Wednesday, July 21, 2021

10 Scientfic Evidence In Support Of Airborne Transmission of SAR-CoV-2 Virus

The ridiculous battle during the pandemic on wearing masks, social distancing, and other restrictions reveals the lack of understanding among many in the general public on how science works, on what is considered as valid scientific evidence, and how our knowledge progresses as more and more evidence and data accumulates. I continue to be amazed at the reasons why some people still resist wearing proper face masks. I can understand if they find it uncomfortable (who does?) and that it is inconvenient (who thinks otherwise?). However, if the reason given is that masks doesn't do anything or isn't effective in reducing the chances of the virus being spread, then I want evidence to back that up.

This is where the public lack the understanding of (i) the nature of valid, scientific evidence, versus simply something you read on Facebook, news websites, or even from talking heads on TV, (ii) where to find such evidence or what should you pay more serious attention to versus those other sources that I mentioned. Here, I want to contrast the type of information that is contained in a scientific paper versus what you find in news article or many public online websites.

(1) When you read something in the news on a typical mass media source, you are told the content, but very seldom are you given proper, exact citation. At best, the type of citation that would be mentioned would be something to the effect that this was published in such-and-such journal or book, etc. Worse still, often times the sources are not even cited, so many of these things are stated as if they are facts, and facts that many of us are unable to verify on our own, if we wish to.

In contrast, scientific publications require exact citation. If you say that this result is in agreement or support by recent discoveries, you must give bibliographical references to those sources, i.e. name of author/s, name of journal where it was published, what page/volume number, date it was published, etc. These details are crucial in someone else verifying the sources of the claim. This is what is often missing in many general public articles, and unfortunately, this is often the source of Fake News, because exact evidence and sources to back the claims are either bogus, unreported, or unrevealed, which prevented anyone from double-checking their validity.

(2) News report and online articles often ignore contradicting evidence. When someone claims that he/she got sick after receiving a vaccine shot, why doesn't he/she consider why a lot of other people didn't get sick? Of if receiving a vaccine shot makes one "magnetic", how come other people aren't? This can also be applied to a lot of "news" programs that reports on certain occurrences that was due to something, but ignore other instances where those occurrences do not happen.

In scientific papers, this is a no-no. In fact, as a referee for several physics journals, I often will check if the authors are ignoring contradicting experimental evidence, or other papers that may be in the opposite to what the authors observed or claiming. These contradictions MUST BE ADDRESSED, i.e. they are not swept under the carpet or just ignored. And they must be addressed in terms of scientific reason, not simply by claiming that the contradicting results were made by Democrats, Republicans, Muslims, Jews, liberals, conservatives, etc. Look at how many so-called discussions or reports attached labels as a means to dismiss something. Such flimsy tactics do not wash in scientific papers.

(3) General public articles and news lacks details and clarity. I read a news article last year where a family decided to go to Walt Disney World in Orlando, FL, and when they got home, they tested positive for COVID-19 and immediately blamed their presence at the theme park for being infected. The news article didn't mentioned any other details about their trip. It did not say if they took a plane, didn't not say how long they stayed, whether they only went to the Disney theme park or did they also went elsewhere, and if they drove there, did they stop anywhere along the way, etc. There was a huge amount of information here that was missing even for a casual reader to be able to clearly analyze the validity of what the family was claiming.

If this claim is to be analyzed scientifically, then an epidemiologist would need to do really detailed tracing of every activity that the family did. Casual and speculative connection between A and B are usually insufficient to draw up valid conclusions.

In a scientific publication, every detailed of a calculation, every detail of the experiment, and every detail of how the analysis was done, must be clearly revealed. Often times, the experimental setup and equipment may had already been published elsewhere, and those will be cited as a reference. Similarly with the calculation and analysis. These details allow for an independent investigator to not only double-check what was done, but also to duplicate the experiment if necessary to see if the results are reproducible, which is a pillar of all scientific experiments (and why the Fleishmann and Pons cold fusion claim failed).

(4) Scientific papers are permanently recorded. They are not like Twitter feed that can be deleted, or news article that may be difficult to find anymore, or Facebook postings that have disappeared. This allows for future citations by other papers, and allows for continuing evaluations, advancements, refinements, rebuttals, contradictions, etc. There is a clear paper trail of who said what and when, which means that it is hard to deny or lie about something, or claim that someone didn't say that or didn't do that.

The whole point in all of this is not to force you to read scientific papers. It is ridiculous to insist that because many of them are not easy to read and are written for other experts. Rather, it is to distinguish on the nature of the evidence, and that if something is backed by proper scientific sources, then the evidence has a greater degree of validity and support than something that someone just rattled off on a TV talk show or on some Facebook post. It is unfortunate that many people, especially politicians, give equal credence to someone testifying that their bodies became magnetized without bothering to invite an expert to debunk such silliness. It seems that whole topics in physics, biology, and physiology were ignored to give air to this craziness.

It is the inability to evaluate the validity of the so-called evidence is one of the fundamental reasons why we are in the state that we are in today.

"But ZapperZ, the topic is about the scientific evidence for airborne transmission of the COVID virus.  Where is it?", you asked.

Good question. I guess this is the long, circuital route to point you to this Lancet article that contains the evidence, and the references to the scientific papers, that support the claim. Compare the types of research that were done, the analysis that were performed, and how the conclusions were drawn, and compare that with the types of "evidence" presented in the popular media and TV news programs.

Have fun reading!

Zz.

Thursday, July 01, 2021

Using Science To Teach Students In The Art Of Falsifying An Idea

The climate of fake news and anti-science during the last few years have given me the impetus to be more conscious and deliberate in alerting my students on how we analyze something, on making rational judgement based on evidence, and how we come to such-and-such conclusions. To me, the issue of believing in fake news and accepting something based on flaky evidence does deeper than what it seems. It boils down to the inability to systematically and analytically evaluate the validity of something. This inability is really a serious issue and could be the root cause of what we are seeing today.

This type of skill is exactly what we use and practice all the time in science. So when I get a group of students, especially if they are non-science students who are taking the course only to fulfill their science credits, then I can't waste the opportunity to instill in them this invaluable technique and methodology that are often used in science.

Using the period where the pandemic forced us to teach remotely, I made extensive use (and still do) of the discussion forum. This is one form of student engagements that many online training courses have deemed to be essential in making sure that students feel connected and engaged with not only the subject matter, but also with other students. This medium gave me the opportunity to get the students to think things through and to present logical and rational arguments.

One of the topic that I presented was to require them to critically address a belief about the cause of the Earth's four seasons. We were going over the reason why we (at about latitude 41 degrees North) experience seasons. I presented a topic whereby someone claims that since the Earth orbits the Sun in a slight elliptical orbit, the seasons are caused by the varying distances between the Earth and the Sun, meaning that when the Sun is closest to the Earth, we have summer, and when the Sun is farthest from the Earth, we have winter.

The task was for the students to come up with typical and common everyday observations and/or knowledge to show why this idea is wrong. In other words, find a very direct and convincing way to falsify the argument.

I thought this was a straight-forward assignment and discussion topic. Unfortunately, I was quite surprised that almost 3/4 of the students didn't fulfill the briefs. What they did instead was to give the explanation for the cause of the seasons, which is the tilt of the Earth's spin as it goes around the Sun. While this is the correct explanation, it does not falsify the original argument. I tried to tell the students that what they did was to present to this person an alternative explanation on why the seasons happen, but they haven't shown evidence why the original premise was wrong! They have not falsified the first idea.

When we do that in an argument/discussion, the person who holds that idea can easily say "All you have done is showed another possible explanation. You haven't proven to me why my idea is wrong. So why should I change my mind?"

Providing an alternative explanation, even if it is the correct one, is distinctively different than falsifying an idea. In falsifying an idea, you do not need to actually have an alternative, correct explanation. In this case, you really don't need to know that the Earth's tilt is the cause of the seasons on Earth. All you need is to examine the original claim, and find evidence that contradicts that claim. In this case, what you can do is assume that it is true, that the seasons are caused by Earth's varying distances from the Sun. If that is true, then the entire Earth would have the same season at the same time of the year, because the entire Earth is at the same distance away from the Sun. Yet, it is common knowledge that Australia, New Zealand, South America and Antartica are in their deep winter freeze while we in the Northern Hemisphere are basking in our summer heat. This observation is clearly contradictory to the original claim, which means that this is a falsification of that idea. It carries no other "baggage", i.e. it doesn't promote an alternative explanation on the cause of Earth's seasons.

