# Unexpected precision **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [March 11, 2021, 5:07pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720 "2021-03-11T17:07:38Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [March 13, 2021, 10:49am UTC](https://boards.straightdope.com/t/unexpected-precision/937720/41 "2021-03-13T10:49:53Z")
After all, it is just a conversion from 37°C. And that is based on what may well be flawed measurements anyway. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [March 13, 2021, 11:15am UTC](https://boards.straightdope.com/t/unexpected-precision/937720/42 "2021-03-13T11:15:33Z")
I had to argue with the marketing department of my former company because the specs we’re getting converted into this kind of false precision. The engineers would say that something would work for 1000 yards so they would claim 914.4 m. I’d complain and they cut off the .4 part. ---
**Author:** ![Reeses\_Monkey](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reeses_monkey/32/2885_2.png) [@Reeses\_Monkey](https://boards.straightdope.com/u/Reeses_Monkey)\ **Post date:** [March 13, 2021, 1:00pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/43 "2021-03-13T13:00:06Z")
Should avacados be bought in guacamoles? ---
**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:** [March 13, 2021, 1:00pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/44 "2021-03-13T13:00:41Z")
Similarly, on the 2003 Battlestar Galactica, they started every episode with an exact count of the number of survivors. Which would be poignant, except that they never did an actual census of the living. They counted each and every death and birth, but they applied those changes to an initial number of “50,000”. And I’ve heard that the reason for precise speed limit signs is that drivers actually obey them, instead of guessing what they think the speed limit is supposed to be. Tell people it’s 25, and they’ll go 30 or more. Tell people it’s 20 or 15, they’ll probably go 25. But tell people it’s 23, and they’ll go 23. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [March 13, 2021, 2:12pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/45 "2021-03-13T14:12:25Z")
Yep, that’s the whole point of those quirky speed limit signs you’ll sometimes see on private roadways, like in a parking lot or on a corporate campus. They are not there for their precision—they are there to draw attention to themselves through their oddness, which they do well well, it seems, as they are still remembered years later on a message board. ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [March 13, 2021, 2:27pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/46 "2021-03-13T14:27:48Z")
> [@Gatopescado](#): > > I’ve noticed the standards of measurements are “Hoover Dams” and “Titanics” And that standard, oft used American measurement of length, the football field. ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [March 13, 2021, 2:55pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/47 "2021-03-13T14:55:16Z")
2.0299999999999994 pounds equals 920.7925110999997 grams, so this is precise to 10 to the minus 13 grams. Meat is composed of various elements, but pretend it’s composed simply of carbon. One mole of carbon has a mass of 12.011 grams, so it’s precise to the 10 to the minus 14 moles. 10 to the minus 14 moles of anything is 6.023 times 10 to the 23 atoms. So this is precise to (ignoring some approximations I’ve just made) the 10 to the 9th (i.e. one billion) atoms. So you should have insisted that it be precise to the atom. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [March 13, 2021, 3:56pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/48 "2021-03-13T15:56:12Z")
Double-decker busses and tennis courts over here. ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [March 13, 2021, 4:11pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/49 "2021-03-13T16:11:42Z")
After repeatedly having the 420 mile marker on I-70 in Colorado stolen by stoners, the Dept of Transportation finally decided to replace it with one that read “419.99”. I remember several years ago reading a letter to the editor in the local newspaper written by some old lady who claimed to be 87 and a half. Which made me giggle, since most people quit adding “and a half” around the age of 5. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [March 13, 2021, 4:15pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/50 "2021-03-13T16:15:16Z")
A report of an explosion said that police estimated that they had used 2200 lbs of explosive. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [March 13, 2021, 4:25pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/51 "2021-03-13T16:25:13Z")
> [@gdave](#): > > There is a G.E. facility which I have to drive through fairly frequently. They have a lot of speed limit signs posted. They used to say “SPEED LIMIT 25 MPH”, but a couple of years ago they started replacing them all with signs saying “SPEED LIMIT 24.5 MPH”. That extra 0.5 MPH was creating some significant safety hazards, I guess. It would be unfortunate if some hotshot in a Bugatti Veyron mistook that for “245 MPH”. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [March 13, 2021, 5:05pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/52 "2021-03-13T17:05:57Z")
