I make the case here it's about what our conceptual models allow us to meaningfully interact with: Is it possible to visualize higher dimensional space?
A lot of our capacities link to specific technological cultures, and just like having bards and monks in a preliterate world allowed The Axial Age to occur, the transition from sacrifice focused religions that were primarily about spectacles, to ethico-philosophical traditions. Similarly we have gravity-wave observatories and weather satellites, and it shifts what model of the world we can interact with, resituating not only our physical cosmology but our mental and social one too, discussed here: Which philosophers and philosophies discuss "worldview epistemologies"?
Wittgenstein said "If a lion could speak, we could not understand him". Nagel suggest in What Is It Like To Be A Bat? that our intersubjectivity is limited by qualia. We know dolphins are smart, but we still can't speak to them, bolstering this view (though that they communicate in holographic pictures has only recently been discovered, a key insight was needed.
Real knowledge, implies to me that some being exists that knows it. Can we understand any random being's mind, and knowledge? We still don't understand Linear A cuneiform from Crete; we need a 'Rosetta Stone' to cross communication gaps.
Or, to link a human (mind) to another being's mode of life and live like them or them live like us: a lion, a bat, an octopus, a dolphin, a parrot, a corvid, an elephant. If something about the mind of a knower means that is impossible, such as them being more advanced technologically than humans but uninterested in communicating, likely full communication may never be established. The classic scifi Roadside Picnic that the film masterpiece Stalker was based on explores such a disconnect.
The consilience we expect to experience with aliens, like sharing mathematical ideas as put on to Voyager, is founded in sharing modes of life, eg solid bodies, readily perceiving spatial dimensions, only moving through time in one direction. The 'journey of unification' science has been on (see Is the idea that "Everything is energy" even coherent?) can be taken to imply all the experiences and phenomena that humans have and choose to share can be integrated together, linked into one language embedded in overlapping experiences. But the bare-bones phenomena of maths & and science contain very little of our 'what it' s like to be - ', our qualia. They are like only understanding the letters in an alphabet, not how elements of experience can be combined.
We need a lot more to understand emergent phenomena than bare physics (ie the mathematics of experiencing situations with 'simple' symmetries - see the unreasonable ineffectiveness of mathematics in biology), and make it tractable to understand. Comparatively biology is like literature, which trivially we can say is 'unified' with an alphabet, but really that tells us very little about being a being.
We have to share minds with a writer, to engage with literature, and we need bridges to get there, a shared language founded in overlapping modes of life.
Similarly with the minds of aliens, and beings beyond our imagination like sentient neutron stars (proposed as plausible in relation to OrchOR).
We cannot know much about thoughts in the mind of a sentient neutron star, not without becoming at least somewhat like one, eg using some vast AI cyborg addition to a human mind ('inhumanising' it).