[Richard Suchenwirth] 2002-11-10 - In the beginning there are Tohu (T) and
Vohu (V): two very little things ("rishons" because they're the first (Hebrew)),
of which T has an electric charge of 1/3 and V has none. And, as
symmetry goes, there are also their anti-rishons - conventionally
written with a bar over the abbreviation letter, but I use lowercase for
easy keyboard input: t (with -1/3 charge) and v.

Rishons (and anti-rishons) always come in groups of three, and if
order doesn't matter, we have four distinct triplets of each:
 Rishons: TTT, TTV, TVV, VVV; anti-rishons: ttt, ttv, tvv, vvv
Now let's enter the realm of elementary particles (for which a language
named Tcl may have some uses ;-), which come in three weight classes: light,
medium, and heavy (or scholarly Greek: Leptons, Mesons, Baryons). The
particular theory that I'm retelling here says that '''leptons''' consist of
just one Rishon triplet, if their charges sum up to an integer:
 ttt  -1  e-  Electron (finally, an old acquaintance...)
 VVV   0  ve  e-Neutrino
 TTT   1  p   Positron
 vvv   0  -ve Electron anti-neutrino
The other four have fractional charge sums, and thus can only be used as
building blocks for bigger structures, the so-called '''quarks''' (and
the complementing anti-quarks):
 TTV  +2/3 u  u-Quark ("up")
 tvv  -1/3 d  d-Quark ("down")
 TVV  +1/3 -d Anti-d
 ttv  -2/3 -u anti-u
There are more quarks postulated, with names like "charm", "strange",
"top", "bottom", but my physics book didn't tell me how they map to
rishons...

'''Mesons''' (middle-weight particles - although D-mesons are double as "heavy" as
neutrons) consist of one quark and one anti-quark, and also sum up to an
integer charge, here demonstrated on "Pions":
 u-u   0   pi0
 u-d   1   pi+
 d-u  -1   pi-
The really heavy guys, '''Baryons''', are made up of three quarks, or
three anti-quarks, and here we meet old acquaintances again:
 uud     1 p  Proton
 -u-u-d -1 p- Antiproton
 udd     0 n  Neutron
Neutrons and protons make up most of all matter. The bad news is that
neutrons don't survive long in freedom - typically after 932 seconds
(~15 min), the following happens:
 n -> p + e- + -ve
The neutron turns into a proton, emitting an electron and an electron
anti-neutrino (please pardon my typography - originally there are bars
over anti-particles, Greek letter ''nu'' where I put the v, and subscripts).
Expressed in terms of quarks, the above becomes
 udd -> uud + e- + -ve
Or, back to rishons from where we started, the change is only in the
second "d" quark, so in rishons that makes:
 tvv -> TTV + ttt + vvv
Finally, enter Tcl. Such process descriptions are strings, and Tcl is
particularly (if you excuse the pun) good at strings. Here's some code
to check whether a process abides by the Rules (which I don't know all,
but two are:
   * at one time you may add a rishon and its anti-rishon, e.g. Tt
   * the end result must be a valid set of rishon triplets.)
Instead of inserting rishons, I start backward by removing matching
rishon/anti-rishons from the postulated result, and see whether we get
back to the start. But first, some helper routines:}
 proc rishon'charge rishons {
    # computes the electric charge of a rishon triplet
    expr [string map {T +1./3 V "" t -1./3 v ""} $rishons+0]
 }
 proc rishon'translate rishons {
    # turn a rishon sequence to more conventional particle names
    set tmp [string map {
        TTT e+ TTV u TVV -d VVV ve ttt e- ttv -u tvv d vvv -ve
    } $rishons]
    string map {
        uud p -u-u-d p- udd n u-u pi0 u-d pi+ d-u pi-
    } $tmp
 }
 proc rishon'reduce formula {
    regsub -all {[^TtVv]} $formula "" rishons
    set rishons [split $rishons ""] ;# turn into a rishon list
    while {[has T $rishons] && [has t $rishons]} {
        lremove rishons T
        lremove rishons t
    }
    while {[has V $rishons] && [has v $rishons]} {
        lremove rishons V
        lremove rishons v
    }
    regsub -all (...) [join [lsort $rishons] ""] {\1 } res ;# group triplets
    set res
 }
 proc has {element list} {expr {[lsearch $list $element]>=0}}
 proc lremove {listVar element} {
    upvar 1 $listVar list
    set pos [lsearch $list $element]
    set list [lreplace $list $pos $pos]
 }
----
Testing:
 % rishon'reduce {TTV + ttt + vvv}
 tvv ;# so the neutron decomposition appears well-formed
 % rishon'reduce {ttv + TVV + TTT}
 TTV 
The latter case is controversial: it describes (backward) how a proton decomposes
into a pair of Pi-mesons and a positron - which violates the rule that
the number of baryons should remain constant. I can't tell - particle
experts, please comment (also on "superstrings", which sound as if they
may be food for Tcl too...)
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The names ''tohu'' and ''vohu'' are quotes from the Hebrew Bible, meaning "desert and empty" (1.Moses 1,2).

Are you sure about that? That doesn't sounds like an accurate translation... also, Which book of the bible is called "Moses" ? --'''LeRoi''' [RS]: I retranslated from the German translation, "(die Erde war) w�st und leer" 1. Moses is the very first book of the (German) bible, Old Testament.

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[Arts and crafts of Tcl-Tk programming]