Thread:BunsenH/@comment-25755405-20161018025800/@comment-24577221-20161018175535

To show how this stuff is supposed to work...

Suppose there are two competing theories about dark matter, the Pat Theory and the Lou Theory. They depend on observations A, B, C, D, and E. A, B, D, and E are rock-solid; C is uncertain.

The Pat Theory depends on A, B, and C, and D and E don't matter to it. The Lou Theory depends on D and E, doesn't care about A or B, and requires that C is false. So if C is true, the Pat Theory may be right, and the Lou Theory can't be right. If C is false, the Pat Theory can't be right, and the Lou Theory may be right.

So it comes down to C, and we aren't sure about C. It might be something like: If the Pat Particle exists, it supports the Pat Theory, and Lou can't be right. If the Pat Particle doesn't exist, Pat can't be right, and Lou may be right. The Pat Supercollider is looking for the Pat Particle. If it exists, it's expected to show up in the Supercollider about once a year, on average. The Supercollider has been running for a year and a half, and hasn't found the particle yet. Maybe it won't, ever, because the particle doesn't exist. Maybe Pat just hasn't been lucky. Maybe Pat's calculations are a bit wrong and the particle will only show up once every ten years.

But for now, both the Pat Theory and the Lou Theory may be true, and both Pat and Lou believe their theories may be true. They're both out there telling other people about their theories... and being human, they are also both telling everyone that the other theories are wrong. They want their own theories to be true; they have emotional investment in being right. If they're good scientists, they are at least polite and respectful about and towards each other, until better information resolves the matter. But neither is going to back down easily. Even if the Pat Particle is discovered, Lou may disbelieve that the observation was good -- "it might be a false positive, a glitch in the collider!" If the particle hasn't been found after several years, Pat will still want to keep looking for it. And from there, things can get ugly... because scientists are people too, with human failings.

But it's supposed to come down to the data.

And it's also possible that neither Pat nor Lou are right. There's also the Sandy Theory, the Casey Theory, and other possibilities that nobody has thought of yet. Because when it comes to physics, there's always more to learn.