Above we see a few of the many, many ``systems'' that exist in the world and can be coordinatized and studied with the same general causality-based analytical methods that we develop in this course. Physicists have been prominant in the study of all of these systems.
The first is obvious - studying the motion of particles in a box (which under suitable assumptions becomes the microscopic model of a gas) is clearly within the purview of physics. We will actually treat some very simple versions of this problem in this course (close to the end of the semester) and physics majors will study it in considerable detail in future, more advanced courses in statistical mechanics.
What of the second? The human brain clearly is a system consisting of microscopic particles that physics can describe, but the laws of microscopic physics are useless to describe the process of cognition. As a colleague of mine (Dr. Richard Palmer, who studies complex systems such as this) is wont to say, more is different. This means that as one goes up in the scale of system complexity, new patterns, new coordinates, new rules and laws, emerge. Although the laws of chemistry can be derived from those of physics, it is a lot of work to do so and one can just as easily experimentally determine the laws of chemistry directly (as in fact was done historically). The laws and patterns of cell biology are in principle derived from biochemistry, hence from chemistry itself, hence from physics, but the patterns that emerge are again different from those that dominate the previous levels. Biochemistry and biophysics can be used to understand the mechanical operation of nerve cells, but cognition - how the brain sees, thinks, understands, feels - is a whole new process with its own rules and models.
Physicists have still made many significant contributions to the emerging understanding of the brain, helping to invent and study ``neural networks'' and various models of brain function with their own coordinates and mathematics that is very different (so different that the former coordinates are no longer even relevant except in very general ways) from the coordinates and mathematics of biochemistry, chemistry, and physics that nevertheless underlie the overall function of organic brains. Scientists in other disciplines that also study the problem find their efforts informed by things they learned back in introductory physics classes.
Finally, in the third figure we have a system that is several layers more removed from physics - the coordinates and mathematics that describes money and economies and marketplaces. However, an interesting thing has happened. The complex system that has emerged from all sorts of human constructs driven by brains driven by various layers of biochemistry and biophysics has coordinates that are very similar to those of relatively simple physical models!
Think of all the pseudophysics terminology frequently used to describe the motion of the Stock Market or economies in general. They all refer to the flow of ``money'', which can be exchanged for (among other things) ``work''. Work is a purely physical term, and in fact work in an economy bears a clear relationship to ``work'' as it is defined in elementary mechanics. Energy in the form of electricity and heat and work real or abstract is worth money.
Market models often refer to ``market forces'' as the active agencies responsible for changes in the coordinates that describe the market at any given time, borrowing from Newton the idea that a force in a very general sense is the cause of a change in a system's trajectory. As you will learn, this is clearly in analogy with the use of the term in physics, although it is mathematically far less precise. Still, it should come as no surprise that the study of physics has been a great stepping stone into careers in money and banking.
The real moral of these three examples, though, is that they are typical examples. The study of physics deepens your understanding of anything and everything, quite literally. It is an actual realization of one of the sermons of Bhuddism - if you study any single thing, perhaps a flower, deeply enough, it will open your mind to the understanding of everything. Physics is a very perfect flower for this kind of mind-opening study.
It should come as no surprise, then, that if you study with a settled mind and devotion of your spirit, you will come out of an introductory course in physics seeing the world around you with different eyes. Other people will ``just'' be playing basketball. You will (sure) be playing the game, but one part of your mind will also be understanding the trajectory of the ball, why and how it bounces off of the floor, why your body gets hot while you play, how your sweat cools it, how spin on the ball alters its bounce, how and why you get ``hang time'' at the top of a leap. The game will be subtly different, as you consciously play the game by both the human and the natural rules.
Will this make you a better player? Well, one thing you should learn in this course is that no pain, no gain is a rule for being good at anything, physics and basketball both included. Sure, understanding the physics of basketball can help your game, but learning the physics of basketball in the (or on the) concrete - by actually playing the game, and sweating, and bouncing, and shooting, and hanging in the air - is even more important. A good player can learn the practical physics of basketball with their ``gut'' as much as with their head, although a truly great player learns it with both their gut and their brain, as there are whole layers of rules and strategies and patterns that go beyond the physics and that are essential for success.
It is crucial to work to obtain a gut level understanding of physics, a conceptual understanding of physics, as much as you work to learn to just solve problems. For example, in this class you will learn just about everything required to fully understand how a bicycle works. Apply force (generated by your weight and muscular activity) to the pedal, exert a torque that is transferred by the chain to the rear tire, where it generates a frictional force between tire and the ground that acts to accelerate the bicycle. The spinning wheels have angular momentum, and consequently leaning to the left or right creates a torque that causes the bicycle to turn rather than just fall over. By pedalling and making small adjustments in direction while leaning a bit to the left or right, you can ride a bike!
Tell that to a six year old, or even a sixteen year old. Obviously, you can't. Or rather you do tell them some part of that (probably the last sentence without all the whys and hows) and then put them on a bike, start them pedalling, and give them a shove. That's how they learn to ride a bike (usually after falling over a few times along the way). Only after they are riding and can feel how the bike rights itself if they turn into a lean, how it turns if they lean into a turn, how it is stable when going quickly and wobbly when going slowly, can they start to study why the bike works this way.
Otherwise they are merely memorizing a set of statements that have no meaning to them and which (as far as they are concerned) may or may not be true. I could just as easily say that there are invisible fairies that hold up your bike while you pedal and make it turn when you lean. You can even memorize a set of rule for how many fairies are present for bikes of different sizes and riders of different weights. Only when you try riding a bike can you try to make sense of the rules, be they fairies or forces and torques, and see which one you end up believing in.
So it is for physics and really all subjects. Whether one is learning physics, learning to ride a bike, learning to play basketball, learning to knit a sweater - there is only so much one can ``learn'' studying the subject in the abstract, and to memorize all sorts of rules without building them into a system you understand is just a waste of everybody's time. To succeed in physics you therefore have to work many problems (one form of ``riding a bike'' in physics) and ideally, explore physics in a laboratory (the other). However, a physics ``laboratory'' is literally everywhere around you - by this I do not mean go into an actual lab and do carefully contrived experiments. The best laboratory is in your hands, in your pockets, on the table in front of you. Since physics describes the motion of everything, everything is a piece of physics apparatus, and many physics professors demonstrate elementary mechanics in class using books, coins from their pocket, a ball, a piece of string.
Here is a set of things you might consider using for exploring physics: