@fmf said
Neither you nor KellyJay is a researcher into the history of the planet and the universe. You both get your "science knowledge" from the research of others.
Does KellyJay's "knowledge" about the Earth being only about 6,000 years old ~ having not researched it himself ~ qualify as some "knowledge illusion"?
Does your "knowledge" about the Earth being billions of years old ...[text shortened]... s and research out there might be, I would consider my own certainty - to a degree - to be illusory.
Even if one were to research some topic themselves in an effort to not rely on previously uncovered information, one must needs resort to acknowledging the efforts of those who have come before, or else their research becomes bogged down into stagnation. The scientific method renders a way to avoid rehashing each new discovery by turning the experiments of one generation into the givens of the next. Once something has been proven, it becomes general knowledge for the next researcher, who can then focus on "seeing further" to the next problem. In this way, scientific discovery benefits not only those who discover it, but all those in the downline, who yes, may consider it "knowledge" and not "illusory", even though they were not there to discover it themselves.
Ben Franklin risked his life, flying his kite in a thunderstorm, to prove that lightning was the same force as electricity. Today, we can take this for granted, or equal to "personal knowledge", without having to risk our own lives flying our own kite in a thunderstorm. Once the wheel has been invented, one does not have to "reinvent the wheel" in order to build a car or a bicycle. The wheel has become personal knowledge, even though we did not invent it. One might say that, once something is known, one cannot "unsee" it.
The way I see it, is that the only knowledge that can be considered "illusory" is not knowledge at all, but rumor.