Cross reference of HP PTM images of Antikythera Mechanism

Introduction

"The Antikythera mechanism is an ancient mechanical calculator (also described as the first "mechanical computer") designed to calculate astronomical positions. It was discovered in the Antikythera wreck off the Greek island of Antikythera, between Kythera and Crete, in 1900. Subsequent investigation, particularly in 2006, dated it to about 150-100 BC..." - Wikipedia, June 2008.

My interest in the Antikythera Mechanism began in 2007: follow this Web link for details and for links to my other work in less ancient computers.

This Web page describes the work I did during June and July of 2007, to index year 2006 PTM images of the Antikythera Mechanism fragments by published descriptions of the fragments. I did this work at no charge and provided the results to the researchers who produced and published the images. The index was added to a Web site which describes and provides those PTM images. Details and citations are below. I am not affiliated with any of the institutions named. My thanks to researchers Dr. Tony Freeth and Tom Malzbender for their correspondence and encouragments. - Herb Johnson

Visual key to fragments

The 2006 Nature article has a Figure 1 set, of visual keys to the fragments, which are reproduced here for reference.

Figure 1, image of all fragments ;
Figure 1_1 a labled shadowgram which identifies the larger Figure 1 fragments, with size scale;
Figure 1_2 a detailed labled shadowgram of small fragment sets;
Figure 1_3 a detailed labled shadowgram of the smallest fragment set.

In the 2006 Nature article figures, all fragments are imaged from side 1, except fragment F which is from side 2. (This "side" information was obtained from Dr. Tony Freeth in correspondence with me during May 2006; I confirmed it later with images F-1.jpg and F-2.jpg.)

PTM vs fragment cross-reference

The list below cross references the screen-captured JPEG's of PTM images, to fragments by name and side. Fragments are as identified in Freeth images and in the 2006 Nature article Figure 1 and its key. These PTM images are often paired by "a" and "b", where the "b's" are images of the "reverse" sides of fragments as imaged in the "a's". Otherwise, image pairs are explicitly identified as "reverse of". When a portion of a larger fragment is imaged, I attempt some description by orientation or feature or relation to another imaged portion of the fragment.

JPEG of AK1a.ptm - * frag 19-1
JPEG of AK1b.ptm - * frag 19-2

JPEG of AK2a.ptm - * upper left, 24-2; lower left, 26-1; center, 21-2; lower right, 25-1.
JPEG of AK2b.ptm - * upper left, 26-2; upper right, 25-2; lower left, 24-1; lower right & center, 21-1.

JPEG of AK3a.ptm - * upper left, 30-2; lower left, (fragmt. near 19-1?). right, 22-1. 
JPEG of AK3b.ptm - * upper left, 30-1; lower left, (fragmt. near 19-2?). right, 22-2.

Note: There is a small fragment between #30 and #19 in the AMRP image set "19-1 to 30-1.jpg" and "19-2 to 30-2.jpg" which seems to correspond to the small unnamed fragment at the lower left of the PTM 3a and 3b images, as described here.

JPEG of AK4a.ptm - * left, 20-1; right, 23-1.
JPEG of AK4b.ptm - * left, 20-2; right, 23-2.

JPEG of AK5a.ptm - * left, 29-1; center, 27-2; right, 28-2.
JPEG of AK5b.ptm - * left, 27-1; center, 29-2; right, 28-1.

JPEG of AK6a.ptm - * frag G-1, text. 
JPEG of AK6b.ptm - * frag G-2. 

JPEG of AK7a.ptm - * frag E-1. 
JPEG of AK7b.ptm - * frag E-2.

JPEG of AK8a.ptm - * frag D-1.
JPEG of AK8b.ptm - * frag D-2, some exposed gear teeth.

JPEG of AK9a.ptm - * frag F-2.
JPEG of AK9b.ptm - * frag F-1.

note: Figure 1 and its key in 2006 Nature article show F-2 side, most other frags show -1 side.

JPEG of AK11a.ptm - * portion of frag G-1, small lobe w/text."opposite" of 12a.

JPEG of AK12a.ptm - * portion of frag G-1, tabbed edge "opposite" of 11a.

JPEG of AK13a.ptm - * portion of frag G-1, large lobe w/text. "opposite" of 14a.

JPEG of AK14a.ptm - * portion of frag G-1, rounded corner w/text. "opposite" of 13a.

