[hshehehjdjdjd]

(Same person, different account.)

> Our understanding of what it means for the sun to be "in the sky" will likely undergo several revolutions in the next 100,000 years.

I wouldn’t bet on it.

> Your perception that the sun is in the sky is causally linked to your belief that it is daytime.

My perception is cause by electrical impulses from my eyes, which are caused by photons hitting those receptors. The photons themselves are caused by the sun, and their incoming vector is caused by its position relative to me. There is a causal chain, thus, causal linkage.

> If I am a schizophrenic and I hallucinate that the sun is in the sky even though it is night time then do I "know" that it is daytime?

Depends on what you mean by know. Your perceptions are not causally linked to a true belief, if that is what you are asking.