Heat and temperature

Monday I showed a 1980 set of videos on heat and temperature by the Ontario Educational  Communication Authority that was acquired by the MITC in VCR format circa 1993. Those videos remain one of the best introductions to temperature and heat which is comprehensive and fits into a 50 minute period comfortably.


Wednesday I ran a series of temperature demonstrations. This term the coconut oil was held in the refrigerator from the night before, and melted more decisively at 20°C. I also briefly mentioned three of the ways heat moves.

Joyann with Dickenson, Mauriney and Rodman

Thursday I was looking at the metal cups and realized that the students could use three different materials.

Joyceleen and Darall

Mauriney and Rodman


 The board layout this term did not focus on confirming Newton's law of cooling, this was not mentioned until the end of the lab. I also opted not to use a variable Tmax and Tmin but rather to use 100°C and the measured room temperature of 30°C. The equations are enough of a mystery without adding in a variable Tmax and Tmin. Desmos will happily regress to these values and generate a more perfectly fitting curve, but then the equation is just a mysterious black box.  As if it wasn't already for the students.


At around 40 to 50 minutes I put the graphs from Desmos up on the fifty inch television. I told the students not to focus too much on the mathematics of the equation, but rather on that the equations generate a line that matches the temperature behavior of the cooling water. The math tells us what the system will do, and to where the temperature is decaying: back to room temperature. The math is telling us what will happen. I note that later there will be math we cannot do, but that also tells us what will happen in a system. Math like quantum mechanics. And the issues of what exactly is quantum mechanics telling us that the world is doing or going to do. The course is really a long setup for why physicists have such faith in mathematics that they are willing to go as far as Tegmark and say that the universe is simply mathematics. Or Everett and the many worlds interpretation that arises from quantum mechanical equations.


Data gathered in the eight o'clock section. Orange dots are the styrofoam cup datga, black x's are the metal cup data, blue open circles are the glass beaker data. The glass beaker held less water than the styrofoam cup and the metal cup.

Data gathered in the eleven o'clock section. Orange dots are the styrofoam cup datga, black and purple x's are the two metal cups data, blue open circles are the glass beaker data. The glass beaker held less water than the styrofoam cup and the metal cups.

With enough time and patience, something the students do not seem to have much of after the first 12 minutes, the curves start to appear.

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