Thursday, May 19, 2016

The Curse Of Being A Physicist

When do you speak up in a social setting and set someone straight?

I think I've mentioned a few times on here of being in a social setting, and then being found out that I'm a physicist. Most of the time, this was a good thing, because I get curious questions about what was on the news related to physics (the LHC was a major story for months).

But what if you hear something, and clearly it wasn't quite right. Do you speak up and possibly might cause an embarrassment to the other person?

I attended the annual Members Night at the Adler Planetarium last night here in Chicago. It was a very enjoyable evening. Their new show that is about to open on "Planet Nine" was very, VERY informative and entertaining. I highly recommend it. We got to be among the first to see it before it is opened to the public.

Well, anyway, towards the end of the evening, before we left, we decided to walk around the back of the facility and visit the Doane Observatory. The telescope was looking at Jupiter which was prominent in the night sky last night. There was a line, so we waited in the line for our turn.

As we progressed up, I and my companions heard these two gentlemen chatting away with the visitors, and then to each other about their enthusiasm about astronomy and science, etc. This is always good to know, especially at an event like this. As I got closer to them, it turned out that they were either volunteers, or were working for Adler Planetarium, because they were wearing either name tags or something. One of them identified himself as an astronomer, which wasn't surprising considering the event and the location.

But then, things got a bit sour, at least for me. In trying to pump up their enthusiasm about astronomy and science, they started quoting Carl Sagan's famous phrase that we are all made up of star stuff. This wasn't the bad part, but then they took it further by claiming that hydrogen is the "lego blocks" of the universe, and that everything can be thought of as being built out of hydrogen. One of them started giving an example by saying that you take two hydrogen and put them together, and you get helium!

OK, by then, I was no longer amused by these two guys, and was tempted to say something. I wanted to say that hydrogen is not the "lego blocks" of our universe, not if the Standard Model of Particle Physics has anything to say about that. And secondly, you don't get helium when you put two hydrogen atoms together. After all, where will the extra 2 neutrons in helium come from?

But I stopped myself from saying anything. These people were working pretty hard for  this event, they were trying to show their enthusiasm about the subject matter, and we were surrounded by other people, the general public, who obviously were also interested in this topic. Anything that I would have said to correct these two men would not have looked good, at least that was my assessment at that moment. It might easily led to an awkward, embarrassing moment.

I get that when we try to talk to the public about science, we might overextend ourselves. I used to give tours and participated in outreach programs, so I've been in this type of situation before. While I tried to make sure everything I say was accurate, there were always possibilities that someone in the audience may know more about something I said and may find certain aspects of it not entirely accurate. I get that.

So that was why I didn't say anything to these two gentlemen. I think that what they just told to the people who were within ear shot of them were wrong. Maybe their enthusiasms made them forget some basic facts. That might be forgivable. Still, it is obvious that I'm still thinking about this the next morning, and second guessing if maybe I should have told them quietly that what they said wasn't quite right. Maybe it might stop them from saying it out loud next time?

On the other hand, how many of these people who heard what was said actually (i) understood it and (ii) remembered it?


Still No Sterile Neutrinos

IceCube has not found any indication of the presence of sterile neutrinos after looking for it for 2 years, at least not in the energy range that it was expected.

In the latest research, the IceCube collaboration performed independent analysis on two sets of data from the observatory, looking for sterile neutrinos in the energy range between approximately 320 GeV and 20 TeV. If present, light sterile neutrinos with a mass of around 1 eV/C2 would cause a significant disappearance in the total number of muon neutrinos that are produced by cosmic-ray showers in the atmosphere above the northern hemisphere and then travel through the Earth to reach IceCube. The first set of data included more than 20,000 muon-neutrino events detected between 2011 and 2012, while the second covered almost 22,000 events observed between 2009 and 2010. 

I think there are other facilities that are looking for them as well. But this result certainly excludes a large portion of the "search area".


Sunday, May 15, 2016

Grandfather Paradox - Resolved?

This Minute Physics video claims to have "resolved" the infamous grandfather paradox. Well, OK, they don't actually say that, but they basically indicated why this might be a never-ending loop.

Still, let's think about it this way instead. During your grandfather's time, presumably, ALL the atoms or energy that will make you are already there, only they are all not together to form you. This only happens later on. But they are all there!

But here you come along from another time, popping into existence in your grandfather's time. Aren't you violating conservation of energy by adding MORE energy to the universe that are not accounted for? Now, unless there is a quid pro quo, where an equal amount of energy in your grandfather's time was siphoned to the future where you came from, this violation of conservation of energy is hard to explain away, especially if you invoke Noether's theorem.

