RedKnight

Thanks folks, I appreciate it. John, it's interesting to see that they "standardize" on using standard deviation (and similiar stats) for expressing uncertainty. Still, I think my question focuses more on precision than uncertainty or accuracy. Tar, I'm sure you're right... we two overthink things, perhaps. But then sometimes concepts are in usage enough that words are generated or borrowed. Like weltgeist. Or menage a trois. There once were times when some people thought of such ideas or in such ways, but there wasn't a word for it (yet). However, apparently my idea isn't sufficiently "popular" to have it's own word or line of study, as it were. At least not for folks who've viewed this. Still... there we are. Thanks for helping, all! Mike

Hi, thanks, tar... I pondered the replies here for a while (sorry for not responding!) and came to see that, indeed, this "5" really is just one sig fig. But, still, there is something going on that I have not yet been able to enunciate well. Or maybe there simply is no specific term for it. Bignose (and you?) has called it measurement accuracy, which is of course entirely accurate. But is there not some more specific term? Mentally, I think of a directional reading of, say, 270 degrees from a compass with a full 360 degree accuracy, with that of some very crude wind vane which, for sake of argument, can only return the general direction and thus only ever returns 0 for north, 90 for east, 180 for south, and 270 for west. Yes, of course this is a contrived example - but then, there are many real-world examples of one device measuring much more accurately than another. In this crude example, a measurement of "270" on the one is a lot different than the other, in terms of the percent circumference of a circle it might possibly describe (1/360 for the one, 1/4 for the other). One can even argue the windvane isn't even really returning 270. A more realistic example would be e.g. comparing an old analog dial-type resistometer (volume knob) with 10 settings, to a modern digital dial knob. But is "measurement accuracy" the best term for this? Isn't there something a little more specific? Such as ... I don't know... instrument-specific inherent precision, or something? Thanks if anyone has ideas!

Thanks for the general info, folks. But I thought it was clear I was looking for a quantitative or decisive answer. (Or a decisive answer that there can't be a decisive answer.) Can anyone answer the question quantitatively? An actual value for how much it matters to flatten mashed potatoes? Or use a tall glass instead of a bowl, for the same amount of water? Just ballpark estimates. Does it matter enough to worry about? In case I need to clarify: "maybe" is not what I'm looking for. "It depends" isn't either, unless followed up with quantitative answers. Thanks! Mike

Hi folks, Info on microwave ovens often talks about the direct efficiency of converting electrical power to microwaves. Ok, that's pretty straightforward; I am NOT asking about that. I can't find much of anything that addresses the "efficiency" of the microwaves that are created, being converted to heat in food. Said another way, what happens to microwaves that "miss" the food; are they simply lost? Many illustrations showing magnetron emissions appearing to bounce around in the oven, and info says the walls are highly reflective... do they keep bouncing until they hit food, conferring very high efficiency? Or is this even the proper way to think about it, since they make standing waves? I realize a lot depends on exactly what is being heated. To make things simple and practical, the core issue driving my question is that I'd like to know how much I should care about, say, spreading a big mound of mashed potatoes flat before microwaving it. How much will it matter in terms of efficiency (which also equals less time and electricity)? Is it extremely inefficient to microwave things that are not flat - like tall cups of water? Thanks if you can help! Mike

Hi folks, Here's an armchair question... A significant figure (sigfig) is the number of figures (a.k.a. digits) to which a number is meaningful, even if the numbers are zero. For example, 10.000 has 5 sigfigs if indeed one has that much precision. But how about in the instance of degrees of a compass, when measuring it as a full 360 degrees... if the current measure is 5 degrees, how many sigfigs does this have? I would think it effectively has three. Or maybe it's simply a question of semantics. Your thoughts? Mike P.S. My first post here! ScienceForum.net looks like a nice active place.