Thermophysics, the experiment 1

Monday 18. August, 2008

Today I had a measurement to do in our university’s physics student laboratory. I had a kettle full of water of 80 degrees Celsius, an aluminium rod and a smaller pot of room temperature water.

The idea was to conduct heat from the bottom of the hot kettle through the rod to the pot. I had temperature sensor in both the upper and the lower end of the rod and in the little pot. The temperatures were read to a computer running some Matlab-script. I was supposed to measure the temperatures for 10 minutes with 1 minute intervals and write them down (It cleary would have been too little work for us if the script had had a for-loop to do this too).

So, for ten minutes I wrote the results down and changed in a copper rod and did the same things to it too. In half way of the second measurement set, my instructor took a look on the first results and was a bit puzzled.

Somehow the upper end of the rod heated as expected, the water in the pot heated as well. But the temperature of the lower end of the rod got lower! How is this possible?

(this is an “I want comments”-post and the real answer to the question above will be revealed later, unless someone finds it out. >:-) )