Feedback from Minute Paper (1/22/07, 1/16/08): 

Most students appreciated the Powers of Ten video that showed how incredibly small we are compared with the size of the universe, yet we are incredibly huge compared to subatomic particles.

Observations and insights gained from today's class:

• I learned that the universe is composed motly of empty space with matter tending to cluster, resulting in a "lumpy" universe rather than a uniform one. (3X)
• There is so much that we still do not know about what is out there...
• I learned that an atom is much smaller than the wavelength of light, which puts the size of these two into perspective.
• Adding a zero to a number can make a huge difference!
• I learned that we know more about large distances (10^24 m) than we do small ones (10^-15 m).

Student questions and concerns - Responses from instructor:

• This class seems rather easy so far. - It will become more challenging, but hopefully not beyond your reach.
• I feel lost in class discussions and generally unprepared for this class (2X) - Be sure to read the textbook and get help outside of class as needed.
• My biggest concern is relating all the many ideas we have discussed in class and from the book. - Try to focus on the main points, since that is what you will be tested on.
• Will I fall behind if I miss class? How can I make up missed class participation? - It is possible to do well in this course by simply reading the textbook and the class notes posted on the course website, but attending class will also benefit your exam performance and class particiption score.  Note that there will be several opportunities throughout the semester for extra credit towards class participation, so it is possible to make up lost points for missed classes.
• Will we be doing any number problems? - Yes, these will begin in Chapter 3, but quantitative problems are not the main emphasis in this Conceptual Physics course.
• Is it possible to do more applications and problems in class to facilitate understanding? - I will do what I can, but remember that watching someone else solve a problem is like trying to learn to ride a bike simply by observing someone else.  You have to DO physics to really understand it.
• What is the expected homework load for this class? - You should spend about an hour per chapter on practice questions and problems, and the homework for each lab should take you less than one hour.
• What types of questions will be on tests? Math, no math? - Exam questions will be similar to the recommended homework and class discussion questions, which range from easy to difficult and include all levels of cognitive reasoning (see syllabus).
• Is the universe infinite?  What is at the edge? - Good question!  Nobody knows for sure, but most astronomers believe that the universe is not infinite, but has an ill-defined limit beyond which we cannot detect any light.
• What gives things substance if they are mostly empty space? - Good question!  In answering this fundamental question, you could win a Nobel Prize!
• I was confused about your explanation about the Doppler effect applied to light like sound waves. - The Doppler effect applies to any wave source, and since light has both wave and particle properties, the change in frequency (color shift towards the red due to the expansion of the universe) can be used to measure the rate at which distant light sources are moving away from us.
• What is the quantum theory of the atom? - Basically, electrons do not follow orbital paths, but their location is defined by probability distributions. This will be explored in more detail in Chapters 13 and 14.
• Will there be pop quizzes in class?  If so, how often? - The clicker questions are a type of pop quiz, but they mostly count for participation credit (10 points for answering + 1 point for each correct answer).
• When will we be tested on the powers of ten? - You were tested today with the clicker questions, and there will be at least one question on the first exam.
• What is the difference between a compound and a molecule? - A compound consists of two or more different elements chemically bonded together in a fixed ratio, while a molecule consists of two or more atoms (of the same or different elements) that are chemically bonded in a well-defined configuration.