# Last edited on 2023-09-15 23:01:49 by stolfi

\title{Observations on the Phaistos disk}

\section{Orientation and lighting}

Between 2004-08-11 and 2008-07-20 the disk at the Heraklion Museum was
rotated on the support by ~140° clockwise as seen from side A. This is
good because it provided radically different illumination conditions.
Unfortunately Wikimedia Commons has only relatively low res pitcures in
the old orientation, the best one being wc006a.jpg (1024x768), whose
side B version is not available.

\section{About the lines}

The lines (spiral, radial, and commas) were traced with a pointed stylus
with round tip, as opposed to a knife like used for cuneiform. The hole
at the start or stop of each stylus, as well as the holes in the
start-of-text (SOT) radial stroke, have round section.

The spiral lines, symbols, and radial lines were written simultanously.
some number of symbols were stamped, then some portion of the spiral was
traced above (centrad of) them, then one or more radial strokes. It can
be seen that the radial strockes were traced outwards and started on the
previously drawn spiral line.

Each full turn of the spiral line was traced in one go.

\section{De-burring}

When a line is drawn with the stylus, the clay that is pushed aside
creates irregular ridges (/burrs/) on each side of the groove. Some of
those burrs can be seen on side A, on the spiral line between lines 1
and 2 from outside in at about 2 o'clock.

Deep stamping might also cause the clay to swell up around the stamp.

Since these burrs are mostly absent on the disk, it seems very likely
that, after each face of the disk was completed, it was lightly rubbed,
e. g. with a moist leather, to flatten those burrs and swells.

That /de-burring/ may have erased the details in lightly-stamped
symbols, so some symbols may have been re-stamped for clarity. The
correction on side A may have been done after that de-burring. This
hypothetical de-burring and re-stamping confounds the analyisis of
overlaps between symbols and strokes.

Another argument for deburring having ocurred is that the flat areas of
some stamps, such as HIDE, have a rough texture. However the texture is
erased except on the deeper impressions. Howeve, this could be due also
to lighter impressions not touching the original smooth clay surface.

One common consequence of de-burring is pushing the outermost edges of
the signs inwards, especially on the more deeply imprinted ones, and
even folding that edge over the interior of the sign. Once one is aware
of this fact, one can easily spot dozens of places where this
deformation occurred.

\section{Other observations}

The artifact is not circular and not quite elliptical, more like egg-shaped,
with the pointy end approximately centered on the SOT position.
But the deviations are small.

On side A, at the 3rd text line at about 8:30 o'clock there is a comma
that seems to have been written before the spiral line *below* the
symbols was drawn. Maybe the line was retouched?

On side A, second line from outside, at about 07:30, one of the two
adjacent hides shows sign of having been partly erased by the deburring
above.

On side B, the LILY on outermost line at 03:00 o'clock seems to have been
stamped over a partly erased VINE.

Some parts of the spiral lines and some radial strokes were re-drawn 
after some time of first drawing.  

When faced with a complex task, people instintively begin with the
easiest sub-tasks. Writing near the center is much hardet than writeing
aong the edge, since the disk must be turned by a larger angle, even 90°
or more, after each symbol. This is an argument for the scribe starting
along the edge rather than at the center. But admittedly not a strong
one.

\section{On the purpose of the disk}

The disk was definitely *not* made to be displayed, because reading each side
requires turning the disk several times.  It was meant to be carried and handled,
like a clay tablet.

The size also argues that it was meant to be transported and handled
rather than displayed. Ditto for the place where it was found.

The intentional firing meant that it was expected to be relevant 
for a long time and resist repeated handling and transportation.

While the stamps were made with exceptional care and craftmanship, the
disk itself was done somewhat sloppily and made with some haste. The
spiral lines are crooked, the symbol positions, spacing, and
orientations are irregular, the correction is crude, etc.

There is no colored paint or glaze. Thus the aesthetic demand
was less than that held for pottery.

That argues against it being a decorative, commemorative, or luxury
object. Could be a personal talisman or prayer. Could also be a message
between high officials, a passport, a land deed, a treaty, a bill of
lading.