It found it challenging trying to convey this message to the students. They learned about the Earth's tilt and the cause of the seasons, and when they were given this topic, they immediately jumped on providing the explanation that they just learned (and understood) without thinking about how to actually address the topic of the discussion and knowing the difference between falsifying an argument versus providing an alternative explanation.

Sadly, the same situation happened again later in that semester when I brought another scenario for them to address: the claim that the phases of the moon are due to Earth's shadow of the light from the Sun. Once again, they were asked to falsify the claim, and once again, more than half of the students provided an alternative explanation on the cause of Moon phases rather than falsifying the idea.

In teaching science courses to non-science majors, I've grown more skeptical about the public's ability to analyze something. What I have observed regarding the "controversy" surrounding vaccines, the wearing of face masks, and even climate change, reinforced my skepticism about someone 's ability to either think things through, or even know what a valid evidence is. My post on the nurse who claimed that the COVID vaccine makes her becoming magnetized is one such example. Something that should have been easily checked and verified by a high-school physics student now somehow is gaining traction. That claim can be easily falsified (and have been), even by people without much scientific training and without knowing any alternative explanation on why certain objects might stick to one's body.

It requires skills to look at an idea, analyze it thoroughly, and rationally argue on its validity or its fault. It also requires skills to know what are valid evidence and what are not. Often times people confuse opinions and conclusions with facts/evidence. Talking heads on TV often spew out opinions that a lot of people mistaken for facts. In a science class, it is more important than ever that instructors make a deliberate effort to show the process of how a scientific idea becomes accepted, what kind of evidence would be considered to be scientific (why do we have to measure the forces at various extensions when just one is sufficient to find the value of the spring constant in Hooke's law experiment?), and how to challenge an idea and show that it may not be correct.

A science education is now more important than ever, not just for the scientific content, but also for the skills that come with it.

Zz.

Friday, June 18, 2021

Bringing Current News Into A Physics Lesson

I chat often with my colleagues from the English and other departments. I often envy them because many of their assignments have the ability to incorporate the hot topics of the day. They often assign tasks such as essay writing that involves subject matter that are relevant for the current times, such as writing about Black Lives Matter movement, the pandemic, etc.

While I always want to do the same, it is less obvious and not so straight-forward in bringing the same thing into a physics lesson. I had managed to incorporate some over the years (direct observation of blackhole in an IR image while we were studying EM waves as an example). But to incorporate topic-of-the-day to match the topic of the lesson is not that easy.

But this time, I managed to do it, and it was a doozy. We were about to dive into the topic of magnetism and electromagnetic field when I stumbled upon a goldmine. It is the claim that the COVID vaccine can cause one to become magnetized!

Now, my class is still being done remotely, so I make extensive use of the discussion forum as one means of student engagement. When the subject of magnetism comes up, the topic of discussion that I created was for the student to read a couple of news reports on this claim being made. The task is not to either belittle or make fun the claim or the people who made them. Rather, it is to rationally examine the claim and use well-established scientific facts to analyze the validity of such a claim. The students had to do this based on what they have learned about magnetic field, the type of magnetism in a material, and what type of materials are attracted to a magnet.

They were encouraged to make their own at-home observation. Everyone had refrigerator magnets, and I asked them to try and stick various items to the magnet, especially the ones that had been used in the testimony reported in the news article. A student also had the bright idea to use a compass that she had and see if the compass needle changes direction if she brought it against her skin (she's fully vaccinated) or her parents' skin. She cleverly argued that if something has a strong enough magnetic field to attract a spoon, it should cause a noticeable deflection in the compass needed.

This ended up being a lively discussion topic in the discussion forum, with students posting pictures, videos, etc. either one something they found, or something they did. It forced them to sift through what they read in the news to find the details that they can analyze and compare with what they learned about magnetism. They studied the validity of the claim only from the scientific point of view without passing any judgement on politics or personal beliefs.

The whole thing went better than I expected. The students were engaged because this was a current and relevant topic, and they get to see first hand how something that they just learned was actually useful enough to be used to analyze a news item. They get to see that a physics topic is not just something esoteric with little direct practical use in everyday life.

Oh, I should also mention that this is an algebra-based General Physics course that is tailored to life-science/pre-med/biology/kinesiology major. Many of the students are quite familiar with the human body and biological functions, so their discussion included several possible explanations on why something would or would not stick to a human skin without any consideration about magnetism.

It is on days like these that I get great joy in being a teacher.

Zz.

Thursday, May 20, 2021

Context Interactions & Physics Faculty’s Professional Development

This is a rather fascinating study of two different physics faculty members at two different schools. I haven't finished reading it carefully yet, but I thought I'd post the link here and let you read along with me.

Abstract: This paper investigates the interactions between context and professional development of physics instructors in a case study of two physics faculty. A phenomenological-case study approach was used to analyze two physics faculty at different institutions over a year and a half using three semi-structured interviews each. The data enabled the identification of relevant context elements; and the impact of these elements on physics faculty's professional development was explored by adapting Bell and Gilbert's framework for teacher development. The analysis shows that both case study subjects used their physics expertise and growing understanding of their context to develop their physics teaching. However, this process of development was enacted differently given the nature of their context, highlighting instructors' strengths in navigating their local context to improve their physics teaching. The results show the subtleties of how context has a salient, complex, and evolving role in moderating faculty's professional development. By taking a faculty-centric approach, this paper broadens the community's awareness of the ways physics instructors develop their physics teaching. This work contributes to a relatively new lens by which the physics community views, discusses, and supports the professional development of physics faculty. 

What the authors call "context" appears to be broadly defined as "... the different entities that influence their professional development .. " which could include the institution, the department, other faculty members, workshops and other faculty development efforts, etc. 

The study focused on two faculty members, and followed them via a series of interviews. In particular, they seem to focus on each faculty member's teaching practices and philosophy, and how they evolve and how they are able to execute their teaching ideas.

Like I said, I'm still in the middle of reading this, but I freely admit that I see bits and pieces of myself in here, especially in the struggle to implement some of the active-learning concepts into my classes, more so during the remote-learning phase due to the pandemic. 

Z.

Saturday, April 10, 2021

Muon g-2 Results Signify New Physics? Maybe Not.

The big news of the week that got all the media coverage is the result that came out of Fermilab's Muon g-2 experiment that confirmed an earlier result from Brookhaven more than a dozen years ago. Fermilab even announced it like.


However, as with any scientific discovery or announcement, one has to take a deep breath and let the process works itself out before we put our stamp of validity to it. This is because there is a theoretical calculation that has also been published along with this result that basically recalculates what the Standard Model predicts as the magnetic moment of a muon, and they found that the new calculation produces a result consistent with the experiment. In other words, there is no new physics if this calculation is verified, because the old Standard Model does, in fact, predicted this new result.

One of the major difficulties in physics is that in many situations, we do not have a simple equation that we can plug-and-chug to get numbers out. In fact, this is why predicting the weather is difficult, because the non-linear differential equations that need to be solved to get the number out can only be done numerically, i.e. it has to be done via some numerical algorithm.

This is made worse when there are a gazillion interactions involved in a system. So one ends up making simplifying models or adopt calculational techniques to allow us to get to some numerical answers. We benchmark the technique to known values and known systems to make sure that it gives accurate and sensible answers, but as we push the boundary even more, there is no guarantee that that calculational technique will work all the time.

The author of the theoretical paper used a calculational technique called lattice QCD. This is a known calculational model that has been described in simple terms in the link I provided above. It appears that using this method, the Standard Model does provide a value for the muon magnetic moment that is consistent with the experiment. If this is true, then it means that the old calculation of the magnetic moment was incorrect in the first place, and that there is discrepancy between what the Standard model predicts, and what the experiment measures.

While this is good news for the Standard Model and is another evidences of why it is an amazing theory, those who are looking for new physics beyond the Standard Model will obviously not be jumping for joy. But that isn't the issue here and not what I want to highlight. Rather, it is the constant reminder that in science, and especially in such exotic areas of physics, every discovery or new ideas must not be overblown or overhyped, because those require multiple verification over a period of time. It is not a situation for instant gratification. A lot of hard work is still to come because we have seen way too many times where something that was touted turned out to not be valid.

This announcement received a lot of media coverage. I just hope that this is a valid "new physics" and not just something that turned out to be what the old theory did predict.

Zz.

Monday, March 22, 2021

Getting My COVID Vaccine This Week

Being under 65 years of age, and with no major health issues (knock on wood), I was not eligible to receive the COVID vaccine in my area during the first 2 waves of its distribution.

But suddenly, it was announced by our state that starting Monday (today), higher-education workers will be included in the expanded criteria to receive the next vaccine distribution. So, after scrambling to find an appointment, I will get my first shot of the Pfizer vaccine this coming Friday, and then the second one later in April. All I can say is : PHEW!

