KateWild: Scientists know they have much to learn and don't know everything. This fuels their enquiry and keeps them asking questions and philosophising about the answers.
Great comment!
This is exactly the point I am trying to emphasize with this thread.
KateWild: That being said, as a student of Chemistry I learned ... there was a right and wrong. The subject is black and white, in assigments there was no room for philosophy or opinion....
It sounds like your teacher did you a grave disservice by not differentiating the approach of science with its practice in a classroom. Indeed, the classroom is the ideal place to teach the philosophy of science. In my experience, experiments rarely turn out exactly as expected.
Just last week, in a classroom demonstration, I tried to replicate the classic heat of fusion experiment of slowly heating a beaker full of ice. The beaker was placed on a hot-plate at a medium-high setting. I also had an electronic probe suspended from above inserted 5 cm into the crushed ice. Th probe was plugged into a laptop with software that graphed the temperature rise in real time. In theory, the temperature of the ice water mixture should stay at 0°C until all the ice is melted. In reality, the temperature flucuated all over the place during the 20 minutes it took for all the ice to melt.
The discrepant results did not disprove the theories concerning heat transfer and the properties of water during the phase change from ice to water.
It's just that the real world is a messy place. There are a number of things that explain what happened. Clearly the temperature of the glass at the bottom of the beaker would be close to 100°C as the hot-plate gets hot enough to boil water. That heat energy is then transferred to the ice/water contents of the beaker. Once melting of some of the ice begins, interesting things happen: convection currents cause the water of various temperature to swirl and twist and turn as the contents seek to maintain some sort of thermal equilibrium. Also, I couldn't be exactly sure what part of the probe was actually measuring the temperature. Perhaps if I place more or less of it into the ice I would have gotten results which more closely resembled the expected theoretical outcome. Also, if I would have measured the experiment without supplying as much heat energy, the results would have been more as expected, but it would have taken hours, not minutes.
All that being said, when I took an average value of the temperatures over the time it took the ice to melt, the value was fairly close to 0°C. So even in the face of disconfirming results, we can learn much.
As a teacher, I love the outliers of data and the unexpected. We often learn more from them than when things go exactly according to the textbook!