The big questions: What is an electron? What is light?

These are the big questions that I am hoping to provide at least some answers to  over the course of this semester. Light and electrons are two of the most fundamental building-blocks of our Universe (as far as we know they have no substructure!). Understanding these two basic elements and how they interact with each other will help you better understand many other fields of science and technology from chemistry to electronics.

Below are the fundamental goals that I would hope that you will take away from the “lecture” portion of this course. These are things that I hope that you will remember many years from now when you have forgotten all of the details. They are divided into two categories: Physics Goals and Skills Goals. There are a completely separate set of goals for the laboratory portion of the course which you will see in lab.

Physics Goals

These are the basic goals of any introductory physics course and are deeply connected to the material we will be covering. While these goals are generally similar to those from P131, I will be expecting that you will be developing a greater proficiency in these goals. Moreover, there are some changes for you to note.

1. Physics is a set of principles and the fundamental ideas that relate them, NOT a list of equations… This is quite possibly the most common misconception that people have about physics: they tend to think of physics as a list of formulae to be memorized and that all solving physics problems entails is finding the correct formula to get from where you are to where you want to be. This could not be further from the truth. Physics is a list of conceptual ideas expressed mathematically. These conceptual ideas form the “rules” that all of the other sciences, biology, chemistry, etc., have to follow. Thus, knowing the basic principles of physics is beneficial to any scientist!
2. (More Emphasis!) These principles of physics can be expressed in multiple different ways… When people think of physics they tend to think of equations. However, the ideas of physics can be represented in words (as was done in Europe in the days before Isaac Newton!) pictures, and graphs. As a budding scientist, it is important for you to be able to think of ideas in multiple formats and to be able to decide which format is the best for a given situation. Given the increased remoteness of the material in this course from your everyday experience, I am going to increase the emphasis on this goal relative to P131; being able to write clearly and succinctly about physics concepts using words will be important!
3. Appreciate the value of the problem solving method used by the discipline of physics… This is the goal most commonly given by non-physics faculty as to why they want their students to take physics, “problem solving.” However, the problem solving method used by physicists is a bit different than that to which you may be accustomed. In physics, we reason from the fundamental principles at play in a given situation. This requires you to look beyond the surface features in a given problem to see how a person throwing a ball, a block sliding down a ramp, and a building standing still are all similar in that they all rely on the same fundamental principle of . As a consequence of     starting from fundamental principles, we physicists like to employ what is known as a “reductionist” approach and think about an idealized world first. This idealized world can seem quite bizarre to people new to physics as it is populated with point masses moving across frictionless surfaces. The goal of this approach is to move to a problem where the fundamental principles are easier to see and understand. The complications that are present in the real world are then added back in later.
4. (New relative to Physics 131) The fundamental principles of nature do not need to conform with “common sense”… You already saw some of this in P131 where some results can seem counter-intuitive. In this course, however, we will encounter many more phenomena that may seem as though they do not make sense. Some of this will be due to the fact that you do not have as much experience with the world of electrons as you do with the world of friction and springs. Some of these topics’ seemingly nonsensical nature, on the other hand, will be due to the fact that the topics represent fundamentally new concepts without any corresponding analog in your experience. For these ideas any analogy will inherently be imperfect and beginning from first principles (see Physics Goal #3) will be even more critical!
5. Learn how to use fundamental principles to generalize from one specific situation to a class of similar ones… Often, we will study a particular principle or idea within the context of a specific situation. The beauty of the laws of physics, however, is that these laws can be applied anywhere and the results of one analysis can often be applied to other related problems. For example, the motion of ANY object near the surface of the earth shares certain features. Thus, by studying the motion of a basketball, you can infer something about a skydiver. The trick is knowing what aspects of a given problem transfer to a new situation and which do not – your guide here are the fundamental principles (see Physics Goal #1).
6. (More Emphasis!) Understand that the physics we study is connected to your everyday experience and the material in your other courses… We want you to see the applications of physics all around you and to connect to your other courses. As such, we may ask you to pull information from your everyday experience or other knowledge to solve problems. Our hope is that physics will provide a new perspective on the material in your other classes. In this class, we will, in particular, be making a lot of connections to the subject of chemistry.

Skills Goals

In addition to physics content, there is a certain set of skills that I want you to take away from this class. These Skills Goals, however, are a bit different and more advanced than for P131 – as benefits a second semester course. These skills are just for the “lecture” portion of the course; the lab portion has additional goals emphasizing data analysis that will be discussed in your first lab sections.

1. (More Emphasis!) Becoming more comfortable working in symbols… This is a very important skill as every field becomes ever more quantitative; you need to be able to work in a wholly symbolic fashion and be able to read and interpret what the symbols in an equation  mean. You began developing this skill in P131, but we will focus on it more heavily in this class.
2. (New!) Be able to combine different ideas into a single analysis… Most of the situations we looked at in P131 were single principle situations; we used either Newton’s Laws or conservation of energy for our analysis. We almost never used more than one idea. However, almost all of modern science is what is called interdisciplinary: the result of combining ideas from multiple places. The trend of holistic health is a good example as it looks at not only biological factors but also sociological and psychological. The study of light and electrons is a great place to practice this skill as they are interesting multifaceted objects and we will need to be able to put multiple principles together to understand them.
3. (New!) Interpretation of mathematical results… In P131, when problems required a number or formula, you would solve it out and be done. P132 will force you to extend your problem solving skills beyond P131 to include one more step critical to more advanced analysis: interpretation of your result. In this class, formulas will sometimes give you special results that require additional consideration. Other times, the result of a calculation may even be nonsense: infinity or imaginary! One of the amazing things about physics is that even these seemingly meaningless answers can tell you about how the world works. In this class, you will expected to develop the skills to interpret these results and learn what they can tell you.

Teamwork goals

I firmly believe in the critical role of teamwork to the success of the scientific enterprise. My own personal experience has confirmed this role many times and research shows that people learn better when they engage with ideas in conjunction with others. Throughout the course, regardless of if you are on a formal team or not, you will be furthering the scientific skills you developed in P131:

1. Appreciate that the “solitary genius” image of a scientist which is so pervasive in our culture no longer exists (if they ever did)… Science, all science, is now done in teams ranging in size from small teams of three to massive collaborations with memberships in the thousands. These skills are something you can put on your CV/Resume as having developed in this class!
2. Appreciate that the work done by a team is usually better than the product of even its strongest member…. You will see over the course of the semester that this is true!. However, the environment in which we find ourselves is not as conducive to formalized teamwork as P131. However, I would strongly encourage you to work with other people both in-class on activities and out-of-class on homework and exam preparation.