Despite former President Obama’s persistent bleating, there is no such thing as “settled science.” The Earth was flat, the Sun circled our planet, and lightning was thought to be a message from Zeus until proven otherwise. The fact is, science continually changes as much of what was assumed to be true is retested and found to be faulty. In my lifetime, dentists once packed mercury-laden fillings in their patients’ teeth while bare-handed. Who knows how many young patients incurred neurological issues due to mercury exposure or how many patients caught dread diseases from the crud under dentists’ fingernails? Luckily, the...