[grive]

I think you simply missed my point twice.

>> "Some external circumstances could change reducing them to a pile of oxides"

(or some other transformations I guess in case of fire.)

That was precisely not what I was talking about (or put another way if you still require abundant explicitness): not the kind of immortality I was describing. Maybe I was not clear enough.

> For example, a star could hypothetically fall into another much larger than it and prolong its life

Well, once again:

>> Of course they can still be impacted by external effects, but sustaining their own internal processes does not require such inputs