JPEG of AK15a.ptm - * portion of frag G-1, edge and space "between" 13a and 11a.

JPEG of AK16a.ptm - * portion of frag G-1, edge "opposite" 15a.

JPEG of AK17a.ptm - * upper: left 41-1, ctr left 44-2, ctr rt 40 (text), right 42-2. lower: left 38-1, ctr left 39-1, ctr rt 43-1, right 37-2.
JPEG of AK17b.ptm - * upper: left 41-2, ctr left 44-1, ctr rt 40 (no text), right 42-1. lower: left 38-2, ctr left 39-2, ctr rt 43-2, right 37-1.

Note: in AMRP images "37-1 to 44-1.jpg" and "37-2 to 44-2.jpg", fragment #40 is imaged on the same side in BOTH images. So I've identified it by features, not numbered side. But among the fragments, the "1" sides seem to be lettered, the "2" sides are not.- Herb

JPEG of AK18a.ptm - * upper: left 8-2, ctr 16-2, right 12-2. lower ctr 9-2.
JPEG of AK18b.ptm - * upper: left 12-1, ctr 16-1, right 8-1. lower ctr 9-1.

JPEG of AK19a.ptm - * upper: left 11-2, ctr left 15-1, right 17-2. lower: left 10-2, ctr left 13-1, ctr rt 14-2, right 18-2.
JPEG of AK19b.ptm - * upper: left 17-1, ctr 15-2, right 11-1. lower: left 18-1, ctr left 14-1, ctr rt 13-2, right 10-1.

JPEG of AK20a.ptm - * frag 3-2
JPEG of AK20b.ptm - * frag 3-1.

JPEG of AK21a.ptm - * frag C-2. reverse of 33a, 34a

JPEG of AK22a.ptm - * portion of frag C-2. right-angled corner

JPEG of AK23a.ptm - * portion of frag C-2. right-angled corner, similar to 22a.

JPEG of AK24a.ptm - * portion of frag C-2, "arm" to center.

JPEG of AK25a.ptm - * portion of frag C-2, small corner on circular depression, to center.

JPEG of AK26a.ptm - * portion of frag C-2, small corner on circular depression, to center. Similar to 25a.

JPEG of AK27a.ptm - * portion of frag C-1, corner with "trench". Similar to 28a.

JPEG of AK28a.ptm - * portion of frag C-1, corner with "trench". similar to 27a.

JPEG of AK29a.ptm - * portion of frag C-1, center near "scales". Similar to 30a.

JPEG of AK30a.ptm - * portion of frag C-1, center near "scales". similar to 29a.

JPEG of AK31a.ptm - * portion of frag C-1 - scale corner. similar to 32a

JPEG of AK32a.ptm - * portion of frag C-1 - scale corner, similar to 31a

JPEG of AK33a.ptm - * frag C-1. reverse of 21a. similar to 34a

JPEG of AK34a.ptm - * frag C-1, reverse of 21a., similar to 33a

JPEG of AK35a.ptm - * portion of frag B-1, center to one edge. Opposite "half" from 37a.

JPEG of AK36a.ptm - * portion of frag B-1, center to one edge. Similar to 35a.

JPEG of AK37a.ptm - * portion of frag B-1, center to one edge. Opposite "half" from 35a, 34a.

JPEG of AK38a.ptm - * portion of frag B-2, edge to near center. Opposite "half" from 39a.

JPEG of AK39a.ptm - * portion of frag B-2, edge to near center. Opposite "half" from 38a.

JPEG of AK40a.ptm - * portion of frag B-2, extended circular "hub" near edge

JPEG of AK41a.ptm - * frag B-2, radial ringed side

JPEG of AK42a.ptm - * frag B-1, inscripted side

JPEG of AK43a.ptm - * frag A-1, whole side imaged

JPEG of AK44a.ptm - * frag A-1, whole side imaged, similar to 43a

JPEG of AK45a.ptm - * frag A-2, whole side imaged

JPEG of AK46a.ptm - * frag A-2, whole side imaged, similar to 45a

JPEG of AK47a.ptm - * portion of frag A-2, corner

JPEG of AK48a.ptm - * portion of frag A-2, corner, similar to 47a.

JPEG of AK49a.ptm - * portion of frag A-2, "above" corner of 47a & 48a.

