The h Bar

Jaime Gallego

22:08

Are you using CAD on uni?

Bernardo Meurer

Nope, personal project

I should eventually have to do it in uni though

I need to design an enclosure to 3D-Print for a project

But I only know how to use Solid Works

and ain't nobody got time to learn OpenSCAD

Emilio Pisanty

@rob indeed

you know Flanders & Swann? I thought they were virtually unknown outside of the UK and you were in the states

LegionMammal978

Anyone here know a bit of dimensional analysis?

Bernardo Meurer

Anyone here know a bit about GSM-enabled IoT microcontrollers?

LegionMammal978

Fine, I'll go see if I can find any luck in Math's chat

Bernardo Meurer

22:23

@LegionMammal978 I'm not mocking you, I actually need help picking a microcontroller that has GSM :)

ACuriousMind

@LegionMammal978 If you have a question, we generally prefer you just ask it instead of asking if anyone maybe knows something about the general topic - maybe someone will even come by later and answer it

LegionMammal978

Then what's the exact difference between 1 mol² (of dimension N ²) and N_A(1 mol²) (of dimension N)?

ACuriousMind

Oh, mol is an annoying "unit"

LegionMammal978

Yeah, that's why I'm trying to figure this out

Because I'm not sure if a certain unit has dimension mol*m^-3 or just m^-3

ACuriousMind

mol is a unit, but it is dimensionless. "Amount" is just a number, it does not have dimensions

Bernardo Meurer

22:46

@ACuriousMind What are you saying? Of course a mol has dimension. It's dimension is a shitton

In fact I argue the mol be renamed to shitton

ACuriousMind

That would still be a unit, not a dimension.

Sha Vuklia

mol was the worst thing that happened to me in chemistry

nobody understood it, for some reason

Jaime Gallego

"Yo dawg, I herd u like MOSFETs..."

Bernardo Meurer

Good lord

Emilio Pisanty

@LegionMammal978 so... which unit is this, specifically?

Anonymous

22:59

@ShaVuklia Really?

Anonymous

The basic concept is quite simple.

Emilio Pisanty

@blue and also pretty problematic

at least as far as being a base unit and getting a dimension of its own goes

Anonymous

@EmilioPisanty Mole doesn't have a dimension.

Emilio Pisanty

@blue tell that to the BIPM

ditto for ISO and the IUPAC

Anonymous

Eh, conventions can be silly

ACuriousMind

23:03

Well, but what is the mole if not a convention?

Anonymous

@ACuriousMind I agree it is a convention. But quite helpful in Chemistry atleast.

Bernardo Meurer

23:16

andrew.cmu.edu/user/twildenh/PowerPointTM/Paper.pdf

Sometimes I fucking love humanity

@ACuriousMind Can you believe that?

Can you believe someone actually thought one day "I wonder if PowerPoint is Turing Complete"

Jaime Gallego

People built Turing machines using Game of Life gliders. No one expects anything less from mankind.

Emilio Pisanty

@BernardoMeurer there's a typo

it says

> only more experienced (and desperate) PowerPoint aficionados fully utilize PowerPoint's advanced AutoShape, Hyperlink, and Transition tools for the purposes of image editing, video production, and game design

it should say

> only damn fools utilize PowerPoint's advanced AutoShape, Hyperlink, and Transition tools for the purposes of image editing, video production, and game design

Bernardo Meurer

Lol

Jaime Gallego

Game... design?

Emilio Pisanty

@JaimeGallego cf supra re: "damn fools"

Jaime Gallego

23:29

I imagine it's some sort of Scratch thingy

Emilio Pisanty

@JaimeGallego well, since they show it's Turing complete, you can code whatever you want

@BernardoMeurer that's your next task

running Doom over PowerPoint

Bernardo Meurer

@EmilioPisanty Meh, I don't want to touch proprietary malware :P

Alas Rust's type system is also turing complete

I would be interested in trying to run doom using only Rust's type system lol

Emilio Pisanty

@BernardoMeurer is there a Doom version in brainfuck?

LegionMammal978

@ACuriousMind So why does the SI define another fundamental unit? Why don't we just use multiples of the dimensionless constant N_A (1 mol)?

