6. What happens when your jelly won’t hold your weight? Is it time to lose some mass?

Jelly chair aftermath

Thomas and Robin got together in the same room for a chat this week. Don’t worry, as a good physicist and a good engineer they avoided eye contact*. The big news last week was the redefinition of the kilogram which was originally based on the mass of Napoleon’s leg**, but latterly on a  lump of metal held in what looked suspiciously like a cake container. So we discussed misconceptions about mass and weight and about one of Thomas’ favourite experiments: the jelly chair.

*Well, that’s an unhelpful stereotype!  In fact we were highly empathetic and talked about our feelings extensively.

**completely made up


Now we have listeners, AND an Instagram page (@physics_teaching_podcast) we thought we would encourage you to share the podcast by having our first competition. Win a beautiful podcast T-shirt (in the colour of your choice) by interacting! To win, tell us why you like listening. There are many ways to do this:

Thomas and Robin will pick a winner in a couple of weeks.

It remains an enthralling and inspiring adventure making this podcast for you.  You’ve already taken it in directions we weren’t expecting; it really is your podcast, so please get in touch: teachers of physics are our very favourite breed of hero!

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Please share ideas or successes – or indeed questions – on our Facebook Page: .  You can also message us via our website contact form at, Twitter @physicstp, email using  the address given in the podcast (if we remember) or by leaving a voice memo using WhatsApp or Telegram to the phone number in our Twitter profile, +44 7898 814716 (don’t call the number, nobody will answer, just hold down the microphone icon and speak your message or upload an mp3 or ogg). Don’t forget to tell us your name because we may use your audio in a future episode.


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