JPEG of AK50a.ptm - * portion of frag A-2, "above" 49a along edge.

JPEG of AK51a.ptm - * portion of frag A-2, corner "opposite" from 47a & 48a.

JPEG of AK52a.ptm - * portion of frag A-2, "central".

JPEG of AK53a.ptm - * portion of frag A-2, corner "adjacent" from 47a & 48a.

JPEG of AK54a.ptm - * portion of frag A-1, "central" to gear

JPEG of AK55a.ptm - * portion of frag A-1, an edge

JPEG of AK56a.ptm - *? end of cylinder w/square hole, possibly end or edge view of fragment A?

JPEG of AK57a.ptm - * portion of frag A-1, between edge of 55a and center.

JPEG of AK58a.ptm - * frag 4-1.
JPEG of AK58b.ptm - * frag 4-2.

JPEG of AK59a.ptm - * upper left 5-1, center 7-2, right 6-1; lower left 2-1, right 3-2.
JPEG of AK59b.ptm - * upper left 5-2, center 7-1, right 6-2; lower left 2-2, right 3-1.

JPEG of AK60a.ptm - * frag 1-2, "flat" side
JPEG of AK60b.ptm - * frag 1-1, "notflat" side.

JPEG of AK61a.ptm - * frags 45-1 to 75-1 in labled array. Numbered by row from right to left, lower row to upper. All are -1 sides except 55-2, 56-2, 61-2, 67-2, 70-2, 72-2. See note for #65, which I believe is 65-2.

JPEG of AK61b.ptm - * rags 45-2 to 75-2 in labled array. Numbered by row from right to left, lower row to upper. All are -2 sides except 55-1, 56-1, 61-1, 67-1, 70-1, 72-1. See note for #65, which I believe is 65-1. Each fragment reversed in place from 61a.

Note: in AMRP images "45-1 to 75-1.jpg" and "45-2 to 75-2.jpg", fragment 65 is labeled "65-2" in both, but the images appear to be of either side. In the 2006 Nature article, "chart 2" shows what appears to be the shadow of fragment 65 in "45-1 to 75-1.jpg", among the other 1-sides imaged. THerefore I'd guess that the "65-2" identification in "45-1 to 75-1.jpg" should be "65-1".

JPEG of AK62a.ptm - * upper, 67-1; lower, from left to right: 33-1, 34-2, 35-2, 36-1.
JPEG of AK62b.ptm - * upper, 67-2; lower, from left to right: 33-2, 34-1, 35-1, 36-2.

JPEG of AK63a.ptm - * left 32-1, right 31-1.
JPEG of AK63b.ptm - * left 32-2, right 31-2.

Background

The list in this document is of PTM images obtained in September of 2005, as part of the Antikythera Research Project by HP researchers Bill Ambrisco, Dan Gelb and Tom Malzbender; and an academic team led by Professor Mike Edmunds of Cardiff University. They imaged the fragments at the National Archaeological Museum in Athens with reflectance imaging techniques called "PTM", of the front and rear surfaces of the many fragments that comprise the Mechanism. IN addition the fragments were X-ray imaged by two methods, and they were visually photographed. Their work and results were published on 30 Nov 2006 in Nature Letters; subsequent analysis was published on 31 July 2008 in Nature Letters. The PTM image work was Web published and discussed on an HP Web page of Tom Malzbender associated with HP PTM imaging process. The X-ray work was Web published on the X-Tek Systems UK Web site; after its acquisition it was published on the Shaw Inspection Systems Web site. (See the Credits section for specific references and Web links.)

I obtained the PTM image set from Tom Malzbender in Feb 2007. However, the PTM image set did not include a cross reference to fragment name or side. I visually compared the PTM images to images in the 2006 Nature paper's "Supplementary Notes", and identified the PTM imaged fragments by matching shapes and contours. Where that paper described sides with textual descriptions, I identified some PTM images as side -1 or side -2. But I could not make a complete list by sides.

In May 2007, Dr. Tony Freeth sent me a set of fragment images scanned from the film images from 2005 above (taken by Xenikakis) which included number and side descriptions made by Zafeiropoulou for both sides of (almost) all fragments. Using these images, which Tony calls the "AMRP images", I have updated my descriptions and they are listed below. Where there are conflicts or inconsistencies, I've added "notes" referencing all these various image sources. (See the Credits section for references and Web links.)

