The Physics Teaching Podcast

Latest Podcasts

  • 13. Lasers, Labs and a Large(r) hadron collider

    13. Lasers, Labs and a Large(r) hadron collider

    Thomas and Robin had such fun talking to Patrick Kaplo (Episode 11) from Windham, New Hampshire that we talked to him again about his Challenge Labs. These are graded practicals where there is a one-shot event at the end of the practical that gives you your final grade. You can listen to how this works in an optics lab… err… practical in this episode or rewind to episode 11 for the sliced pendulum experiment.

    Time Stamps

    • CERN Plans @ 00:20
    • Thomas uses Podcast ideas in his lesson @ @ 2:57
    • Challenge Practicals @ 6:48
    • Formative Feedback @ 9:53
    • Refractive Index based Challenge Lab @ 11:15
    • Post interview chat 19:40

    Summary

    Size isn’t everything, but no-one told CERN: they’ve announced designs for the next generation collider. Thomas and Robin are looking forward to find out just a little bit more about the Big Bang and the nature of matter. Thomas celebrated an inaugural ‘podcast day’ when in the same day he used the electric motors, mystery tubes and Perimeter Institute resources ( ‘Bubble Chamber Detective’) from previous episodes.

    Friend of the Podcast Patrick Kaplow returns to be embarrassed by Robin’s hero-worship. Never has anyone been audibly grateful for thousands of miles of ocean. Patrick tells us about “Challenge Labs”, where there is a one shot answer that gives you your grade. He goes on to describe a simple refraction/reflection experiment to test students’ understanding where the grade is determined by a one shot attempt at predicting a laser beam’s path through a prism.

    A brief caution: don’t forget to check with CLEAPSS (or your local Health and Safety body) that any Laser pens or cheap lasers are safe to use.

    Join in!

    Please share ideas or successes – or indeed questions by messaging us on BlueSky: https://bsky.app/profile/physicstp.bsky.social .  You can also message us via our website contact form on every page of the web site at  the.physicsteachingpodcast.com, or email using the address given in the podcast (if we remember). We are moving away from X but can be found there as @physicstp.

    Music

    The music is used under the Attribution-NonCommercial 3.0 International License

  • 12. Shrink-Rays, Spectrum and String…

    12. Shrink-Rays, Spectrum and String…

    Thomas and Robin discuss why – when they are less likely than a podcast from the gym in January – media are still obsessed with Shrink Rays and mysterious (not Alien) Space signals. They soon move onto far more entertaining matters as they talk about teaching the EM Spectrum. Thomas tells us about his lovely “How long is a piece of String?” lesson. One of Robin’s favourites, it’s a great way of engaging reluctant students in the exploration of measurement, errors and uncertainty.

    Time STamps

    • (not) Shrink Ray @ 2:50
    • Signals from Deep Space @ 4:50
    • Electromagnetic Spectrum @ 6:37
    • How Long is a piece of string? @ 14:18

    Summary

    It’s not a Shrink Ray: this is published in Science Magazine, but theengineer.co.uk is a bit more accessible. Remember to tell us your examples of how putting “Laser” on the front of everything makes the students think anything is better. Whys is any signal from space immediately attributed to Aliens? The BBC should know better. Helen CK’s question on Facebook about how to teach the Electromagnetic Spectrum finally gets addressed. (Sorry for the delay, Helen!) Your ideas will be bigger and better than ours so please share. Equally, if there’s something you want to throw open to the community, just let us know (twitter, contact form, instagram). If you find your students reluctant to engage with uncertainty and measurement, then you will love Thomas’s “how long is a piece of string?” practical.

    The EM Spectrum

    Helen CK contacted us long ago asking for ways to teach the e-m spectrum. Thomas and Robin chatted about how they would teach it. Thomas from the future visits to remind them that the Electromagnetic Spectrum song by Emerson Foo and Wong Yann is not to be missed (below). N.B. Take care with this song because there are some spurious ones set up in YouTube to fool and embarrass unwary teachers. Thomas mentioned “any number of Doppler effect videos on YouTube”, this is a good one.

    Join in!

