/sci/ - Science & Math

i've heard of slugs, but not lbf

>>12153314
it’s foot-lbs, brainlet

>>12153314
1 lbf = the force required to accelerate the mass of 1 slug at a rate of 1 ft/s^2.

>>12153314
Lbf is pound force.

>>12153307

>>12153336
but pound is a unit of force...

>>12153307
I don't prefer it. Almost every unit in the US customary system is retarded. Fahrenheit is infinitely better than Celsius outside of scientific use, though.
t. Burger

>>12153390
>Celsius
>0 = cold
>10 = chilly
>20 warm
>30 hot
>40 scorching
>Fahrenheit
>80
>not even that hot

>>12153410
>F
0 = really cold
100 = really hot

>C
0 = kinda cold
100 = dead

>K
0 = dead
100 = dead

>>12153410
>Fahrenheit
>0-100 roughly encompasses the range of likely human experience

>Celsius
>that same range is contained between like -15 and 40

>>12153373
Someone's jelly

>>12153427
>>12153443
Amerisharts can't do negative numbers it seems

>>12153427
>having absolutely random point as 0 instead of the point when snow starts
So convenient

Fahrenheit is more accurate eurofags

>>12153528
>be amerishart
>cant comprehend negative numbers
>cant comprehend fractions
>scale starts at random points

>>12153472
>>12153513
>>12153550
cope

>>12153307
1 lbf = 1 slug * ft/s^2

>>12153616
And what does one slug equal?

0 being the freezing temperature is the perfect system for the everyday human experience.

>>12153639
a base 10 system that represents the range of typical human experience on a 0-100 scale seems like a pretty perfect system for people

>>12153513
The original scale made sense - 96 was mean human body temperature, 32 was the triple point temperature of water. This meant all you'd need to calibrate any temperature to this scale was your own body and some ice water (readily available for a sizable chunk of the year in parts of Europe at the time, and trivially available now), after which you can simply bisect the scale a few times to arrive at a base delineation for the scale which is accurate to a bit over half a degree on the Celsius scale.

The problem was people kept convincing Farenheit to change shit - make it a 10 scale, use this fucking brine as a calibration mark, use the boiling water to calibrate shit, etc etc until all of the elegance of the original model was completely lost.

>>12153637
What does one kilogram equal?

>>12153468
Someone's coping

>>12153472
Needing negative numbers for something like temperature which is a measurement of a positive quantity is a big fail. At least with Fahrenheit, though negative numbers on that scale exist, you're not going to encounter them except in extreme cases. With Celsius, negative numbers indicating a positive quantity are common.
Obviously for lab work and special applications rather than civil meteorology, Kelvin or even Rankine should be preferred.

>convincing an entire culture to measure a big chunk of their sensory experience in reference to salty water because they can't comprehend negative numbers

>>12154461
>convincing an entire culture to measure a big chunk of their sensory experience in reference to a random lump of crap sitting in a vault in France
>convincing an entire culture to measure a big chunk of their sensory experience in reference to an arbitrary fraction of an estimate of the circumference of the planet as drawn through an arbitrary city
>convincing an entire culture to measure a big chunk of their sensory experience in reference to an arbitrary fraction of the time it takes the planet to rotate
All units other than those based on physical constants are equally arbitrary.

>>12154487
Yes but some are more convenient than other

>>12153639
Water doesn't instantly freeze the instant the ambient temperature hits 0C. There are so many other variables involved that it really isn't useful to have it at that point versus any other arbitrary point.

>>12153307
Yeah we got horses what’s your problem

>>12153639
>0 is the freezing temperature in a perfect system everyday humans never experience
ftfy ;)

All units except planck are arbitrary

>>12154487
Not to mention
>basing all this on the number of fingers we have
>ignoring our inability to divide evenly by three

>>12153307
As a structural dynamics guys in America, I prefer slinch i.e. 1/386.09 lb-s^2/in

>>12154500
the stupid, it hurts

>>12154500
Water doesn't instantly freeze at any point so let's disregard all other points where Celsius is more useful than Fahrenheit.

