As we have to cut our courses to the essentials... what are the essentials?

I've been asked a number of times about what to do if you have to teach a portion of the year online.  What are the most essential elements of a conceptual physics course?

First and most important, please read this post about the purpose of teaching physics.

But even once you share my goals about purpose and experience and culture, the question remains - what topics are you retaining?  Which are you cutting?  What are you doing with your class when you're exclusively online?

In all seriousness - at levels below AP - I recommend that if you have to be online to start the year, you just play with your class.  Do Sporcle, Dungeons & Dragons, intellectual games like Charty Party or Codenames, Crayon Physics Deluxe... whatever a nerd like you (and me!) would do with your family or friends on a Saturday night.  These are the sorts of things that my college friends did on weekends; come to the AP Physics readers' lounge and you'll see these things, too.  That's not physics, you say.  It's not.  It's relationship building.  And when you get back to actual school, your students will be way on board with studying physics because you didn't pile on the work when they were stuck at home without same-age companions for the seventh month in a row.  And physics taught live in person can feel like a video game, anyway.

But what topics do you cut out to trim to the essentials?  What do you try to "teach remotely" if you have to?

On one hand, building skills in conceptual physics is topic-agnostic.  You can teach effectively, you can give students an excellent first-year experience, with any combination of topics.  I recommend picking topics that you have equipment available for.

Then, for this oddball year, I recommend starting with non-cumulative topics.  We've done this for years for our 9th grade class - at boarding school, a 14 year old is often so overwhelmed living life on their own in an intense new culture that they aren't paying so much attention to their studies.  We do serious physics in the fall trimester.  However, a student who falls behind or doesn't quickly adapt to high school academic life isn't lost.  Quite frequently, a student does poorly on our Thanksgiving exam, but comes back in December with new life - more confidence, more experience living in our community, more willingness to study.  And they just jump right in, because we're starting from scratch with motion.  (Had we started off with motion and force, they'd be totally left in the dust when we move on to momentum and energy!  But if you don't get circuits, you can still do fine in motion and force.  These topics don't really build off one another.)

Originally when we designed our course, conceptual physics looked like this:

1. optics
     a. reflection/refraction
     b. lenses
     c. mirrors
2. waves
     a. v=λf
     b. sound and light
     c. dopper/resonance/diffraction
3. circuits
     a. Ohm's Law
     b. resistors in series and parallel
     c. power in bulbs
4. motion
     a. position-time graphs
     b. velocity-time graphs and acceleration
     c. equations describing motion
5. force
     a. direction of force and motion
     b. Newton's second law
     c. Newton's third law
6. motion and force in two dimensions
     a. adding force vectors in two dimensions
     b. Newton's second law in two dimensions
     c. projectile motion
7. impulse/momentum
     a. conservation of momentum in collisions
     b. impulse-momentum theorem
8. energy
     a. forms of energy; the energy bar chart
     b. making predictions using energy bar charts
9. harmonic motion
     a. objects on springs
     b. pendulums

About four years ago, our school changed schedules; we lost a small percentage of our time with students.  So, we had to cut - we cut out mirrors, we cut out doppler/resonance/diffraction, we cut out harmonic motion.

It's not so possible to make careful plans this year.  The world was different a month ago, and certainly three months ago.  The world will be different again in October and January, in ways we can not predict. 

So what should you cut?  I certainly recommend starting with non-cumulative stuff this year, or planning the non-cumulative stuff for the most uncertain times.  If you must be entirely online and you must do some sort of real physics, do optics and waves (and circuits, if you have to!)  Then when you return, dive into motion using your carts and tracks and detectors.

My boarding school is planning a college-style schedule... that is, we're all coming back to campus, but we're leaving at Thanksgiving and most likely not returning until January.  So... I'm cutting the circuits unit, and moving the more difficult and more experimentally intense motion unit to October.  If we can come back in December, I'll cover circuits then; more likely, we can either try to study circuits with the excellent Phet simulation; or, I can cut it entirely and play games with my class online in December.  I'll see how things go.