Zome Primer

12 Coherence Proofs

12   Coherence Proofs

1In a structural system or any pattern the question arises; what is the pattern made of? What are the relationships between different elements of the pattern?

2 In a checkerboard pattern such as that shown in figure 9.100 all distances between neighboring intersections are the same. And the distance between two intersections of any line is simply a multiple of this base distance. This base distance then naturally becomes the unit for building the pattern.

3 In our pattern created by the star with five-fold symmetry, the situation is different. There are many different lengths between intersections. If the growth patterns follow simple rules such as those followed in forming the two-dimensional pattern of figure 9.102, then all distances between intersections can be expressed as simple sums of components whose lengths are equal to powers of the divine proportion times some constant. This is also true in three dimensions - the A and B lines of the 31-zone star forming a growth similar to our 2-dimensional growth intersect each other at points where the distance between any two intersections on an A line equals

s1ATr1+s2ATr2+…snATrn(12.1)

4 and the distance between two intersections on a B line equals a polynomial

q1BTt1+q2BTt2+…qnBTtn(12.2)

5 The building blocks for our system are then a series of lengths related by the divine proportion. An A series, a B series and a C serieseach of slightly different lengths.1

12.1   Two Dimensions

12.1.1   Definition 1

6We call any particular polynomial of the form

s1kTr1+s2kTr2+…snkTrn=fi(𝑘𝑇)(12.3)

7si and ri are integers.

8 We call the class of all such polynomials F(𝑘𝑇) then;

fi(𝑘𝑇)+fj(𝑘𝑇)∈F(𝑘𝑇)(12.4)

fi(𝑘𝑇)−fj(𝑘𝑇)∈F(𝑘𝑇)(12.5)

(Tn)fi(𝑘𝑇)∈F(𝑘𝑇)(12.6)

9 We are interested in the distances between intersections along the lines of certain sets of patterns.

12.1.2   Definition 2

10A pattern is a number of extended lines which point in five different directions in one plane with at least one line pointing in each direction.

11PIC

Figure 12.132: 

12.1.3   Definition 3

12The lines are labeled;

ilnn=1,2,3,4,5i=1,2,…

13n names the direction - i names the particular line pointing in that direction. The angles between lines are;

π5,2π5,3π5,4π5

12.1.4   Definition 4

14An intersection is named by any two of the lines which intersect there, such as

jln×klm(12.7)

12.1.5   Definition 5

15If on a line all intervals between intersections are equal to different fi(𝑘𝑇), then the intersections “fit” each other.

16 An intersection fits a line if it fits all intersections on that line.

17 A line glp fits another line flq if the intersection glp×flq fits all the intersections of flq.

18 A pattern fits if all the intersections on all the lines fit.

19Lemma 12.1.1.If on a line lnan intersection Infits an intersection Imthen Infits all Iowhere Iofits Im.

20Lemma 12.1.2.Any ilm,jln,hlp,m≠n,n≠p,pform a triangle similar to T1or T2

21PIC

12.1.6   Definition 6

22These triangles are called the Golden triangles because their sides are in the divine proportion.

23Lemma 12.1.3.If the two vertices of a Golden Triangle fit each other then all vertices fit each other.

24Lemma 12.1.4.If a line jlmfits a line hlnand if all lnfit some line ilmand if ilmfits all lnwithout the line jlm, then, all intersections jlm×lnfit jlm×hlnand the line jlmfits all ln.

25PIC

Figure 12.133: 

26Lemma 12.1.5.If jlmfits hlnthen all lp,p≠m,n×jlmfit 𝑗𝑙𝑚×h𝑙𝑛and if hlnfits all lpwithout jlmthem jlmfits all lp.

27Theorem 12.1.6.If a pattern fits and a line jlmis added and jlmfits some line jln,n≠m, then the new pattern including jlmfits.

28A pattern fits if all the intersections on all the lines fit. (Definition 5) To prove the new pattern fits we must prove all the new intersections fit the lines they are on.

1.
There are no new intersections on the lines klm,k≠j, therefore all the intersections on these lines fit.
2.
All the intersections jlm×lnfit jlm×hlmand the line jlm×hlmand the line jlmfits all ln. (Lemma 4) Therefore all the intersections of the lines lnfit.
3.
All the intersections lp,p≠m,n×jlmfit jlm×hln. (Lemma 5) Therefore, the intersections of line jlmfit jlm×hln. Therefore, the intersections fit on all the lines lm(step 1) and jlmfits all lp,p≠m,n(Lemma 5) which means that all the intersections on all the lines lp,p≠m,nfit and our theorem is thus proved.

12.2   Three Dimensions

12.2.1   Definition 1

29In three dimensions we have a pattern made up of the diameter lines through vertices and face midpoints of the icosahedron.

30 The lines through the vertices are the A lines.

31 The lines through the face midpoints lines are B lines.

32 There can be other lines parallel to the original 16 lines. They are given the name of the line they are parallel to.

33 We name a line

iAn1n=1,2,3,4,5,6i=1,2,…

jBm1m=1,2,3,4,5,6,7,8,9,10j=1,2,…

34or generally

hXip1p=1,2…10h=1,2,…X=A,B

12.2.2   Definition 2

35All lines of a 3D pattern are connected directly or through other intersections to the original pattern of 16 lines.

