What is truth ?

Truth is more or less identified as a constant or as an absolute state of things , which does not change. But does truth change or ,rather, can truth change ?

The Church burnt St. Joan as a heretic - Was that the truth?. The Church canonized St. Joan. Is this the truth?.

Sun rises in the east and sets in the west - Is that the truth?. Sun is stationery; it is the earth's rotation which causes it to raise and set - Or is this the truth ? .

Copernicus said the Earth was flat - Was that the truth?. Galileo said that the Earth was round - Is this the truth?.

Well, earth is round - has to be, aint't it !! The point to be noted is that we are aware of this because we have only seen pictures of it or we believe in the word of a few people who has seen the earth from far (space shuttles/satellites ..) or it is the accepted common belief .We have never seen it , still we believe in it.
However,tomorrow if substantive proof is given , which appeals to our reason, we might be willing to believe even otherwise !!

If that be the case, if everything can change, then what is truth ??

The point is we get so convinced by our view of things, most of which was just told to us and some of which are experienced by us, when we are given a new perspective of the same thing, we just simply refuse to believe it. It happens day in and day out in our everyday lives. Sometimes we are the perpetretor or the receipient of this thinking. How many ideas or thoughts would have never seen the light of day due to this . One can just wonder !