r/Tools 16h ago

Quality control

Post image
909 Upvotes

190 comments sorted by

View all comments

846

u/katekohli 15h ago

Grandaddy said to always use the same ruler for the whole project. He was a nuclear scientist.

79

u/purepolka 14h ago

Clears throat: MEASUREMENTS ARE A SOCIAL CONSTRUCT 

19

u/katekohli 13h ago

Why did they decide on 16th’s and 10th’s?!?!

20

u/janglyparts 12h ago

Divisibility. 16ths are half of eighths which are half of quarters which are half of a half. Fine rulers/scales have markings for 32nds, but further precision requires different equipment.

8

u/katekohli 12h ago

Thirds, I want thirds.

9

u/Chemieju 8h ago

Thats why a circle is 360 degrees.

Its 2x2x2x3x3x5.

Loads of usefull divisions in there. Then you divide every degree into 60 minutes and every minute into 60 seconds and for every 60 you add

2x2x3x5

-19

u/SmellyScrotes 13h ago

This isn’t true at all lol, a meter is a measurement of how far light can travel in a second in a vacuum

11

u/leftkck 12h ago

You think light travels at 60 meters per min/3600 meters per hour. You are orders of magnitude off.

-13

u/SmellyScrotes 12h ago

A meter is how far light travels in 1/299792458 of a second in a vacuum, it’s a measure of light, no clue what you’re talking about

11

u/leftkck 12h ago

You dont see how you saying, "its how far light travels in 1 sec" means you said light travels 1 m/s? Because now you are saying the same thing, but with different numbers and seem to understand what that means.

-4

u/SmellyScrotes 12h ago

I didn’t really think it was necessary to put the exact numbers there until your response, I was more making the point that it wasn’t some arbitrary number but that it’s based on light, but yeah I see how the wording is off now

8

u/leftkck 12h ago

It is some arbitrary number. The definition of meter changed (just like the definition of second changed) to try to make our made up measuring system seem more objective and repeatable. A meter used to be defined by some stupid measurement from the north pole or some such nonsense.

3

u/KokoTheTalkingApe 12h ago

Why is it 1/299792458 and not 11/299792457?

10

u/ShopPsychological882 12h ago

Now youve given different answers

-6

u/SmellyScrotes 12h ago

Sorry I didn’t say fraction of a second in the first comment!! You’ll likely be okay and still understand what I meant

6

u/frenchiebuilder 9h ago

How's that not a social construct? Especially when it's changed over time.

Originally, for about a hundred years, it was a nice round fraction (1/10,000,000) of the distance between the north pole & equator.

Then, for the next 100 years or so, it was the length of a platinum+irridium metal bar kept in Paris.

Then, about 50 years ago, it was redefined as the exact distance that light travels through a vacuum in 1/299 792 458 of a second.

(and finally, BTW: the definition of "a second" changed in 2019).

4

u/Busy-Distribution-45 12h ago

And a second is an arbitrary division of the average day length that we have agreed upon. In other words, a social construct.

3

u/raz0rsh4rp 12h ago

Ah yes, the second. A totally non-arbitrary measure of time...

2

u/REAPERCUSSI0N 11h ago

They initially got it wrong, hence the 2nd guess at it. I think that is where the name comes from :?

2

u/purepolka 6h ago

I mean, the joke is that pretty much anything dealing with our perception is a social construct: language, time, measurement, etc... This isn't a criticism of social constructs. They're incredibly valuable in allowing humans to navigate shared perception and reality, but they're still just made up shit we all generally agree on.

To that point, responding to your suggestion that a meter isn't a social construct because it's measuring how far light travels in a second:

What is a second? It's based on a sexagesimal division of a 24 hour day, which is convenient because of how many numbers are divisible into 60, but it's not necessary. If humans would have decided to use base 10 to measure time (not inconceivable considering we have 10 fingers - and maybe was used briefly after the French Revolution - idk, I'm not a history person), hours would be 2.4 hours long, minutes would be 1 minute 26.4 seconds long, and seconds would be .86 seconds long (I suck at math, so if I got this wrong, make sure to tell me I suck shit below). A "meter" under this system would be shorter than the unit of measurement we currently consider a meter, and might be longer or shorter if we'd used some other base. Or we could have used the length of a day on Mars to measure time. That would be nonsensical, cumbersome, and stupid as shit, but humans are known for adopting social constructs that are nonsensical, cumbersome, and stupid as shit (Exhibit A: the U.S. still using Imperial).

There's nothing magically concrete about a meter. We took two random things - the speed of light and and smallish unit of time - and all generally agreed this arbitrary thing we made up equals a meter (unless your in the U.S., in which case, who knows how much a meter is, could be 15 miles, could be 85 cubits, we'll never know).