A “quale” (singular form) is a brain state with the following properties: (a) like the abnormal activation of a colorblind synesthete’s color pathways in the occipital lobe, or like the first-ever feeling of sexual desire, it is in principle an objectively measurable event with detectable correlates in brain and body, and (b) it’s incommunicable.

Ahh, I was fully on board until the 'incommunicable'. Not even sure what it means to say something's uncommunicable by definition, except that it seems to introduce a brand new element of mystery. Is the 'quale', then, the element of the redness that doesn't go across when I tell the other person about the letterbox? Sounds like putting a name on 'the stuff we don't fully understand yet' - not helpful.

To be honest though, it's not a particularly interesting question. We are physics. All we're doing is shedding light on the particular oddities that arise from experiencing the brain from the inside - there are no deep insights here for me.