Several of the symbols depict stuff that could be merchandise, tribute,
donations (e.g. to a temple), or gifts (e.g. to a ruler).

\section{On the correction}

The correction on side A required erasing two or three signs and two
word separators, stamping five in their place ( CAT CAT BEE PLUMED
SHIELD), and displacing two word separators in the CCW direction. The
goal must have been to insert swo signs that had been skipped, proabbly
PLUMED and SHIELD. That required re-stamping the previous word CAT CAT
BEE in the space that would be tight for even 2 normal signs, and
stamping PLUMED SHIELD crowded and overlapping the CAPTIVE. During the
erasure, a largs flake of clay broke off where the PLUMED is now, and a
smaller one where the first CAT is.

In the correction area, a chunk of clay flaked off between the new
PLUMED and the stroke, possibly as the new radial stroke was traced.
Some (but not all) of the flaked-off clay was pressed back in posiiton,
partly obliterating the face of the PLUMED and the stroke. There may be
a fingerprint to the right (counterclockwise) of the radial stroke,
below (distad) of the BEE.

The scribe may then have re-stamped the PLUMED to fix the damage 
caused by the fill-in.

\section{Direction of writing and reading}

The direction of writing is from outside in.  The strongest argument is 
based on how the text transitions between the two outermost turns.  That
transition only makes sense if the outermost turn was written first.

Since the stamps were made separately from each other and from the disk,
the facing direction of the symbols was chosen by the stamp maker, while
the direction of writing was chosen by the scribe. The stamp maker may
not have thought of the direction of writing when he made the stamps.

The arguments of Revesz for the LR reading order, based on sign crowding
and curved radial strokes, ignores this correction. While the rest of
the text was presumably written in reading order, these five symbols may
have been stamped in any order.

Revesz's argument based on the direction of the commas is very weak. A
better explanation is that the commas were drawn in the distad and
counterclockwise direction because the scribe was right-handed, and
pulling a stylus over the clay is more natural and safer than pushing it
foward or sideways (as would be needed to draw the commas in any other
direction).

\section{Symbol orientation}

Since symbols are either upright or upside-down, but rarely rotated by
other angles, we may guess that the each stamp had a handle or body that
was symmetric under 180 degree rotation.

\section{Hoax}

The hoax hypothesis has been conclusively dismissed by the findings of 
other objects with very similar symbols several decades after the 
disk was found. But there are other arguments against it.

The sloppy correction on side A argues against it being a hoax.

The two features that suggest a hoax, because they seem out of all
tradition, are the use of stamps to create the symbols, the spiral
writing, and the lack of any resemblance of the symbols to known
alphabets. But there ARE a small number of instances of spiral writing.
Stamping is known from signet rings, cylindrical seals, and the stamps
of the Indus Valley civilization. There is one vessel from Knossos that
has a impression of a stamp that is identical to the SHIELD symbol,
although isolated and much larger. Another vessel has the COMB symbol.
Likely there were many writing systems that have disappeared without
leaving a trace in the archaeological record.

\section{Objects depicted by the symbols}

Most of the symbols clearly represent objects, animals, or human beings.
We can therefore guess that the symbols that are unidentified (like
BOOMERANG, CARPENTRY_PLANE, COLUMN, SLING, DOLIUM, OX BACK, GRATER,
SHIELD, TRAINER, SMALL_AXE, WAVY_BAND, FLUTE, VINE, LID, COMB) are
objects too, just we don't know which objects.

In the "strong" syllabic hypothesis, each sign was meant to suggest, to
speakers of the language of the disk, some word that began with the
syllable that is the sign's phonetic value. Thus, for example, if that
language were English, the sign for the syllable "ka" could be the head
of a cat, and that for "fi" could be a fish.  This hypothesis would explain why the signs
are completely original, rather than copied from the scripts of some
other contemporary scripts, like Egyptian, Sumerian, Linear A, etc.

