From this sentence, I am not quite sure why are these two prepositions "on" and "in" used. And, can we swap the word further with on to be the second sentence?
If we look further on in time, to the year 2737 BC, we arrive at the discovery of tea by a Chinese emperor.
If we look on further in time, to the year 2737 BC, we arrive at the discovery of tea by a Chinese emperor.
No. Swapping changes the meaning.
Further on in time, means looking at a time that is further from the present (than a previously referenced time).
Looked on further in time - one wouldn't use that because "look on" has a different idiomatic meaning.
You could, however, say something like "Kept looking further back in time.." to mean that one continued looking (if it had already been stated that one had been looking at another period already).
