Far be it from me to offer advice on etiquette. I'm blunt, crass and occasionally unreasonable. I've improved quite a bit from my twenties, though ("Let's think about that a little more before we implement it" vs. "That's a really stupid idea", for example). And occasionally I ask for advice, like I'm about to do. Yes, believe it or not I really don't know everything. That's not a job requirement for blogging. Which is a good thing, or the number of blogs would soon plummet to zero and there wouldn't be anybody around to argue with.
Here's my issue. Let's say you're at a lecture. I'm not an engineer, but I'm going to say it was a lecture about engineering, and let's say you're an engineer. It's a really good presentation and you're very interested until about halfway through, for no reason you can tell, the presenter says something that's completely wrong.
I'm not just talking about matter of opinion wrong. I'm not even talking Wrong on the Internet, which is a whole nother thing. I'm talking scientifically wrong. I'm talking the equivalent of an engineering lecturer saying that, just incidentally, E does not equal MC squared, it equals RB cubed. (RB cubed. RB cubed. Hm, I'm getting hungry.) Or, to be a little less esoteric, let's say the engineering presenter just told everybody that sound travels faster than light. Which is, by the way, completely untrue, and has been scientifically disproven any number of times.
(It's also obvious. Try sending a friend of yours about a football field away with a pair of cymbals and have your friend play the cymbals. If you're watching, you will clearly see that the cymbals come together a second or two before you hear the clash. Why? Because light, which involves things you can see, travels faster than sound, which involves things you can hear. And if you have a friend that is good-natured enough to play cymbals on a football field with you just so you can prove a point, then, hang onto that person. Such friends are rare.)
What's more is how the lecturer announced this piece of laws-of-physics-bending news. Not merely "Here's a fact," but, "Here's a fact that everyone else on the planet (or at least all engineers) already know. You people are the only people on earth who don't already know this, and I'm doing you the great favor of telling you, so be grateful, already."
Let's say that after you get over being surprised, you look around to see how your fellow engineers are taking this bit of news. You expect that most of them will look skeptical or be frowning. Instead, they're all earnestly writing this down. Well, why not. Somebody has just said that black is white, that freedom is slavery, that peace is war, and nobody knew this before. What's worse, the guy to your left says, "Man, this is fascinating. I never knew half this stuff."
Okay, end of hypothetical and time for the question. What do you do?
Seriously, is it ever okay to interrupt a lecturer? Should I have held up my hand, like a polite elementary-school student, and then, after being duly called on, should I have said, "I'm sorry, ma'am, but you're wrong"? Should I have brought up all the scientific evidence to the contrary (Google on a cell phone is a wonderful thing) and engaged her in a debate? Should I have waited for a break, then approached the lectern (hopefully without getting tackled by security) and told her privately that she's mistaken and hope she corrects herself? Or what, exactly? What do you do?
I know what I did do, which is to say, nothing. I sat there and watched my fellow engineers (okay, they weren't really engineers) take notes on this scientifically incorrect point and nod sagely as though they'd been handed a great truth. And I've been feeling bad about it ever since. I mean, this is forty or fifty people that are now walking around with a completely incorrect concept about how the world works. Who knows how much trouble it will cause them in the future? but on the other hand, I can pretty much guarantee that if I had interrupted said lecturer, everybody there would remember nothing about sound being faster than light but everything about some fat chick interrupting the speaker about something scientific and, I don't know, a pair of cymbals and a football field.
Would that have been a good thing? I have no clue.
So anyway, if there is a Miss Manners among us, or if some arcane book of etiquette actually covers this particular situation, I'd be golden if one of y'all would let me know. In the meantime, I remain silent in the face of physics-changing factual errors. Cheers.