I ran into an interesting article today, about how juries suddenly think they're experts on how evidence should be presented at a trial having watched CSI. Take this example from the article:
A disappointed jury can be a dangerous thing. Just ask Jodi Hoos. Prosecuting a gang member in Peoria, Ill., for raping a teenager in a local park last year, Hoos told the jury, "You've all seen CSI. Well, this is your CSI moment. We have DNA." Specifically, investigators had matched saliva on the victim's breast to the defendant, who had denied touching her. The jury also had gripping testimony from the victim, an emergency-room nurse, and the responding officers. When the jury came back, however, the verdict was not guilty. Why? Unmoved by the DNA evidence, jurors felt police should have tested "debris" found in the victim to see if it matched soil from the park. "They said they knew from CSI that police could test for that sort of thing," Hoos said. "We had his DNA. We had his denial. It's ridiculous."
It struck me that this type of problem is hardly limited to crime scene investigation. Almost all of the cranks you see are people with next to no knowledge in a subject area who have heard snippets about it and think they've come up with some insightful breakthrough - never having actually gotten an education in it. And then there are creationists who think they know enough about biology to disprove evolution, or enough about astrophysics to prove the universe couldn't be 13.7 billion years old, or enough about geology to... Well, you get the picture.
But by far the worst offenders in this area are conspiracy theorists. These people are not only experts in crime and how to keep a conspiracy secret (from everyone but themselves, naturally), but they'll make arguments based on their "expertise" of almost any area of science and engineering, from the "speed of gravity" to how a flag waves in a vacuum.
The problem is, for any of these areas there are actually numerous people who are unquestionably experts looking at the same data. If there were a problem, why wouldn't the experts see it? Ah yes, they must be in on the conspiracy, too. Only the average people (who coincidentally have a worse understanding of the principles involved) will dare to point out the flaws.
The Idiot Box
But what is it that makes so many people falsely believe they understand these situations as well as experts? Well, like in the CSI example, a big cause of it is likely television. People these days watch it a ton, and they expect it to be true. There's some innate expectation on people that they wouldn't be allowed to say (or show) something on television if it weren't true (or scientifically accurate or at least plausible in the case of fiction). Possibly this is due to a simple trust for authority (which might explain why this prediliction isn't present in everyone), but I can't say for sure - I'm no expert on this matter.
So, people watch a lot of TV and expect what they see there to match with the real world. Unfortunately, a lot of things get in the way of this. First of all, the writers of shows almost never have a good grasp of the science involved (that's why Bad Astronomy exists: to set them straight). Sometimes they'll consult experts, but not often. The second problem is that the writers will often actively choose to go against what's accurate in order to increase drama or humor.
The result of this is that television is filled with ridiculous notions such as exploding cars, sound in space, lack of inertia in space, gunshots sounding like explosions (they're more like firecrackers in general), etc. People get so used to the TV version of science that the real-world version ends up seeming less real.
Lies to Children
Another problem that leads to false expertise is that many of these people simply don't realise their knowledge is incomplete. Almost every adult has taken various science classes in high school, and many of them roughly remember the lessons they learned. However, high school science is vastly simplified compared to expert-level science, but this isn't always made clear if they don't go on to learn more. For instance, students are generally taught that both mass and energy are conserved, but it's less often they're taught that nuclear reactions can convert between the two, and that thus all mass is energy, and this combined quantity is what gets conserved. For that matter, even that's a bit of a simplification as there are a couple subtle complications to it, such as conservation looking the other way for a moment for quantum tunneling to occur, or in cosmological redshift where energy is drained from light as it travels across space for a long time (this is sometimes handwaved away as a form of potential energy).
It requires a vast amount of knowledge to be an expert in any academic subject, and most people simply don't have it. In general, to become an expert you should expect to graduate from high school, go through around 8 years at university, and then spend many more years in postdoctoral studies. On top of that, it's expected that you get published in a reputable journal multiple times and/or gain significant praise and/or awards from peers in the field.
Starting from a bit more than Scratch
But what if you disagree strongly with a major tenet of a certain a field, and still wish to become an expert in it? For instance, let's take the classic example of evolution in the field of biology. The first question that needs to be answered is whether you started to disagree with evolution because you studied biology for 10 years and it just didn't add up, or whether you disagree with evolution for other reasons. In the first case, you're probably alright. You've already done all the studying, and can hopefully show that you understand the material and maybe convince other professionals of the flaws in the model. If you can do so reasonably, you can get to be regarded as an expert.
In the second case, however, you're making a fundamental error. You've come to a conclusion on a subject when you haven't studied it extensively for yourself. Now, if you were accepting the word of experts on this subject and trusting that they've probably come to the right conclusion, this isn't bad at all, but that's not the case we're talking about here. What's happening here is that you either disbelieve in the theory either due to your own faulty knowledge or due to the authority of a non-expert. If you want to become an expert, you have to accept where the evidence and greater understanding leads you. You can never become an expert by starting with an assumption and then trying to find all the evidence that justifies it.
In short, my advice to anyone who wishes to become an expert in a field but holds a differing belief from the bulk is this: Drop that belief, try to get rid of any emotional investment you may have in it (try to revert back and start at zero, before it was ingrained in you), and go where the evidence leads you. Start your investigation with questions, not answers. In fact, this is probably good advice even if your beliefs coincide with those of experts; you'll learn how it was all figured out from scratch, will ask all the right questions, and if the theory turns out to be wrong you just might discover this.
But of course, I'm no expert on expertise, so you don't have to take my word for it.