The 10,000 cakkavāla (“dasasahassilokadhātu“) is mentioned in the “Dhammacakkappavattana Sutta (56.11).” That is what I had in mind.
- Dasasahassilokadhātu (dasa sahassi lokadhātu) means 10, 000 cakkavāla. But it does not say a Buddha appears per 10,000 cakkavāla.
- So, my first recollection may be wrong (“…As I remember, our solar system (cakkavāla) is one of a 10,000 cakkavāla in a cūḷanikā lokadhātu. …”)
I have heard (and am confident) that only one Buddha can appear in a cluster of cakkavāla.
- But how many cakkavāla are in such a cluster? I am not sure.
- If it is a cūḷanikā lokadhātu,” it will be a cluster of 1000 cakkavāla.
- If it is a mahāsahassī lokadhātu,” it will be a cluster of a billion cakkavāla.
- In AN 3.8, the Buddha only says his voice can be heard across a mahāsahassī lokadhātu. It does not say there can be only a single Buddha per mahāsahassī lokadhātu.
If someone has a Tipitaka reference, please post it.
P.S. Scientists estimate our Milky Way galaxy to contain 100–400 billion stars (i.e., cakkavāla): “Milky Way.”