[H]ere, for example, the Supreme Court waxed eloquent on the impressive qualifications of plaintiffs' experts. Yet something doesn't become “scientific knowledge” just because it's uttered by a scientist; nor can an expert's self-serving assertion that his conclusions were “derived by the scientific method” be deemed conclusive, else the Supreme Court's opinion could have ended with footnote two. . . . Our responsibility, then, unless we badly misread the Supreme Court's opinion, is to resolve disputes among respected, well-credentialed scientists about matters squarely within their expertise, in areas where there is no scientific consensus as to what is and what is not “good science,” and occasionally to reject such expert testimony because it was not “derived by the scientific method.” Mindful of our position in the hierarchy of the federal judiciary, we take a deep breath and proceed with this heady task.