Centripetal Forces

Not to be confused with Centipetal Forces, the militia units of the the Centipede army.

This xkcd got me thinking:  High school physics, where most kids are told about the fictitious status of centrifugal forces, generally sticks to Newtonian physics.  This makes sense because pre-modern, F=ma primitivism are the most useful sort of physics to those of us not charting spaceship courses or building nuclear bombs.

But, as xkcd points out, there is a real reactive centrifugal force when there is a centripetal acceleration acting on a mass.  Moreover, this is the way Newton constructed his law.  It’s only when you turn to modern physics and use a rotating reference frame that centrifugal forces become fictitious.

So why would teachers abandon their own standard reference frame and seek out a counterintuitive teaching moment?  Particularly since a centrifugal force certainly feels real, so said teachers are going to be arguing against students’ lived experience of physics; it’s pretty self-defeating to take one of the few moments where an inaccessible subject becomes tangible, and tell people their senses are giving them crap data.  Especially when people’s senses are actually correct from a certain point of view.

And yes, I’m bitter about having my elementary physics understanding shut down at some past point in my education.  It soured me on modern physics forever and drove me to a field where the one and only goal is static equilibrium.  Now I’m in perpetual pursuit of clean, perfect nothing; that ideal state where all forces cancel and the structure stays still, undeflected, undeformed, unbesmirched.  Driven to nihlism by renegade physics teachers.

Thus a simple request for the future of our children: more an better physics, please.

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