The purpose of this course is to teach Physics in a way that makes sense. Because this text exists as a blog, it can be updated easily. I always welcome feedback on anything here. I am a working Physicist, and I have taught college — both undergraduate and graduate courses. I also home-schooled both my sons through from elementary through high school.
My goal is to make Physics accessible to high school and college students who have a desire to learn. Physics is widely-varied science that is all about problem-solving. It also benefits from hands-on learning — experiments, projects, etc. I plan to create a series of experiments that can be done in your garage or kitchen.
Again — I welcome your feedback. Sign up for our email list to be notified as new content is created.
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History of Physics
The original students of nature were not called scientists, because the word “science” didn’t exist until the mid-1800s. They were studiers and investigators, seeking to learn more about all subjects. They were referred to as “philosophers,” meaning lovers of knowledge. Those who studied the world outside the human body were called natural philosophers. Even today, the highest degree in college is the Ph.D., or Doctor of Philosophy.
Beginning in about the mid-1700s, “philosophy” was a pastime of the wealthy, and they held parties where the “parlor games” were science demonstrations. This encouraged all the high-society and highly educated people to pursue scientific studies. It also caused our knowledgebase to grow, so that by the mid-1800s, pieces of “natural philosophy” were sectioned off as their own subjects. Asimov explains it like this:
As the field of science broadened and deepened, and as the information gathered grew more voluminous, natural philosophers had to specialize, taking one segment or another of scientific endeavor as their chosen field of work. The specialties received names of their own and were often subtracted from the once universal domain of physics.
Thus, the study of the abstract relationships of form and number became mathematics; the study of the position and movements of heavenly bodies became astronomy; the study of the physical nature of the earth we live upon became geology; the study of the composition and interaction of substances became chemistry; the study of the structure, function, and interrelationships of living organisms became biology, and so on.
The term physics then came to be used to describe the study of those portions of nature that remained after the above-mentioned specialties were subtracted. For that reason [physics] has come to cover a rather [mixed] field and it is not as easy to define as it might be.
What has been left over includes such phenomena as motion, heat, light, sound, electricity, and magnetism…All these are forms of energy so that a study of physics may be said to include, primarily, a consideration of the interrelationships of energy and matter.
My interpretation of what Asimov is saying: science can be thought of as a “tree of knowledge.” As branches grow and get very large, they are “pruned away,” taken and planted to begin new disciplines. Physics is “what’s left.” Does that mean that physics is a “leftover” discipline? Sort of. I like to think of it as the scientific roots from which all other branches of science grow. So, physics is the “root” of all science!
Because of the history of physics, it encompasses a broad variety of topics. This is a possible source of trouble for students. Another trouble spot is math. Math is the language of physics, and it’s hard to understand the subject if you don’t speak the language. Isaac Newton invented calculus to describe physics and to work physics problems.
AAAAAACCCCCCKKKKKK! But I don’t know Calculus! You might be surprised. You may know more about it than you think. As I go through the descriptions of each piece of physics, I will teach you the “Calculus Basics” you need to understand how to do the physics. It will be the how, not the why (save that for your Calculus class!).
I plan to present Physics in 8 easy pieces. Let’s meet them now.
Mechanics is the study of objects that move and interact with one another. Engineers call it Statics (objects not moving) and Dynamics (objects that move). Ever wonder if you dropped a pebble off a building, at what speed would it hit the ground? Mechanics can tell you. Want to know how big of a winch you might need to pull a car out of a ditch? Mechanics can tell you. Want to know how much fuel your rocket needs to get to orbit? Mechanics can tell you.
- Vibrations and Waves
How do I build a guitar string that will vibrate at middle C? V&W can tell you. Vibrations are a very efficient way to transmit energy down a wire, string, rope, etc. V&W will show you how. How is sound created, transmitted, and heard? V&W explains it all. This section will help you to understand sound and get ready for optics.
- Heat and thermodynamics
Ever wonder how much energy it takes to boil 4 cups of room-temperature water? Thermodynamics (or just “thermo”) can tell you. What’s the most efficient way to cool my can of soda? Thermo can tell you. How does an air conditioner work? Thermo has the answer.
- Fluid mechanics
How strong does the wall of a fish tank need to be? In other words, how much force does the water push on the side of the tank? Fluid mechanics can tell you. How heavy can my boat be and still float? Fluid mechanics can tell you.
- Electricity & Magnetism
Ever wonder how electricity works? Wonder how static cling works? Magnets? Electro-magnets? Electricity & Magnetism (E&M) will tell you. How does the power company get power to your house, and how do they know how much to charge you? E&M will tell you. Radio Waves? Signals on the internet? E&M is your friend. This is the piece of physics that is the most math intensive and most troublesome for students, because it’s “hard to touch” — it’s very abstract. But, dear reader, you’re in luck. This piece is Doc Bateman’s specialty. I’ve been explaining this one for 30 years. No fear!
Electronics is a wonderful hobby. How does it work? How can I wire up simple circuits and get them to “do things” or measure things for me? This section will tell you. How do I know which part I need to perform a certain function? This section will tell you. Want to create sensors that you can use to take data with your computer? Read on!
How do lenses and mirrors work? Why do they do what they do? What kind of lenses do I need for a certain magnification? How do rainbows work? What does it take to build a telescope or a microscope? What lenses magnify and which ones shrink? Optics can answer all these questions.
- Modern Physics
What is “modern” physics? Several new theories were developed just after 1900, hence the name “modern.” These include quantum physics, the theory of relativity, and nuclear physics. These all are very strange concepts, but have been proven accurate. This is the study of the very tiny (quantum and nuclear physics) and the very fast (relativity). What happens when something travels very fast, close to the speed of light? This section will also talk about the limits on our knowledge. Something called the Heisenberg Uncertainty Principle tells us that we can know an atom’s location or its speed, but not both. Does light behave like a wave or a particle? Yes! Both! Hang on for a wild ride in this section with Modern Physics.
 Asimov, Isaac, The History of Physics, Walker and Co., 1984.
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