course not.

This is where researchers introduce what is called ‘confidence levels’. In other words the number of surviving patients must be so large that the researcher feels confident that the drug must be working. On our given data, the 90% confidence level is around 56 surviving patients. But suppose for a second that the drug doesn’t work at all and the patients still die at a 50% rate, how often then would the researcher obtain that 90% confidence level? How often would they reach the 85% confidence level (around 55 patients)? Creating a simple program to randomly generate patients who die at a 50% rate shows that the researcher would publish erroneous results at the 90% confidence level ~7% of the time. At the 85% confidence level their results would be wrong ~10% of the time.

One might say that this is not significant, that the probability is still fairly small. And this is true, but it is important to remember that there is still a significant probability that the results are incorrect.

Confidence levels vary between different fields, some fields require a greater threshold and some fields require less. So consider yourself warned, next time you read about a study, check to see what the confidence level and sample size were before you consider whether or not to believe it.

Thursday, December 11, 2008

Why I Never Trust Studies (Part I)

Every so often you'll hear a study come out that declares something like 'study shows health benefits to doing X' or 'study proves that Y is true!'.

Now, reporters like these sort of declarations because they are definitive and something that might get them on the front pages. Researchers like them too because its a lot easier to get funding after you've published some definitive results. You'll never see a front page headline stating 'study on health benefits of Z inconclusive'. And you can't really publish a decent article with those results either, but scientifically sometimes a null result is just as important as a positive result.

Moreover, unless the reporter has a lot of time on their hands and access to the methodology of the study you won't see the reporter digging through the methodology of the study making sure everything checks out. Generally, they let other researchers do that later. But if something is wrong in the methodology and it is found out later the correction usually doesn't front page news.

Take for example, the studies that showed that moderate alcohol drinking is good for your heart. I'm sure you've all seen articles like this or this that discuss studies that claim that drinking alcohol (especially wine) is good for you. One article you've probably not seen is this one, which points out that many studies make a fundamental flaw in their methodology and hence are questionable at best.

If you begin digging deep into the actual methodology of a study you'll find that sometimes the headlines aren't entirely true. Take for example the MSNBC article I linked to above, which outlines how drinking wine is good for your health. The chemicals that they credit for being so helpful, the resveratrol and flavanoids, are found in the grapes themselves and do not arise because of the fermentation process at all! These chemicals are also found in green teas. But an article saying 'Eating grapes good for your health' wouldn't make the front pages because everyone already knows that. Saying 'Drinking wine is good for your health' is much better.

So, okay you might think, some of the studies may use poor methodology and the results of some studies may be skewed intentionally by media and/or unethical researchers. But surely, an ethical researcher using proper methodology and using proper statistics would never publish a result that is incorrect. Right? Wrong again, and I'll prove it to you in Part 2.

Wednesday, December 10, 2008

Changing the Internal Combustion Engine

There's been a lot of talk about the automotive industries these days and changing the way they do business, including looking at alternative fuel sources. But while alternative fuels often get all the attention, there is another area of research that has long been overlooked by the general public. Namely, can we change the internal combustion engine itself?

In some ways, it'd be nice to think that we could end our dependence on oil altogether and find some other way of power our vehicles but that isn't going to happen anytime soon. In the meantime, can we do something to the internal combustion engine to make it more fuel efficient?

Most fuel saving methods that people generally think of involve changing aspects of the car rather than the engine itself. Using plastic rather than steel, making the car more aerodynamic, making the vehicles smaller and so on. But the US government, working together with scientists from around the world have been examining how we can change the engine itself.

The article "Research Needs for Future Internal Combustion Engines" published in the November 2008 edition of Physics Today discussed some of the challenges and opportunities that exist as researchers continue in their attempts to reform the traditional internal combustion engine. In particular they discuss the potential for homogeneous charge-compression ignition (HCCI) to increase the efficiency of the engine by 50%.

A traditional engine relies on a spark plug to ignite the fuel but in an HCCI engine the mixture of fuel and air is compressed to the point at which it auto-ignites as shown in this diagram from an article in the January 2006 edition of New Scientist magazine.

