Scientists Build World's Most Sensitive Scale 68
Adrian Bachtold at the Catalan Institute of Nanotechnology in Barcelona has created the world's most sensitive scale. The new subatomic weight scale can measure masses as tiny as one yoctogram, less than the mass of a proton. From the article: "Bachtold hopes the scales could be used to distinguish different elements in chemical samples, which might differ only by a few protons. They might also diagnose health conditions by identifying proton-scale differences in molecular mass that are markers of disease."
01 April ... (Score:1, Interesting)
Oh come on, this has to be a 1 April gag.
Have they fixed... (Score:4, Interesting)
Have they fixed that whole "kilogram standard losing mass" thing yet?
Re:Buying one will put you on "the list" (Score:4, Interesting)
How precision is "precision"? What do model builders need, and what for?
In Europe most people weigh cooking ingredients (rather than measure volume, as in the US). My pretty average digital kitchen balance cost about £15 and is accurate to 1g (up to 5kg).
(I've also never bought coke. Is 1g a small enough amount, or do you need to measure 0.1g or whatever?)
Re:Buying one will put you on "the list" (Score:5, Interesting)
How precision is "precision"? What do model builders need, and what for?
Model railroad cars work best when all the cars have a certain specified mass. Too light and the odds of derailing increase, too heavy and the engine can't pull them. Also a "large" differential means that when going around curves you'll derail. If you're just taking premade or pre-designed cars out of a box you probably don't have to bother, but if you're substantially modifying the car, then it gets pretty important. I'm too lazy to look up the "standard mass for a N scale boxcar" but someone motivated could probably google for it. Obviously getting the G scale mass correct requires nothing more than a bathroom scale, but a N scale mass is going to require at least a very good kitchen scale, if not higher precision.
The R/C planes and model rockets I built had a mass goal, where the designer believes a skilled builder should be able to get the completed airframe down to a certain weight. Theres not a heck of a lot you can do if you are over, other than evaluate your skill level, etc. Maybe enormous glue fillets cause more problems via weight than they gain in strength. I'm old enough to have caught the tail end of tissue and dope covering (monokote was dominant... have been out of the hobby for a 1/4 century, is monokote still dominant? If its such ancient history no one knows what it is, monokote was a mylar film with heat glue on one side that you'd stick to the wood with a special little iron, then a hair dryer made it slightly shink to eat the wrinkles along with of course warping the airframe a little). The relevant part of the tissue-dope covering method is its easy to make a strong covering that is as thick and heavy as a rain tarp, but the goal is to apply the dope thinly enough that it weighs nothing. Besides, that stuff was expensive, at least to a kid, so don't waste it. Most people lied about the weight of their models, "its one ounce below the designers spec" is codeword for "damn thing is a pound overweight and I can't figure out why"
The R/C car people I hung with always weighed in the cars. Depending on your class of vehicle you had to be a certain mass. Too high or low was pretty strong evidence of modifications to a stock class car, and even the unlimited classes had certain limits, for safety and fairness I suppose. The track I ran at had a maximum weight, probably spec'd by insurance or just made up to fit the safety tires that protected the viewers.
The RC helicopter guys I knew measured the weight of their blades as accurately as they could before they even attempted to balance on the razor-edge balancing thingy. If one blade weighs a tenth of a gram more than the other, its a waste of time to even begin balancing until they match on the scale.
I'm old enough that the epoxy resin and hardener for fiberglass had to be weighed because of volumetric variation and temperature coefficient of expansion issues and if I recall the catalyst was shipped bare, without fillers, so the modern technique of "just squirt out equal volumes by size" didn't work. To do a small fiberglass repair, you'd squirt out a glob of epoxy resin that looked "about right" then measure it to be, perhaps, 22.0 grams. OK that means you need to carefully squirt out precisely 1.1 additional grams of catalyst, then mix and apply to the boat fiberglass. Too much catalyst means its weak and sets prematurely. Too little catalyst and maybe it wouldn't set at all, which was always an unholy PITA.
"need" is not relevant to model building. Completely wrong word, at least for non-working models. You do not need a 1/24 scale model of a PanzerKampfwagon-IIIe or a R/C sailboat. You do not need to paint it the precisely correct color. "want" is the word you should have used. And the value of that "want" is nothing more than how much hobby money is available at the time of purchase. Its actually very much like watching TV... lots of "need need need" words but its really "want want want"