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I A model of what makes up the physical world

  1. May 12, 2018 #1
    Hi there I am a high school science teacher and I want to present my senior classes with a model of the fundamentals of the physical world to serve as a mind map for us when we reach each topic.
    I have started by creating the one below and then realised I may have left off momentum...is momentum worth mentioning as a separate bubble, or just a "mix" of matter and energy? I would really appreciate any opinions. Thanks upload_2018-5-13_8-52-3.png upload_2018-5-13_8-52-3.png
     
  2. jcsd
  3. May 12, 2018 #2

    sophiecentaur

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    This sort of grouping of ideas is very personal and you may well find it useful for yourself.
    However, you may need to consider the sort of group you are teaching. Students can be very literal and spend a lot of time worrying about how to apply any such classification system to specific topics and quantities. "Where does this fit in Sir?" could be a frequent question to expect so you'd need to be ready with answers. :wink:
    The Hyperphysics site uses such concept maps and you might find their ready made versions useful - (although yours is one layer higher). This maps are very handy as a practical way of checking that the content of a course has been dealt with or for a revision programme. It could be better than just a straight list.
     
  4. May 12, 2018 #3
    Thank you so much Sophiecentaur.
    The reason I have gone up another level from the hyperphysics is that I like to teach by including a single "anchor", using "the power of one" as I call it..ie just one mind map (preferable with symbols that show relationships) page that we can always come back to as a class and orientate ourselves as to where we are up to, and what we have covered in our understanding of physics.
    I also like to try and portray a simplicity to the whole subject of physics that reassures the students that the understanding is eventually possible, it just needs to be broken down into its bits, which is where each of the following lessons fits in.Otherwise I find some students see physics as very complicated confusing and daunting.
    My concern was that this diagram may had a glaring error with something vital left out eg momentum, that would hamper their understanding further down the track, or some relationship between the concepts that was obviously wrong.
    I am going to try and teach the topic by presenting matter, energy and forces as types of "purities" first and look at their definitions, history of understanding and models we now have of each of them. I then intend to go to the textbook and start with the mechanics, thermodynamics chapters etc where we will meet each of these purities and their interactions with each other. I will then ask the students to map out where each of the textbook topics sits on the mind map and place the relevant equations for the topic onto the mind map as we go, just to give them a framework to the whole course.
    Any feedback is welcome, thanks.
     
    Last edited: May 12, 2018
  5. May 12, 2018 #4

    Vanadium 50

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    This is a very good reason not to teach this invention of yours. Also, what about torque?

    Adopting this kind of invention is bound to cause more confusion than clarity.
     
  6. May 13, 2018 #5
    Thanks Vanadium.
    I would consider torque to be a type of force...just rotational
     
  7. May 13, 2018 #6

    sophiecentaur

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    And so it goes on, I'm afraid. You can expect to be flooded with more of that sort of query from students who will take every opportunity 1. to be confused and 2. to challenge you (I have been there).

    Looking at your diagram, I see it is a sort of hybrid Venn diagram with no apparent intersection of space / time with the other fields. That implies there is some 'exclusion' involved, which could cause further aggro.

    To sum it up, I would say that your idea is too abstract for students whose preoccupations are with learning concrete facts for exams. The diagram will surely be taken as literally as the equations of motion that you write on the board and you could then have to pick up the pieces. Physics is not Philosophy.
     
  8. May 13, 2018 #7

    Vanadium 50

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    And that's why I don't like this. Torque is not a "type of force" - it has different units. Yes, there are some analogs, but ultimately you are forcing yourself to teach wrong things to shoehorn conventional physics into this personal invention of yours.
     
  9. May 13, 2018 #8

    ZapperZ

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    The only thing I would pick upon is the relegation of momentum to being just a " ... mix of matter and energy... ", which it is not. This is extremely apparent when you do collision problems, where in the majority of cases, momentum is conserved but kinetic energy is not. So how can one be a mix of the other when they obviously follow different conservation laws?

    In fact, at a more fundamental level, momentum and energy conservations are due to different symmetry rules of our universe. So they are definitely not of the same specie.