Because the fuel combusts at a lower temperature it means that emissions of chemicals like nitrous oxides and soot are reduced. As well, HCCI engines have higher energy conversion efficiencies than standard engines so they require less fuel. Compressing the fuel to the point of auto-ignition means however that the cylinder must be capable of withstanding extremely high pressures and since you are relying on auto-ignition rather than an active spark to initiate the reaction you have much less control over it. Moreover, HCCI engines are subject to a great deal of wear and tear and would need more maintenance than a traditional engine.

In any case, the proponents for HCCI engines have a long ways to go in promoting their new vision of the internal combustion engine to the public at large, which has largely been looking to discard it completely. If the internal combustion engine can be reformed and improved we should not hesitate to support the initiative and should examine the possibilities in as unbiased manner as possible.

As the case of ethanol has shown, politicians are too eager to jump on some bandwagons without seriously thinking about the scientific pros and cons of a technology or advance or the problems that might arise. Until a true alternative fuel is found, its best to keep your options open.

Tuesday, December 9, 2008

Fluorescent Light Bulbs

Perhaps a good place to start is with fluorescent light bulbs and how foolish it was to ban incandescent light bulbs in the first place.

Lets start with what everyone has been told about fluorescent light bulbs. Fluorescent light bulbs require less energy, produce more light and last longer than an incandescent light bulb. That much I think everyone knows so I don't intend to belabour the point.

The point that not many people are aware of is that they contain mercury. As a first year physics TA, one of my more enjoyable labs was showing the spectrum of light from a fluorescent light bulb and having them guess what element (from a set of four elements) the light spectrum was from. Incandescent lights work by heating a metal filament and hence have a continuous light spectrum, that means if one was to separate the light into all its component colours it would contain all of them. Fluorescent lights, because they involve a process of excitation and emission from mercury (followed by fluorescence which converts the emitted radiation into visible light) instead has a light spectrum composed of many lines. You can actually make your own spectrometer out of a CD and prove it to yourself.

Returning from my original train of thought: mercury! I think its widely accepted that mercury is hazardous so I won't dig up the Material Safety Data Sheets (MSDS) for it to highlight my point.

Fluorescent light bulbs generally contain only 4 mg of mercury. That doesn't seem like a lot, and especially if you consider that those mercury thermometers that we used to use have up to 1000x the amount of mercury. But America uses millions of light bulbs every year, and far fewer of the mercury thermometers. Moreover, many people are still not aware of the proper disposal methods of fluorescent bulbs throwing them away just like they tossed their old incandescent bulbs in the garbage bin.

Landfills may have all kinds of protection to contain hazardous gases and liquids but there's a long way between your garbage bin and the landfill and a lot of workers that may be exposed to the mercury if the bulb breaks en route.

The last point I'll make is this. Per any set unit of time the fluorescent light bulbs consume less energy but if people, accepting this to be true, use fluorescent light bulbs longer then the net benefit decreases.

So in short, there is nothing wrong with fluorescent light bulbs from a scientific point of view. The problem lies in human behaviour towards them and if we fail to inform the public adequately concerning the risks and proper handling methods for these materials then banning incandescent bulbs will cause more environment problems than we solve.

Fun Facts!

A Watt is most often understood in the context of a light bulb. We all know that a 100W light bulb is brighter than a 60W one, and logically that the 100W one will consume more energy. However, the unit Watt is more a unit of energy consumption. So for example, the horsepower of can be converted to Watts. Moreover, the rate of energy you consume walking up the stairs can also be written in units of Watts.

Inaugural Post

Its always bugged me reading blogs that very little was ever posted about things from a science perspective.

Science today is an integral part of our everyday life. Our automobiles are increasingly complicated, with advances being made in fuel cell technology, ethanol fuels and electric cars. Computers are used by everyone but understood by few. Sure, lots of people know about binary code and most people know how to use HTML (I'm still learning), and maybe you even know how to assemble a computer from its varied parts (I can't). But how many people know exactly how a DVD works or why a BluRay disc is better? Heck, most people probably don't even know how one of those fluorescent light bulbs work.

If you do, congrats! In any case, beyond informing any readers about new advances in science I'll probably delve into some of the political implications behind the different advances. Things like public subsidies for ethanol production, the recent ban on incandescent bulbs, etc..