    Please share ideas or successes – or indeed questions by messaging us on BlueSky: https://bsky.app/profile/physicstp.bsky.social .  You can also message us via our website contact form on every page of the web site at  the.physicsteachingpodcast.com, or email using the address given in the podcast (if we remember). We are moving away from X but can be found there as @physicstp.

    Music

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  • 11. Poppers, Pendulums and Pond-hopping

    11. Poppers, Pendulums and Pond-hopping

    The days are getting longer, and the monster Christmas term is behind us. Thomas and Robin refuse to let January blues dull the joy of physics teaching as they kick 2019 off with a cracker (pun intended). Two kinematic experiments are the focus, one using a pop-up toy and one that needs fire and blades.

    Thomas and Robin also mourn those long-forgotten pieces of equipment buried in obscurity at the back of the cupboard. Please don’t leave them there to fester. If you have a piece of equipment you are unsure about, why not send us a photo by email or post about it in the forum, and do head that way if you want to talk about the episode, or anything else in Physics Teaching. 

    Robin started the new year with a series of panic attacks after hearing about practicals that are both fun and difficult. The anxiety was only compounded by assertion that practicals can be graded, and don’t always evidence progress! He is currently recovering with the help of a Valium prescription and a copy of OFSTED’s annual report.

    How great was it to hear from New Hampshire this week? Thanks so much to Patrick Kaplo from Windham High School for telling us about physic teaching in New England and giving us a practical in memoriam. Patrick joins our growing list of podcast heroes, not least because of this quote from the New Hampshire State Education Dept: ” Mr. Kaplo drives engagement in his classes by asking his students to build six foot tall trebuchets, ride CO2[sic]-powered fire extinguisher rocket carts… fire vacuum-powered ping-pong balls over 400 MPH, and visualize wave phenomena in an 8-foot long fire tube…”. As they might say in the States, we are totally getting him back again!

    Robin has been trying to avoid cultural references that befuddle Thomas, but when he exclaimed “Jurassic Park!” he probably confused everyone. Anyway, this youtube video might help. For the record, Robin is much more like Alan Partridge than Thomas… in fact he’s more like Alan Partridge than Alan Partridge.

    Success!

    Join in!

    Please share ideas or successes – or indeed questions by messaging us on BlueSky: https://bsky.app/profile/physicstp.bsky.social .  You can also message us via our website contact form on every page of the web site at  the.physicsteachingpodcast.com, or email using the address given in the podcast (if we remember). We are moving away from X but can be found there as @physicstp.

    Music

    The music is used under the Attribution-NonCommercial 3.0 International License

  • 10. Ways to teach… Electricity

    10. Ways to teach… Electricity

    Merry Christmas Physics teachers!  In a bumper festive edition, Thomas and Robin have rounded up your ideas and tips on how to teach electricity.  It’s quite rare to reach a clear conclusion in a discussion of teaching, but there was consensus that if you are going to use a model, then the rope model is a great starting point, and Thomas has written a full description of a way to use the rope model in his blog.  We also acknowledged some other models and their usefulness: the important thing is to reflect and evaluate, but then again isn’t it always?

    Resources

    You can see all the tips and suggestions in a gallery at the bottom of the page.

    We were delighted that the excellent PhET resources were mentioned by a couple of people. There are several electricity simulations, for example the DC construction kit.

    Robin mentioned the Supporting Physics Teaching Web site, and its resources on electricity. It’s a great resource but is more akin to an Encyclopedia than a guide.   For a nice clear description of the rope model read the article by Tom Norris about teaching electricity. Tom also sent us a message after the interview:

    Traditionally, in ks3 electricity schemes, you teach the electricity concepts, and *then* comes a lesson where you teach about electricity models. I personally wouldn’t do the “evaluating models” lesson unless I’m happy students’ understanding of electricity itself is at an expert enough level to be able to spot the subtle nuances of what the models do well and not so well. And also, secondly, because I don’t think knowledge of electricity models is anywhere near important enough to give a whole lesson to. The most important resource physics teachers have is time, and I the electricity topic I want to spend every lesson teaching about electricity itself. I don’t see electricity models as ‘content for students to learn’, rather, electricity models are something that I, the teacher, turn to, to help me explain/demonstrate the electricity concepts that I’m teaching.

