rahula80 wrote:"This great earth, Ananda, is established upon liquid, the liquid upon the atmosphere, and the atmosphere upon space. And when, Ananda, mighty atmospheric disturbances take place, the liquid is agitated. And with the agitation of the liquid, tremors of the earth arise. This is the first reason, the first cause for the arising of mighty earthquakes." (Digha Nikaya 16)
"Ayaṃ, ānanda, mahāpathavī udake patiṭṭhitā, udakaṃ vāte patiṭṭhitaṃ, vāto ākāsaṭṭho. Hoti kho so, ānanda, samayo, yaṃ mahāvātā vāyanti. Mahāvātā vāyantā udakaṃ kampenti. Udakaṃ kampitaṃ pathaviṃ kampeti. Ayaṃ paṭhamo hetu paṭhamo paccayo mahato bhūmicālassa pātubhāvāya."
Note the terms carefully, as English renditions are approximate.
"vāta" (noun) translated as "atmosphere"
"vāyanti" (verb) translated as "disturbances"
Both are from the same root, vā, which is the root for a number of terms involving air, gas, wind as nouns, but the dynamic sense of movement in general. These terms are closely connected in the Indic languages, but not really at all in English.
The general model was that the earth rests on "udaka", which often gets translated as "water". It could just as well be "liquid", in the sense that the mantle of the earth rests on the molten magma below. And this rests on some sort of "air / gas" as a movement. This in turn on space, but considering most Buddhists don't accept "space" as a thing per se, it is more like saying "and this doesn't rest on anything"!
One could also render a sense of "... liquid rests on gas / movement, gas / movement rests on space ...", "... when the moved / gas makes a great movement, the liquid moves ...", etc. In the Indic it is not as far fetched as it seems in English. As has been pointed out earlier, all the English terms such as "earth", "water", "air" or even more abstract "solid", "liquid", "gas", etc. don't quite match up with their meanings in ancient Indian thought. We have to go into that thought world to work with it (in a kind of Schleiermacherian sense).
Movement seems to be movement of the gas, which in turn moves the liquid, which moves the earth. The last two points are basically the same as the seismic model we have today. The first part is not though. But what exactly is this "movement / gas" anyway?
Still not quite the modern model of science, but it is interesting to look into.
Another issue is the idea that the Buddha was just following the world view of his day and age. I ask: Which worldview? There were several different worldviews around that time, some of them match, others do not really. Moreover, have a good look into what period the appropriate worldviews even surfaced. It may be surprising. To paraphrase Gombrich, one best know which comes first and which later in order to ascertain causal relations.
But as I've said elsewhere, just look into other versions of this text, and ask whether or not it is part of the earliest strata of suttas, or one of the later strata, in the first place. The later strata tending to have more content added by the compilers, rather than the straight teachings of the Buddha. That would be a scientific (sic?) way of asking the very question in the first place.
Please compare this to the other versions of the text and have a look. Give some dates for this material. Give some dates for other similar material in non-Buddhist systems. Who made this statement in the first place?