TOK in Physics

Thinking OK

As Physics teachers we do not have to know all the ins and outs of the TOK course however we are expected to know what it is about and when to point out aspects of the course that might be interesting in a TOK context. I like to call the course "Thinking OK", whenever the students are thinking then it is relevant to TOK and that's pretty much all the time.

Students study 6 subjects, they might not realise it but in each subject they are being asked to think in different ways, in the TOK class they are expected to reflect on the way they think in different areas and discuss the similarities and differences. So in a discussion on the role of emotions students might compare the role of emotion when writing an essay on the book 1984 and when they did an experiment to measure g. The problem is that rather than drawing on personal experience students often pick examples that they know nothing about such as comparing the role of emotion when George Orwell wrote 1984 to the role of emotion when Newton developed the laws of motion. I see my role as physics teacher to point out the interesting ways of thinking that are occurring during my lessons so that when students enter the TOK class they can speak from personal experience.

For Whom the TOK Bell Tolls

When you start to think about it there are interesting TOK aspects in every one of our lessons, I call these TOK moments. whenever one of these moments occurs I ring a bell (The TOK bell) this is a bit of fun and students seem to like it. I start doing this from the very first lesson even though at this time students haven't got a clue what TOK is, by the end of the course they are telling me when if i forget to ring it at a relevant moment. This is how it might go:

What is physics?
It's about making sense of the physical universe.
How do we know about the physical universe?
We make observations, we use our senses to observe our surroundings. Imagine you suddenly arrive in our universe, somewhere out in space, what would you observe?
Points of light.
Are the points of light all the same?
No they have different positions.
How do we describe the differences?
Some are near some are far, some are to the left some are to the right, some are up some are down.
OK, so we need 3 dimensions of position but is it enough just to say near and far?
No we need to define a scale


In the first few minutes of the first lesson the TOK bell rings loudly

So what is TOK about that?

To refer to Richard van de Lagemaat's introduction

"The first task in TOK is to see that there is a problem of knowledge, that we cannot simply take our knowledge claims for granted." We know that one star is further away from another because we observe it, to observe we are using our sense of sight. To build a theoretical model of our universe we need to me make measurements but how do we know that our measurements are reliable?

"the difference between reasonable beliefs and unreasonable ones." When we move our head from side to side we notice that close objects move in relation to distant ones so if this happens does that mean that one object must be closer than the other or could the some unknown force be moving them?

The Interminable Unanswerable Questions

TOK can, if you are not careful, turn into a a series of unanswerable questions. How can we know atoms exist if we can't see them? What would happen if we travelled faster than the speed of light? What is there beyond the universe? etc. In Physics we like to have questions that we can answer and there is nothing wrong with that as long as we make sure that everyone understands the conditions.

In my opinion there is no point in questioning the law of conservation of energy every time we use it, this is a law and should be used as such, laws can never be broken etc. The TOK point here is that we should make sure that the students are aware of what we are doing, treating certain statements as truths. if we didn't accepts anything then we could never  make any predictions or answer any exam questions. Students should know of the rules of the game but should be aware that it is a game. So sometimes we are actually training students to think uncritically rather than critically.

Physics as an Area of knowledge

In TOK speak physics is an area of knowledge so some time will be spent in the TOK classroom discussing physics as a natural science. Here I have taken what is written in the IB guide about natural sciences and put it in a physics context. These are the sort of questions that will come up in the TOK class so what we need to do is make sure that students in our classes realise when we are thinking in a way that is specific to out subject.


Physics is a natural science that strives to search for understanding of the physical universe, through observation measurement and experimentation theories have been developed enabling us to make predictions and devise new ways to solve practical problems. Advances in physics have led to technological developments that have influenced the way we live in ways that could not have been imagined, taking science out of the laboratory into the public eye leading to diverse attitudes towards the nature, scope and value of physics

Nature of physics

  • Why is physics called a "natural science"? What is and isn't physics?

  • Is physics about facts or is it a way of thinking? Poincaré said “Science is built of facts the way a house is built of bricks: but an accumulation of facts is no more science than a pile of bricks is a house” Is this true for physics?

  • In physics are there any assumptions that are unprovable? 