> [@F.U.Shakespeare](#): > > On an undergraduate engineering exam, I solved a problem and wrote the answer as “~ 31.26 degrees”. The professor showed a sense of humor when he marked it correct but added, “ _How_ approximately?” When I was younger I had a friend who would calculate his gas mileage to six decimal places. At least this was in the day of digital pumps where you could get hundredths of a gallon displayed but even so I had to teach him about significant figures and anything more than four in his case was gilding the lily. ---
**Author:** ![TheGunIsMightierThanThePen](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thegunismightierthanthepen/32/2981_2.png) [@TheGunIsMightierThanThePen](https://boards.straightdope.com/u/TheGunIsMightierThanThePen)\ **Post date:** [March 13, 2021, 5:12pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/53 "2021-03-13T17:12:50Z")
There’s a [subreddit](https://old.reddit.com/r/oddlyspecific) where these kind of numerical oddities pop up every now and then. [![](https://i.imgur.com/PbuBmva.png) ](https://i.imgur.com/PbuBmva.png) [![](https://i.imgur.com/pO6iQUc.jpg) ](https://i.imgur.com/pO6iQUc.jpg) Not sure if these pictures have been doctored, though. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [March 13, 2021, 5:14pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/54 "2021-03-13T17:14:19Z")
> [@bob\_2](#): > > After all, it is just a conversion from 37°C. And that is based on what may well be flawed measurements anyway. The way I heard it, Farenheit set the scale with zero as a saturated saline solution to depress it as far as possible – he hated negative numbers – and 100 as human temperature, using his wife’s measurement. Apparently she was running a little warm that day and subsequent measurements by others set ‘human’ at 98.6 rather than fiddle with the scale. ---
**Author:** ![Precambrianmollusc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/precambrianmollusc/32/63_2.png) [@Precambrianmollusc](https://boards.straightdope.com/u/Precambrianmollusc)\ **Post date:** [March 13, 2021, 5:41pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/55 "2021-03-13T17:41:39Z")
> [@DesertDog](#): > > he hated negative numbers I heard he would stop at nothing to avoid them. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [March 13, 2021, 5:50pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/56 "2021-03-13T17:50:41Z")
> [@Precambrianmollusc](#): > > > [@DesertDog](#): > > > > he hated negative numbers > > I heard he would stop at nothing to avoid them. - I’ll smack you once I stop laughing. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [March 13, 2021, 5:54pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/57 "2021-03-13T17:54:49Z")
> [@Precambrianmollusc](#): > > I heard he would stop at nothing to avoid them. > [@running\_coach](#): > > I’ll smack you once I stop laughing. I’ll be next in line. It took me a second but it was worth it! ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [March 13, 2021, 5:55pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/58 "2021-03-13T17:55:56Z")
> [@Ludovic](#): > > I’ll be next in line. It took me a second but it was worth it! It’s gonna look like that scene in _Airplane!_ ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [March 13, 2021, 5:57pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/59 "2021-03-13T17:57:11Z")
Farenheit wanted 0 and 100 to be the extreme ranges of the temperature in Europe, or at least around where he lived. You can’t use hottest and coldest as temperature references since you can’t arbitrarily generate those temperatures, so he had to come up with something repeatable that he could use to get approximately those temperature ranges. He basically started with Ole Romer’s scale and multiplied the values by four to give him the precision that he wanted. He then tinkered with the scale a bit so that there would be exactly 64 degrees between the melting point of ice (which he set at 32) and human body temperature (which he set at 96). This allowed him to easily create a scaled thermometer by repeatedly bisecting the thermometer’s range between these two points (halfway between 32 and 96 gives you your 64 degree mark, halfway between 32 and 64 gives you your 48 degree mark, etc). The scale was later revised when it was noticed that water boiled at 212 degrees, so 32 and 212 became two fixed points on the scale, with exactly 180 degrees between them. There has been a bit more fiddling with the scale since then, but that’s the basic history of how Farenheit came up with it. ---
**Author:** ![Precambrianmollusc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/precambrianmollusc/32/63_2.png) [@Precambrianmollusc](https://boards.straightdope.com/u/Precambrianmollusc)\ **Post date:** [March 13, 2021, 6:08pm UTC](https://boards.straightdope.com/t/unexpected-precision/937720/60 "2021-03-13T18:08:08Z")
I wish I could claim originality, but it’s an old math dad joke about the mathematician who hated negative numbers, and DesertDogs lead in was too good an opportunity to not use it. [Previous page](https://boards.straightdope.com/t/unexpected-precision/937720.md?page=2) [Next page](https://boards.straightdope.com/t/unexpected-precision/937720.md?page=4)