>>12153672
One kilogram equals for example one liter of water, also one kilogram equals one thousand grams.

>>12153427
273K = kinda cold

>>12153307
I have used slugs once, EVER, in my entire life when we measured out a slug of water in a hydraulic well to check the refresh rate of the aquifer. It was part of a class assignment in my hydrology I class. The teacher reminded us that the likelihood of using slugs in actual research was 0, but just in case .... oh boy!

The need to convert slugs to foot pounds never comes up, so I don't know why you're using it as an example of anything.

>>12153383
No, pound is a unit of mass. When used to express forces, the force is usually compared to the force of gravity on the stated number of pounds of mass.

>>12154487
Well, obviously those random and arbitrary fractions were based on something a lot more reasonable. It's just that they chose those arbitrary definitions because they were mostly constant, akin to how current units are defined using universal constants. The main advantage of the metric system is the ease of conversion between units, especially using bases of 10.

>>12155897
Jesus, customary units can't even get its shit straight by itself.

I was taught pound is a unit of force, and slug is a unit of mass. That's fucking retarded to call two different units the same thing in the same unit system.

>>12153383
>>12155897
>>12156943
pound was and is a unit of force. a bill in 1963 that tried to establish standards for imperial units randomly decided to create two units: pound-force (lbf) and pound-mass (lbm)

prior to this (and basically still through to today), masses in imperial units were either measured in slugs, which were defined as 1 pound over 1 ft/s^2, or more commonly were simply given as the force in pounds with the implication that the mass was the stated weight over g. either of which is a better option

>>12155847
>One kilogram equals for example one liter of water
so the mass of an abitrary liquid filling a cube with sides of an arbitrary length - very scientific and reasonable

>>12155909
>The main advantage of the metric system is the ease of conversion between units, especially using bases of 10.
There's literally nothing stopping the imperial system from employing "gigapounds" or "millimiles" apart from convention.

>>12158266
>apart from convention
what do you think unit systems are? they are pure convention. you won't be able to buy tools gauged in the way you are describing because it's outside convention. the only exception I can think of are mils (thousandths of an inch) which are often used in PCB fabrication

>>12153672
It could be a one killograme of steel or a one killograme of feathers, they are equal.

>>12158406
So in order to define a kilogram, you first need a kilogram of something.

... bit circular, innit?

>>12155847
>>12158262
The idea that 1kg is 1litre of water is now out dated and much more complex method is used. Look it up on wiki if you're interested.

>>12158413
i'm not interested, reddit.

>>12155843
>all other points where Celsius is more useful than Fahrenheit.
All zero of them. When in your life have you ever needed to know the boiling point of water? Ever? I'm betting the answer is zero. The freezing point of water is somewhat useful to know but only as a general range.
When it comes down to it, remembering 0 and 100 or 32 and 212, both are extremely easy tasks and it reflects poorly on any population that isn't able to do either (or both).

>>12158413
>and much more complex method is used
Yes it's called redefining something arbitrary in terms of something physically significant so it seems less arbitrary.

It's like me defining the length of my forearm as one "smoogle" and then centuries later after its inexplicably become a common use of measurement someone redefines a smoogle as "the distance light travels in 1/337224364th of a second" and acts all smug about it like the smoogle is encoded into the fabric of the fucking universe.

>>12158420
>do I fit in now

>>12158513
sorry, can you go back?

We don't want you here. You weren't invited, and you degrade the quality of the content on the site. Maybe you wouldn't feel the need to be so defensive somewhere where you fit in better?

Thanks!

>>12158413
>>1kg is 1litre of water
still a fact of nature

>>12158454
No it's to get a more accurate measurement of mass.

>>12158420
Why are you here it you have zero curiosity for learning?

I like the argument that
>but we went to the moon using these crazy fucking units :D
Yeah. Guess which units NASA used in their calculations.