    Tom Norris

    Lucky shot of an arc sparking

    Thomas was delighted by the idea of driving a aluminium foil capacitor with the EHT. He duly did it and was delighted with the results.

    What an exceptional community we are building!  All of this week’s podcast came from our growing listenership, so a million thanks.  Keep spreading the word, and if you liked the slightly different format (or not!), do let us know.  Similarly, if there’s anything you’d like to cover, please do share.  We plan another special on energy soon.

    Have a good rest and we’ll see you in the New Year!

    Join in!

    Please share ideas or successes – or indeed questions by messaging us on BlueSky: https://bsky.app/profile/physicstp.bsky.social .  You can also message us via our website contact form on every page of the web site at  the.physicsteachingpodcast.com, or email using the address given in the podcast (if we remember). We are moving away from X but can be found there as @physicstp.

    Music

    The music is used under the Attribution-NonCommercial 3.0 International License

  • Using The Rope Model of Electricity

    Using The Rope Model of Electricity

    In the next podcast we inevitably talk about the rope model. I tried it a few times in the past and hated it ?. It was only in making the podcast that I finally understood how to do it and how good it is. Not knowing how to do it is as much a function of my comfort with the donation model as it is my being alone in my school with no other physicist to talk to. But talking to Robin and Stuart about electricity really got me thinking. 

    When I did the rope model it didn’t work because I had quite a few kids involved in the demo. I found it really hard to make the rope run smoothly through their hands (not least because the rope had a huge knot in it!) and it was a very static sort of demo. There was no fluidity at all, no flow. I had visions of attaching pulleys to the walls of the room to make it work (I like big scale). I chatted to Stuart about this and he was able to tell me a way to do it that worked. It works so well, and is so easy to do. I was bowled over.

    my recipe for an effective rope model demo:

    1. Have a rope that is in a 3-4m loop where the join is as smooth as possible. (Cutting and melting together a rope is ideal).
    2. Choose one student only.
    3. Hold the loop and pass the other end to the student. Tell them to grip it lightly (they don’t want rope burns) in one hand with the rope passing vertically down through their fist (this is the detail I never understood – one student, one hand).
    4. Explain that the rope is the electrons and the grip is the resistance.
    5. Pull the rope hand over hand through their (one, stationary) hand.
      • Question: What do you feel in your hand? 
      • Answer you want: Warmer
    6. Tell them to add another hand, holding with the same light grip. The rope will get harder to pull, make this obvious, it will naturally run more slowly.
      • Question: why is the rope moving more slowly?
      • Answer you want: because there is more resistance.
      • Question: how can I increase the current to make it move as fast as before?
      • Answer you want: Pull harder.
      • Explain that this means more energy being delivered by the cell to the rope, or greater pd.
    7. Pull harder, to make the rope move at the original speed again.
    8. Tell them to grip tighter with one hand, but not to tell you which hand that is.
      1. Question: what has happened to the rope speed?
      2. Answer you want: slower.
      3. Question: does the rope/the pd know which hand is gripping harder?
      4. Answer you want: no.
      5. Question: what is happening at the tighter hand?
      6. Answer you want: warmer.
      7. Explain how this is energy transfer
      8. Question: are the electrons in any way different before and after the hands?
      9. Answer you want: no.
      10. Remind them that electrons just go where they are pushed/pulled by the pd, they aren’t changed, they don’t make a choice, they just go where they go.
    9. Get another rope, get them to hold one loop in each hand, but you pull them together. You can model parallel with this but I wouldn’t go too far as the model does tend to break down a bit.
    10. You can show AC nicely too. Remove one loop then tell them to hold their fist horizontally, not vertically. Now grip the loop in both your hands and pull it backwards and forwards. The hand gets warm just the same.

    Good luck with this. Maybe report back in the forum?

  • Somebody Out There Likes Us

    Robin and I started with very limited ambitions, it wasn’t quite “more listeners than presenters” but not far off. We agreed to do episodes until the end of the academic year and then see where we stood. At that point we had not got much further than me telling Robin he and I should start a podcast and then months later him finding the statistic that about 50% of schools in the UK have one or zero physics teachers. We just wanted to try something, try to build a community and see what happened. I am a regular listener of The Cycling Podcast and modelled a lot of our approach on them.