Assuming that hypothesis, we will refer to the specific word that eash
sign was expected to recall as the sign's \emph{mnemon}. This hypothesis
then requires that the object depicted by each sign be readily
recognized from the drawing, and naturally elicited the correct mnemon.
Thus, in most cases, the sign should be some object that was quite
familiar \emph{to the original users of that script}, and the mnemon
then would be the common name of that object. Naturally there may be
exceptions, including some cases of metaphor (like the drawing of a
shield standing for the mnemon "war") or abstraction (like the sketch of
two bars forming a right angle standing for the mnemon "corner"). And
cases where the object was just a poor choice by the script designer.

The PAPYRUS symbol is definitely NOT a papyrus plant. (If the designer
of the script was familiar with the plant, she would not have drawn it
that way. If she was not familiar with the plant, she would not have
used it as the mnemon.) However, it could be a silphium plant. It must
have been already an important spice, and its shape (as depicted in old
coins) does not seem entirely dissimilar. But it may be any other plant
or weed common in the region, such as fennel, chard, etc.

The BEEHIVE symbol looks more like a bread oven. Note the opening in the
bottom part. On the other hand, there is an Anatolian tomb that looks
impressively like that beehive symbol, including two doors at the base,
one open and one walled up. (But coudl that "tomb" too be actually a
bread oven?)  The sharp pointed "foot" is puzzling.  Perhaps it was 
a portable oven, with that foot meant to secure it to the ground?

The DOLIUM sign is almost certainly the conch (shell) of a big sea
snail. Could be a spotted tun (/Tonna dolium/ or /Eudolium crosseanum/)
but also a triton (/Charonia lampas/ or /Charonia tritonis/). One such
shell, dated 3600-3000 BCE, was found at Phaistos. The shell is at the
Heraklion museum and is assumed to be a ritual object, labeled "triton".
See "images/misc/wc031m.jpg". See also Addley 2021.<ref name=adle2021>
Addley, Esther (2021).
"[https://www.theguardian.com/world/2021/feb/10/conch-shell-in-french-museum-found-to-be-17000-year-old-wind-instrument
Conch shell in French museum found to be 17,000-year-old wind
instrument]". ''The Guardian'', 2021-02-11.</ref>

The EAGLE may be carrying a prey in its talons. The head and beak
however do not look like those of an eagle.

The COMB sign has four teeth on each side. The potter's mark found on a
vase bottom has six teeth. If they are indeed the same sign, then those
teeth may be just schematic. The actual number of teeth may be arbitrary
and/or much higher.  The thing may have been the standard of a town or clan.

The CAPTIVE could be a slave.

The BULLS_LEG could be the hoof of a *horse*, with the leg added only to
make it recognizable. The hooves of horses a much more important concept
than the lower legs of cows, for obvious reasons. The drawing is
distinctlively more similar to the hoof of a horse than to that of a cow
or sheep. While the shapes in profile overlap to some extent, the
latter, besides being cloven, is flatter and more elongated, with a
sharper and slightly upturned tip. Moreover, the cow's "foot" (actually
its two main fingers) extends at 45° forward of the leg for several
centimetres, whereas the "foot" of a horse is somewaht shorter and more
vertical.

The HELMET looks more like a sack full of stuff and closed by tying. The
bottom corners are generously rounded rather than sharp, as one would
expect in a drawing of a helmet by the skilled artist who created the stamps.

The tail of the ARROW is too big, and the end of the stem is blunt not
sharp. Thus it does not look like an arrow at all. It may be an arrow
TAIL, or a feather.  The drawing quite resembles how of palm leaves are pictured
in certain Mesopotamian works.  It couls also be a fan.

The GRATER looks like a crawling animal with spots, like a grub or sea
cucumber, with short and fat legs without feet. It has either 4 legs
depicted all in flat perspective (unlikely, given the perspective
drawing skill shown in PEDESTRIAN, TUNNY, DOVE, and other figures) or 4
pairs of legs, of which only one side is shown.  It could also be a peripatus, 
the dots then being meant to suggest the many knobs that cover its body.

