Yes it is way better! If flat Earth is so outlandish (which it is), it should be easily dismantled in debate and journalistic investigation. Not wanting to allow it full stop for fear of internet trolls grouping up is no solution at all.

Sure: journalistic investigation should quickly dismantle it, which means they shouldn't report it to the public. It would be like reporting someone's words that you have found are lies, just to be fair and balanced.

On the other hands, debates with a general audience (i.e. non-experts) are a terrible way to judge scientific arguments. Non-experts are simply unable to judge for themselves the strength of most scientific arguments, because they simply don't know the fields well enough. The vast majority of the arguments will fly by us and we'll be left as confused or more; and we'll pick winners based on charisma rather than any deeper thought.

Yes but people must do that every day anyway. It's like saying no expert opinion or statement is valid unless you check credentials first and they meet some arbitrary bar of merit.

And even then, we've witnessed a long history of 'credentialed' people being corporate puppets for certain agendas, peddlers of their own self-importance and fraud or just plain wrong.

We should pick experts, but we should pick from a range, not just the experts we like or decide are on the right side. And sometimes also pay attention to the non-experts, they can ask very interesting questions and provide good thought experiments, even if naive.

We should pick experts that other experts believe in. If we happen to be experts in a field, or even adjacent fields, then by all means, let's pick experts based on our own understanding of their arguments. Knowledge does transfer to some extent, so if you're a mathematician or physicist or statistician, you could probably judge some climate or medical papers based on their statistical methods - especially when you find flaws (even if the math is perfect, if you don't know why they chose a particular model and how well it might actually fit the thing being modelled, you may not be sure they are not choosing a known bad model).

But if we're not, the only thing we can meaningfully do is to look at what other experts are saying is the right opinion, and judge based on popularity in their field.

For pure scientific debates, I'm all for inviting any scientist with some amount of credentials to the table.

But for public policy debates, I think the track record is exactly the opposite: for every major public policy issue that required scientific knowledge, inviting the reactionary types dug out by the sleazy PR industry has done a dis-service to the public. We've seen this with tabacco, with led, and with global warming in just the last century.

Define 'some amount of credentials' and I'll bet I can find you scientists with them that support the thing you say is loony.

And as I said: that's fine - let them publish in scientific journals, let them give lectures at universities, let them participate in scientific debates.

But as long as their opinion is out of the mainstream of their field, keep them away from discussions of that field with the general public - especially when the general public has to make policy decisions based on that field.

If their scientific arguments are not convincing to their scientific peers, then they shouldn't be given a podium to try to convince the public through rhetoric and charisma.

I wonder how long it would have taken to discover the gut-brain links if experts were not allowed to speak out of their fields. Do we also measure the credentials of the peers and check their biases before allowing them to approve arguments and enter the mainstream (whatever that's supposed to mean)?

This line of reasoning is fraught with danger, though yes we should always at least try to ensure the arguments come from expertise and experience.

The gut-brain link was not discovered by bringing in gut experts on TV to opine on questions of public mental health, nor vice versa.

I feel that you're mixing up two meanings of public debate: one is the more general notion of "any debate which is accessible to the public" (like an open-enrollment scientific conference, or publishing in a science journal), and the second one is "debating for the express benefit of the entire public", such as a news television debate.

In the first one, I completely agree with you: anyone willing to put in the work to present a rigorous scientific argument should be allowed in, even if their theory is currently way outside the mainstream, and even if they are potentially biased.

For the second one, I don't think it's in anyone's real best interest to bring in dodgy experts that everyone in their field considers to be proven wrong. Especially not 1:1, suggesting to the general public a priori that what both experts are saying carries equal weight. Particularly so in something like a climate debate, where there are 99 scientists that are convinced the evidence for man-made global warming are overwhelming for every 1 that has even a moderate doubt.

Think of the following scenario: for some bizarre reason, Congress is considering a law to forbid GPS systems to make adjustments to their clocks based on the altitude of the satellites. The public will vote on this issue, so TV stations are presenting scientific views. To be balanced, they are bringing in both a world-renowned researcher in General Relativity (say, Niel deGrasse-Tyson), and a researcher who believes Newton's law of universal attraction is the final word on the effects of gravity (not sure they could find one).

Will the public be able to judge the merits of the GR non-linear equations to understand the merits of their arguments? Or would the public be better informed by only just bringing in Neil and letting them know that he represents overwhelming scientific consensus?

Like Newton's gravity? Its replacement bubbled efficiently to the surface...