The Museum of HP Calculators

HP Forum Archive 21

 Voyagers widthMessage #1 Posted by Gerson W. Barbosa on 12 Dec 2012, 6:28 p.m. The width of the Voyagers, in decimal inches, is remarkably close to pi. From the picture:``` width = 3 + 2/16 + 2/128 = 3 + 18/128 = 3 9/64" = 3.140625" width = 7.98 mm = 7.98/2.54" = 3.1417" ``` Geek designer or coincidence? :-)

 Re: Voyagers widthMessage #2 Posted by Walter B on 12 Dec 2012, 10:35 p.m.,in response to message #1 by Gerson W. Barbosa Olá Gerson, IMO you must decide first which of both indicated values you want to believe in - the upper (indicated in Imperial English Thumbs) or the lower (indicated in mm)? Then please repeat your measurement a few times (no cheating!) to gain a feeling for your standard deviation. If you've got more than one Voyager, measure them all to gain a feeling for their standard deviation. Then return and renew your claim. Cumprimentos d:-)

 Re: Voyagers widthMessage #3 Posted by Gerson W. Barbosa on 12 Dec 2012, 11:21 p.m.,in response to message #2 by Walter B Hallo Walter, The first value was read on the Vernier inch scale and the second one on the millimeter scale. The latter should be more accurate, since the divisions are closer to each other. Anyway, what I can read is 3 9/64" and 7.98 mm, which are equivalent to 3.14" (with three significant digits at most -- the value 3.1417 was fanciful, of course). I measured two HP-15C units (from 1983 and 1989, respectively), having found the same results (both definitely greater than 3 1/8"). But you're right: more measurements should have been made. Also, perhaps I should use a decent instrument instead of this cheap one (Made in PRC :-) Cheers, Gerson. Edited: 12 Dec 2012, 11:22 p.m.

 Re: Voyagers widthMessage #4 Posted by Gerson W. Barbosa on 13 Dec 2012, 3:38 p.m.,in response to message #2 by Walter B Would this convince the skeptical? :-) ```HP-16C 2403A02548 3.1415 HP-15C 2343B75099 3.1415 HP-15C 2905B29505 3.134 HP-12C CN04808261 3.1345 HP-11C 2540B16771 3.1345 HP-12C+ CNA83816873 3.133 HP-15CLE CNA13207R7 3.1405 ```

 Re: Voyagers widthMessage #5 Posted by Walter B on 13 Dec 2012, 4:45 p.m.,in response to message #4 by Gerson W. Barbosa It clearly shows you can tilt a caliper in a way it indicates 3.1415". d;-)

 Re: Voyagers widthMessage #6 Posted by Gerson W. Barbosa on 13 Dec 2012, 6:59 p.m.,in response to message #5 by Walter B Despite Gerson's Law, no tilting and no data manipulation :-) The golden ratio form factor of the Voyagers is well known: lenght/width = 128.46 mm / 79.76 mm = 1.611 (~ phi)

 Re: Voyagers widthMessage #7 Posted by Nick_S on 14 Dec 2012, 2:32 a.m.,in response to message #4 by Gerson W. Barbosa Thanks for the pointing out your discovery. So in addition to being the golden ratio of length:width, the calculator is around Pi inches in width. One day maybe someone will make a smart phone with these appealing dimensions. Perhaps, if you fitted the callipers on `blind' (read-out hidden or off) with measurements across samples, as well as replicates on each calculator, this would allow a better estimate of the width that allows for variance components due to both sampling and measurement error. That might just convince a sceptic... Nick

 Re: Voyagers widthMessage #8 Posted by Gerson W. Barbosa on 14 Dec 2012, 6:17 a.m.,in response to message #7 by Nick_S According to this article, the dimensions of the plastic ABS case are 5 x 3 1/8 x 5/8 inches. On the other hand, regarding the HP-15C LE HP says they are 12.9 x 8.0 x 1.52 cm (5.1 x 3.1 x 0.6 inches), or 5.08 x 3.15 x 0.60 inches, assuming the cm dimensions are correct. Gerson.

 Re: Voyagers widthMessage #9 Posted by Joerg Woerner on 13 Dec 2012, 4:01 p.m.,in response to message #1 by Gerson W. Barbosa Cm and not mm. The caliper is in cm and the calculator is 79.8 mm. One inch is 25.4 mm or 2.54 cm. Please bid on the next Texas Instruments TI-1890. No enter key but 20 metric conversions built in. Cheers, Joerg

 Re: Voyagers widthMessage #10 Posted by Gerson W. Barbosa on 13 Dec 2012, 6:21 p.m.,in response to message #9 by Joerg Woerner Quote: Cm and not mm. I see now the mistake has been repeated in my first reply to Walter (m is not close enough to c so I can call it a typo :-). Cheers, Gerson.

 Re: Voyagers widthMessage #11 Posted by Philippe Cairic on 18 Dec 2012, 7:25 p.m.,in response to message #1 by Gerson W. Barbosa The width of the 42S is pretty close to that too... I like to think it is not a coincidence :-)

 Re: Voyagers widthMessage #12 Posted by Gerson W. Barbosa on 18 Dec 2012, 7:52 p.m.,in response to message #11 by Philippe Cairic Quote: The width of the 42S is pretty close to that too... You're right: ```HP-42S ID939005390 3.144" HP-42S 3132B19700 3.143" HP-32SII 3533S00038 3.149" HP-17BII 3518S07942 3.149" ``` Quote: I like to think it is not a coincidence :-) Perhaps someone with access to more precise instruments (and better measuring technique) could confirm this :-)

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