So thinking of my first experiments – consistent as they were (within their own world of haphazardness) – I wasn’t really satisfied that I’d ended up with a measurement of the right thing. It was informative and revealing, but what about:
- – The fact that I had done my observations at room temperature (the rate of cooling would have been different if the temperature were much lower or much higher).
- – The fact that the vessel was made of plastic (of course the ability of the vessel to conduct heat will have an impact)
- – The vessel was unheated on the first observation, but would have warmed up a little on later experiments (so slowing the rate of cooling?)
- – The size of the vessel – surface area – probably has an impact on the speed of cooling, and especially, I’m guessing, the surface area of the top of the water.
- – The fact that I had poured water into an open topped vessel of itself was likely to be important – what of the water that had remained in the kettle,
- – What if I had poured the water into another contained and covered vessel? (such as a Bouno pouring kettle)
- – And after all of that, it’s the temperature at which the water actually hits the coffee grounds that matters – so how to measure that?? And could this be particularly important if the rate of cooling on the pour is actually faster than the rate of cooling when water is standing.
I decided to repeat my experiments with some variations –to take account of what I thought would be the most important aspects:
- Pour water into a ceramic mug – different material, smaller surface area, especially smaller top of the water.
- Measure the temperature in the water boiler (kettle used to boil the water). Without lid (practicality rather than best experiment).
- Measure the temperature in a Buono kettle (having been poured from another kettle which boiled the water). With lid replaced between readings.
- Measure the temperature of a Buono kettle with lid being slowly poured directly onto the bulb of the thermometer – the closest I can easily get to measuring the water as it hits the coffee.
Inadequacies in all of the above in the way that they are conducted, what they are demonstrating, and whether they are measuring anything near reality – but interesting and a bit of fun. And some conclusions possible, I think!
More to come in future days -including the realisation that Newton had a law for ( some of) this……
please note: boiling and hot water can be dangerous if not handled with care!
(despite the haphazardness of some of my approaches above, I did take some care and would suggest anyone else does the same: and children should be accompanied by an adult)