    As we started I had no idea about format, content, approach, social media, iTunes ratings, post production, how to talk to a microphone and had never considered a T-shirt or shop (or adding a forum) But I am top loaded with running web sites and general geekery, so I figured I would muddle through.

    It was a revelation to me (physics teacher, but never an audiophile) to find that a microphone has preferred orientation. Listening back you can tell the episode where I worked out where to point my mouth when recording.  I found a great T-shirt supplier when looking for somewhere to buy a jokey shirt for Robin. They actually make the shirts on demand and provide a WordPress plugin, so one thing led to another and now… a shop! Just a bit of fun of course, as Robin says in Episode 9, this is nothing about money… But if it helps build a community then that’s brilliant.

    As I went to sleep on the night before episode 1 I was not convinced I wouldn’t grab my phone at 4am and cancel it. Now, as we approach the recording of episode 10 I feel more comfortable hearing my own voice. I’ve also been dragged kicking and screaming in to social media and I feel a community is growing. (We have had a few emails thanking us for doing it and the interaction on Twitter has been fun). It has also been hugely enjoyable talking to different people and learning from them: I recorded another PIM this week which will most likely be in Episode 11. Please do continue to send us ideas. We love hearing them all. You can use the form below.

    Finally, to get some 5* ratings in iTunes is pretty stunning to be honest, so thank you very much, listener(s!).

  • 9. Mentors, Motors and Merch

    9. Mentors, Motors and Merch

    Robin hadn’t heard about the recent Falcon landing failure so Thomas filled him in.  Cutting-edge space technology is still frontier science: we need your students to be the engineers of tomorrow!  Regular listeners will know how much Matt Groening influences the podcast, and just in time fro Christmas, we have launched our first ‘merch’, setting up a shop on the web site.  A shop where you can buy the T-Shirt? Yes, all your Christmas present problems are solved!  Listen out for a secret (??) code that allows you to get your shirt at cost. This time next year we may be stocking TPTP box sets and underpants: our ambition knows no limits.

    Care in the community…

    Physics teachers can be empathetic too! Robin worries about how hard this time of year can be, and especially for young-in-service teachers and the terrific Jo Kent draws on her wealth of experience to give her advice. She highlights how an empathetic ear can make all the difference, and on a more practical note, how networking can help to build communities.  She specifically mentions TalkPhysics and Thomas compares it to PTNC. (The IoP has a page where several other ways of networking are listed). Jo goes on to tell us about her Pint Pot Motors in a Practical In Memoriam. Below you can see the images she talks about below and she also sent us her PowerPoint and the video her father made.

    It remains a privilege and a joy making this podcast for you.  We love hearing from you and you are a very big part of the adventure; guide us, tell us what you want to hear about. It really is your podcast, so please get in touch: teachers of physics are our very favourite superheroes! 

    Jo’s Pictorial Instructions

    A Working Motor

    The Motor Jo’s Dad made:

    Also Thomas made the motor and shared it on Twitter:

    Join in!

    Please share ideas or successes – or indeed questions by messaging us on BlueSky: https://bsky.app/profile/physicstp.bsky.social .  You can also message us via our website contact form on every page of the web site at  the.physicsteachingpodcast.com, or email using the address given in the podcast (if we remember). We are moving away from X but can be found there as @physicstp.

    Music

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  • 8. Venn Hats, Meows and a Mysterious Tube

    8. Venn Hats, Meows and a Mysterious Tube
    Mr Benjie

    As David Bowie once mused “Is there seismic activity on Mars?” ( I think that’s what he said…), and who are we to argue?  So we kicked off discussing NASA Mars Insight Lander and then Robin confessed to group about his tendency to get on a self-righteous soapbox (see episode 7!).  Luckily this week’s chat was the perfect antidote to stress as he chatted to Carole Kenrick: primary teacher, secondary teacher,  artist and PhD student, she wears many metaphorical hats … and has a podcasting cat called Mr Benjie.

    Carole tells us about two of the practicals she likes the most: decay-dice and mystery tubes. Decay dice take the simplicity of rolling one die, developing it in to a beautiful mathematical model. She uses mystery tubes from the Berkley Understanding Science web site and they kindly provide instructions to make them. Thomas couldn’t resist making a mystery tube of his own and “Thomas from the future” appears to tell how he got on.

