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.


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“Air Is Heavy”

After mentioning my memories of my first physics experiment I decided to look for that exercise book. I turned the house upside down a couple of times looking for the battered little grey blotter before my wife remembered a plastic bag of old school books in the roof. I had strong memories of putting the book away in a very safe place so was somewhat sceptical. Of course she was correct and the book was orange.

The write up of “Air is Heavy” makes me happy. A simple experiment that shows something fundamental that has a short write-up, a correct conclusion, and is not marked!

As for my conclusions in the first experiment, “Air Is Every where”, I am not too sure about the my conclusions! There are several more experiments (“Gas Cannon”, “Warm air expands”, “Light”, “Bottle Volcano”) in there, and some terrible and wrong ideas about why a couple of them worked. Maybe we will look at that in a future podcast.

This was done right at the end of my time in Primary School, so I had just turned 11 years old.


This is corrected for grammar and spelling but not physics!

Air Is Everywhere

Air is everywhere. It fills every gap and crack in the world.  There is a layer of air all around the Earth which holds everything down. You can only feel air with the wind or breathing.
We put an upside-down jar in the water and the air started pushing up because it was under water. No water got in to the jar.

Air is Heavy

We hung two balloons up and they balanced each other.

We popped one and the yellow one was pulled up.

This shows that air weighs something.