There is certainly a push by the school to get things back to almost normal, in the sense that many of the classes are starting to be offered in person or in a blended/hybrid modality. Certainly classes that have a significant laboratory component are the ones that will probably start to be offered in person. I definitely would prefer to have the vaccine before I have to come in to the campus, so getting the vaccine now is a major peace-of-mind aspect of this whole thing.

It is certainly looking more certain that I may have to ditch my Zoom pants on most days and have to start dressing up again when I teach my classes this Fall! 😀😁

Zz.

Wednesday, March 10, 2021

Tripple-Layer Mask Blocks Secondary Atomization of Cough Droplets

I had already posted several physics papers on the efficacy of masks, even single-layer ones, in reducing the airborne aerosol. Now comes another paper that deals with how cough droplets actually can break up into smaller-sized droplets that may pass through single and double-layered masks, especially when moving at such high speed from a cough.

It turns out that having a mask with 3 layers or more might be the most effective here (I wonder at how many layers will we will of suffocation? :)) The new research is to be published in Science, and you can get the paper at the link to read to your heart's content.

A review of this paper can be found here. It is fascinating to read that expertise in the study of jet engines are being leveraged in studying the dynamics of this problem. But do you think people who don't believe in wearing masks to reduce the virus transmission will buy any of this? They believe in smartphones and jet engines, don't they?

Z.

Wednesday, March 03, 2021

English And The Language Of Physics

I love reading articles like this where the history of how things become the way they are now is revealed.

This Symmetry article tells the story of how English became the language of physics and why it became dominant in the publication of physics articles and journals. It has almost nothing to do with science, but everything to do with politics, social upheaval, and world events. If Germany didn't have the Nazi coming into power, we probably would be doing physics in German, or if the Soviet Union didn't close off the interactions of non-Soviet scientists, we'd be sharing ideas in Russian as well.

Zz.

Tuesday, March 02, 2021

Impact of COVID-19 Pandemic On Physicists

We, physicists, are people too (shocking, I know!). The impact of isolation, stay-at-home and work-from-home orders, and the cancellation of experimental work, in-person conferences, workshops and others do have academic, emotional, and psychological impacts on this group of people

This Physics Today article looks at such an impact on the physic community, and how they are dealing with it.

How are YOU dealing with it? Are you back on campus, in your lab, or in your office? Or are you still working from home?

Z.

Thursday, February 25, 2021

Combining The Best Of Both Worlds

This is a fascinating and important advancement in the physics of light sources. It seems that it has been shown experimentally how one can get the short, intense light pulses that one gets from a FEL source, and combine it with the repetition that one gets from a synchrotron light source.

Now a Sino-German team has shown that a pattern of pulses can be generated in a synchrotron radiation source that combines the advantages of both systems. The synchrotron source delivers short, intense microbunches of electrons that produce radiation pulses having a laser-like character (as with FELs), but which can also follow each other closely in sequence (as with synchrotron light sources). 

Another review of this work, from Nature where it was published, can be found here.

While this is an important step, it really is a proof-of-principle experiment, and it requires a bit more experimental work to show that this can be viable.

Although this paper represents a crucial step towards generating high-power, small-bandwidth light pulses in a particle accelerator, steady-state microbunching has not yet been demonstrated. Deng et al. have shown that, after one turn in the synchrotron, the microbunched beam can produce coherent radiation. The next challenge is to prove that this scheme can achieve such a feat over many turns. This will be difficult to accomplish experimentally for at least three reasons.

But if this can be demonstrated, a lot of things that are done at a FEL can be performed even more at an "ordinary" synchrotron light source, a facility that is a lot more plentiful.

An important point that I want to point out here is that, these are all "tools" that allow us to study things. Without these tools, we have no ability to experimentally detect, see, or measure things. It enables us to do things that we could not do before. So the advancement in science, technology, medicine, etc, depend on not only having these tools, but also the continual improvement of these tools. Advancement in science requires all of these things to occur to able to explore more difficult and complex ideas and scenarios.

This advancement in accelerator-based light source has nothing to do with high-energy physics. In fact, if you look at the type of applications that are being mentioned, there's nothing about particle physics at all!

.....on an accelerator that could extend the capabilities of these machines even further, potentially yielding applications in a next-generation chip-etching technology called extreme-ultraviolet lithography and an advanced imaging method known as angle-resolved photoemission spectroscopy.

So once again, this is my continuing attempt at trying to make people aware that "accelerators" do not automatically mean "particle collider" or "high energy physics". In fact, the majority of particle accelerators in this world are not involved in high energy physics experiments.

Zz.

Monday, February 08, 2021

Wonders of Physics Competition

I mentioned about this more than 10 years ago in this thread. I went to UW-Madison and attended the early incarnation of this lecture-room demonstration that became a huge hit with the public. I also had Clint Sprott as an instructor in one of my courses.

Due to COVID-19, the Wonders of Physics show couldn't be held, and probably not in the near future either. To their credit, they are creating a contest instead, where you can submit a 2-minute video of an original demonstration of a physics concept.

So maybe one of you are creative enough to enter this contest. :)

Zz.

Thursday, January 21, 2021

When Flipped Classroom Flopped?

I've mentioned about flipped classroom before, and that I use this format in a couple of my classes during the remote environment. This article goes the other way and pointed out when and why flipped classroom can flop and be rather ineffective.

I must say that the way this was described, it doesn't quite match what I am doing. While the students do have to watch videos and/or read something before they come to the first class of the week, they have pre-lecture quizzes that tests on whether they did watch the videos or read the material, and had a general understanding of the important ideas. These are graded and become part of their overall course grades. So there is incentive for them to go over the pre-lecture stuff.

Secondly, I don't just quickly dump them into breakout room right at the beginning. We meet twice a week and these are very long class sessions (3 hours) that often comprise of the subject matter and hands-on demos or labs (virtual labs). So I get to go over the important highlights of the subject, do a few examples, shoot off a few polls, give them a few online apps or simulations, and only then do I send them to breakout rooms to work on solving problems. In fact, in many instances, their breakout session is where they get to do their online virtual experiments and get to discuss what they are doing with one another.

I may have mentioned this before, but I did my own end-of-semester survey, and the overwhelming majority of my students liked the pre-lecture material and found them useful. So for me, the version of flipped classroom that I run appears to not be a flop.

Zz.

Monday, January 11, 2021

Physics Labs At Home

I've made several posts on various virtual experiments that may be done in conjunction with the standard physics courses. While many of these are adequate, nothing beats an actual, physical experiment that requires actual observation and measurement in person.

This paper lists a few experiments that a student may be able to do at home using items that a student may find at home. Since almost everyone having smart phones, there are certainly many activities that can be done using such devices. I've asked my students to use their smartphones to install sky-viewing app to be able to track planets, stars, and other celestial bodies. We have also used various apps that made used of the accelerometer in the phone to measure acceleration. I also have an app called "Gauges" (iOS) that allows you to use your smartphone to be an altimeter, speedometer, barometer, accelerometer (of course), magnometer, and to measure sound level and luminance. I am in the middle of designing a few "in class" (and now, it is "at home") activities using these capabilities.

While virtual experiment is fine for the present unusual situation, I still believe that this is not the same as actually doing the measurement itself and physically performing the experiment. So I'm trying to find activities that a student may be able to do him/herself, or in collaboration with another student if he/she does not have all the necessary equipment. I want to incorporate this as part of the lesson rather than an actual "experiment", so that the student can see the phenomenon that they are studying or about to study.

Have you designed simple at-home physics experiments for your students?

Zz.

Monday, January 04, 2021

General Physics Experiments Done Remotely

Oooh, yes please!

The problem that I have with online/remote physics courses is that we had to resort to a lot of "simulations" applications to do our "experiments". This is not what an experiment is supposed to be, because there has to be a components of errors and equipment issues that are involved in doing any physical measurement. So these simulations do not reflect reality.

The closest that I've seen so far is the one offered by Pivot Interactives, where you see a series of videos of actual experiments being done, and you get to measure what the person doing the experiment actually measure. It includes all the experimental uncertainties, quirkiness, etc. that the students have to also consider.

But here's another step further that gets the students even closer to being there and doing the actual experiment. I came across this article on UC Santa Barbara's effort to put their Sophomore-level quantum physics course online whereby the students can operate the equipment remotely and perform the actual experiments without being in the lab.

The automization of the quantum mechanical labs allows for students in the Physics 5L class to interact remotely with equipment using an online portal connected to the apparati set up in the lab, according to Fygenson. 