12.2.3   Definition 3

36Intersections on A lines “fit” if all the intervals between them can be expressed as polynomials

s1ATr1+s2ATr2+…snATrn=fi(𝐴𝑇)(12.8)

37si,ri= integers and A= an interval of length.

12.2.4   Definition 4

38Intersections on B lines “fit” if all intervals between them can be expressed as polynomials.

s1BTr1+s2BTr2+…snBTrn=fi(𝐵𝑇)(12.9)

39si,ri= integers and B= an interval of length.

12.2.5   Definition 5

B=cos⁡(π6)cos⁡(π10)A(12.10)

12.2.6   Definition 6

40A 3D pattern “fits” if all the intersections on all the lines fit.

12.2.7   Definition 7

41An R section is a plane containing two A lines and two B lines. The angle between the two A lines is 𝜃; the angle between the two B lines is ϕ; the angle between an A and a B line is

π−𝜃−ϕ2orπ−𝜃−ϕ2(12.11)

12.2.8   Definition 8

42A T plane is a plane perpendicular to an A line. A T plane is named by this A line

TAn

43Lemma 12.2.1.There are five Rsections perpendicular to each Tplane. Each Aline is contained in five different Rsections. Each Bline is contained in three different Rsections.

44Lemma 12.2.2.The projection of the interval Aalong any Aline onto a Tplane

=Asin⁡(𝜃)(12.12)

12.2.9   Definition 9

k=sin⁡(𝜃) or =0.A(12.13)

45Unsure: What does 0.A resolve to? (if the interval is on the Aline perpendicular to the Tplane).

46Lemma 12.2.3.The projection of the interval Balong any Bline onto a Tplane

=Bsin⁡(π−𝜃+ϕ2)=k𝑜𝑟=Bsin⁡(π−𝜃−ϕ2=T−1k)(12.14)

47PIC

Figure 12.134: 

48Lemma 12.2.4.The projection onto any Tplane of any interval along any line kXir1between any two intersections which fit in the 3D pattern is a polynomial

s1kTr1+s2kTr2+…+snkTrn=fi(𝑘𝑇)(12.15)

si,ri=integersk=Asin⁡(𝜃)=Bsin⁡(π−𝜃+ϕ2)

49Lemma 12.2.5.The angles between the lines projected on a Tplane are

π5,2π5,3π5,4π5(12.16)

50PIC

Figure 12.135: 

51Lemma 12.2.6.3D Patterns which fit project onto all Tplanes 2-dimensional patterns which fit.

52Lemma 12.2.7.All intervals between intersections of lines of the 3D pattern appear as intervals between intersections in the projections on some Tplanes.

53For an intersection

iXknl×iXjml(12.17)

54not to appear as an intersection in the pattern projected on a Tplane, the intersecting lines must lie in one of the five perpendicular Rsections.

55At most, two different lines intersect iXknl. The two intersections

iXknlorgXtpl

56lie. Therefore, there is at least one Tplane in which both 3D intersections project as 2-dimensional intersections.

57Lemma 12.2.8.If some pairs of intersections

iXknl×hXjmlandiXknl×gXfpl(12.18)

58did not fit in our 3D pattern, that is, we cannot find any polynomial f1(XkT)that equals the interval between them, then also for some Tplane we cannot find a polynomial fi(𝑘𝑇)which equals the interval between their projected intersections.

59Lemma 12.2.9.Any misfits between intersections of the 3D pattern project as misfits between intersections on some Tplane. Therefore, a 3D pattern which projects on all Tplanes as a 2D Pattern which fits is a 3D pattern which fits.

60Theorem 12.2.10.If a 3D pattern fits and a new line is added kXinlwhich intersects and fits some other line hXjnlthen the new 3D pattern including kXinlfits.

61Proof.In each T plane the projection of the line kXinl fits the projection of the line hXjml. In each T plane the projection of the 3D pattern without kXinl fits. Therefore, the projection is with the line kXinl fits on each T plane and the theorem is proved. □

62 The coherence proof demonstrates that if one builds a structure using the A and B lines of the 31 zone star (the C lines may be used only within the forms defined by the A and B lines) and always follows the rule that new parts are added at intersections of existing parts or at points along existing parts which can be reached by subdividing a large part into component small parts, then no matter how far or intricately one builds, two extensions of two entirely different limbs of the same structure can always be locked back together in a perfect fit with a combination of our simple parts.

63 We have shown that the intervals between intersections are all equal to certain polynomials in T. Because

Tn=Tn−1+Tn−2(12.19)

64all the terms of any such polynomial can descend by subdivisions into a polynomial with only two terms-

fi(𝐴𝑇)=𝑟𝐴Tn+𝑠𝐴Tn−1(12.20)

65There are many interesting side-lights to these investigations. One of which is that it is impossible to divide any one of our building blocks ATn into equal pieces.

66 There are much shorter proofs of the coherence of this system, but the short proofs don’t lead one through so many characteristics of the structure.