It is in 'elementary' physics that this parallel language features so strongly, which makes 'elementary' physics especially difficult to absorb. Once we begin to look, we find errors in many texts. Some may come from overhasty publication, some from oversimplification, but many are familiar howlers copied from each generation by the next. Few teachers are sufficiently expert or insufficiently busy to detect every flaw in the texts they use. If they were, we should welcome such flaws for the opportunity they provide to alert students to the questionable authority of the printed word.
Flaws range from factual error through faulty analogy to ambiguous use of language.
A fault in the text will not only confuse the student in that particular, but it will undermine his self-confidence. The most threatened are adults, primary school teachers especially, who have to rely so much upon their texts. This article aims to promote honest debate focused upon clearer and more accurate writing. As a start I have picked one topic which screams for attention. Newton 's Third Law of Motion Slogans and sloppy language turn this essentially simple concept into one of the most confusing.