As a university physics professor, I regularly teach introductory physics courses (both calculus and algebra based). Most introductory physics textbooks cover the same set of topics:
- Newtonian mechanics
- Waves and sound
- Modern physics (relativity, atomic, nuclear, particle)
There is something puzzling but profound about this list of topics. Why do I say this? Most of this material is hundreds of years old. Let’s think about this.
Newton’s Principia was published in 1687. Maxwell’s On Physical Lines of Force was published in 1861. While there have been many advances in mechanics and electromagnetism since the 17th and 19th centuries, the material covered in introductory physics has been essentially unchanged for hundreds of years. The same is largely true of thermodynamics and optics.
What about the small number of topics listed under the heading “modern physics?” As covered in the introductory physics textbooks and courses, most of this material is still about one hundred years old. Thus, even though many of he most exciting discoveries in physics have taken place more recently (I am using “recently” very loosely here = the last 100 years) we don’t cover any of these things in our introductory physics classes.
This has bothered me for a long time and I even feel like a bit of a heretic in bringing this up. But I think this is a real problem. Imagine introductory Astronomy without any images from the Hubble Space Telescope. Imagine introductory Biology without a thorough treatment of DNA and genetics? These things are laughable. You are probably thinking something like “that would be crazy, it would be so boring and students would be left with a horribly inaccurate impression of the subject.” What is so special about physics that we completely omit all of the spectacular discoveries of the last 100 years? Are students not suffering under this arrangement.
Here are some of the reasons I have heard for not covering “more recent physics”:
- All of those engineering, chemistry, biology majors really, really need to know all of this classical physics. The faculty in these other departments would protest loudly if we made any change.
- These same majors don’t need to know anything about more recent physics.
- All of the more recent physics is horribly difficult and mathematical, beyond what is realistic to cover in an introductory class.
- To understand more recent physics, you first have to completely understand classical physics.
Do we really believe all of these reasons? Does this bother anyone else? What would it look like to begin to change our introductory physics courses to address this problem?