Pronouncements in the press tend to be pretty dramatic. Drama is pretty much the only way to get into the news, so sometimes it is the scientist and sometimes the reporter who gooses the story.
Always remember that what you read is typically what comes out after a reporter has digested the information.
Pronouncements fall into several categories:
- Solidly backed by experiment and theory. Sometimes reality is weird (e.g. quantum mechanics) and you need some experience to understand it; and reality is often inconvenient. Look for humility, stable consensus and eagerness to talk about experimental verification, but those aren't perfect guarantees.
- Within the bounds of a current consensus that works OK. The consensus might be wrong, but that would be a big deal. Sometimes we know the current theory has holes, but nothing has been better so far. For example, quantum mechanics and theories of gravity don't play well together, so string theory (which is supposed to unify them) has been popular for a couple of decades, despite the fact that it hasn't gotten anywhere. The rest of us muddle along with two inconsistent theories and apply each in the place where it works best.
- Badly scrambled: either this is speculative and not really in the consensus or the reporter garbled it. This, for example. The theories about universe bubbles are part of some cosmological theories, but they're quite speculative, they're untestable, and connections to particle physics are even more speculative. The reporter was hunting for something weird enough to print, and I doubt that Hill or Lykken was happy with the story. Look for something that would be hard to test, or which doesn't seem tightly related to the experiment at hand.
- Within a current consensus that doesn't work worth beans though we pretend it does (some fads in psychiatry come to mind). AGW is so political that it is hard to have a science discussion about it, although you may have noticed that the "A" (anthropogenic) and "W" (warming) have pretty much disappeared from the media reports. The consensus didn't work so well... If you don't have domain knowledge of the field, about the best you can do is know a little of its history. If the consensus changes frequently, don't trust it. (Don't trust the pronouncements or the consensus.) But the only way to know the history of a field is to either study it (which isn't easy to do) or live long enough and pay attention. Watch for supporters with vested interests.
- A wondrous new paradigm shift with new science and new vistas. This is very very rare. I can think of "jumping genes," but not too much else recently. Not something you need to worry about most of the time.
- Botched experiment. This is actually rather common, as scientists eager for publication and possible future research grants rush out press releases before the peer review. Hint: is the news about something that has been accepted for publication? If not, be cautious; and even if it has been accepted, know that there are some vanity science publications out there...
- Hollow. We've no shortage of "theories" about healing energies or ways to disprove Einstein or allow perpetual motion. In the physical sciences these are usually easy to spot if you have the habit of trying to be precise about meanings of words or of looking for what a theory predicts mathematically. I'm not so sure how to spot them in linguistics or neurology or psychology. A rule of thumb: if the speaker explains how he is overthrowing current paradigms or going against an intrenched establishment, he's usually full of it. But not always. Sometimes the intrenched establishment is full of it (see above), and sometimes they both are.
- "What a noble mind is here o'erthrown." Doing important work in one field doesn't mean you're going to be right at whatever your hand finds to do. Linus Pauling was a genius, but got a bee in his bonnet about vitamin C and lost track of his own disciplines. Look for simple solutions to hard problems; chances are they're too simple and the visiting expert has left some things out.
Just a few possibilities ... You can also win a little by looking for poison citations. Someone who cites Fort, or has research that cites only his own work (Noam Chomsky)--dubious. Each field has its own usual suspects. Perpetual motion or disproving special relativity are obvious ones in physics, but I don't know what their counterparts are in archaeology or embryology. Maybe somebody should make a list.