I Is calling fictitious forces "not real" just about terminology?

[sophiecentaur]

If it's completely inconsequential in the context of Newton's 3rd Law, then it should be cut by Occam's razor.

Logically you could argue that you are correct but does your approach actually help understanding or discussion. It often makes things more difficult and my two words "hair shirt" apply. Reductionism for the sake of tidiness alone can get in the way of teaching and learning because we are all human and less tidy than you may want.

 

[A.T.]

It often makes things more difficult

How does dropping the arbitrary and irrelevant cause & effect assignment make applying Newton's 3rd Law more difficult? If anything, it makes things simpler, because no time is ever wasted on wondering how to identify the cause vs. effect in a given scenario.

What exactly is gained by pretending that the cause & effect assignment has any relevance for Newton's 3rd Law, and thus wasting the student's time on figuring out that it actually doesn't?

 

[Herman Trivilino]

And then the other becomes a 'reaction', which in common uses of those words happens after the 'action'. But that's not the case for a 3rd Law force pair, where the forces act simultaneously.

It also invokes the notion that the action is the cause of the reaction, elevating the status of the action above that of the reaction. These vocabulary choices matter in the introductory physics classroom. Students often carry them into their higher education and eventual profession. True for both physicists and those who major in something other than physics.

The famous author and provider of in-service professional development for physics teachers recommends the vocabulary Third-Law pairs of forces. And emphasizes that forces are interactions between objects so that the Third Law layers on to that concept, emphasizing that the interaction is in all ways symmetrical.

There are lots of ways to demonstrate this concept to students and it's essential that the students see them actually performed. Talking about them is not sufficient. Showing videos of them robs the student of experiencing them and in many cases having that kinestetic experience.

 

[wrobel]

I have always been wondering how such a banal thing can generate endless discussions.

 

[A.T.]

It also invokes the notion that the action is the cause of the reaction, elevating the status of the action above that of the reaction. These vocabulary choices matter in the introductory physics classroom. Students often carry them into their higher education and eventual profession. True for both physicists and those who major in something other than physics.

Exactly. Misguided notions about basic laws, sometimes stemming from misleading formulations, often stand in the way of analyzing problems correctly.

For example, when feedback loops are involved, naive linear cause-effect intuitions often fail. See the endless internet discussions about DDWFTTW (directly downwind faster than the wind), where even engineers and physics professors argued that it would be perpetual motion, after they run the cause-effect-loop in their heads.