The online portal models the equipment setup, with buttons and knobs in the same order as where they would be on the actual equipment. Students can observe what happens in the lab using cameras aimed at the machines, Fygenson said. So far, the automated lab has been used in Summer 2020 and Fall 2020 and will be used again in Spring 2021.

That's brilliant! But that also involves a lot of money and effort to connect all of those equipment so that they can be operated remotely. Not many schools have that kind of resources and expertise.

I did a quick search and found an earlier report on this with an accompanying video. This gives you a better idea of how this is all done. It looks like from the video, the experiment being demonstrated as an example is the diffraction grating spectroscope looking at emission lines from various sources. This would be a very nice experiment to be done remotely.

Both articles indicated that they are sharing access with other schools, but did not indicate what one should do to get such access. I suppose I will have to contact one of the people listed at the end and see if I can have my students do at least that spectroscope experiment.

Anyone else have done something similar, or have used this?

Zz.

Thursday, December 31, 2020

E&M Lab Manual for Virtual Classes

This appeared on arXiv on Christmas day. It is a series of lab manual for intro E&M virtual experiment suitable for online courses.

The pdf document itself contains the just the lab instruction. Most of the virtual experiments made use of the applications found in PhET. It is in the abstract that we get a bit of an explanation. The authors claim that:

Student learning outcomes (understand, apply, analyze and evaluate) were studied with detailed lab reports and end of the semester lab-based written exam which confirmed the virtual lab class was as effective as the in-person physical lab class. 

Unfortunately, they provided no evidence or data to support this, at least not in the document.

In my lessons, I try to incorporate the "experiment" as part of the lecture itself. So I had students perform one part of the virtual experiment, and then we discuss the outcome before they write down their observations. Then we move on to the next topic or examples before we come back to doing more of the simulation or measurement. So in many cases, the students encounter both the theory and the observation at almost the same time. The exception being when we did Lenz's and Faraday's law, where I actually gave the students the equipment and instruction, and let them discover for themselves the induced current and how the induced current behave with changing magnetic fields. So they observed the phenomenon first before they learned about the theory.

In any case, this set of lab instruction might be useful to be adapted to my remote classes. We'll see how that goes this coming Spring.

Zz.

Thursday, December 24, 2020

Happy Holidays and a Better 2021

It has been a crazy year! I think I've posted the least amount of posts in this blog this year than any other year since I started this eons ago. There have been just way too much distraction and pressure coming from all the workload and learning new stuff that I had to just to be an effective instructor. It doesn't help that I think my teaching workload felt like it doubled for remote classes. I'm doing almost twice as much for remote courses than I do for in-person classes. It's crazy!

And I'm sure that students similarly felt a different set of burden and pressure with remote courses. The course feedback that I've received, even though overall they were positive, clearly reflected the frustrations the students have with remote learning and the way different remote courses were ran.

Looking into 2021, I know that we will be totally remote once again for Spring 2021. While I was more prepared to face Fall 2020, I am even more well-prepared for Spring 2021. I know the adjustments that I need to make, and I know things that I need to change. I will also be trying new stuff. Remote labs are something that I continue to struggle with. Honestly, I prefer the official online courses' approach to labs where they send kits to students, and we designed experiments for the students to do at home. However, these courses that I've been teaching are not online courses, but rather face-to-face (f2f) courses that had been forced to be delivered remotely due to the pandemic. So we have no kits. We rely on online simulation as "labs".

But in Spring 2021, I am going to adopt the lab environment of Pivot Interactives. A couple of our faculty members used it extensively this past semester, and they had good things to say about it. I've given it a test drive, and I can see how this may be as close to an actual experiment as it can get without actually physically doing it. Any of you out there use Pivot Interactives? What do you think of it?

Anyhow, with the possibility of the vaccine looming on the horizon for everyone sometime in 2021, there is a glimmer of hope that things will start moving back to "normal", whatever that may look like. So if you are celebrating the holidays at this time of the year, I wish you a wonderful holiday season and a significantly better 20201. Thank you for reading this blog and letting me indulge in spewing my thoughts into the ethereal world of the internet.

Zz.

Saturday, December 19, 2020

Flipping Your Remote Classroom

I wrote just a few days ago about my effort in continuing my flipped classroom when we went into the remote mode (as opposed to being in an online class mode which is totally run asynchronously). I then ran across this article out of UC-Berkeley about doing the exact same thing.

It definitely seems consistent that for a flipped classroom, there should be a synchronous part, otherwise it doesn't make any sense. And it is nice to see the different variations of a remote flipped classroom, which gives me more ideas on how I can further tweak my own classes.

Do you run a remote flipped classroom? How do you do it?

Zz.

Friday, December 18, 2020

Intro Physics for Life Sciences

I came across this article out of Michigan State University, about the issue of teaching intro physics to life science majors. I find it rather interesting (amusing?) that this is still an issue being discussed at many large universities when smaller universities and community colleges have long focused on designing such courses for these life sciences/pre-med majors.

Without naming names, I know of 3 major universities in the Chicago area that do NOT have special intro physics courses for such majors. They lump them with the same group of students majoring in physics, chemistry and engineering. So not only are they required to know calculus in those calculus-based intro physics courses, but also they are competing with students whose major are more closely aligned with physics. It is why many of these life-science majors often opted to pay for these courses at city colleges and community colleges and get their transfer credits.

I had written something on this two years ago about teaching physics to life-science/pre-med majors. I am more convinced than ever, just as stated in the article, that you cannot teach this as you normally would to physical science/engineering students. It helps that the course was designed for life-science majors (we used text that are full of examples out of biology, medicine, etc.), but the course objectives and learning outcomes are generic and not specific to these majors. At the curriculum level, there is still a disconnect between the students' need and the official objectives of the course. As an instructor, I am bound by the course objectives and learning outcomes, but of course, I have leeway in implementing those. That means that I try to emphasize more on the topics that are more relevant to their needs and more applicable to life sciences than others. As the article pointed out, while planetary motion and central force problems are part of physics (and part of the course objectives), I do not emphasize it as much as I would in a calc-based physics class.

There can be more refinement and improvement in the design of courses for these students, making them even more relevant to their area of studies. This can only lead to a win-win situation, where the students will actually see the value and connection between physics and biology/medicine, and we can motivate the students more easily on the importance of physics in their fields. I see nothing wrong with that at all.

Zz.

Tuesday, December 15, 2020

Flipped Classroom Under Remote Learning

In my normal face-to-face (f2f) classes, I ran them as flipped classroom. I had the students watch videos and/or read short items related to the material for that week and have them do a short quiz on what they had viewed or read. All these before they attend the first class for that week. By they time they got to class, they should have a good idea of what the material is about.

In class, I went over the salient point of the material, and did a few examples. I also did polls on the topic to gauge how much they had understood the material. When those are done, I gave them a list of problems where they will work in groups to solve them.

Fast forward to the present day, where we have gone online with our classes. The school where I'm at tried to distinguish courses that were already designed to be online courses, versus courses that were f2f classes, but were forced to go online due to COVID. The school called those latter courses as "remote", to distinguish them from "online". While there was no mandate to do so, they recommend that remote courses be taught with large synchronous component, preferably live during the published class time. In other words, try to make it as close to f2f session as possible via the synchronous sessions.

All of my classes so far have been "remote" classes, although I have signed up to teach an online course next semester since I am now qualified to teach online classes after all that training that I went through during the summer. And for all of them, I have kept the flipped classroom model. The students had to watch videos or read the material, and did the short quiz, all before our first synchronous session of the week. During our synchronous session, I covered the major points of the material, did a few examples, did polls, and then I assigned then to breakout rooms to work on various problems.

It worked similar to the f2f format except that I couldn't see what they were working on. In a regular f2f class, I could see their work since they use a whiteboard slate to do their work, and I could hear them discussing the problem with one another. In the remote format, I could only jump from one breakout room to the next, but I couldn't see what they had done. They would tell me if they had problems, but other than that, I could only rely on what they tell me. It was not as informative as I wanted to.

But the students seemed to think that this was effective. I had my own survey at the end of the semester, and a few of the questions were directly related to the flipped format, especially on what I called the "prelecture" items (videos/reading material, and the quick quiz). An overwhelming majority of students from this past semester (Fall 2020) seemed to like having the prelectures and found them to be useful! A smaller majority of students (but still a majority) found the polls and the breakout room exercises to be useful.

I think that this is one of those pre-COVID teaching methodology that may work rather well in the remote setting IF there is a regular synchronous component that resembles a class session. It makes no sense if the class is purely asynchronous, since most of the material are online already and there are no "lectures" for there to be "prelectures". But for the "remote" modality that the school has defined, the prelectures work in almost the same way as in a f2f class, and from the feedback that I received, the students seem to find them useful. I may have to work some more on making the polls and breakout room activities more beneficial to them, but in some respect, parts of it may be out of my control since those also depend on the participation of the members of their group.

