noise is whatever you're not interested in studying/analyzing at the moment.
it's more a property of a thinking agent than it is of the universe.
if you see it everywhere it's because we are the same type of observers, maybe other kinds of hypothetical agents can segments the universe in different ways.
Your retina does quite a lot of noise filtering at the beginning of visual processing.
Background radiation is also a noise property of the universe, as is the background microwave radiation from the start of the universe. Is this just noise because it's an artefact of the measurement aparatus?
