District courts already exercise extensive control over what and how scientific evidence gets presented to a jury. Before trial, experts submit reports detailing their opinion (these can be hundreds of pages with supporting appendices). There is then a period of expert discovery, where the experts are deposed for a day or more each and grilled by the other side’s lawyer. Then there are “Daubert motions,” where each side asks the judge to exclude parts of the other expert’s testimony. Excluding testimony based on unsound and unreliable methods is the key focus of the Daubert motions. This is a process that takes months, and involves hundreds of pages of additional briefing, plus usually oral argument to the judge. And those decisions are then reviewable on appeal. Appellate courts routinely throw out jury verdicts because expert testimony was based on unreliable methods. By the time the case gets to the jury, the expert evidence has been vetted and the jury is presented with a very controlled picture of each side’s argument.

The issue is, experts genuinely don’t agree on much of anything. Is salt bad for your blood pressure? Many medical doctors would say yes, many would say no. There is almost no subject where you can’t find highly qualified experts that have conflicting opinions.