In the end, I'm pretty happy to know that some resemblance of the flipped classroom model appears to be effective in the remote classes with regularly-scheduled synchronous sessions. Since Spring 2021 promises to be more of the same, it is something that I'm going to keep on doing, with a few refinements here and there.

Zz.

Friday, December 11, 2020

Forcing A Square Peg Through A Round Hole

 Many of us survived another semester of remote or online learning. Phew!

Unlike Spring 2020, Fall 2020 remote learning wasn't as problematic and disastrous, mainly because many of us were expecting it, and knew what to expect. In my case, I mentioned earlier that I spent the entire summer getting trained as an online instructor, mainly because I want to learn about some of the best-practice method of teaching online. I honestly do not want to be an online instructor because I much prefer the standard face-to-face (f2f) instruction modality. But the reality right now is that many classes are being taught remotely, and I need to have the knowledge and skill to deliver lessons that way.

Having chatted (via Zoom) with a few colleagues from my dept. during a number of online meeting, I was shocked (or maybe I shouldn't have) at how many of my fellow faculty members think that remote lessons are simply the same as f2f lessons, but delivered remotely or online. I've even had one instructor telling me that he was trying to make his remote classes to mimic his f2f classes as closely as he can!

Regardless of how logical or effective that is, let's look at what are the facts here. Remote classes are already significantly DIFFERENT than f2f classes in a number of elements: locations, in-person contacts, immediate and direct response, and on-site actions. In other words, remote/online lessons are a completely different beast than f2f lessons. So what is the rational for treating them to be the same thing?

The one very clear message that I received during the several workshops and training I did over the summer is that if you treat remote lessons the same way as f2f lessons, your classes will SUCK! Even the layout of the learning management system (LMS) page has to be redesigned to make it more obvious and easier to navigate, because this is where the students will have to go to to find stuff. Items need to be there at their fingertips because no one is around for them to ask to get immediate feedback.

One issue that was brought up during my conversation with my colleagues is the issue of student engagement. Instructors were lamenting that their students often do not turn on their cameras during their synchronous sessions, often do not actively participate during those sessions, etc. They consider this as lack of engagements and want to know how to increase the sense of "community" and participation.

I told them that maybe what they are using to gauge student engagement is rather limited to what they are familiar with in f2f classes. For online/remote learning, student involvement includes more than just participation during synchronous session. It can also mean participation in asynchronous activities. This is where group projects, discussion forums, etc.. count as student engagement. In the effort to make their remote classes as close to f2f classes, many instructors forego other viable means of online student engagement activities, simply because they were either not aware of such means, or they do not see the importance or significance of such means. But these other means have been shown in many studies to be effective, if done properly, to engage students and keep them interested in the subject matter. These other means may not have been necessary in f2f environment, but we are not there now. It is now a different beast, and it requires different means to achieve the same goal.

For many of us who did have the online instruction training, we learned quite a few valuable lessons and philosophy in using online and remote tools in delivering instructions. In fact, most of us think that we will continue using many of these online tools even when we go back to fully f2f classes. I would certainly like to continue having Zoom office hours, because it gives quite a flexibility in scheduling meetings with students at various times even when I'm not on campus. I also now have sufficient tools to be able to show a "pen and paper" solution online when students need help. And I know that my LMS page is significantly improved compared to when I had it for my f2f classes. There are a lot of things that I will continue to do even when we go back to "normal".

But the moral of the story here is that instructors need to be aware that remote classes is NOT the same as f2f classes delivered remotely. They can't be the same. Forcing it to be is trying to force a square peg into a round hole, and then wondering why it doesn't go through.

Zz.

Sunday, December 06, 2020

The Sad Ending of Aricebo Observatory

It was less than a month ago, on a Nov. 19, 2020 report, that the National Science Foundation announced the closure of the famed Aricebo Observatory in Puerto Rico due to structural and safety problems. Unfortunately, on Dec. 1, 2020, the collapse of the central structure happened, with dramatic footage released by the observatory.


While the famed telescope is gone, it will live forever in many footage from movies and tv shows. This is in addition to the numerous scientific discoveries that it has made throughout its operation.

Zz.


Sunday, November 08, 2020

Students Experiences with Emergency Remote Teaching

With COVID cases going back up in many places, including here in the US, many schools are still sticking to remote and online classes. Even those that opened their campuses are now starting to fall back to such modality of learning.

At some point, there needs to be an assessment on how students are dealing with all of this, and the degree that it has impacted their learning process. The migration from regular face-to-face (f2f) classes to emergency remote classes due to the pandemic is a highly unusual case and requires quite a bit of investigation.

This is one such study, conducted on physics students at the University of Colorado-Boulder. It surveyed the students perception of how the lesson was delivered during this past Spring 2020 when all schools in the US shut down in March and changed to online learning.

Having gone through it as an instructor, I know that it wasn't easy for everyone involved. In many cases, a lot of the quality of instruction certainly suffered to a certain extent. So it should be informative to learn the students' perspective on this, and it may be useful as a guide, considering that there is a strong possibility that many of us will continue with remote learning this coming Spring 2021.

As for me, I feel significantly better prepared. I spent the past Summer 2020 getting trained as an online instructor, even though I intend to stick to just f2f courses if and when we do get back to "normal". But learning the "best practice" method in online lesson delivery was extremely helpful. But the best part was that these training courses and workshops are themselves online courses, done asynchronously like most online courses. So I got to experience first-hand what it feels like to be an online student, to feel sometime the confusion on where to find things and what to do next. The fact that you are on your own means that even the design of the learning management page can be a factor, that things need to be arranged in such a manner that things that are important need to be front and center, and easy to find. So I think that I learned almost as much about teaching online from just being an online student myself as from the course's material and lesson.

Spring 2021 will continue to be in the remote-learning format. But I think I'm getting the hang of this. I know that I no longer feel that I'm bumbling in the dark. I still need to refine many of the stuff that I do and execute, but things no longer feel daunting. I know that I'm working almost twice as hard preparing for these online lessons (we have synchronous sessions during the scheduled class time) when compared to the old f2f classes. But now, I feel that I know what to expect and I'm well-prepared for it.

Zz.

Thursday, October 22, 2020

Mask Physics

There is no controversy about the need to wear a mask to reduce the possibility of COVID-19 transmission. Every scientific research that I've read supports that.

Here are some more from the physics side of it. This is approaching it from purely the point of view of physics of fluids.


Visualizing droplet dispersal for face shields and masks with exhalation valves

Visualizing the effectiveness of face masks in obstructing respiratory jets

On respiratory droplets and face masks

Zz.

Friday, October 16, 2020

Roger Penrose - Is Mathematics Invented or Discovered?

 Now that he has just be awarded the 2020 Nobel Prize in Physics .... :)

This is a video of a conversation with Roger Penrose on his opinion of mathematics and its ability to describe our world.

 

Eugene Wigner also had written a rather popular essay on what mathematics is and its "unreasonable effectiveness" in describing our world.

Zz.

Tuesday, October 13, 2020

Death by Spaghettification

This is probably a rather unpleasant way to die, but it may also be the most spectacular way.

Astronomers have observed for the first time the ripping apart of a star as it got too close to a massive blackhole.

When an unlucky star wanders too close to a supermassive black hole in the centre of a galaxy, the extreme gravitational pull of the black hole shreds the star into thin streams of material,” explains study author Thomas Wevers, an ESO Fellow in Santiago, Chile, who was at the Institute of Astronomy, University of Cambridge, UK, when he conducted the work. As some of the thin strands of stellar material fall into the black hole during this spaghettification process, a bright flare of energy is released, which astronomers can detect.

What is even interesting is that the unfortunate star is about the same size as our sun. So you kinda feel a bit for the poor thing.

But of course, all of these happened quite some time ago. It is probably quiet now in that part of the universe.😁

Zz.

Thursday, October 01, 2020

Total Amount of Matter in the Universe

We now have the most accurate measurement to date of the total amount of matter in our universe. A new paper published in The Astrophysical Journal[1] seems to indicate that our universe is composed of 31% matter, with the rest being dark energy.

And of that 31% of matter, 80% of that is dark matter, which we are still searching for. This means that the "ordinary matter" that is known within the Standard Model of elementary particle and that makes up you and I is only about 6.2% of the entire matter+energy of our universe. The remaining 93.8% are made up of "dark" stuff, i.e. dark energy and dark matter.

