Since we're straying from the personal existence to the universal existence, let's try to get back on track. It's this simple.
If you can describe the universe that you perceive in minute detail, if you can dissect it, uncover layer after layer of reality underneath... if the simulation is that detailed, who's to say it isn't reality?
Admittedly, science shows that our perception of the external world is shaped by our preconceptions of what should be there. Case in point: in a study done with interviewees, two objects in their environment are changed abruptly, outside of their focus. Most of them don't notice the second change, despite the fact that it is the interviewer that has changed. If I write purple and ask you what color it is, chances are, you'll say purple.
Many people cannot perceive things that are outside their experience properly, and try to fit it within the framework of previous knowledge and experiences. None of your memories are real. They are digital reconstructions from your past. You remember like this:
1. I got on my bike when I was ten, and got chased by a dog.
2. It was a red bike
3. It was a white dog
4. Was it a poodle? Maybe... put that in there
5. Was it a BMX? Must have been, couldn't ride a big bike back then, put that in there
6. Where was it? Old house? Call up the props department, need a background.
7. Okay, assemble the set, cue the action, and...
Similarly, your brain constructs images of your surroundings based on pre-conceptions pre-loaded into your RAM (random access memory, to borrow a computer term) and ready for use. It often takes a while to load those images and constructs for things that are far from your mind. That's why it takes some time to recognize people we haven't seen for a long time... your brain has to dredge the constructs up out of long term memory. That's why people see Jesus in tea leaves and wall stains... his image is ALWAYS in their RAM.
Errh... the point? Our brains create our subjective reality, so whether the external universe is what it seems or not, the end result is the same. A false reality that accurately recreates the... errh... real thing, is for all intents and purposes, REAL.
But yes, Famine is right... you can only prove to YOURSELF that you exist, because you can observe your own existence. You cannot observe the existence of others, you can only infer that they exist from evidence given by the environment, you cannot directly observe their conscious existence.
).
