Is there a URL for the Math Gaz paper(s)? On Wed, Aug 29, 2012 at 4:17 PM, Adam P. Goucher <apgoucher@gmx.com> wrote:
Oh, wow, you beat me to it by six decades. Slightly embarrassing on my part...
Searching 'nomogram' has returned some related diagrams involving degenerate cubics (unions of three lines, or a line and conic). I seem to recall that the Richter scale involves a similar principle.
Sincerely,
Adam P. Goucher
http://cp4space.wordpress.com/
----- Original Message ----- From: "Richard Guy" <rkg@cpsc.ucalgary.ca> To: "math-fun" <math-fun@mailman.xmission.com**> Sent: Wednesday, August 29, 2012 9:08 PM Subject: Re: [math-fun] {Spam?} Elliptic curve calculator
See: A single scale nomogram, Math. Gaz., 33(1949) 43 or
37(1953) 39. R.
On Wed, 29 Aug 2012, Adam P. Goucher wrote:
You may be aware of the Abelian group operation on elliptic curves. We
can exploit this to multiply, divide and square-root real numbers just by drawing a straight line on an elliptic curve marked with two logarithmic scales:
I've tried it on a printed version, and can achieve somewhere between 2 and 3 significant figures of precision, depending on the calculation.
Obviously it is of no practical use today, since we have electronic calculators and so forth. But in theory, this could have been made way back in 1830, when it could have been used for calculations in navigation and ballistics.
Sincerely,
Adam P. Goucher
http://cp4space.wordpress.com/
______________________________**_________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/**cgi-bin/mailman/listinfo/math-**fun<http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun>
______________________________**_________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/**cgi-bin/mailman/listinfo/math-**fun<http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun>
______________________________**_________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/**cgi-bin/mailman/listinfo/math-**fun<http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun>
-- Dear Friends, I have now retired from AT&T. New coordinates: Neil J. A. Sloane, President, OEIS Foundation 11 South Adelaide Avenue, Highland Park, NJ 08904, USA Phone: 732 828 6098; home page: http://NeilSloane.com Email: njasloane@gmail.com