It seems unlikely that the original users of that script had strainers
shaped like the STRAINER. What object that drawing depicts is quite a
mystery.

The drawing was obviously meant to have rows with 1, 2, 3, 4, 5, 6, and
7 dots in hexagonal grid pattern. The engraver began with 7 dots on the
top row, then 6 in the next row, then 5 in the next one. On the next
row, she seems to have made a mistake by making 5 dots instead of 4,
squeezed together and misaligned with the diagonal rows of previous
dots. Anyway, on the next row she returned to the correct pattern by
making 3 dots. But that row came out a bit too low, leaving insufficient
space for the two remaining rows. So she skipped the two-dots row and
put a single dot, again with extra-wide space between it and the
three-dot row.

The SMALL AXE does not look like an axe at all. It looks more like a
manta ray or other similar animal. The squarish flat (distad) end would
be the head, and the deep hole in it would then be the mouth, assuming a
ventral view. Unfortunately, its only occurrence is partly damaged: it
is missing a corner of the flat part, just below and distad of the hole,
so we cannot tell what is the true shape of that corner. The outer edge
adjacent to that missing corner is intact and is just a smooth rounded
turn. However, the missing inner edge may have had additional detail,
like a mouth (and the clay may have flaked off because of that detail).
Anyway, the edges of the two side "wings" are slightly curved in the
centrad direction, like streamlined fins, rather than in the distad
direction as would be usual for an axe. The central spur is bent to one
side, which again woudl make no sense for any axe-like blade. On the
other hand it is aligned with the head, as would be proper of a fat and
short tail.

The OX BACK could be a stockfish: the body of a fish, with head and side fins removed, tail trimmed, cut open, flattened out, and sun-dried.

\section{Cracks}

There is a crack on side B, near the SOT, that runs across three symbols,
two spiral lines and one radial stroke. The crack changes direction at
those incised lines and follows them for a millimeter or so, and is
visible at the bottom of one of the spiral lines. It also seems to cross
the boundary of an OX BACK without being obliterated by it. Thus the
crack must have appeared after those lines were incised and the symbols
were stamped. Possibly because of drying, or of pressure applied on the
opposite side. The crack does not seem to extend through the disk to
side A.

There is another crack on side A (not opposite to the one above) that 
crosses three spiral lines, four symbols, and one radial stroke.
It too follows the spiral lines, strokes, and also the symbol outlines.

\section{Start-of-text marks}

The two SOT marks are almost but not quite aligned across the disk.
Looking from the "a" side, the "b" SOT is about 8 degrees clockwise of
the "a" SOT, relative to the approximate geometric center of the disk.

\section{Nature of writing}

The small set of distinct symbols and the highly disparate nature of the
objects depicted argues against a purely or mostly logographic script.
What text could possibly mention doves, eagles, cats, bees, mattocks,
gauntlets, hooves, ships, daisies -- multiple times each? Most, if not
all, of the signs must have phonetic value.

It could be a rebus writing system, where each sign could represent a
short word whose sound is used to make up longer words. E.g., one could
use a "bee" sign, four dots, and a hand to make the word "beforehand".
But such a system would be difficult to write (one would have to think
up of component words with suitable sounds) and even more difficult to
read correctly (as the reader woudl have to guess the specific word
represented by each sign -- in that example, "bee" rather than "wasp" or
"insect"). And it would probably still need hundreds of different signs.

So it is more likely that the writing is the next step after rebus:
namely, a syllabic with mnemonic glyphs. Each sign stands for a
syllable, and the assignment is standardized; but each sign is the
drawing of something whose name starts with that syllable, so that the
syllabary is easier to memorize.

Most scripts began that way, but after a few centuries of use the signs
evolved until the objects were no longer recognizable, their shapes
simplified to the minimum needed to distinguish them from each other.
That evolition generally happened when the script was created with a
drawing instrument, where each stroke of the drawing is a separate
movement of the hand. It could be a stylus scratching on an ostracon,
clay tablet, or waxed wood tablet; a small knife making wedge
impressions on clay; or a brush writing on paper. Then the time taken to
write each sign is proportional to its graphical complexity, namely the
number of "strokes" needed to draw it.