This means that we still do not know the nature of a huge portion of what makes up our universe. Would it be nice to be alive 50 or 100 years from now when we know more about these things then (hopefully!).

Z.

[1] https://iopscience.iop.org/article/10.3847/1538-4357/aba619

Sunday, August 23, 2020

Teaching In Fall 2020

 At the start of a new semester, I'm amazed at how much I've learned over the summer about online and remote learning. Taking the workshops on learning about how to deliver such classes was definitely worthwhile. My perspective on such modality has expanded and I think I am significantly better equipped than when this whole mess has started.

The biggest takeaway from everything that I've learned is that taking what you do in a face-to-face (f2f) classroom and importing it wholesale into a remote or online class does not work very well, even when delivered synchronously. f2f and online are two completely different beasts, and the mechanics, pedagogy, and "psychology" are very different. Based on what I have learned about some of the best practices method, student engagements and interaction are significantly more important in online courses for their success. So there has to be a conscious effort to design the course so that the students have to engage with the material, with the instructor, and with other students. This seems to be a very common and central pedagogy in almost everything that I've read about online learning.

Luckily, the tools that we use for that can promote such engagements. It appears that many Learning Management Systems (LMS) have upgraded and add features to their software over the summer. I know that the one that I'm using seems to have been loaded with a lot more capabilities than what I remembered earlier in the year. I've employed a bunch of tools in the LMS system for the asynchronous part of my class, and I've planned many activities during our synchronous sessions via Zoom (breakout rooms, polls, etc.). This includes a few "live lab sessions" in my physics class where the emphasis will be more on simple observation, extensive analysis, qualitative explanations, and a few quantitative  calculations. We'll see how that will work.

I think that taking the workshops over the summer and being an online learner myself with those two workshops gave me a more accurate perspective from the point of view of an online student. Just finding things itself can be an issue, and you have no one to ask immediately. I used to arrange my LMS page in terms of modules. There's a module for quizzes, there's a module for homework, there's a module for exams, there's a module for labs, there's a module for lecture notes, etc. So if you want to find the document for Lab 5, you go to the lab module and search for Lab 5 document. If you want to take a quiz, you go to the quiz module and take the quiz that's relevant for that week.

While on paper this all looks fine, when you actually go through something like this, you realize that you have to jump to several different modules for find all the tasks that you need to do for that week. I noticed that this is not what they did and how they presented it in all the online workshops that I took. Instead, they organized everything weekly. In Week 1 of the course, these are all the stuff you need to do. Then we go to Week 2 and these are all the stuff you need to do, etc. Each week, the lecture notes, the quiz, the homework, etc.. are all there, in the same folder or module. You don't have to go jumping around to different module to find all the things you need to do. This is such a simple thing to do and yet, it made for a more intuitive approach once you go through it as an online student.

In the end, I'm not as stressed out about my classes being completely online this semester as I was in Spring. I think I'm better prepared for it, and more well-equipped. And boy, I hope it shows in the students' performance this semester. Stay tune....

Zz.

Friday, July 17, 2020

Followup On Far-UVC Light Kills Airborne Coronavirus

This is a follow-up on the topic that I posted last time regarding evidence that far-UVC light can effectively reduce airborne virus transmission.

I read more about it, and found this extensive Physics World article that highlights the current development of the application of far-UVC light in virus sterilization. So obviously, this is a very active area of research right now. There are compelling evidence that far-UVC may be safe to human beings under limited exposure while still be effective in eliminating airborne viruses such as COVID-19.

But another issue that I've been trying to dig through is that, while far-UVC may be safer in terms of very short penetration depth into the skin and cornea, I haven't read much on possible ozone generation. One of the nasty effects of UVC light is that it can create ozone gas.

I sent to the International Ultraviolet Association webpage (didn't know one existed till recently), and went through their FAQs. One of them addresses the specific issue of ozone creation:
Does far UV (200 – 225 nm) generate ozone?

From a photochemical perspective, yes.

The Chapman cycle (Chapman, 1930) describes the counteractive processes of ozone formation and degradation from the interaction of light with molecular oxygen (O2) and ozone(O3). The rate of generation of ozone by far UV-C (known as the Herzberg continuum in atmospheric science) outweighs the rate of its degradation; the tipping point at which this generation/degradation balance flips is ~242 – 243 nm. (Andrew et al., 2003; Santos, Burini, and Wang, 2012), Far UVC (200-225 nm) only generates ozone in the upper atmosphere, where path lengths are very long. In a normal laboratory setting, ozone would not be generated because oxygen (O2) is a very weak absorber in the far UVC region.

As with any process, the risk of such hazards should be assessed on an application-by-application basis. A low power lamp operated in a well-ventilated area may not generate a measurable ozone concentration; a high-power system in an enclosed space may constitute a substantial risk.

Now, I don't quite understand why the "path lengths" have anything to do with ozone generation in the upper atmosphere, but it seems to imply that in a lab setting, far-UVC is not an effective ozone producer because it is a weakly absorbed by oxygen molecules. I can't get access to those articles while I'm at home, and I'm not even sure if my institution subscribes to any of those sources. So if anyone has more info on this, let's hear it.

This will be a tremendous way to reduce airborne transmission if it can be show to be effective and safe. But as with many things, it needs to be investigated carefully.

Zz.

Monday, July 13, 2020

Far-UVC Light Kills Airborne Viruses, And Safe To Humans Too?

First, let me give you the link to the paper that was published in Nature recently.

I actually have 3 separate topics to discuss here all based on this single paper.

The first is the science. UVC is used to kill viruses and sterilized stuff. We know that already. But it is also unsafe to human and we do not want to be exposed to it. But it turns out that far-UVC, having wavelengths in the range of 207-222 nm, is not totally harmful to human. In fact, ...
a regulatory limit as to the amount of 222 nm light to which the public can be exposed, which is 23 mJ/cm^2 per 8-hour exposure
means that humans can be exposed to this range of UVC for a limited amount of time. This is the basis of that research, i.e. using that wavelength and intensity of far-UVC, and see whether it can greatly "inactivate" the amount of viruses carried in airborne aerosols. They found that an exposure of just 25 minutes, very much below the regulatory limit. So there is a way to kill off viruses in airborne aerosols in the same space that human beings are around!

Certainly the implication of this research can be quite important, considering that airborne transmission of the COVID-19 virus is a strong possibility, which is why we are all wearing masks in public. There is now a way to greatly reduce such mode of transmission if this research is verified. The only thing I'm a bit weary about is the health and safety aspect. I know that they cited several sources that seems to show that the far-UVC is harmless to human, and the regulatory limits that have been imposed. Still, I'd like to have this one to be more well-established before I get really excited about it. For example, although the exposure limit is given in per 8-hour doses, how often can someone be exposed to that limit, say, in a month? Is that 8-hour dose limit per day? And certainly, long-term effect needs to be considered in anything of this sort.

But still, I find this result to be very promising, and it certainly is a new piece of information to me that far-UVC is actually not that harmful to humans.

The second aspect of this paper that I want to highlight is to the general public who often do not quite understand the nature of scientific publication. The main reason for scientists to properly publish their work is so that the rest of the community, especially those experts within the same field of study as the work, can scrutinize the work and evaluate its validity. So having something published does not automatically makes it valid. This is important to remember and understand. It requires scrutiny and verification by other experts in the field, and can sometime takes years. Think of how long of a time period from the moment the Higgs mechanism was proposed till its experimental verification at the LHC.

Therefore, it is imperative that a paper contains all the relevant information used to arrive at its conclusion or result. In this case, it is an experimental paper that produces a result. For it to be evaluated by other experts, it must contain all the necessary information. If you look closely at the end, the authors included their methodology, the exact equipment that they used, the experimental setup, the nature of the data analysis used, etc... etc. In other words, everything is as transparent as possible. It allows for someone else to repeat the experiment, and that is a crucial aspect of experimental science - REPRODUCIBILITY. It is something pseudoscience cannot do!

The third and final aspect of this paper is educational. I'm excited at the various values that they used in this paper, because I can already see myself using them in my general physics lessons. I'm already planning on using many of these numbers and asking my students to calculate (i) the amount of power per unit area based on the exposure time, (ii) the energy per photon of 222 nm light, (iii) the number of photons that impinges on a unit area during the exposure time, etc... etc. This will be perfect especially for the general physics course that I have taught that is aimed at life-science/pre-med majors. I always like taking something current, and very relevant to our times, to use as a material in our lessons. The students can immediately see first-hand that what they are learning is, in fact, very useful and has a direct effect on them beyond just wanting a good grade at the end of the semester.

So yes, I'll be holding on to this paper for quite some time.

Zz.

