was there some doubt that i intended a base 10 context? deliberate misinterpretation does not change objective truth.
in base 10, 2+2=4 today, tomorrow, or thirty thousand years from now.
if you say, i weigh 300 lbs in a gravity field of 9.8m/s/s. this is time dependent, as tomorrow with gain or loss of mass, the weight will change, but objective truth is still objective, and is not subjective.
I can agree to disagree. Maybe this will clear the confusion related to "objective reality", which is nothing but an assumed perspective, voluntarily promoted to the absolute level of truth:
You should know why you believe 2+2=4. If the reason why you believe it ceases to be valid, you should be ready to change your belief. In other words, I can imagine observations which would convince me that 2+2=3 (for more details refer to http://lesswrong.com/lw/jr/how_to_convince_me_that_2_2_3/)
You can never be 100% sure of something because that would take away from you the possibility of ever updating your beliefs if new evidence comes. And rationality is about creating beliefs based on evidence.