We sould keep in mind that Tachyon did not indicate a modern interpretation of the greek letters but rather an older Egyptian meaning.
To the Wiki-mobile!
http://en.wikipedia.org/wiki/Greek_letters
This lets you back track to the older Phonecian and gives more source information.
Pi:
Pe is usually assumed to come from a pictogram of a mouth (in Hebrew pe; in Arabic, fem).
It is oddly reminiscent of the "speech glyph" found in surviving Aztec codices.
Tau:
Taw is believed to have come from a simple mark; a cross or asterisk-like marking, perhaps indicating a signature.
In ancient times, a symbol for life and/or resurrection, whereas the 8th letter of the Greek alphabet, theta, was considered the symbol of death.
Omicron:
The letter name is derived from West Semitic ʿen "eye", and the Proto-Canaanite letter had an eye-shape, ultimately derived from the hieroglyph (picture of an eye)
Lambda:
Lamedh is believed to have come from a pictogram of an ox goad or cattle prod. Some have suggested a shepherd's staff.
Said to signify unity under oppression, explaining its use as a homosexual symbol (how old this usage is is not clear)
If what we think is Lambda is actually Gimel (early Gamma)
Gimel:
In its Proto-Canaanite form, the letter was likely named after a "throwing stick, boomerang," ultimately deriving from a Proto-Sinaitic glyph based on the hieroglyph below: (bent stick)
The word gimel is related to gemul, which means justified repayment, or the giving of reward and punishment
Sigma:
The Proto-Sinaitic glyph, and possibly its Proto-Canaanite descendant glyph, according to William Albright and Brian Colless, may have been based on the hieroglyph for the uraeus in Semitic called shamash "sun" (also the meaning of the rune Sigel) with a phonetic value IPA: [ʃ]: (Snake with sun as seen on pharoh's crowns)
This next part about Sigma isn't important, just kinda awesome
"Shin also stands for the word Shaddai, a name for God. Because of this, a kohen (priest) forms the letter Shin with his hands as he recites the Priestly Blessing. In the mid 1960s, actor Leonard Nimoy used a single-handed version of this gesture to create the Vulcan Hand Salute for his character, Mr. Spock, on Star Trek."
