Friday, April 29, 2016

LHC Knocked Out By A Weasel?

You can't make these things up!

CERN's Large Hadron Collider, the world's biggest particle accelerator located near Geneva, Switzerland, lost power Friday. Engineers who were investigating the outage made a grisly discovery -- the charred remains of a weasel, CERN spokesman Arnaud Marsollier told CNN.
If you are a weasel kind, be forewarned! Don't mess around at CERN!


Thursday, April 21, 2016

Online Students - Are They As Good?

This is essentially a follow-up to my post on Education Technology.

So, after doing this for a while and trying to put two-and-two together, I'm having a bit of skepticism about online learning and education. I know it is in-fashion right now, and maybe in many other subjects, this is effective. But I don't see it for physics.

I've mentioned earlier on why students who undergo online learning via the online interface that they use often lack problem-solving techniques, which I consider as important as understanding the material itself. However, in this post, I also being to question if they actually know what we THINK they know. Let me explain.

My students do their homework assignment "online", as I've mentioned before. They have to complete this each week. I get to see how they perform, both individually, and as a group. I know what questions they got right, and what they got wrong. So I can follow up by going over questions that most students have problems with.

But here's the thing. Most students seem to be doing rather well if I simply base this on the online homework scores. In fact, just by looking at the HW statistics, they understand 3/4 of the material rather well. But do they?

I decided to do some in-class evaluation. I give them short, basic questions that cover the material from the previous week, something they did in their homework. And the result is mind-boggling. Many of them can't answer the simplest, most basic question. And I let them open their text and notes to answer these questions. Remember, these are the topics that they had just answered in the HW the previous week that were way more difficult than my in-class questions.

For example, a HW question may ask for the magnitude and direction of the electric field at a particular location due to 2 or more charges located at some distance away. So for my in-class question, I have a charge Q sitting at the origin of a cartesian coordinate, and I ask for the E-field at a distance, say 3 cm away. And then I say that if I put a charge q at that location, what is the force acting on it that charge? Simple, no? And they could look at their notes and text to solve this.

If the students could manage to solve the more difficult HW problem, the question I asked should be a breeze! So why did more than half of the class gave me answers as if they had never seen this material before?

This happened consistently. I will ask a very basic question that is way simpler than one of their HW question, and I get puzzling answers. There appears to be a huge disconnect between what they did in the online HW, and their actual knowledge of the very same material that they should have used to solve those HW problems. They performance in completing the online HW has no correlation to their understanding of the material.

All of this becomes painfully obvious during the final exam, where they have to sit for it in class, and write down the solution to the questions the old-fashion way. The majority of the students crashed-and-burned. Even when the questions were similar to the very same ones they solved in their HW, some did not even know how to start! And yes, they were allowed to look at their notes, texts, and their old HW during the finals.

So what are the reasons for this? Why is there such a disconnect between their performance online, and what they actually can do? While there might be a number of reasons for this, the only one that I find most plausible is that they had some form of assistance in completing their online work. This assistance may be in the form of (i) previously-done HW from another source and/or (ii) another person who is more knowledgeable or had taken the course before. The online performance that I see often does not accurately reflect the level of knowledge the students actually have.

So this led me into thinking about all these online courses that many schools are beginning to offer. Some even offer entire degree that you can get via online courses. I am well-aware of the conveniences of these forms of learning, and for the right students, this may be useful. However, I question the quality of knowledge of the students, on average, that went through an online course or degree. If my haunch is correct, how does one know that the work that has been done online was done purely by that student? Sure, you can randomize the questions and insert new things in there, but there is still the question on whether the student had an external assistance, be it partially or entirely.

I asked on here a long time ago if anyone have had any experience with students in physics who went through an online program, either partially or for an entire degree program. I haven't had any responses, which might indicate that it is still not very common. I certainly haven't encountered any physics graduate students that went through an online program.

Like I said, maybe this type of learning works well in many different areas. But I don't see how it is effective for physics, or any STEM subject area. Anyone knows how Arizona State University does it?


Thursday, April 14, 2016

Debunking Three Baseball Myths

A nice article on the debunking of 3 baseball myths using physics. I'm not that aware of the first two, but that last one, "Swing down on the ball to hit farther" has always been something I thought was unrealistic. Doing that makes it more difficult to get a perfect contact, because the timing has to be just right.

