“Stop saying zero gravity” 

While shopping around for a new bed, I discovered that the phrase “Zero gravity” has gone thoroughly mainstream. Apparently, there are “zero g sleeping positions” available now if you are willing to put down a few thousand dollars. 

What numbers among physics students have heard of  “Zero gravity”? Do students think that astronauts on the ISS are floating because of the absence of gravity there? I have anecdotal evidence gathered over the years from student answers to these two questions. I wanted to gather data on this and distributed a survey over social media. Those who responded to the survey include students from a top public high school, a large state flagship university and a private liberal arts college all in the northeast U. S. I am hoping that the results are of interest to all of us, physics educators. 

Here is the abstract of my presentation at the upcoming AAPT Summer 2021 virtual meeting.

The term “zero gravity” first appeared in NASA’s technical bulletins in 1968. Since then “zero g” has become extremely common in popular usage. We also often hear talk of astronauts on the International Space Station (ISS) being weightless or experiencing zero gravity. I present here preliminary results of a survey conducted on social media of college students in the U.S who have taken a physics course in high school or college. Participants were asked about their familiarity with “zero g” or “zero gravity” and also if they thought that astronauts float because of zero gravity. The results show that a very high percentage of students surveyed are aware of the term. Significant numbers among them think that astronauts float due to the absence of gravity, a belief that does not appear to be based on a conceptual understanding of free fall/circular motion and scientific reasoning.

Is it a good idea to use 'The Big Bang Theory' clips to teach physics?

When The Big Bang Theory (TBBT) aired for several years on prime time network television, it was a like a breath of fresh air for me. The show had scientists and engineers as major characters. It also had several physics related plot devices and dialogues. Several female characters on this show were smart, successful scientists. One actress playing a major role was a neuroscientist in real life! So it would seem that the clips of TBBT would be ideal science teaching devices. 

But TBBT had a major flaw in the way it portrayed Sheldon, the character who seemed to exhibit behaviors consistent with Asperger Syndrome. In several episodes, Sheldon is repeatedly shown to be inviting mockery and exasperation from all around him.

Margaret Weitekamp in Physics Today (January 2017, page 40) writes on how BBT reinforces and also plays against stereotypes.

Leaving this problem aside, what of the physics itself seen on the show? Or how accurate is TBBT Physics? Don Lincoln at LiveScience discusses several plotlines of the show that do not ring true from the perspective of a FermiLab physicist. His quibbles have to do with the theory of "Super Asymmetry" as introduced in the show in addition to portraying the scientific endeavors as a two-man set up as opposed to reality of hundreds of scientists collaborating together on projects such LHC.    

I am intrigued by the so called “low brow” Physics interspersed throughout TBBT. How do we use this tool in the classroom and how good is it?

My answer is:  use with caution. Here is an illustration as to how.

I have used the problem below in class along with the video to address a common misconception in kinematics: stopping distance depends on the mass of the moving object.

The problem statement:

While Penny is giving Sheldon a ride in her car, Sheldon complains about how fast she is driving and describes what would happen to them in the event of a crash.

Is Sheldon "wrong" to include Penny’s weight while calculating the stopping distance of her car?

Yes, stopping distance, in theory, depends only on the square of the velocity of the car and the deceleration supplied by the brakes. 

The magnitude of deceleration is simply a product of the coefficient of kinetic friction and acceleration due to gravity. 

So, for a given velocity, the deceleration provided by dry pavement is independent of the mass of the car and its riders.

BUT, in practice, the coefficient of friction is seen to vary with the weight with which the vehicle and driver push down on the road. 

So... coefficient of friction is not really a constant when we talk about HUGE moving masses such as semis and trucks. 

But for Sheldon and Penny, no, their mass is not a factor in stopping. That is the caveat, folks. 

  

 

How did I learn physics in India?

Professor Tom Greenslade  is Millikan Medal winner, a living resource on the history of physics & classic physics laboratory experiments, and prolific author of over 300 research works. So, I was absolutely thrilled to receive a sweet note from him on my meter stick demo paper.

He shared with me the details of how he got started in physics education and I wrote him a long reply on my family background and what it was like learning physics in India. Our emails brought back so many memories and I started thinking about the differences in the way physics is taught in the United States and India.

As it happens, AAPT WM2021 had a whole session dedicated to international perspectives on teaching/learning physics. Not sure it is a new initiative but I cannot think of a better way to expand AAPT’s reach and inform physics educators around the world how their counterparts in other countries teach physics.

Two presentations in WM2021 caught my interest. The first was someone who had their high school and undergraduate physics education in Srilanka. She detailed how high school or college students in their classes in Srilanka are never encouraged to ask questions or to meet their professors outside of class. Students are entirely on their own as far as making sense of the material is concerned. I could relate to most of her presentation having experienced things very similar in India. Just like her, I had to surmount the language barrier - learning all the school subjects in my mother tongue (Tamil)  till Grade 11 and then switching over to learning everything in English .