    At the level that it is aimed for, I would rather stick with the "subject" categories made by Hyperphysics, with the caveat that these subjects are all interconnected, not separate i.e. a force is a force - of course, of course - no matter whether it is due to a spring, a charge particle, gravity, etc...

    Zz.
     
  10. May 13, 2018 #9
    you can see problems arising really quickly with this sort of diagram. Consider a student asking " ok - if there is force and matter - what is a force if there is no matter?" the diagram suggests this. the diagram suggests also there is matter without energy. I know YOU may know the specifics related to these kinds of questions, but a student may not even bother asking this but just use it to internalize their own misconceptions, or worse - reinforce them.

    Perhaps you would consider treating it more as a tree - in which you can treat the entire course as a build up of ideas from some core questions? i'm only spit-balling here, as i really am not certain of whether this approach is a good idea anyway - i personally find issues with the hyperphysics set up as well, which is useful to a point but suggests linear arrangements of ideas that may not really or should be set up that way.
     
  11. May 13, 2018 #10

    berkeman

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    Hpyerphysics already has a pretty good starting diagram, with details down in the diagram (clickable). Why not just start with something more standard like this? Plus, you could use Hyperphysics as an online teaching resource for your class...

    http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

    hphconw.gif
     
  12. May 13, 2018 #11

    bhobba

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    IMHO what I think is the mind map for physics is Noether's Theorem:


    It explains what energy, momentum and angular momentum is and why they are conserved. It is very profound.

    Another thing they need to understand is what the concept of force really is. Take Newtons first law - it follows from the second and the second is just a definition. The content is in the third law - which is easily shown to be equivalent to the conservation of momentum - but as shown above that follows from Noether. Just what is classical mechanics telling us. Have the class investigate and discuss this.

    The answer you as the teacher should know is the real basis of mechanics is what is assumed in Noethers theorem - the Principle of Least Action which follows from Feynman's path integral approach to QM. Newtions laws are not laws in the usual sense - but rather a prescription that says - get thee to the forces - but they need to discuss and understand, under your guidance, why this is. Your students can read about it here:
    https://www.amazon.com/QED-Strange-Theory-Light-Matter/dp/0691024170

    This will teach your students the actual modern view of what physics tells us about the world.

    Have they done calculus and have some previous knowledge of physics? If so I would recommend the following for what you want to do:
    https://www.amazon.com/Introduction-Classical-Mechanics-Problems-Solutions/dp/0521876222

    It's really first or even second year university, but its the only book I know that presents at the lowest mathematical level possible the correct basis of modern physics - it has Noether and all that. Supplement it with the first few chapters of the Feynman Lectures, plus of course the QED book by the same great teacher I mentioned, and you will have a course that will prepare your seniors with a deep understanding of physics - excluding EM. But they will understand concepts that will prepare them for things like why do fields have energy etc.

    If they do not know calculus then I think there will be a lot of work for you in preparing a course and notes.

    Good luck. If I was a teacher it is what I would do. Its unconventional and hard in that you have to do t yourself - no standard text for it - but your students will get what I think is the core of modern physics.

    Thanks
    Bill
     
  13. May 15, 2018 #12
    Thank you all very much for your great ideas...this is such a fantastic forum!
    I may start with this mind map and call it one idea for a beginning concept map of physics... aimed at identifying for students some of the most basic and important things that make up the and shape the physical world...the stuff that physicists study..rather than the fields of physics study which I see the hyperphysics mind map to be more like.

    The model I presented certainly has its limitations as pointed out by a number of posters eg where would torque be? (yes its not really a force). Where would momentum be? (yes its not really on the intersection of mass and energy) I may end up placing labels for those ( and other things that are too hard) in the spaces outside the balls of matter, energy and forces...yes a bit shoehorn I know, but in the absence of a more correct mind map, it may be my starting point.

    I will certainly not present it as a truth, but may rather offer it as scaffold for a beginning to understanding some big concepts in physics, that can be thrown away later when the students try to "join the dots" in their own ways.

    The Noethers theorem video was fantastic by the way..thanks bhobba...I may play that to my students when the question comes up of "which system should I consider if I want to know that momentum will be conserved?"
     
    Last edited by a moderator: May 15, 2018
  14. May 15, 2018 #13
    oh...and in my travels I have found this...I love it ...not exactly what I was looking for but so interesting!
     

