Do we all remember the world’s loveliest teacher, Miss Honey? A compassionate, nurturing educator who never raised her voice and was loved by every child in her care. She was the perfect foil to Roald Dahl’s tyrannical headteacher Agatha Trunchbull who terrified pupils with her violent outbursts and militant approach to learning. Miss Honey was the light in Matilda’s day, and Miss Trunchbull was the monster hiding in the shadows!
Today the husband and I are opening the Ballantyne School. I like to think that I am Miss Honey and he is Miss Trunchbull. As if to prove me right immediately Norm started the PE lesson, or to be more accurate beasting the kids in the garden. They are doing burpees, mountain climbers, squats, jumping jacks, shuttle runs, planks. I am EXHAUSTED just from watching…..
If he gets too bossy we will have to put a newt in his coffee.
But for today the most important thing that we have learned is you can drink tea through a chocolate finger which then melts from the inside and it is AMAZING.
And that got me thinking about physics. Biscuits are starch and sugar, and when heated the sugar melts, which scientists say releases more flavour. They also say that the reason the tea flows through the biscuit is down to the fluid sticking to the walls of the narrow channels in the baked treat, a phenomenon also known as CAPILLARY ACTION. This is the same action that flowers use to suck up water from a vase, or how kitchen roll absorbs the many, many spillages we have in our house.
You can test this yourself, and here is a lovely simple explanation.
We did our own experiment which involved testing a couple of different biscuits to failure. We (Archie, Georgie and Dahlia via messenger video) made our tea with a splash of milk, left it to cool for 5 minutes, then dipped our digestives in to half way and timed how long they took to break off. We used Custard Creams, Lotus Biscuits and Chocolate Fingers. We would love to include some others in our biscuit league table! So if you have any other biscuits at home…. (don’t go shopping for this. STAY AT HOME. As much as I believe biscuits are a necessity the sad truth is that they are not) ….try the experiment and tell us how long they lasted. If you get any super tough ones then stop at 5 minutes!
You can tell us your results on Insta @bernadetteballantyne, where you can also see Archie inhaling chocolate fingers…..or post as a comment to this on Facebook…..
We will share our results (and any you send) in another post.
Finally here is a more in depth explanation by a very clever scientist called Len Fisher who described this using the Washburn equation for capillary flow.