In July I made a set of JPEG images from the PTM image set, as a series of screen captures, for convenience. These images have the same file name as the PTM images but have a ".jpg" extension. With those PTM snapshot images and the ARMP images, I completed my descriptions. After my notes and references were reviewed by him, I provided the notes and index to Tom Malzbender; they were subsequently added to his Web site where he makes the images available, at this Web link as of 2008. The captured images were not needed, but are available here on my Web site (with permission). Further use of these images requires a license, and the phrase "© Copyright 2006 Antikythera Mechanism Research Project" must be included when in use, among other considerations.

Credits and Web Links

The following is quoted from the HP PTM Web site June 2008:

"Images from the Antikythera Mechanism Research Project. Supported by the Leverhulme Trust, this is a collaboration between the University of Cardiff in Wales, the National & Kapodistrian University of Athens, the Aristotle University of Thessaloniki and the National Archaeological Museum in Athens, under the aegis of the Ministry of Culture, Greece."

"Essential technical support has been given by X-Tek Systems, Hewlett-Packard, Images First, Volume Graphics and Keele University."

"For information on use of these pictures please contact Professor Mike Edmunds, Cardiff University, Wales; or Tom Malzbender, Senior Research Scientist at Hewlett-Packard."

Additional credits as provided by Dr. Tony Freeth:

The Antikythera Mechanism fragments were described and shown in the "Supplementary Notes" of the 2006 Nature Letters paper by Freeth, Tony, Y. Bitsakis, X. Moussas, et al. (vol 444, 30 Nov 2006, "Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism", doi:10.1038/nature05357). The images were named by letter A through G and by number 1 through 75, in a set of image and legend charts. The article and Supplement are available on the Nature Web site.

Those images were film photographed by Costas Xenikakis for the Antikythera Mechanism Research Project in 2005. Identification of Fragments A - D originate with Svoronos (1908). Fragments E, F, G and smaller fragments were identified by number and side by Maria Zafeiropoulou, Senior Archaeologist at the National Archaeological Museum in Athens in 2005. First publication of the additional fragments by number and side is in the 2006 Nature paper cited above.

Additional work was published by the Project, in 31 July 2008 in Nature Letters, vol 454, 31 July 2008, "Calendars with Olympiad display and eclipse prediction on the Antikythera Mechanism", doi:10.1038. The article and a Supplement to that article is available on the Nature Web site as noted above.

Additional credits

This is not a comprehensive list of Mechanism Web sites or even the Project's participants. The Antikythera Research Project Web site IS at "http://www.antikythera-mechanism.gr/". At various times, this site may not respond: try again another time or day. Links from there show the Project's work on imaging the Mechanism and analysis of results; and links to a number of working models. There's an FAQ. There are also links to prior work. As of 2009 one can register on the site to comment and discuss.

(A Web site at "antikythera-mechanism.com" references the Project but has little additional information beyond a general description of that project and of the Mechanism.)

Tony references the Project page from his Web page on his images-first.com Web site.

As of 2007, the PTM image work was Web published and discussed at this HP Web page of Tom Malzbender, part of a series on the HP PTM imaging process.

Mike Edmunds is Professor of Astrophysics at Cardiff University and the academic lead author of the 2006 Nature article.

High-resolution X-ray tomographic images of the Mechanism were taken on the Museum site in late 2005 by a team led by Roger Hadland of X-Tek Systems UK. X-Tek designed and provided the x-ray tomographic equipment. These radiographs are now displayed on the Shaw Inspection Systems Web site, as Shaw acquired X-Tek. There are digital radiographs of each fragment at this link. They are named by fragment letter and number. Likewise, there are "computed radiographs" of fragments A, B and C (taken at various X-ray strengths) which reveal selected internal features.

Previous references to the Antikythera Project from the Web site of the National Archaeological Museum in Athens apparently are no longer available as of mid-2008. The Museum's Web site for the Mechanism seems to be at this Web page and site of the Hellenic Ministry of Culture, as part of the "Metals collection".

A subsequent paper in Nature was published by several members of this Project. Calendars with Olympiad display and eclipse prediction on the Antikythera Mechanism, by Tony Freeth, Alexander Jones, John M. Steele & Yanis Bitsakis, was published 31 July 2008. This paper discusses the glyphs (text) on the Mechanism as revealed in the previous Project work.