Since I provided a demonstration myself of source fallibility in my last post (gas compression technology), time for a bit more on sources, knowledge, and whom to trust how much about what. On the least interesting level, it was just a matter of an unsupported statement by someone speaking out of his field of expertise. That's the least reliable sort of statement you can have. The more important or interesting the topic is to you, the less confidence you want to put in the statement. That's true whether it's me talking about old technologies (you have no reason as yet to think that I know much about that area), or engineers regarding climate change, or ....
As I've encouraged, the first comment/correction included a source. More or less reasonable source (vs. quoting some other blog by some other nonspecialist in the topic) beats an unsourced comment. Next step would be for me to provide the even better source I'd read for my original comment.
Here we get a little more interesting for doing science. I don't remember that source. For me the source I read beats a Wikipedia article. I read the source and could see how good it was, by an author of what expertise, etc.. But where does that leave you? Some might be tempted to figure that I'm a good guy (of course I am! :-) so I must be more trustworthy than a Wikipedia article. As a social matter, that works. But the science-minded here know what you're left with, for thinking about science, is that Wikipedia article. Science is not only about knowledge, but about shared and sharable knowledge.
If someone can't share the source or support for their knowledge, it isn't science for you. They might be right. But without that sharability, it isn't science. The more interesting, surprising, or important the point is, the more important you be able to follow up someone's first comment with a source.
Even when I'm within my professional areas, therefore, requests for sources where you can learn more are welcome. I won't always be providing them in the original note as it can make for awfully slow reading for you. Still, when you're surprised by something (say, because it contradicts something you thought was true), do ask for a source. In my serious areas, I can provide you with them, and usually several. Of course I'll ask you to be even-handed about it -- while questioning where my source is, please go back to where you learned the point I'm disagreeing with and check out the sources on that, too.
Old comment: "It isn't what you don't know that's the problem. It's what you know that isn't so."