Physics and Buddhism: 4 elements and rupa kalāpa

[RobertK]

@Paulo

From Abhidhamma perspective, every citta is a discrete act of cognition that necessarily requires a distinct object, right?

yes sure.

@Paulo

I find it difficult to accept the premise that colours and sounds do not exist independently of cittas; surely, denying their objective existence collapses the essential distinction between nāma and rūpa? Why the universe of discrete dhammas without cittas should have to be coloursless?

yes . The causes for rupa are 4 - Kamma Citta Utu (temperature / heat) and Āhāra** (nutriment / food).
For instance, the kalapas that comprise what is called the refrigerator in the kitchen are caused by utu. Even I can’t see the refrigerator they keep arising and ceasing.
Saraputo, independent existence.