How can we be sure this is reality?

[Tiberius]

I think we are going in circles here.

I think you are completely misunderstanding the nature of science in relation to absolute truth. It's great that science seems to work, and it gives us nice results that we can use to predict things about the universe. However, it is not absolute truth, nor does it claim to be, so we cannot hold it as such. Science is similarly limited in that it can only tell us about the "nature of nature" within what we perceive as reality. If what we perceive as reality is in fact a computer simulation of some kind, then all our science has told us is the nature of the computer simulation. It tells us nothing about the nature of reality outside the computer simulation.

Note: Before you jump on me, I don't believe reality is a computer simulation. I just don't have any evidence that it isn't one, hence, it is a possibility.

Degree of accuracy of prior data and proper use of method insures less chance of mistakes. But "technically" no, we cant.

...so close...

Science is limited but it is our best tool so far.

...yet so far...

You have absolutely no grounds upon which to stand whilst you call it "our best tool so far", because you have no absolute truth to use to measure its results against. For instance, science tells us that we evolved over billions of years. This appears to be the case when looking at data within our perceived reality. However, if our perceived reality is actually a simulation that started last Thursday (with all data effectively fabricated to make it look like it was much older), then all that science is completely and utterly wrong. Science only works within the confines of our perceived reality. If reality is not how we perceive it, science may be wrong. Given this fact, we cannot say "science is our best tool so far" when talking about whether it can demonstrate reality.

No I am not going to place my bets on this being a dream or a simulation even if "technically" we cant absolutely know. Like I said in a prior post, I am quite comfortable, and consider it a very safe bet that my computer won't suddenly turn into a squid, even if "technically" I don't know the future.

I agree, but just because we aren't making bets doesn't mean we aren't certain or that science somehow has all the answers.