Friday, July 10, 2020

Simple Way To Help Your Instructor During Remote/Online Learning

Dear Student,

Many of you may continue having some form of online or remote learning this coming Fall 2020 and maybe even for the next few semesters. Even if you get back to face-to-face instruction, you may still need to communicate with your instructor electronically. So this advice that I'm going to give you will be applicable especially if you require remote assistance from your instructor.

In STEM subjects, specially math, physics, engineering, etc., face-to-face instruction has the imminent advantage over remote learning because of the simple ability to write and sketch. In physics especially, when we approach or discuss a concept or a problem, a sketch is often required to set up the situation. This is then usually followed by the writing down of mathematical equations, and then the grinding out of the math to solve the problem. In a typical class situation, these are done on paper, and it is the simplest and quickest form to do such a task.

Doing this during remote learning can be challenging. Most of you may be require to show your work, or to show what you have attempted if you need help from your instructor on a homework problem, or even during quizzes and exams. What most students end up doing is to pull out their smartphones, snap a photo of the page with their work, and then e-mailing the image file to their instructors.

I have been on the receiving end of such submission, and in at least half of the cases, it was very difficult to read and decipher the image that I received. Most students do not inspect the images for legibility. I often receive images that are dark, with poor contrast, and often having shadows that made some parts easier to read than others. In addition, the angle that the images were captured may also be rather odd, because most of these were not captured straight on.

Here, I'd like to make a suggestion on how you, as a student, can help your instructor by submitted a clearer and more legible image, using the same equipment that you already have. This is also to your advantage because in the case of a quiz or an exam, if your instructor does not understand or can't read what you wrote, you probably will not be given credit for such work if it is required.

OK, so here is what you should do. Install a scanner app on your smartphone or mobile devices that you frequently use. There are many scanner apps available on iOS and Android platform. Many of these are free or with minimal cost. Next time you need to send a snapshot of your work, use the scanner app instead or using the standard camera app. It makes a tremendous difference, and I'll prove it to you here.

I have an iPhone, and the scanner app that I have is called ClearScanner. The free version of this app has limited capability (no OCR), but it is still sufficient for what you will need it for (I have the full, paid version).

In the first image, it is a page filled with handwritten work. I took this using the iPhone standard camera app. I did not make any edits on the image quality, didn't do any cropping, etc, other than change the image file size. This is what I get.


Now, I hate to say this, but I will. Most of the submission that I received from my students were not even half as good as this. But let's go with this in any case. Now, already you can see that, as someone who has to figure out what has been written, this may not be impossible to do, but you are asking that person to do quite a bit more work here. The low lighting and the crazy angle that the image was taken present a challenge to read this accurately.

Compare this to the image of the same page but taken by the scanner app. I took it from the same angle, and under the same lighting condition. The only difference being that the scanner app asked me to confirm that correct boundary of my document in the image. In this case, the boundary is the edge of the paper. Once I confirmed that, the app took over and produced this image:


The difference is night and day. Not only is the writing clearer here, but the crazy angle is also gone. The app corrects for the angle and presents it as if you scanned it on a flat-bed scanner. And all this with hardly any more effort than taking a regular photo.

I will show another example. In the photo below, another common "feature" of images that I receive can be seen, i.e. shadowing.


Once again, it doesn't look bad in this image, but the ones that I have received were a lot worse than this. I had to do my own image editing to be able to see clearly the writing that was in the shadow.

So how does it look using the scanner app? Again, I didn't do anything to the image other than confirm the boundary of the document. This is what I get:


It looks almost identical to the previously scanned page, with the shadow removed. I assure you that this is a different image than the first scanned image above.

This is such a simple thing to do, with hardly no additional steps and effort, and yet, it produces such a remarkable difference in clarity. Which one, do you think, will your instructor prefer to receive?

Students in my class during the previous semester were told to install such apps if they have the capability. It made a tremendous difference in the quality of the document that they submitted. Many of them also told me that the app was useful to capture even written notes on whiteboard in class. So you  may find that it is one of those handy and useful app that you didn't realize you need till you have it.

Zz.

Thursday, July 09, 2020

Possible Discovery Of A New Type of Tetraquark, And Possibly Misleading Reporting Article

We have had reports of the discovery of possible tetraquarks and pentaquarks before (i.e. particles with 4 quarks and particles with 5 quarks, respectively). There is an extensive overview of the experiment and theory in this article. So the announcement out of LHCb is not that new. What is new is that this could possibly be a new type of tetraquark made up of 4 heavy quarks.

“Particles made up of four quarks are already exotic, and the one we have just discovered is the first to be made up of four heavy quarks of the same type, specifically two charm quarks and two charm antiquarks,” says the outgoing spokesperson of the LHCb collaboration, Giovanni Passaleva. “Up until now, LHCb and other experiments had only observed tetraquarks with two heavy quarks at most and none with more than two quarks of the same type.”
You may read the preprint here.

That should clear up very much of what the brouhaha is. I probably would have glanced over this had it not be the fact that I stumbled onto another news reports of this discovery, but with a different tone that could be misleading.

First of all, let's look at how CERN produced its news release. The first paragraph read like this:

The LHCb collaboration has observed a type of four-quark particle never seen before. The discovery, presented at a recent seminar at CERN and described in a paper posted today on the arXiv preprint server, is likely to be the first of a previously undiscovered class of particles.
Notice that it says "... a type of four-quark particle ...". This means that there are already other four-quark particles, and that this discover is for a new type that has not been observed before.

Now, compare that to the reporting done by two (count 'em) particle physicists on The Conversation (a place that I go to regularly) on the same discovery. Here is what they wrote:

The LHCb collaboration at CERN has announced the discovery of a new exotic particle: a so-called “tetraquark”. The paper by more than 800 authors is yet to be evaluated by other scientists in a process called “peer review”, but has been presented at a seminar. It also meets the usual statistical threshold for claiming the discovery of a new particle.

If you don't know any better, by reading the first sentence alone, you'd think that this is the first ever discovery of a tetraquark, which would be false.

Certainly, if you read the article further, you'd come across the passage that clarifies what this discovery is:

All tetraquarks and pentaquarks that have been discovered so far contain two charm quarks, which are relatively heavy, and two or three light quarks – up, down or strange. This particular configuration is indeed the easiest to discover in experiments.

But the latest tetraquark discovered by LHCb, which has been dubbed X(6900), is composed of four charm quarks. Produced in high-energy proton collisions at the Large Hadron Collider, the new tetraquark was observed via its decay into pairs of well-known particles called J/psi mesons, each made of a charm quark and a charm antiquark. This makes it particularly interesting as it is not only composed entirely of heavy quarks, but also four quarks of the same kind – making it a unique specimen to test our understanding on how quarks bind together.

So this is not the first discovery of a tetraquark, but rather a discovery of a type of tetraquark, which is what the CERN article implied.

I know I'm being picky, but I've always said that communication between scientists and the general public is extremely tedious. Often times, what you wrote is not what they understood! And once something or some impression has stuck into their heads, it is very difficult to change that. Having a misleading idea immediately imprinted at the very beginning of an article is a horrible thing to do, even if the rest of the article is accurate. At worse, the reader holds on to the original misleading idea, and at best, the reader becomes confused with conflicting understanding. In the world where a lot of people have attention deficit and all they care about are quick bites of news, the message conveyed in the very first paragraph, or even the very first line, is all that they read and get.

Zz.


Friday, July 03, 2020

Simple, Basic, COVID-19 Math

This is highly elementary for most of you. But I've learned a long time ago that what I consider to be obvious and trivial, is not the case for many members of the public. This is one such case because I've heard this uttered in the media, in print, and among some people.

There is a large increase in the number of positive COVID-19 cases being reported in many states in the US. A lot of people, who shall remain nameless, make the excuse that this is due to the increase in testing, and that it shouldn't be alarming. The more you test, the more you find, they argued.

So I'll illustrate this with simple, basic math.

Let's say you have a population of 1000 people. And let's say that 200 of them has COVID-19. This means that 20% of the population has the virus.

If you randomly test 100 people, you'll get 20 people who is positive.
If you randomly test 200 people, you'll get 40 people who is positive.
If you randomly test 300 people, you'll get 60 people who is positive.

So yes, in terms of absolute numbers, the more people you test, the more number of positive results that you will get. HOWEVER, look at the percentage of positive test. No matter how many people you test, the percentage will still be 20%. The absolute number will increase with increasing number of tests, but the percentage (some people call it positive rate) does not change considerably. This is what a lot of people appear to not fully comprehend.

