{Circles and Ellipses}[2nd September 1990]

[Redbook7:273-275][19900902:2325b]{Circles and Ellipses}[2nd September 1990]

19900902.2325

[continued]

[This journal entry was originally intended to continue from the last previous entry, with a multiply-struck-through text starting (in what appears to be the final attempt before deletion): ‘In C.A.S. terms, their state may be defined in terms (I guess) of radial distance from the centre (greater) and (I guess) of degree: the lower the worse; in view of the problem with distance, it might be better to emphasise that CAS relates to curves, not just circles. I think the basic model of inner and outer circles may look something like this:’ (There follows a rough diagram, also multiply-struck-through, which appears similar to the next diagram reproduced in this ts* from p273, but without any letters, arrows or other markings). All this is scored out and replaced by the following marginal note:]

Too tired to make sense here: the basic idea is the I[nner] C[ircle] as circle, the O[uter] C[ircle] as ellipse(s) with centre of circle as one of [the] ellipse’s** foci; but the O[uter] C[ircle] keeps turning out as a wider circle with different centre and same C point on both circumference[s], which is not what I wanted.***

*[See next entry]

**[ms has “ellipses’”, which must be a mistake]

***[(But) see next entry]

[continued]

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