What is your epistemology?

[Tiberius]

Ok, my apologies. I did indeed misread you; thanks for the clarification.

However, given that you accept that P must be true, by what method do you arrive at the conclusion that gravity is true, and that therefore your justified belief in gravity makes it knowledge?

Now you're just being a solopsist. You think we could be brains in a Vat too? What about a computer sim?

No, I'm not being a solopsist, and there was nothing in my response to even suggest such a thing. This is a red herring.

There is a difference between believing that we are brains in vats or computer simulations, and accepting the un-falsifiability of these positions. I accept that I cannot prove we are not brains in vats or computer simulations, and thus I accept that my belief that I am a real person, living in a real universe, is not proven "truth". It is not knowledge, and it never will be. This doesn't change my belief that it is true.

Your insistence in equating absolute certainty with knowledge leads you to such stupid and wildly impractical conclusions

It isn't my insistence, it is one of the definitions of knowledge. Namely, the one that you use:

Certainty can be defined as either (a) perfect knowledge that has total security from error, or (b) the mental state of being without doubt.

A "true, justified, belief" is knowledge that has total security from error, since something that is "true" cannot be "false" (law of non-contradiction). Whether you accept it or not, if you have true justified belief (aka knowledge), then you also have certainty in the most absolute sense.

Relative knowledge, on the other hand, depends on the second definition (b). If you have a belief in something, and you are without doubt in that belief, then you can be said to have relative knowledge.

I was speaking of the effects of gravity, they could be angels pulling shit down, but given the description of the circumstance it would still be true. The justification would not be true however, where as the explanation offered by general relativity would be justified in many senses, especially when reliabilism is used as epistemic justification.

I've covered how we cannot reliably confirm that even the effects have existed. As soon as you observe something, there is nothing you can do to prove (in an absolute sense) that what you just observed was actually observed, or whether it was a delusion, or a falsely implanted memory. As a result, a belief it remains.

In that sense it would be impossible to know any past events to be known to be true regardless of whether or not they were in fact true, you can take this position all you like but this makes it impossible for you to be consistent on any matters of historical fact.

Indeed it does, and I've argued this from the start. I do not believe that we can know whether anything we "know" is truth or not. It may be true, and it may be false. There is no objective way of telling. I disagree that it means I cannot be consistent on matters of historical fact. As I have said before, what you call knowledge using your system reliablism, I simply call justified belief. We believe the same things are true, byt very much the same methods, but whilst you make the claim that they are "true", I say "I cannot know if they are true or not". This does not affect my belief that they are, and as such, I am on the same playing field as you are.

It does not follow that because of the Gettier problem you are incapable of knowing anything other than what is logically necessary

I never made that claim; you imagined it. I only noted that the "true, justified, belief" definition of knowledge that Plato came up with wasn't the most complete, and that there were objections to be noted. That was as far as I took it. In most cases, "true, justified, belief" works fine; all Gettier's problem shows is that in some special cases, more is needed for something to be called knowledge.