Burning Questions About a Candle

Answer the following questions concisely. That is, use short sentences or sentence fragments, and only say what really needs to be recorded. You may want to work in pairs or small groups, each writing down observations, then periodically comparing notes and asking each other questions. If you do it this way, just remember: don't make critical comments! Be critical in your thinking, in the sense of always asking yourself "What does that mean anyway?" and not in the sense of "That's clearly wrong" or "What a dumb observation." Be positive in your approach, focus on the candle, and keep asking yourself questions in your own mind, especially questions that lead to further observations and more questions.

What is it made of, chemically and physically?

What are the individual parts and what are they made of?

How is the candle shaped? Why?

Do some physical "tests" on the candle using what you have on you or laying around the room. What do these tests tell you about:

Macroscopic properties of the candle components

Microscopic properties

Molecular properties

Hypothesize what will happen when you light the candle and start it burning

Write down what you think in terms of the observations you made above, especially with regard to the three levels of organization of matter at the:

macroscopic,
microscopic
and molecular levels.

Use a separate sheet of paper and be complete but concise.

Now light the candle and watch what happens

For the first set of observations, don't worry about asking questions so much as just making as many quick notes as you can:

• You should plan on spending a fair amount of time on this (more than a minute and less than an hour or two).
• It is important that you record your observations as quickly as you can and then come back to some of them later for further thought and extended observation.
• Try to make at least 10 distinct and separate observations initially.

Take one observation that you recorded above and:

• Break it down into three levels: macroscopic, microscopic and molecular.
• See if you can coordinate what is happening between the molecular and the higher levels of organization.
• Most important, speculate on what is actually happening at each one of these levels.
• Now ask yourself for each of the three levels above, why the behavior that you observed took place.
• What was the molecular property involved?
• What changes in that property occurred during the burning process? Go into as much detail as you can.

Now pick another observation or two and carry out the same level of in-depth analysis.

• Try to relate the observations you made above to those that you make in this section.
• You should find that as you practice this process of observation and recording your thoughts, you become better at asking questions about what is happening, and then writing down answers. This iteration is part "doing science."
• Repeat this process several times: this repetition is also part of doing science.
• Now try to "watch" yourself observing and asking yourself questions:
  • How can you do this better, with conscious awareness?
  • Can you see possible ways of getting the answers while you are asking the questions?

Testing Your Hypothesis by Doing an Experiment

After you feel like you have made enough observations to give you a pretty good understanding of what is actually happening during the burning process, it is time to do an experiment:

• An experiment results when you ask a question and postulate some method for answering that question.
• The experiment itself is actually the process of getting the answer. So, here is what you have to do:
  • First, try to ask a good question. Think about the observations that you made, especially those that you don't really understand, and try to formulate some kind of hypothesis (or good guess) about what is happening.
  • Once you have a good question, try to think of ways that you can answer that question. What kind of measurements or observations (either with your own eyes or with other methods) would help you get the answer?
  • Once you have some idea of how to actually do the experiment, go ahead and do it.

If you are creative, you should be able to design experiments that can be done with what you have laying around the lab or that you can easily acquire with very little effort. For example, holding a piece of glass over the candle as it burns (probably at an angle would work better) can help you answer questions about what is evolved or given off during the combustion process. Think of other simple ways of investigating further what is going on and see what kind of good experiments you can come up with.