This is no different than a serve in tennis, and why hitting the ball at its highest point during a serve gives you a better chance at getting at the racket's sweet spot.


Monday, April 11, 2016

"Fart Detector" Wins Chinese Physics Prize

OK, there are many aspects this story.

When I first read the title, I honestly read it as "Fast detector", which is reasonable, because fast detectors are useful. But when I read it again, I did a double take. So of course, I had to open the link to the story and figure out what this is.

Turns out that that wasn't the original intent of this detector. Rather, it is trying to sniff any odor in a moving air and to locate the source. Of course, the media, even in China, took it to its most obvious "application" such as sniffing (pun intended) the source of a fart. Question is, what do you do when you find the culprit? Is it unlawful in China for someone to fart in public? Do you shame this individual for such an act?

Finally, it turns out that the prize given is the "Pineapple" prize because "...the fruit which in China is said to be so ugly that only the brave and curious would explore its delicious interior..."


I guess this is another example of beauty in the eye of the beholder. I had never, even a second, consider the pineapple to be an "ugly" fruit. In fact, if you've been in to Hawaii or the tropics (especially in South East Asia where the fruit is abundant), it is considered to be beautiful enough to be used as decorations!

In any case, I don't think this research work is "useless" to even qualify for an Ig Nobel prize.


Friday, April 01, 2016

Education Technology - Is It All Good?

First of all, I'm sure I'm a dinosaur as far as education technology is concerned. I come from an old school where HW assignments are done on paper, and students submit them to a TA or instructor to have them graded. Or a situation where students do their quizzes or exams by writing them on paper and submit them after completion.

I'm still not used to an education system where students do their HW online, and even do their weekly quizzes and exams online. I'm sure there are many different systems and ways of doing this. However, I still see two things from the students perspective: (i) it is tedious to draw a sketch, which is often needed in tackling physics problems, and (ii) it is tedious to write mathematical equations.

Because of this, a lot of online exercises often simply ask you to enter just a number, or pick from a multiple choice of solutions. This is what I often deal with right now with students' homework assignment. Oh sure, I have the option of assigning my own HW questions if I wish, but the majority of the instructors opt for the former, and I need to be consistent with others.

So what problems do I see with this education methodology? First of all, you do not get to see how the students approach the problem. All you see are answers, and if they get them right, or wrong. You don't know if the students don't know where to start, or if they simply make some silly math error along the way. You cannot diagnose if they have a serious problem or not in understanding the material.

Secondly, despite my strong recommendations that they actually write down and work out the problem till they get the answer, and then enter that answer online, most students simply scribbled out their work to get an answer and once they are done, the scribble is either discarded, or they can't comprehend what they did when they go back to it later on. They do not have a clear detail on what they did, be it right or wrong, that they can learn from later on. So how exactly do they revise for their exams?

Seeing and understanding how problems are solved, and learning from mistakes, are the most effective means of understanding a topic and being able to solve problems. I think I kept most, if not all, of my upper/graduate-level physics class homework assignments (they are somewhere in boxes in the basement). So I don't know how the new generation of students learn and more importantly, RETAIN the stuff that they had learned and done.

The consequence from all of these is that, when they had to sit down for an exam, where they had to write down all the work, many students crashed! Despite being shown how to properly solve problems in class (I did numerous examples), many students still can't properly sketch out a problem (some didn't even bother to do one), and it was jaw-dropping how many still start off their work by writing in just numbers in an "equation", without first writing the symbolic form.

I've been trying to remedy that in subsequent classes that I taught. I have weekly written quizzes to get the students into the habit of solving problems properly, etc. But I think most of them already have the mindset of doing things online, because many of their other classes adopt this method of education. So my way of doing things are more of the "ancient" method of education. I continue to let then do HW assignments online just so they cover the same type of material as students in other similar classes, but I'm insisting that they do their quizzes the old fashion way.

I'm not a techno-phobia. In fact, I posted a blog entry on the easiest way to do lab notebooks using tablets. But in this case, technology may be a hindrance to learning. It may work in many other subject areas, but I somehow don't see it working in physics and mathematics (and maybe the rest of the STEM subjects). These are often not a plug-and-chug subject areas, and it is not conducive to online interface.