oscar - yes, Christians often claim certainty, and most of them are scientifically ignorant and have no clue what they are claiming certainty about.
I will also tell you as a fact that most non-Christians claim certainty where they have no knowledge to be able to claim certainty. Let me name a few topics for which the vast majority of people simply spout "truth" as a matter of faith, not actual knowledge:
1. Global warming: Most people know nothing about this science, and repeat the claims of global warming alarmists as a matter of faith, as taught to them by the Prophets of doom on the nightly news and in political speeches. Whether global warming is true or not is not the topic -- the fact the believe believe it with certainty without any knowledge is the topic.
2. Evolution: Many people believe evolution is a scientific fact, when in fact it is a theory. And, the details of this theory are fluid - for it is not an uncommon occurence to find a media article about a new scientific discovery, a new fossil, etc that changes their understanding of evolution. but bottom line, many people believe as fact that which is fluid theory, because they have no actual knowledge of the details
3. Alien life: many people have an opinion they will state with the assertion of fact that life does/does not exist outside out little corner of the solar system, when it is simply impossible to know.
Three random areas of "science" for which many people state as fact things for which they know essentially nothing, other than what someone else told them.
Science itself takes as fact many things which change as new information is revealed, and other things they take as fact because, well, because it appears no new information will ever change that fact (1+1=2).
A Christian that wants to say "God created the heavens and the Earth" does not necessarily have to disagree with *any* science...and in fact would be a fool to do so. What a Christian's obligation is, is to say "God created the heavens and the earth" and take the subsequent stories, and then *combine* them with the scientific facts available to determine what he believes. God created...science says Big bang theory...oh, hey! Maybe the christian now has the methode of God's creation! There is no need to aruge...in fact, it fills in a hole, becaus the scientists do not have a single clue as to what was there before the Big bang...
So you see my point - it is foolish for a Christian to refute science with God's word. They actually have a much more difficult task of aligning scientific truth with God's Word...but in no way does it diminish science.
You say religious people claim certainty...I say scientific people claim just as much certainty, and leave little room for options outside their own beliefs, even though science is constantly changing. But the bottom line is that I assume you believe there are "laws" that "control" the universe we live in...laws...certainties...and it is these certainties that science is driving to discover and understand. I don't understand why a Christian saying "Here, I know a couple of things for certain" is such a bad thing, especially if they accept that these "certain things" are hardly scientific...
young earth is a silly theory if you can't refute the science that disproves it, and in the absence of science to disprove young earth, a Christian is obligated to understand why he doesn't understand the language of his book. Many do. Ham doesn't. it doesn't mean Christians as a whole are wrong it mean Ham is wrong, just as scientists argue about String theory and take up sides.