# Looking to nature for precision? **URL:** \ **Category:** Factual Questions\ **Created:** [June 18, 2014, 4:23pm UTC](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077 "2014-06-18T16:23:32Z")\ **Posts on this page:** 9\ **Page:** 3
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 20, 2014, 4:41pm UTC](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077/41 "2014-06-20T16:41:31Z")
> [@](#): > > Quoth **here and there** : > > Ok… maybe the tower of Pizza was a bad choice . > I am sure there are ways to double check a towers height, and record its change over time. Sure. For instance, you could drop an object off of it, and time how long it takes to reach the bottom. Except that that’s no use if the clock you’re using is calibrated by dropping things off of that tower. > [@](#): > > And I don’t think that, nowadays, scientist have to travel to Paris or wherever that kilo is… > unless, of course, they can justify the expenses . It is still a pretty big inconvenience, which is part of the reason why the standards organizations are trying to come up with something better. But it’s at least less inconvenient than a tower: The lab in Paris can make copies of that standard kilogram, calibrate them using the primary reference, and then ship those copies around the world to various nations’ standards institutes, who then in turn make second-order copies from those, and ship them to labs within the country who want them. It’s a lot harder to make copies of your standard tower and ship them around the world. > [@](#): > > The point here is, that it’s relatively easy to create standards. Sure, creating standards is a cinch. It’s just hard to create _good_ standards. ---
**Author:** ![Furious\_Marmot](https://avatars.discourse-cdn.com/v4/letter/f/dfb087/32.png) [@Furious\_Marmot](https://boards.straightdope.com/u/Furious_Marmot)\ **Post date:** [June 20, 2014, 4:48pm UTC](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077/42 "2014-06-20T16:48:31Z")
> [@Dewey\_Finn](#): > > The OP modified the question [here](http://boards.straightdope.com/sdmb/showthread.php?p=17479000#post17479000), so that we are now seeking “some of the most consistent or constant things in nature that could be used as some kind of standard.” Presumably this revised situation means that the rulers are still available to be used for measurement. According to the restatement post by the OP, we have “primitive” rulers and the goal is to find “some of the most consistent or constant things in nature that could be used as some kind of standard.” Crystals are a bad choice for the consistency part of the question, because they are not consistently sized. As for the new standard part of the question, we can measure a single crystal, but that is only as useful any other object in making a new standard. We might as well use an iridium rod like they did with the meter the first time around. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [June 20, 2014, 5:05pm UTC](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077/43 "2014-06-20T17:05:57Z")
Iridium rods aren’t often found in nature. And yes, you’re probably not going to find multiple crystals of the same size (although, in theory, you could cleave them to the same size). I don’t think there is any natural object that is consistently the same size. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [June 20, 2014, 5:08pm UTC](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077/44 "2014-06-20T17:08:45Z")
would the smaller something is make it have closer tollerances, for example a very small seed form a plant shown to show consistent size seeds. I have seen seeds so small I can barely see them with the naked eye much less detect any visual differences in size. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [June 20, 2014, 8:24pm UTC](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077/45 "2014-06-20T20:24:08Z")
Once again, history has beaten you to it: [Barleycorn (unit) - Wikipedia](http://en.wikipedia.org/wiki/Barleycorn_%28unit%29) ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [June 20, 2014, 9:16pm UTC](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077/46 "2014-06-20T21:16:46Z")
> [@HoneyBadgerDC](#): > > would the smaller something is make it have closer tollerances, for example a very small seed form a plant shown to show consistent size seeds. I have seen seeds so small I can barely see them with the naked eye much less detect any visual differences in size. I doubt it. I’ll bet that if you measured those seeds, you’d find as much variation as in larger objects. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [June 21, 2014, 12:12am UTC](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077/47 "2014-06-21T00:12:42Z")
The key to precision seems to be less about finding something consistent and more with defining idealized circumstances that greater and greater precision of measurement would allow us to approach a true measurement. So a base case might be: Fill a bucket with water. Place a copper cylinder with a radius 5x its height (i.e. a coin) flat-side down onto the water. If the surface tension of the water holds the coin up, create a larger coin. If the coin sinks, shrink the coin. The largest coin which can be found that does not sink after 24 hours is one grobnoggler in diameter. But then to account for differences of circumstance, you’ll have to define things like: 1. The copper must be absolutely pure copper, made using X methodology so that its density is consistent. 2. The water must be absolutely pure H20. 3. The air pressure must be the same as sea-level. 4. Etc. ---
**Author:** ![here\_and\_there](https://avatars.discourse-cdn.com/v4/letter/h/f07891/32.png) [@here\_and\_there](https://boards.straightdope.com/u/here_and_there)\ **Post date:** [June 21, 2014, 10:26am UTC](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077/48 "2014-06-21T10:26:49Z")
> [@Chronos](#): > > Sure. For instance, you could drop an object off of it, and time how long it takes to reach the bottom. Except that that’s no use if the clock you’re using is calibrated by dropping things off of that tower. > > It is still a pretty big inconvenience, which is part of the reason why the standards organizations are trying to come up with something better. But it’s at least less inconvenient than a tower: The lab in Paris can make copies of that standard kilogram, calibrate them using the primary reference, and then ship those copies around the world to various nations’ standards institutes, who then in turn make second-order copies from those, and ship them to labs within the country who want them. It’s a lot harder to make copies of your standard tower and ship them around the world. > > Sure, creating standards is a cinch. It’s just hard to create _good_ standards. Sorry, but, people you don’t seem to get it… You have, somehow, created the notion of some “ideal perfection” in your mind. But it’s not like that. It’s all relative. The trick is to know “how much” relative it is. The kilogram copies you are referring they are not “ideal” copies. But they know how “bad” copies they are. They know that this copy is 1.00001 kg and the other copy is 0.9999999999 kg, because they have compared it with the original “true” 1kg. In my example you could simply look at your cheap quartz clock and see how “off” it is by the standard you have created. The “bad” kilogram standard have served us well for many years. And the Roman “meter” was just a line curved in rock. Before building anything, they would curve a line, and say “this is the meter”. And everything, in the project, was build proportionally to this “meter”. Of course someone can guess that they didn’t draw that line randomly. They probably had to compare it with some standard. But nothing as accurate as what we have today. And their buildings are still standing. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 21, 2014, 2:10pm UTC](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077/49 "2014-06-21T14:10:00Z")
Of course I know that we can’t achieve “ideal perfection”. That doesn’t mean we should feel free to be as sloppy as we like. Yes, the Romans were sloppier than us, and many of the buildings they built are still standing… but you may not have noticed, but some things built in the modern world are a lot more complicated than a Roman building. [Previous page](https://boards.straightdope.com/t/looking-to-nature-for-precision/691077.md?page=2)