But in the English language, "lived" means "aged". So the travelling twin does not "live" the same number of years, or seconds, or any other standard unit of time, because they are not comoving with the earth.
But in science context here, it is important to distinguish (as I have already more than once) the difference between "lived" as the concept of "existence state per se" without any inherent "aging" interval parsings for that existence state per se.
In the physics context, the "aged" is directly related to internal processes being "timed" according to whatever "parsing of external existence state" is applicable internally by a clock/process in that frame/condition applying to the clock/process.
See? As I have tried to get across to chinglu, his inadvertent conflating of "lived" (a purely philosophical "Existence per se" concept) and "aged" (a strictly Physical Time interval parsing of external existence state according to local standard/non-standard COMPARATIVE time RATE/INTERVAL of PROCESS in question) is what is causing all the confusion and cross-purpose arguments.
For while the twins
philosophically "live/exist" through some common "external duration" referent irrespective of how many orbits are involved, they SPECIFICALLY and RESPECTIVELY
"physically age/process" DIFFERENTLY at different RATE depending on internal process duration-parsing system of 'timing rates' applicable to THEM ONLY.
Understanding the subtle difference and inadvertent conflation involved so far in this discussion, is very important to cut through the cross-purpose exchanges which will otherwise go on forevermore.
In short: they philosophically "live/exist" for the same external duration referent, but they physically "age/process" for different internal timing referent created by internal clock/process as compared with other internal clock/process of the other twin/clock.
Good luck, arfa brane, chinglu, everyone!
////Late Edit: in similar vein of "Reductio ad Absurdum" method:
PS: chinglu, everyone, please consider the case where both the traveling twin and his clock are vaporizd by nuclear explosion after only 5 external common referent Earth-orbits. Then that twin/clock would not 'live/exist' anymore, but the stay-put twin/clock would! So then, who is to say what that twin/clock has to claim about anything at all to do with either the other twin/clock OR the Earth-sun dynamics/orbit number? See? These twins/clocks are entirely disconnected from each other and the astronomical external referent. The only 'connecting' factor is the observer bringing HIS 'take' on what it all 'means' in reality process timing terms. And that observer is NOT the 'destroyed twin', but chinglu/scientist who must be CAREFUL NOT to conflate philosophical 'live/exist' concept with physical 'age/process' events when making the analysis to make sense of it all. Good luck all! ![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)