Is the burden of proof on atheists?

Actually scientists CLAIMED the earth was a sphere. That's a positive claim. We had the burden of proof then, and we proved it. Now theists are making the positive umption that there is a God. Since it is a positive claim, the burden of proof is on them... not atheists making the negative claim that there is no god because there is no evidence. You make a positive claim, you prove it. You make a negative claim (there is no god) when there is no evidence until someone proves otherwise. Negatives and positives, dear. Negatives and positives.