But left unsaid was how much students depend on TUTORING which happens entirely outside the school or college. Dedicated academic support services run within educational institutions simply do not exist in India or Srilanka or any of the South Asian countries (as far as I know). But there are thousands of privately run ‘coaching classes’, prep courses, YouTube channels and neighborhood tutors for every subject. So, in this sense, students are not entirely ‘independent learners’.

The other presenter gave a somewhat opposite point of view and argued that students learn best when teachers go out of their way. The presenter suggested that the best way to improve learning is for educators to play Mom and Dad and envelope students in tender loving care.

I am, as in many other areas of life, from the Twilight Zone. I did not have access to any kind of physics tutoring in or out of college or high school. My siblings, physics majors no less, tried to tutor me and we ended the torture fifteen minutes into it by mutual agreement. Nor was I lucky to have physics educators who were great at teaching or had the time and energy to care truly about student learning. I have always been an independent learner and the lack of a support structure can be seen in my career trajectory. 

But physics experiences early in life have a way of staying with you. I was raised by my grandparents in a small town in South India. My grandfather’s prized possession was a pan balance with a set of weights (masses, rather) which he used to weigh old newspapers. (In those days, one could sell old paper to recycling collectors and make small sums of money.). Milk vendors would come home and measure out the required amounts in liter and milliliter containers. 

Growing up a girl in patriarchal society meant staying home all day and training how to be a good housewife. That meant lots of time observing my mother in the kitchen. I learnt how to cool hot milk quickly by placing a long metal spoon in it so that the heat could be conducted away. I watched as she placed hot food on a stainless steel plate and left it on the floor. Since the coldest air in a room is denser, it stays close to the floor and placing food in metal container on the floor guarantees faster cooling. I also understood why stew that boils quickly is a huge problem if all the vegetables in it need to cook completely. 

Having no access to a public water distribution line and facing a drought in the area, grandpa had to dig a second well in the front yard. I would overhear well diggers talking about the pipe length needed to pump water out of the well.

Now I realize why torque, static equilibrum, density and heat transfer are my favorite introductory topics to teach!

What I am working on

1. 'Need to Touch' - One way to keep students from using smartphones in physics class for non class related activities!

2. 'Educating John' - What the Chief Justice of SCOTUS got wrong during oral arguments on the affirmative action case and why racial and ethnic diversity among students and faculty can enrich physics education.

3. Is 'Big Bang Theory' doing more harm than good for drawing students into physics careers?  -  What students may or may not learn watching top rated TV shows.

4. Is it time to add a 'disappearing Normal Force' question to the physics FCI and MBT screenings? - Why I refuse to place the blame entirely on engineers every time my students think that gravitational force is zero on the International Space Station.

5. Brian Lehrer declares "Confirmation Bias!" -  What happened when I called into a popular radio show about a Pew research study on trying to educate people on climate change.

Spring in Fall

Since the last time I posted on this blog, our collective love of social media has evolved into tolerance mixed with hatred and nippy October days in Northeastern U. S. have been turning into summer like scorchers due to climate change. On the personal side, I have trouble remembering what I opened the fridge for, the need to color my hair every week and blissfully become unaware of when I am embarrassing my child. But I continue to enjoy watching Physics sneak into pop culture- a female character in the movie Zootopia uses a drop of water as a liquid lens to magnify the word printed on the newspaper underneath ...a drug commercial features a Physics teacher demonstrating rocket propulsion with balloon cars in class ....a new Ghostbusters character has AAPT credentials on his wall. Good times, good times. Therefore, to celebrate the rebirth of my publicly shared writing, cuing Julie Andrews ...

Introductory Physics textbooks - Then and Now

Of late, I have been reading and rereading Arnold Arons' Physics teaching bible of 1990 - "A Guide to Introductory Physics Teaching". From the time of its original printing it has been a physics teacher's best friend. A physics educator reading this gets invaluable insights on not only how students learn Physics but also on what they need to unlearn to gain a deeper conceptual understanding. The book has managed to distill into a few chapters some of the most important ideas that were born out of the pioneering Physics Education researchers.

About thirty years ago, College and University Level Physics textbooks in the United States underwent tremendous changes in style and presentation. I must confess though that I do not have personal experience with them as a student. When I was an undergraduate Physics major in India in the late eighties, we were still using low cost textbooks, mostly written by Indian University professors, printed on cheap paper and heavy black ink. Not to detract from the quality of writing, it was always funny to encounter a perennial topic starter - "Let us consider ..". It did not matter if the topic at hand was from Newtonian mechanics, Optics, Electromagnetism, Modern Physics or Thermodynamics. And we were lucky if we could decipher the markings and finer details of schematic diagrams. Meanwhile textbook content itself always seemed to be a mile wide and an inch deep.

