Irrespective of whether your argument that profane and religious roots are never mixed is right or wrong (it is actually wrong, as apmoy70 demonstrated), who claimed the two roots were etymologically related in the first place?Ain't that obvious?
(let's sum it up again)
There's no etymological connection between words "Gaia" and "Earth"!
and that is wrong, plain and simple.Gea, and alternates should not be considered on profane terminology like: soil, land,terrain and similar because it is a religious category that keeps itself apart from the common speech / language.
Possibly, although the loan would've had to have been very very early, much earlier than your 2000 B.C.E timeframe mentioned below. The word exists in Akkadian, a language attested at least as far back as 2600 B.C.E. and it's already in an evolved form in Akkadian, as erṣetu, indicating it has been a Semitic word probably since before the East/West branching of the Semitic languages.I am not an expert in Arabic but the Arabic arD, quoted in the beginning, may well be related here.
Surely you jest? There is certainly a tendency, but it's in the opposite direction.There is a tendency to label every IE word which has a similar form in Semitic as a Semitic loan,
It's certainly a possibility, either direction of loaning for this root is a possibility, but it would have to have been at a very early stage in the development of both families, since it exists in most members of each family, and shows the regular sound changes in both as well that we'd expect from a seasoned native word.however it is well known that IE peoples were thriving in Anatolia and the Middle East as far back as 2000 BC so, to be objective, we should also consider an equal possibility of IE loans into Semitic.
Sanskrit ardha(half) ->Earth doesnt make much sense,Let us put the discussion on somewhat more scientific basis. This is what the etymological dictionary says:
earth (n.) O.E. eorþe "ground, soil, dry land," also used (along with middangeard) for "the (material) world" (as opposed to the heavens or the underworld), from P.Gmc. *ertho (cf. O.Fris. erthe "earth," O.S. ertha, O.N. jörð, M.Du. eerde, Du. aarde, O.H.G. erda, Ger. Erde, Goth. airþa), from PIE root *er- (2) "earth, ground" (cf. M.Ir. -ert "earth"). The earth considered as a planet was so called from c.1400.
The furthest it takes us is the Gothic airþa. According to the Grimm's Law, the Gothic þ would lead us to "proto-IE" dh and to a reconstructed *e(a)rdh. We can not check it on the "proto-language" but we may turn the good old Sanskrit. We readily find there not one, but two suitable words: 1) ardha "side, part; place, region, country" and 2) ardha "half. halved, forming a half; one part of the two". Both are semantically compatible: the first one - if we interpret the ancient meaning of "earth" not as soil but in a more generalised meaning "place, world" (importantly in the etymological dictionary we find that the word "earth" stood for "the (material) world" i.e. not just "soil". The other one is also possible if we recall the Vedic (also IE) cosmogony in which Sky and Earth formed a perpetual union. There are many words for it: rodas n. du. "heaven and earth"; dyāvā "heaven and Earth etc." Therefore, ardha "one part of two" may well be taken as an allegoric name for one half of the union - the earth.