WildHeart75 writes: "Wanna talk about senseless? How about those who do not believe the Bible to be accurate because it was written by man, yet believe every word man tells them about science, which man founded. A scientist can make anything up and people will believe him, because.......he is a scientist, he would know...yet, the same people try to discredit the Bible on the basis it was written by man?"
Talk about projection! Your entire world view is based on nothing other than a credulous appeal to authority, so what do you do? You impugn others with your own credulity. Who, exactly, believes a scientist on the ludicrous grounds you claim? Have you ever actually read a scientific paper? (I'm not talking about popularizations you might check out of a library; I'm talking about primary, peer-reviewed work.) Do you have the slightest idea how stringent the requirements are to get published in the professional science journals?
One doesn't believe a scientist because he/she wears a lab coat and speaks in polysyllabic words. One grants provisional assent to a scientist's conclusions based on the integrity of the research performed and the soundness of the conclusions drawn from such work. The work itself must fulfill certain minimal requirements, e.g., it must be potentially falsifiable; the experiment (if one was performed) must be -- in principle, at least --repeatable; the raw data conclusions were drawn from must be public so one's peers can evaluate the adequacy of the conclusions. Scientific work must also jibe with currently accepted models of how the world works; otherwise, if the work is of such a nature that it calls into question prevailing models, those models must be either modified to accommodate the new findings or be scrapped altogether in favor of new, more adequate models.
Have you ever paused to wonder why it is that YECs who publish never (let me repeat that, NEVER) publish their "work" in professional, peer-reviewed scientific journals but instead target their books and papers at scientific illiterates in the general public? Let me give you a clue. It starts with a "p" and ends in "olitics".
In answer to the question posed by this thread's title, YECs believe in a young earth for the following two reasons: (1) failure to grasp the science at issue and (2) submissiveness to authority based on successful cult indoctrination. How else to explain such irrationality?