Any how, students like me survived these textbooks and  actually learned to learn on our own. At around the same time, an American Physics student could count on the timeless classics "Resnick-Halliday" and "Sears-Zemansky" to present material clearly and more effectively. Yes, they actually had pictures and schematics in color! I realize now that the strength of the "Great American Textbook" sprang from the highly acclaimed PSSC series and the strong research tradition of the universities and colleges.

Yet there were severe problems underlying student learning and understanding. To give an example, Arons describes in his book, testing students (on their Ph. D. qualifiers, no less) on not observing vertical deflection of electrons in the Cathode Ray Tube in the absence of electric and magnetic fields. He was surprised to read the majority of the student responses indicating that they had failed to apply one basic concept  of kinematics - objects fall at the same rate independent of their mass; even though they have a minute amount of mass, electrons would still undergo a very small deflection in the vertical direction, behaving like a projectile whose horizontal velocity was very large compared to the initial vertical velocity (zero!). The lack of observation of vertical deflection had everything to do with the very small value of electron flight time in the CRT and nothing to do with their mass.

The book goes on to prescribe techniques for teaching Physics for deeper understanding and offers new insights based on research on how students learn Physics.

Now, I am happy to say that most of the introductory Physics texts have modified their presentaion reflecting the values of Physics Education Research. Textbooks are even more colorful, with photographs, organization of "learning paths" and end of chapter questions and examples more in connection with real world applications.

The laboratory manuals are changing too. Even publications for in-house use are heavy on inquiry based labs; (the lecture classroom meanwhile has become more of a place to facilitate group learning rather than information transmission by the faculty via lecture and demonstrations)

I am excited to be teaching in these times when customization of textbooks is becoming more prevalent; If and when my institution adopts it, it will remove the long standing student complaint of professors making them buy an expensive textbook and then end up using only about half of its content.

Are there really bad Physics textbooks on the market at the present time? Absolutely. I hope to write extensively on this blog about one such book which tried to incorporate all the ideas out of Physics Education Research and then ended up botching the operation. 

As they say, the way to hell is paved with good intentions.

Yes, cable television is actually good for you

9. Always on NASA TV.

I never get tired of watching the free floating astronauts on the international space station. I used to wonder how some of them live there for up to six months continuously. After watching them busily go about their duties and chores, I am convinced that they would not have all that much time to ponder about missing the earth. Judging from all their interviews, the incredible view of the planet just outside their window is reward enough for their toils and longing for home. Anyway, hot showers and the sense of smelling coffee and food are what they miss most, according one astronaut.

In a few days, space shuttle Discovery will launch carrying NASA's helpful, strong and yet friendly robot  Robonaut 2. This robot weighs slightly more than 300 pounds but has been designed not to hurt a fly, let alone an astronaut human. Right now, Robonaut has no legs or lower body and will stay tethered to a pedestal on the space station. But how will he/she behave under zero gravity when fitted with legs? I can not wait to watch!

Yes, cable television is actually good for you.

10.

The redeeming value of Cable TV is in C-SPAN. And C-SPAN is more than just politics. Folks at C-SPAN do not just follow our elected officials representing us in Congress. There are call in talk shows, features covering important gatherings of the academia and even insider video tours of the White House and other historicallly important buildings.


My favorite however, is the weekend show BookTV , an amazing place to find book reviews. I have enjoyed watching many shows of "After Words", a meet-the-author interview program. Some of these shows feature important works that the mainstream channels or networks would not normally attempt. 



One such show was an interview with Michael Belfiore, author of "Department of Mad Scientists", a book on DARPA, Defense Advanced Research Projects Agency. Now if you, like me, have been led to believe that Steve Jobs and his "iPod people" are the only idea makers around, this is the show to watch. DARPA did not just transform our life with internet and GPS. It is working on more and much more. Like "bullets" that fly themselves. A car that drives itself. A truly bionic arm. I know, it is mostly for the military. But as Belfiore explained on the show, there are quite a few ideas brewing in there which could end up impacting civilian life in a major way.   



(Yes, I love lists.That means there is more to come.)

The best things in life are free ...during the ninety day trial period

Google returned about 1.5 million hits for the search phrase "Physics Sucks". That is about twice as many hits for "Math Sucks" and a hundred thousand more than what I got for "Chemistry Sucks". (My intention, by the way, was not to use a vulgar search term. Instead, it is probably the most likely phrase a frustrated college student might use in association with a painful course, required or elective.)


