Physics shows that what we percieve to be the unidirectional arrow of time is an illusion; that time doesn't necessary "flow" in any direction, and that the concepts of past and present are ultimately meaningless. Is there any discussion of the nature of time as a concept in Buddhist teachings?
Lord Buddha definitely does talk about Past, Present and Future; but I guess your questions is mainly about, "Do we have something called time?" or "What is time?"
With regards to Abidhamma, there is no "Paramartha" dhamma which we can relate to time: i.e. there is Citta, Cetasika and Rupa and Nirvana, but no reference to time. One of the best explanations I've heard is that the impermanence (Anicca) that we see is what we comprehend as time: i.e. the change that we see, is what we associate with time.
Sorry if it's not very helpful.
Not the Buddha, but these dictionary entries define akalika and kalika, and include these notes:
Ñánavíra on Citta, see footnote: "The notion of two successive 'moments', A and B, as akálika or non-temporal is a confusion. Either A and B are simultaneous (as e.g. viññána and námarúpa), in which case they are indeed akálika; or B follows A and they are successive (as e.g. the in-&-out-breaths), in which case they are kálika."
I think this is sometimes the intended meaning in the Pali, sometimes not. When one speaks of the simultaneous arising of nama/rupa+consciousness the meaning is simultaneity; when one speaks of consciousness depending on nama/rupa or other cases of 'fruition' the use is without interval, immediately successive.
It is probably most useful here to go to the ultimate roots: a = no; ka = shit; li = line; ka = shit. The track of scat left by an animal. The hunter sees: This is the track a week old, this is only two days old, this is from yesterday, and here it is now, eating. That would point to the original meaning of the term to be closer to successive than to simultaneity.
So it's describing two, or three, cases:
- Two events happen at the same time, or,
- One event depends on (happens immediately after) the other
- Slow or delayed:
- One event succeeds (happens later, after) the other