    Thomas' early prototype
    Thomas’ early prototype

    Carole also introduces us to “Physics Fairy” (no, really, check it out!) and explained how it came into non-existence from working with Force Goggles from the Supporting Physics Teaching web site.

    New Competition – Closes 13th December

    Help us with our planned “Electricity” episode by giving us your top tips… and pitfalls. Either tweet us with the hash tag #physicstpelectricity or comment in the thread on our Facebook page. Thomas and Robin will choose a winner on the 13th of December and will send you a signed copy of Ben Rogers’ wonderful book The Big Ideas in Physics and How to Teach Them.

    It remains an enthralling and educational adventure making this podcast for you.  We love hearing from you and you are a very big part of the adventure; guide us, tell us what you want to hear about. It really is your podcast, so please get in touch: teachers of physics are our very favourite superheroes!

    Join in!

    Please share ideas or successes – or indeed questions by messaging us on BlueSky: https://bsky.app/profile/physicstp.bsky.social .  You can also message us via our website contact form on every page of the web site at  the.physicsteachingpodcast.com, or email using the address given in the podcast (if we remember). We are moving away from X but can be found there as @physicstp.

    Music

    The music is used under the Attribution-NonCommercial 3.0 International License

  • Refutation Text for the Jelly Chair

    Refutation Text for the Jelly Chair

    I said in Episode 6 I would share what I came up with for the Jelly Chair lesson and refutation texts. I did put some thought in to this but think that there is room for improvement. I ended up writing a few sentences for the kids to do:

    • The ancient Greeks thought that arrows were pushed through the air by the god Apollo. We know this is wrong because…
    • Many people think that objects will slow down and come to rest if no resultant force acts upon them but really…
    • A typical GCSE level understanding of balanced forces allows a person to sit on a chair made of jelly. This is false because…
    • Galileo showed that two balls of different weights accelerate at the same rate when dropped.. Before this people thought heavier objects fell faster but this is wrong because…
    • Some people think the International Space Station has no forces acting upon it because it is in Space, the evidence that they are wrong is…
    • When a helicopter is hovering it is very common for people to think that the weight of the helicopter has an equal and opposite force that is the down-force from the rotors. This is wrong because…

    I was particularly happy with the last one (though I have no idea if that is an actual misconception or not), and even happier when one of the students said something like:

    The down-force is equal to the weight!

    They had truly understood the situation, and was able to explain to their partner that the weight and down-force must be equal in magnitude and in the same direction as weight if the helicopter is hovering (not equal and opposite).

    As I roamed the class and spoke to the students I was pretty confident the refutation sentences were having impact. The challenge is to use them again and again and embed them in my practice.

    The podcast strikes again. Thank you Ben Rogers!

  • Kicking a Rock on the Moon

    Kicking a Rock on the Moon

    Physics for You

    In Episode 6 I mentioned a thought experiment with a concrete-filled rugby ball. I have used this model for years and knew it came from a text book long ago and I have since been searching for it. I was convinced it came from Peter Warren, the head of department where I did my teacher training and author of one of the books that was used to teach me back in the early 80s. It turns out that Pete is still teaching, but did not draw the cartoon.

    It actually came from Physics for You by Keith Johnson, and it is still available, new from Amazon in the 5th addition. I actually own a Johnson (it has sat on a shelf in my office untouched for years) and did not think to look in it until I had sourced a couple of Warrens from amazon.  The character kicking the rock (in this case) is Professor Messer.  I assume Johnson drew them all himself, as did Pete in all the cartoons in his books.  I excitedly looked up @ProfessorMesser on twitter to see if he had an online presence but it turns out to be a real person.

    One of the Warren books I sourced is a gold mine. It is the advanced physics laboratory book and this would be a super resource for anyone new to A level teaching. I got it for 20p just a week ago but a quick check on amazon shows it is now £28+! It contains many practicals that I consider routine but has given me some new ideas too. For example, my school does not have a position sensor/force sensor etc. so I have not been able to datalog damping. This book has a beautifully simple way of doing it: attach a magnet to a hanger boinging on a spring, bounce it up and down inside a coil and measure the current in the coil. 

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