In matters of science, which would you trust?

the beauty of science is that we are constantly learning. learning from our mistakes and errors in reasoning so we don't make those same mistakes again. this explains why our technology is moving forwards and not backwards. we're not sending messages via horseback anymore, we have email. no doubt what we know today in the field of science is more than what we knew 100, and far more than what we knew 2000 years ago. so isn't it reasonable to trust any scientific theory we have today over theories we had 2000 years ago, if the two theories contradict one another? example: we don't still believe the earth is flat, do we? can you think of any field of science where we rely more on outdated theories than the current accepted theory? you find me one and i'll consider creationism as being truth.