    Attached Files:

  15. May 15, 2018 #14

    bhobba

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    It's more than why its conserved - its what momentum, angular momentum and energy is.

    But you are teaching the course - not me - I will leave it up to you how you explain the implications, and what they are, to your students. Oh what she calls energy is really the Lagrangian - in classical physics it has a simple relationship to energy (kinetic minus potential energy) - but not so for things like fields etc. That too can take your class in an interesting direction.

    Thanks
    Bill
     
    Last edited: May 15, 2018
  16. May 15, 2018 #15

    Vanadium 50

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    I disagree that you should teach Noether's theorem. Yes it's pretty. Yes it's important. But the students do not have the background for this, so it can only be taught at the level of a popularization. This is doubly so because it means cutting and skimping on something else. The last thing you need in an introductory class is more material to cover.

    I disagree even more strongly that a teacher's personal "model of what makes up the physical world" should be taught. Beyond the specific objections, there's a more fundamental one: you are charged with teaching conventional physics.
     
  17. May 15, 2018 #16
    What about space, time, mass, matter, fundamental interactions and symmetries? Almost everything else comes from these.

    --
    lightarrow
     
  18. May 15, 2018 #17

    Mister T

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    That's a great approach. But in my opinion you are going about it all wrong. Instead of some kind of general overview, start with specifics and work your way towards the generalities. Teach first the thing, and then the name of the thing afterwards.

    What seems clear from the literature is the general-to-specific approach reinforces the notion that physics is a confusing and daunting topic to study.

    Matter occurs naturally. Things like energy and force are creations of the human mind, they are part of the modelling process used to describe how matter behaves. So they are in fundamentally different categories.

    Also, if you teach them about these "purities" of yours it's something that they will have to unlearn if they take more advanced courses. And if they don't take more advanced courses they'll be left with a serious misconception.

    But your diagram doesn't have mass, it has matter. They are two very different things. The former is yet another one of those human inventions created in an attempt to understand matter. It was thought that mass is a measure of the amount of matter, but the Einstein mass-energy equivalence showed us that that is wrong.
     
  19. May 16, 2018 #18
    Personally I dont have a problem with students shedding their mind maps (or any models that I give them) as they grow. Just as I am mandated to teach the Bohr model of the atom to my juniors, I do it with the expectation that they will be presented with alternative models as they progress through their learning. Do I have a problem that they will have to unlearn what I have taught them, not really. No model in science is presented as the absolute truth otherwise it would not be a model, and the whole nature of science as a collection of certainties would be a gross representation of what science is and how science, and scientists, work. Personal metaphors have a very valuable place in learning and understanding in my experience and I have always been encouraged in my training as a teacher to be transparent as possible with my students in those areas (see Hattie's effect sizes on student learning). So to those of you who have a philosophical problem with teachers sharing their own personal metaphors/models in the classroom, then I understand where you are coming from and you are entitled to your opinion, but I do not completely agree with you, and exploring those personal opinions on the moral rights and wrongs is not really the purpose of this post.
    Thank for all of your ideas, they have really helped.
    NB I am thinking of joining the matter and energy balls as "matter-energy" later when we reach the E= mc2 bit.
     
  20. May 16, 2018 #19
    Independently of the models/concepts/paradigms used, as student, even at university I had difficulties in understand that *it was a model*!
    At every stage of teaching I would try to make them understand this, as well as possible.
    Regards.

    --
    lightarrow
     
  21. May 16, 2018 #20
    Ok...so another question... what is physics the study of exactly? I feel I might have a better chance of making a mind map if I had this I am looking for a reliable comprehensive and meaningful definition of physics?
    I know its the study of the universe, but that's too general to be meaningful or useful to me. And I know what the fields of study of physics are but thats not really the same thing.
    My oxford dictionary says "physics is the study of the laws that determine the structure of the universe with reference to the matter and energy of which it consists."
    What about laws that reference to time and space dimensions in which it exists? surely it is a study of these as well? not to mention the momenta, torques etc?
    As a physics teacher I think I should know a thorough definition...or at least learn one now!
    Many thanks
     
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