Physics Class, Is It All Greek to You?

2017-03-06T07:52:00.000-08:00

If you have ever taken a physics class or seen a physicist scrawling across a black board in a movie or TV show, you may have found yourself wondering how there could be any meaning in all of that mess. It looks like chicken scratch or maybe some obscure language made when someone threw Greek and mathematical notation into a blender. In many ways that is exactly what physics notation is, a specialized and obscure language combining mathematical notation, Greek letters, and unique particularities picked up over centuries of use. This “language” can form an overlooked barrier between students and their instructors obscuring the nature of the difficulty students often have learning physics.

In my experience as a physics student one of the most frustrating things for me was physics professors and textbook authors being unable to clearly communicate. It is often not even that their grammar or use of English words is poor, but that they do not seem to clearly define new ideas or present information in an organized flow. For many students physics represents a fundamentally new approach to looking at the world and I believe it is often a communication failure that makes learning challenging concepts start to seem insurmountable. However, I do not think it is sufficient to just write off most scientists as being intrinsically poor communicators, for hidden in that chicken scratch is a language where they communicate their ideas, that is beautiful and elegant. It just requires changing your perspective to see it. Maybe the differences between the poets and the scientists are not as great as one might first expect; maybe it is just that they have a language barrier obscuring their meaning from each other.

I have recently had the joy and frustrations of attempting to teach physics to non-physicist as a teaching assistant. The majority of the frustration came from students looking at a question and saying, "I don't know". Sometimes I could even walk the student through every individual part and discover that they understood the ideas, they just were not putting them together to answer the question. I think the problem is generally not that people fundamentally cannot understand physics concepts, but rather that people do not consider the difficulty of the language barrier. At first I thought the issue was that the students believed they were not good at physics, so they did not give it an honest effort. Now I think that the issue is really that we are teaching the class in a language they are not familiar with. If I had a lecture and a book where someone taught me the Greek words for color, blue, red, and yellow and then that afternoon, or the next day asked me "What color is the sky?", it wouldn't matter that the question is conceptually simple; my response would still likely be "What?", "I don't know." or maybe me randomly providing one of the three colors that I knew. This is very analogous to commonly seen student responses. They have at most a week or two, and sometimes less than a day, of practicing new physics vocabulary and syntax before they are expected to read and write in it fluently.

To demonstrate my point, I will compare two simple examples the sentence, “That is a fat cat.” and the physics equation “∑F=ma”.

In the sentence “That” is a pronoun identifying the focus of the sentence and “cat” is a noun indicating another relevant object. In the equation, the variable “∑F” represents one of the objects being focused on in the equation, in this particular case a sum of the forces, with the focus on it being implied by its isolation on one side of the equation. Other relevant objects, namely the mass and acceleration are represented by the “m” and the “a”.

In a way that is similar to appending suffixes onto the end of words to systematically change a word’s meaning, physics has a convention for using subscripts to systematically change meaning. If I put “F_G”I mean a gravitational force, while if I put ”F_N“ that is a normal force, but like languages have irregular verbs, in physics one may see forces represented irregularly, like “n” for normal force or “f_k“ for kinetic frictional force.

Then in the sentence “is” is the verb, which communicates action or relation, which is comparable to operators in an equation, in our example this is the equal sign. In physics equations, multiplying, dividing, summing, taking derivatives, and many other operations fill this role. In this simple equation, there is a hidden multiplication operator between the “m” and the “a” which must be correctly interpreted.

But the analogy is not absolute, physics is a math based notation so the operators have an inverse; so when I say that “∑F=ma” and you interpret that as something along the lines of “the sum of all of the forces is equivalent to the mass multiplied by the acceleration”, I am not only expressing that concept, but I am also communicating that the inverse operation is true and that “m=∑F/a”. In a more complex equation this may be extended to an extent where your final “equivalent” form is saying something that was not at all apparent from the original, in a way that rearranging a sentence rarely can.

Physics notation, like normal communication, is very contextual. If you walked into your kitchen and saw Elvis the 38.5lbs cat eating your lasagna, then the sentence, “That is a fat cat,” is just literally communicating the idea that you are identifying a weighty feline. While if you are walking down wall street and a business man gets out of a limousine in front of you, then the exact same sentence is interpreted completely differently as idiomatically identifying a man you believe lives a life of luxury based on the work of others. Similarly, in the physics equation if the problem is looking at the rotation of the moon around the earth you are likely expected to consider “∑F” to only mean the force of gravity the earth exerts on the moon, while technically the sun and everything else are also applying forces, but if your problem happened to be about astronauts playing golf on the moon, then you would be expected to neglect the force of the gravity from the earth on the golf balls and only consider contact forces the balls are experiencing from the club and the force of gravity from the moon, but not the force of gravity from the astronauts or other sources.

Just as these intricacies and exceptions get more challenging as you delve into a new language so to do more challenging physics concepts introduce new peculiarities into the notation and interpretation of problems.

In the end, I believe physics has its own language; as do math, chemistry and probably all of the sciences. I would even extend the analogy to say physics notation is a branch of the math language, similar to how English has Germanic roots. A metaphorically minded mathematician might go as far as to say that physics notation and convention is a less proper mathematical dialect full of "y'all"s and prepositions without objects.

I think it is important for both students and professors to keep in mind that the students are not just learning the concepts, but also the language to communicate them Hopefully they can work to bridge the communication divide. Students by realizing it takes work to understand how things are said, and professors by being mindful of the need to talk to students in a more traditional flow and carefully demonstrate and explicitly acknowledge the intricacies and oddities of physics syntax and vocabulary.

Blog Introduction "Tell all the Truth but tell it Slant"

2017-03-06T07:19:00.002-08:00

Hello I am a physics masters student hoping to go into science writing. I am planning to use this blog to encourage myself to write more, particularly on the topic of science. The title of this blog is referencing Emily Dickinson's poem "Tell all the truth but tell it slant." I have not looked into getting permission to post the full poem on this blog yet, but it is easy to find by googling. Such as here:
https://www.poetryfoundation.org/poems-and-poets/poems/detail/56824

I chose the name as a reminder that while truth is built upon facts it still matters how you tell them. That semantics aren't trivial, and that metaphor, analogy and coming from several varied perspectives are essential for effective communication, especially of science. I do not currently have a distinct plan for topics and posting schedules and I know that will likely harm my ability to build any following but I am doing this to write and help me investigate interesting ideas and I hope at least a few people will find it interesting and useful. I would appreciate any constructive feedback that people are willing to take the time to give.

I hope to tell the truth, but do it slant, to be interesting, engaging, relatable but not condescending. If you like my style and have suggestions for topics please leave a comment mentioning it. Scienc, like a lot of life, is about telling a story. Scientist tell a story about how some small part of the universe works, but often the story is in a style only a small number can relate to; I hope that I can find a way to tell my stories, both science and non-science in a way that people find accessible.

Tell it Slant

Physics Class, Is It All Greek to You?

Blog Introduction "Tell all the Truth but tell it Slant"