I believe that, in addition to the student being a Science junkie, sustained effort  is required to tame the Physics beast. Then it can be very rewarding. But my experience tells me it is next to impossible to ask the current generation of entitled and distracted college students to put in an honest minimum of three hours of work every week. Therefore, it makes sense to compare enrollment, retention and course completion rates for Physics on a yardstick different from that for humanities, math and even other Science courses.


But is there a way to establish a tradition of a Physics course that draws in students promising high quality teaching delivered for comparatively low cost to students? The built-in promise is "Hang in there; we, the faculty at a two year college also throw in small class sizes and caring, highly qualified instructors for no additional cost. it will be well worth your effort." When the course runs like a well oiled machine, class after class of students have come in and finally succeeded in Physics after failing at four year institutions, then it is time to jack up course tuition! If I sound like a greedy entrepreneur, I am just following the good old American know how of the technology era: websites that give compelling, quality content free for a trial peiod, draw in millions of users and then promptly build a paywall.

Ah, if only the departments at public institutions had the leeway to set different tiers of tuition...

(To be continued)

My top ten list for Physics teaching

10. Wired magazine's "Top Ten Amazing Physics Videos". Students loved the Large Hadron Collider rap video from this link which I showed as the grand finale to my College Physics course.

9.  What do catcher's mitts, automobile airbags and Spiderman's webbing have in common? They all can be understood by doing rate of change of momentum calculations. Dr.Jim Kakalios, Physics Professor at University of Minnesota shows how! 

8.  School for Champions is a gentle introduction to high school Physics for students who have never encountered Physics at the secondary school level.

7.  Thank God for technology. Professor Walter Lewin of MIT has become an internet legend through his old school, superstar lecture style videos reaching millions of Physics students worldwide.

6.  Harvard Physics Professor Eric Mazur declares war on old school style Physics lectures . It is absolutely wicked fun to watch his "confessions".

5. Since my alma mater can not be far behind in streaming videos, master Physics educator Prof. V. Balakrishnan holds students in rapt attention on Classical Physics. I wish he had been my Physics teacher much much earlier in my career than the graduate course he taught me.

4. It is more reliable than Wikipedia and very accessible for student research on Physics. I often turn to Hyperphysics for a quick search myself.

3. There are Physics simulations on the internet and then there is PhET, University of Colorado at Boulder's pride and joy.

2. David J. Griffith's "Classical Electrodynamics", an engaging text which I used in my beginning years of graduate school still brings a lump in my throat when I read these lines "The implication is tantalizing. Perhaps light is an electromagnetic wave."

1.  I include "Feynman's Lectures" not just as a nod to popular sentiment and timeless appeal. Every day, when I boil water for tea first thing in the morning, I can not but replay in my mind his two paragraphs on molecular motions leading to evaporation.

You will notice that the top two items on the list are not visual elements. Good old solid pieces of writing. And they do not need hyperlinks.

Physics laboratory and buying premium at Wal-Mart

We live in, ahem, interesting times. Distance education is exploding. Outsourcing of Tutoring and Homework Help is so yesterday. Getting student papers graded in India is the trend. Then there is the new all-you-can-eat buffet of college courses at $99 a month. So what does an aging laboratory (used to teach Physics to non majors) do to stay afloat in the midst of crippling budget cuts? How can one possibly leverage the "strength" of several rooms full of antiquated equipment? When the tough decision to throw out some of these (perfectly fine) instruments is made, is it possible to actually make money off of the old equipment?

I got to thinking about this while poking around at work setting up another one of those Freshman College Physics experiments. That led to a quick search of all the glamorous and not so well known "History of Physics" courses out there. Not too many to list. But the American Institute of Physics does have a list here.

The most recent one is/was offered by Michael Fowler at University of Virginia. The course is a graduate seminar and the syllabus comes with goodies, lots of online simulations. (Loved them). The other courses on the list have similar catchy names such as "Women in Science and Mathematics" and "Cold War Science". The most ineresting course I found on the AIP link is called "Replicating Classical Experiments" given by Jed Buchwald (MIT). Which brings me to the point of this post.

Is it possible for a small two year college to offer and market a "History of Physics" course and where would the students come from? There has always been a liberal arts market for this type of Science course. "Physics for Presidents", "Physics for Poets" and "Kitchen Chemistry" are big draws for non Science majors. However, rising tuition costs could start driving even the affluent students at the Ivies to cheap courses at the small, local four year and two year colleges. As long there is transfer, of course.

The other segment of the market would be the numerous science teacher preparation programs in the country. The graduate schools of education often include a "History of Science" course component. An education Master's with specialization in Physics could then include this an elective.

With aggressive marketing and excellent course delivery (read strong institutional support to the instructor), a successful "History of Physics" course should be a long term money maker.

On the methodology of delivering this course with a Physicist and a Physics Historian, I found this article and a discussion on that has to wait for another post.