Methods of gaining knowledge

  • What is meant by the “scientific method”? Is the scientific method the same in all sciences? Is the scientific method the same in all cultures?

  • Are the methods used in physics the same as in other sciences? What are the implications of any variations? For example when analysing data in physics are the same methods used as in biology? How many laws of biology are there? What kinds of reasoning are used in physics?

  • It is a feature of the way physicists work that new theories are continually tested and revised so theories that have been around for a long time become stronger and stronger.

  • There are lots of famous quotes that can be used to start a discussion, here is one:

    One aim of the physical sciences has been to give an exact picture of the material world. One achievement of physics in the twentieth century has been to prove that this aim is unattainable.

    Jacob Bronowski
  • Physics is an experimental science, what counts as an experiment? Can experiments be undertaken in history? Can experiments be carried out in cosmology?

  • What are the similarities and differences between physics and human sciences? To what extent do different fields of study overlap? Is it true to say that human sciences are less scientific because they are more complex? Could scientific methods be employed in the human sciences?

  • What is the role of imagination and creativity in physics? Does the formulation of a hypothesis require imagination or is it the product of rigorous application of theory?

  • Will we eventually be able to explain everything or will some things remain unexplained? Are there some phenomena that will never be explained by science?

Knowledge claims

  • In physics we use theories and laws to make explanations, is this the same in other subjects?

    The ball is close to the Earth so according to Newton's universal law of gravity will experience a Force. This force is unbalanced so according to Newton's 1st law of motion it will accelerate. The unbalanced force is in the direction of the centre of the Earth so according to Newton's 2nd law the ball will fall downwards.
  • To what extent can all the natural sciences be understood through the study of just one science, for example, physics? If biology relies on chemistry, and chemistry relies on physics, can it be said that all natural sciences are reducible to physics? If so, what would be the implications of this position?

  • Why are there 3 sciences when everything is physics? Can the working of the human body be broken down into the forces between small red balls?

  • Scientific knowledge grows in complexity do other subjects grow in the same way? Will there ever be a time when all the problems in the universe have been solved and the development of science comes to a halt?  what would be the consequence if science stopped developing?

  • A large part of the physics course is about things that we can not see directly, atoms, em fields (well actually em fields are the only thing we can see), black holes etc. Are these entities actually exist or are they simply inventions of the human mind used to make predictions? Does it matter if they exist or not?

  • Some of physics is based on direct experiment for example Snell's law but some is based on things that have happened without us controlling it, most of astro physics is like this. Are experimental theories stronger than ones that can't be tested?

Natural sciences and values

  • Are the methods and findings of physics affected by their social context?
  • Should physics be allowed to progress without regulation or should there be some independent body that controls the direction of research? Should the funding of research be decided by business or governments?
  • Are physicists morally responsible for the application of their discoveries? If someone is to be held responsible for the atom bomb how far back should be go, Bohr, Rutherford, Thomson? Should  research in physics ever be stopped on moral grounds?

  • Developments in physics sometimes have major implications in other areas. The discovery that the sun was the centre of the solar system had implications for religions for example. Is science affected by advancements in other areas?

Physics and technology

  • Is scientific knowledge valued more for its own sake or for the technology that it makes possible? Is there any science that can be pursued without the use of technology?

  • Advances in physics often lead to advancements in technology such as the mobile phone. Does it matter that although most people use a mobile phone few people understand the physical principles that it operates on. What is the difference between science and technology? Are science and technology inseparable?

  • There are many examples where advancements in physics have taken place after a technological advance has been made e.g. The telescope, microscope, particle accelerator, computer, etc. In some cases the technology was invented to solve a problem but not always. What implication does this have on research in physics?

Metaphor and reality

  • In physics we make great use of metaphors and analogies, gas atoms like lots of little bouncy balls, light like ripples spreading out on the surface of a pond etc. Could we have physics without analogies? Does the use of analogy ever cause problems? Is understanding the model the same as understanding reality?

  • In physics computer simulations and animations to help us visualise things that we can't see. Is visualisation important? Can we understand something that we can't see? Have computer simulations removed the need for imagination?

  • In physics words such as energy, potential and amplitude have very specific meanings how does this compare to the use of language in poetry? Does the use of language affect our understanding of concepts?

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