Of course, in real life, the percentage won't be exact, but if we keep having these tests, it will hover around some value and not change systematically or monotonically over time if there is no change in the number of people infected. So what you need is not the absolute number but also the overall percentage of positive result per day, let's say. That is of more importance if you are trying to see if things are getting better, or worse.

The situation, of course, is more complex than this. But the point in all of this is that you simply can't dismiss the increase in numbers by claiming that it is due to an increase in the number of testing. That is not the whole picture. What if you do the above exercise again and instead, you get 50 out of 200 being positive one week, and 90 out of 300 being positive the week after that? Can you still attribute that to increase in testing only?

Zz.

Monday, June 29, 2020

Building PIP-II at Fermilab

PIP-II is being built at Fermilab as a new linear proton accelerator for its needs in years to come.



Zz.

Wednesday, June 24, 2020

Lightest Known Blackhole, Or Largest Known Neutron Star?

I tell ya, after years and years of searching for gravitational waves, and then finally discovering it several years ago, the LIGO-Virgo gravitational waves detector has become an amazing astronomical/astrophysical observatory, making one amazing discovery after another. The existence of such gravitational waves are no longer in doubt that they are now being used as a means to detect other astronomical events.

This is one such case where it appears that a 2.6 solar-mass unknown object collided with a 23 solar-mass blackhole.[1] If this 2.6 solar-mass object is a blackhole, it will be the lightest known blackhole. If it is a neutron star, it will be the heaviest known neutron star. Both scenario will require a reworking of current theories, because a blackhole that light, or a neutron star that heavy, was thought to be unlikely.

Neutron stars and stellar black holes are the final stages of evolution for large stars – with black holes being more massive than neutron stars. In theory, the maximum mass of a neutron star is about 2.1 solar masses. However, there is some indirect evidence that more massive neutron stars could exist. There is little evidence for the existence of black holes smaller than about 5 solar masses, leading to a mass gap in our observations of these compact objects.

What is intriguing about the August 2019 merger – dubbed GW190814 – is the mass of the smaller object, which appears to fall within this gap. “Whether any objects exist in the mass gap has been an ongoing mystery in astrophysics for decades,” says Charlie Hoy of the UK’s Cardiff University, who played a key role in analysing data from the detection and writing the paper that describes the observation, which has been published in The Astrophysical Journal Letters. “What we still don’t know is whether this object is the heaviest known neutron star or the lightest known black hole, but we do know that either way it breaks a record.”

The actual paper is available to be read for free here since it is an open access article.

Like I had said to the students in my astronomy classes, this is going to go down as the golden age of astronomy. Since the beginning of human history, we only had light as our only detector of the heavens. Now, we have not only neutrinos and high-energy cosmic rays, but also gravitational waves as our means to look at the heavens. We have three different and separate ways to look at our sky!

Zz.

[1] R. Abbott et al., The Astrophysical Journal Letters,896:L44(20pp), 2020.

Tuesday, June 23, 2020

The Physics Of N95 Masks

Many, if not most, of us have heard of N95 masks when the pandemic first appeared, especially when there were reports of their shortages. Why are they so in high demand? This MinutePhysics video tells you why they are the ones that front-line health care workers need to be wearing.



Zz.

Monday, June 22, 2020

Back To Remote Learning In Fall 2020

While there has been no official word yet, there are strong indications that come Fall 2020, my classes will go back to totally remote learning once more, continuing what happened during the second half of Spring 2020.

It is not surprising to me. I've been expecting it, and in some ways, I've been preparing for it. I mentioned earlier that I've enrolled in Quality Matters courses to give me formal training and credentials in running online and hybrid courses. I just finished the first workshop, and I have one more to do with them before I do the last required course with my own institution.

I must say that the one course that I've completed so far was more useful than I initially expected. There were a few "eye-opener" moments that I never realized before. It is one thing to anticipate and guess what a student needs from an online course, it is another when one actually goes through it, and are shown some of the best-practice methods of online education from the point of view of the student.

At the end of the first course, I realize that what I've learned was not only useful for the next time I have to teach a remote or online course, which will be this Fall most likely, but I'm going to take what I've learned to also improve my face-to-face courses, whenever I get to teach one. I know that many of the things I put on the Learning Management Systems can be reorganized better, because if it is suitable for online students, then it certainly is appropriate for face-to-face students.

But of course, one of the unique challenges with teaching a science course is labs, and how one can effectively do such a thing with a remote class. I've been looking at material put out by Pivot Interactives, which looks promising. I attended one of their webinars, and I like the way they show the experiments. I intend to sign up for the instructor trial version during the next week or so to check them out further. Do you have any experience with using them, either as a student or as an instructor? If you do, I'd love to hear from you.

There are more challenges unique to teaching math and science online, and I'm going to explore them during the next few weeks. I'll post them here whenever I encounter them, and maybe you might have an idea on the best-practice way to tackle them.

Zz.

Friday, June 12, 2020

More Experimental Verification of General Relativity

This is another one of those "The more they test it, the more convincing it becomes."

New "free fall" measurement in extreme high gravitational field has upheld one of the foundations of General Relativity. This time the measurement comes from a white dwarf orbiting a neutron star (a pulsar). A neutron star is a star that has huge gravitational field, so this is an amazing testing ground for GR under extreme condition.

"Above all, it is the unique configuration of that system, akin to the Earth-Moon-Sun system with the presence of a second companion (playing the role of the Sun) towards which the two other stars 'fall' (orbit) that has allowed to perform a stellar version of Galileo's famous experiment from Pisa's tower. Two bodies of different compositions fall with the same acceleration in the gravitational field of a third one."

"The pulsar emits a beam of radio waves which sweeps across space. At each turn this creates a flash of radio light which is recorded with high accuracy by Nançay's radio telescope. As the pulsar moves on its orbit, the light arrival time at Earth is shifted. It is the accurate measurement and mathematical modeling, down to a nanosecond accuracy, of these times of arrival that allows scientists to infer with exquisite precision the motion of the star," says Dr. Guillaume Voisin.

You can get free access to the actual paper here.

Zz.

Thursday, June 11, 2020

BEC In Space

 Not as amusing as Pigs In Space, but still quite impressive.

The ISS is useful after all! :) Physicists have created the first controlled Bose-Einstein condensate in low earth orbit, thus eliminating the issue of gravitational effects[1] that affects the stability of the condensate.

A review of the work can be found here.

As discussed, Bose–Einstein condensation requires low temperatures, at which atoms hardly move. However, when a BEC is released from a magnetic trap so that experiments can be carried out, repulsive interactions between the atoms cause the cloud to expand. Within a few seconds, the BEC becomes too dilute to be detected. The expansion rate can be reduced by decreasing the depth of the trap, and, thereby, the density of atoms in the trap.

On Earth, the planet’s gravitational pull restricts the shape of possible magnetic traps in such a way that a deep trap is needed to confine a BEC (Fig. 1a,b). By contrast, Aveline and colleagues found that the extremely weak gravity (microgravity) on the International Space Station allowed rubidium BECs to be created using shallow traps. As a result, the authors could study the BECs after about one second of expansion, without needing to manipulate the atoms further.

But this is more than just an achievement on the scientific level. It is also a technological feat because of the numerous requirements that are needed to be able to have an experiment on the ISS, as stated in the review:

Aveline and colleagues’ technological achievement is remarkable. Their apparatus needed to satisfy the strict mass, volume and power-consumption requirements of the International Space Station, and be robust enough to operate for years without needing to be serviced. The authors’ Earth-orbiting BECs provide new opportunities for research on quantum gases, as well as for atom interferometry, and pave the way for missions that are even more ambitious.

If you have ever designed an experiment, you know of all the issues involved, not just the scientific ones. This includes engineering, robustness, economics/costs, etc. So I can't imagine what they had to come up with to be able to send something up there and basically run this with very little to no involvement from the astronauts onboard.

Very well done indeed!

Zz.

[1] D.C. Aveline et al. Nature v.582, p.193 (2020).

Thursday, June 04, 2020

DESI Begins

A new eye on the sky is about to add to our knowledge of dark energy.



It's interesting that in the list of funding agencies, NASA is absent. This goes to show you that many of these research activities that seem to be "astronomy-related" are not the sole domain of NASA. In fact, the area of particle-astrophysics is more closely related to particle physics than astronomy.

The video didn't clarify explicitly that in looking at the "spectrum" of light from each of these celestial bodies, one gets the radial velocity of these bodies with respect to us (i.e. via the amount of redshift), not its distance from us. That last piece of information can only be "deduced" using the radial velocity and the Hubble equation, i.e. the Hubble constant, a number that is still being refined.

Still, this new telescope is going to be quite exciting in revealing more of the mysteries of dark energy.

Zz.