I haven't come across a popular account of this issue.


Saturday, May 07, 2016

"... in America today, the only thing more terrifying than foreigners is…math...."

OK, I'm going to get a bit political here, but with some math! So if this is not something you care to read, skip this.

I've been accused many times of being an "elitist", as if giving someone a label like that is a sufficient argument against what I had presented (it isn't!). But you see, it is hard not to be an "elitist" when you read something like this.

Prominent Guido Menzio, who is Italian, was pulled out of a plane because his seatmate thought he was writing something suspicious while they waited for their plane to take off. She couldn't understand the letters and probably it was "Arabic" or something (what if it is?), and since Menzio looks suspiciously "foreign", she reported him to the crew.

That Something she’d seen had been her seatmate’s cryptic notes, scrawled in a script she didn’t recognize. Maybe it was code, or some foreign lettering, possibly the details of a plot to destroy the dozens of innocent lives aboard American Airlines Flight 3950. She may have felt it her duty to alert the authorities just to be safe. The curly-haired man was, the agent informed him politely, suspected of terrorism.

The curly-haired man laughed.

He laughed because those scribbles weren’t Arabic, or some other terrorist code. They were math.

Yes, math. A differential equation, to be exact.
You can't make this up! But what hits home is what Menzio said later in the news article, and what the article writer ended with.

Rising xenophobia stoked by the presidential campaign, he suggested, may soon make things worse for people who happen to look a little other-ish.

“What might prevent an epidemic of paranoia? It is hard not to recognize in this incident, the ethos of [Donald] Trump’s voting base,” he wrote.

In this true parable of 2016 I see another worrisome lesson, albeit one also possibly relevant to Trump’s appeal: That in America today, the only thing more terrifying than foreigners is…math.
During this summer months, many of us travel to conferences all over the place. So, if you look remotely exotic, have a slightly darker skin, don't risk it by doing math on an airplane. That ignorant passenger sitting next to you just might rat on you! If by being an "elitist" means that I can recognize the difference between "math" and "arabic", then I'd rather be an elitist than someone who is proud of his/her aggressive ignorance.

How's that? Are you still with me?


Thursday, May 05, 2016

Scanning Probe Microscopy

The Physical Review is marking the 35th Anniversary of Scanning Tunneling Microscopy (STM) and 30 years of Atomic Force Microscopy (AFM) with free access to notable papers from the Physical Review journals in these two experimental techniques.

So check them out!


Monday, May 02, 2016

Walter Kohn

Walter Kohn, who won the Nobel Prize in Chemistry, has passed away on April 19.

He is considered as the father of Density Functional Theory (DFT). If you have done any computational chemistry or band structure calculation in solid state physics, you will have seen DFT in one form or another. It has become an indispensable technique to be able to accurately arrive at a theoretical description of many systems.


ITER Is Getting More Expensive And More Delayed

This news report details the cost overruns and the more-and-a-decade delay of ITER.

ITER chief Bernard Bigot said the experimental fusion reactor under construction in Cadarache, France, would not see the first test of its super-heated plasma before 2025 and its first full-power fusion not before 2035.

The biggest lesson from this is how NOT to run a major international collaboration. Any more large science projects like this, and the politicians and the public will understandably be reluctant to support science projects of that scale. The rest of us will suffer for it.


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.


Wednesday, March 30, 2016

Has Bill Nye, The Science Guy, Lost It?

Or did he ever had it in the first place?

My attention was brought to this via Hamish's blog at Physics World. He pointed out the sharp critique against Nye in Sabine Hossenfelder's "Back Reaction" blog entry. It all stemmed from Nye's video answering a question regarding quantum entanglement, where it appears that Nye got tangled in it himself.

You may read the criticism yourself (be warned, there are some "colorful" language being used in there).

I think that while Nye has done quite a bit in the media to popularize science, I often find his off-script or unscripted responses a bit suspect at times. This is another one such example. It is my impression that he knows the pop-science version of science, but not the intimate detail. Of course, you often do not need the intimate detail when dealing with the general public, which is why he could manage to do this for this long. But when confronted with something that requires a bit more in-depth knowledge, especially in physics, this is where he trips.

I don't know why he doesn't consult an expert when he responded to this person in this video clip. After all, I'm sure it isn't "live", and he could have easily checked if what he was saying was accurate, or nonsensical. Unfortunately, he went into the realm of nonsensical, and he didn't even realize it.