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Definition of Tensegrity: Revision History

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20Oct2011 Update Dick Fischbeck link.
30Sep2009 Fix link to Geodesic listserv.
04Sep2008 Mention Snelson's Sprawl Piece as another example of a tensegrity with discontinuous tension. Get rid of most of the contractions. Mention Tim Tyler's criticism, re: purely tensile rivets, and try to answer it and expound on it. Hem and haw a little bit more about the suspension bridge.
13Aug2007 Add prestressed concrete to the list of tensegrity examples. Thanks to Dick Fischbeck for reminding me about this one. Emphasize that it is the external effects of components that matter for the definition rather than the stresses they undergo internally. Thanks to Tim Tyler for reminding me of this.
13Jul2007 Change "Internationalization" to Language.
12Jul2007 Add a section on Internationalization.
10Jul2007 In geodesic domes and spheres, mention a single-layer hexdome as a tensegrity that looks an awful lot like a geodesic. Thanks to Tim Tyler for pointing this out.
06Jul2007 In Tensegrity Examples, mention kites. Add some more details to the description of bicycle wheels.
29Jun2007 In the References, mention Val's new book.
20Jan2006 Revise suspension bridges. Add spider web. Break "Definition" section into "Definition" and "Subsidiary Terminology".
18Jan2006 Add suspension bridges as force-field-dependent and anchorage-dependent tensegrities. Note that the other non-self-sufficient tensegrities are all anchorage dependent. Remove link to tensegrity domes and leave them as a classification exercise for the reader.
19Dec2005 Add links for Dick Fischbeck, Spencer Hunter, Tim Tyler and Kenneth Snelson. Clarify Snelson's terminology and approach to tensegrity.
29Jun2005 Note that potential for being prestressed is perhaps a definitive quality of tensegrity.
24Jun2005 Dick Fischbeck persuaded me to take "prestress" out of the definition again. This time I won't use it as a classifying property though. Take attribution to Phil Earnhardt out of the human body example and thank him in the Acknowledgments though I will say here that he was the one who suggested classifying other biological structures on a case-by-case basis. Remove copyright notice since it's not legally necessary for copyright and a bit distracting. In the circus tent example, add a link to Camp Elsewhere's Tensegrity Shade Structures.
25Oct2004 Rephrase the Definition to refer to "pattern integrities" rather than structures, and use "not required to" rather than "never". Add References. Add "internal compression only" to possibilities for Classification of Tensegrities. Take "presence of prestress" out of Classification of Tensegrities and put it in the Definition (makes it easier to reject some things which aren't tensegrities to my way of thinking). In Tensegrity Examples, link to A Tensegrity Technology.
22Oct2004 Add bow to Tensegrity Examples. Thanks again to DF.
20Oct2004 Create separate section for Not-a-Tensegrity Examples. Per Spencer Hunter's recommendation, take the Roman arch out of Tensegrity Examples and put it in Not-a-Tensegrity Examples. Add ball of yarn (courtesy of Dick Fischbeck) to Tensegrity Examples. Link to Val's thesis.
19Oct2004 Add "force-at-a-distance component" and "pneumatic compression components" to the list of distinguishing properties to use in tensegrity classification. This is an attempt to balance Spencer Hunter's criticism that including pneumatic structures, stone walls etc. is too inclusive with my fascination with the inclusion of such things as tensegrity. Providing them with their own special tensegrity niche allows them to be easily excluded from consideration when necessary. Spencer's remarks also motivated the addition of circus tent to the Examples. Use "complementary examples" rather than "counter-examples". At Dick Fischbeck's suggestion, add compressed gas cylinder and sand bag to the Examples. Mention bridges in the Roman arch narrative. Emphasize that inclusion in the tensegrity category is not a measure of structural superiority. Call it a Preface rather than "Prefatory Remarks".
18Oct2004 In Classification of Tensegrity Structures, mention the pervasion of continuous tension, and reorder the categories so the most commonly present are at the top of the list. In Examples, mention exceptional qualities rather than things that hold for all the examples. Mention that there are some geodesics that seem to fit in the tensegrity category though these are atypical. In Bucky Works, J. Baldwin says the third version seems to be the one that does the job, and I think that's true here. I want to flesh things out a bit more, but this is the basic skeleton.
16Oct2004 In the Examples, take deresonated domes and spheres out of the tensegrity category and note that rotegrity domes and spheres are similar. Note that the Earth should be explicitly included in the Roman-arch structural system so that gravity is internal to it and that New England stone walls and Egyptian pyramids can be analyzed similarly. Add the human body, atoms and the solar system. Add Contact Information.
15Oct2004 First draft.

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