The pressure to simplify is much reduced when the script is mostly
carved in stone. In that medium, signs will be big and the work needed
to carve each sign depends much more on its size than on its complexity,
since if the drawing is complicated, the strokes will have to be
narrower and shallower. The pressure to simplify is also small when most
writing consists of short texts on luxury or cerimonial items, like
vases, sarcophagi, tomb walls, jewelry, weapons. Then the time spent
writing complex signs is just a small part of the overall decoration. A
vase covered in complex painted glyphs takes just as much time to
produce as one covered in a leaf and flowers design.

The Egyptian and Mayan scripts illustrate these points (except that they
had evolved further in the direction of alphabetic rather than syllabic
writing). There too we saw a simplified version of the glyphs for use in
"drawing" media, and a fully detaied "pictorial" version for use in
"carving" media, both used within the same time frame.

\textbf{On the other hand}, the strong clustering of certain glyphs in
some sections of the text, such as PLUMED HEAD on side A versus HELMET
on side B, argues for a logographic system, since different sections
could well have different subject. For instance, PLUMED HEAD and its
combination with SHIELD and other symbols many be a title like "king" or
"general", and HELMET may be a sack of grain, so that on side A there is
a list of names and on side B a list of tribute.  

\emph{On the third hand}, the anomalous distribution of HELMET and other
symbols may be due to some common words (like "chief" or "from") or
endings (like "-ed") being topic-specific.

\section{Overstamping}

Some sign occurrences look like they have been stamped twice, perhaps to
restore the sign after damage by adjacent signs, lines, or corrections,
or to reinforce a stamping that was too light or otherwise imperfect. In
some of cases, the stamp may have shifted between stamping half óf the
sign and stanping the other half, so that the two halves are displaced
compared to their relative positions in a "normal" occurrence.

In Bs083 HELMET, the right half seems to have been overstamped but with
a small shift to the left.

Around and inside BS089 there are some "gear teeth" marks.

In the CLUB sign Bs031, the bottom 2/3 of the stamping may have failed
because of a depression in the clay. Then a deep broad hand-drawn stroke
almost completely obliterated its bottom half, perhaps substituting for
the missing stem. The bulb at the bottom was re-stamped but somewhat off
the right place. The three lower dots on the right side of the stem
appear to have been added with a stylus, while the three lower dots on
the left side are just missing.

Sign Bs014 SLING seems to have been stamped too lightly or incompletely
erased, then stamped again a little bit to the left (closkwise).

The E25 SHIP Bs037 seems to have had the "crossbeam" on the "rear mast"
retouched with a sharp stylus after the print got damaged at that spot.
The SHIP at Bs047 seems to have had its stern re-stamped after the first
stamping fell outside the edge of the disk.

Even on clean stampings, the stamp was often held with a tilt or even
rocked while being applied; so that points on the glyph's surface that
should have been lying on a plane -- such as the shallow grooves on
BEEHIVE or WOMAN -- will lie on a curved surface and/or will not be
parallel to the disk's surface.

The clay often stuck to the stamp causing it to flake off the disk,
especially on small details surrounded by deep groves, like the leaves
of E35 PLANE TREE on Bs062. Those bits of clay may have clogged the
stamp so that the next impression would have been be defective.

The walls of the ridges on the stamp that create the grooves, and in
particular the outer wall of the stamp, were sloped at various angles
relative to the face of the stamp. Thus, depending on the depth of the
impression, the position of edges would vary (and then be further
displace by deburring). The position of a groove's edge is reliable only
if the the impression is deep enough so that the flat area of the stamp
adjacent to that edge got into contact with the clay and molded it too.

The vertical (radial) word-separating strokes usually start precisely on
the upper turn of the spiral line, often with a slightly deeper point
punch, but end a bit more irregularly with respect to the lower turn of
the spiral line, often with a gradual taper rather than a sharp stop.
These features confirm that they were drawn in the distad direction,
after the upper turn of the spiral was drawn.