Cosmic expansion and cosmic contraction DN2 talks of many aeons of cosmic expansion and cosmic contraction.

What does this mean in Buddhist cosmology?

Is this similar to Big Bounce in physics?
What does "aeons of cosmic expansion and cosmic contraction" mean in Buddhist cosmology?

Quoting from Dharma: Its Early History in Law, Religion, and Narrative
By Alf Hiltebeitel:







An "aeons of cosmic expansion and cosmic contraction" is a translation of saṃvaṭṭa-vivaṭṭakappa:


  vivaṭṭakappa
  masculine
  an ascending aeon


and/or:


  Vivaṭṭa, (m. &amp; nt.) (vi+vaṭṭa1) 1. “rolling back, ” with ref. to the development of the world (or the aeons, kappa) used to denote a devolving cycle (“devolution”), whereas vaṭṭa alone or saṃvaṭṭa denote the involving cycle (both either with or without kappa). Thus as “periods” of the world they practically mean the same thing &amp; may both be interpreted in the sense of a new beginning. As redupl. -inter. cpds. they express only the idea of constant change. We sometimes find vivaṭṭa in the sense of “renewal” &amp; saṃvaṭṭa in the sense of “destruction, ” where we should expect the opposite meaning for each. See also vaṭṭa &amp; saṃvaṭta. Dogmatically vivaṭṭa is used as “absence of vaṭṭa, ” i.e. nibbāna or salvation from saṃsāra (see vaṭṭa &amp; cp. citta-vivaṭṭa, ceto°, ñāṇa°, vimokkha° at Ps. I, 108 &amp; II. 70).—Fig. in kamma° “the rolling back of k. ” i.e. devolution or course of kamma at S. I, 85.—Abs. &amp; combd with saṃvaṭṭa (i.e. devolution combd with evolution) e.g. at D. I, 14, 16 sq.; III, 109; A. II, 142 (where read vivaṭṭe for vivaṭṭo); Pug. 60; Vism. 419 (here as m. vivaṭṭo, compared with saṃvaṭṭo), 420 (°ṭṭhāyin). In cpd. °kappa (i.e. descending aeon) at D.


... in other words, according to the book quoted above, "a period in which the world is created and destroyed".



The word kappa is usually translated as an aeon. The PTS dictionary says,


  -- 2．（temporal） a “fixed” time，time with ref．to individual and cosmic life．As āyu at DA．I，103 （cp．kappaṁ）； as a cycle of time=saṁsāra at Sn．521，535，860 （na eti kappaṁ）； as a measure of time：an age of the world Vin．III，109； Miln．108； Sdhp．256，257； PvA．21； It．17=Bdhd 87=S．II，185．There are 3 principal cycles or aeons：mahā°，asaṅkheyya°，antara°； each mahā° consists of 4 asaṅkheyya-kappas，viz．saṁvaṭṭa° saṁvaṭṭaṭṭhāyi° vivaṭṭa° vivaṭṭaṭṭhāyi° A．II，142； often abbreviated to saṁvaṭṭa-vivaṭṭa° D．I，14； It．15； freq．in formula ekampijātiṁ，etc．Vin．III，4=D．III，51，111= It．99．On pubbanta° &amp; aparanta°，past &amp; future kappas see D．I，12 sq．paṭhama-kappe at the beginning of the world，once upon a time （cp．atīte） J．I，207．When kappa stands by itself，a Mahā-kappa is understood：DA．I，162．A whole，complete kappa is designated by kevala° Sn．pp．18=46~125； Sn．517； also dīgha° S．II，181； Sdhp．257．For similes as to the enormous length of a kappa see S．II，181 &amp; DA．I，164=PvA．254．-- Acc．kappaṁ adv．：for a long time D．II，103=115= Ud．62，quot．at DA．I，103； Vin．II，198； It．17； Miln．108； mayi āyukappaṁ J．I，119，cp．Miln．141．Cp．saṅkappa．


When used, the word kappa may have a prefix which qualifies it (as in saṃvaṭṭa-vivaṭṭakappa above), which describes what kind of kappa it is. If it doesn't have a prefix it's assumed to be a Maha-kappa (a great kappa, a world kappa, an aeon). Maybe for that reason it's translated "aeon". I'm unsure whether kappa always definitely means long time periods (i.e. longer than a human life).

Even if it does imply a long, long time (which it seems to, both, in general, and in context in this sutta), I don't want to accuse the Buddha of exaggerating or false speech, but people do sometimes describe subjective time loosely or figuratively (e.g. "the bus took ages to arrive").

Anyway, it appears to mean some kind of time period, especially related to life, maybe the life-time of something.

Is this similar to Big Bounce in physics?

I doubt it; and generally I presume that nothing in Buddhist phenomenology is similar to physics.