Emilio Pisanty

presumably it's possible

Bernardo Meurer

23:32

Nah, doing the graphics would be too insane

I don't even know if it would actually

Because of GFX

Emilio Pisanty

@BernardoMeurer GFX are still part of Turing compts, no?

35

Q: Why is the mole/"amount of substance" a dimensional quantity?

According to the BIPM and Wikipedia, "amount of substance" (as measured in moles) is one of the base quantities in our system of weights and measures. Why? I get why the mole is useful as a unit. In fact, my question isn't really about the mole at all; I just mention it because what little infor...

Bernardo Meurer

Yeah, sure, you could do all the maths happening in the GFX, but displaying it would have to be provided by the language somehow

Emilio Pisanty

12

Q: Why is the mol a fundamental physical quantity?

I am starting to study physics in detail and as I read about physical quantities, I was puzzled why mol (amount of substance) is taken as a physical quantity. A physical quantity is any quantity which we can measure and has a unit associated with it. But a mol represents the amount of substance ...

conventions units si-units metrology general-physics

Bernardo Meurer

I image at least

In brainfuck this would be quite a herculean (perhaps sisyphean) task

Emilio Pisanty

@BernardoMeurer surely there's translators from C to brainfuck, though?

LegionMammal978

23:35

@EmilioPisanty Still don't see how the accepted answer helps

Bernardo Meurer

@EmilioPisanty Not as far as I know, alas I'm not a brainfuck expert

Brainfuck cannot do the low-level brouhaha C can

Emilio Pisanty

@LegionMammal978 point is, has been treated in main already, and that's as far as it got

LegionMammal978

@EmilioPisanty I haven't seen any of those (although I have seen BF to C)

Emilio Pisanty

@BernardoMeurer can it not?

huh

LegionMammal978

Besides, BF mostly just describes Turing machines, whereas C has many, many, many layers of abstraction

heather

23:37

ah man, today's been great

Emilio Pisanty

@heather kudos

Bernardo Meurer

@EmilioPisanty Brainfuck is not compiled, is it?

LegionMammal978

@EmilioPisanty Perhaps it would work with some sort of virtual memory scheme for interrupts, etc.

@BernardoMeurer No, not really

Emilio Pisanty

@BernardoMeurer no idea

heather

i spent basically the whole day hanging out with friends at an amusement park. we all just joked around and rode high-adrenaline rides.

LegionMammal978

23:38

(source: am from PPCG)

heather

absolutely amazing.

Bernardo Meurer

You're better off just using Assembly

Emilio Pisanty

also, my level of caring is at about 15-20% on that topic

Bernardo Meurer

And then may god have mercy on your soul

Emilio Pisanty

@BernardoMeurer naw, the challenge is running Doom on brainfuck

Bernardo Meurer

23:39

Because I'm coding MasterMind in assembly right now and I want to blow my brains off

Emilio Pisanty

@BernardoMeurer there's already Doom versions written in assembly, no?

Bernardo Meurer

@EmilioPisanty I don't know. All I did was run Doom on a calculator :P

Emilio Pisanty

@BernardoMeurer or does the C compiler skip assembly and go directly to machine code?

I mean, if you can't translate C to assembly, what's assembly even for?

Bernardo Meurer

@EmilioPisanty I can't speak for all C compilers, but I know that GCC generates ASM first (IIRC)

If you call GCC with the -S flag it will generate assembly for you

Emilio Pisanty

@BernardoMeurer so you can just compile to assembly and you're done

Bernardo Meurer

23:41

holy shit

I will do the assignment in C

and compile to assembly

fuck you system

Emilio Pisanty

@BernardoMeurer will you be asked to explain your code?

Bernardo Meurer

Yes, but the professors never have any idea what the fuck I'm up to anyway, lol

Emilio Pisanty

I guess it depends on how human-readable the gcc-compiled assembly is

Bernardo Meurer

My programming prof doesn't even bother to read my stuff, he just sees it works and gives me an A

Emilio Pisanty

probably not very

Bernardo Meurer

23:42

Oh it's shit alright

the ASM GCC generates is ultra-optimized brouhaha

Alas you can turn optimizations off

Emilio Pisanty

@BernardoMeurer how was this not an obvious option from the get-go?

Bernardo Meurer

maybe that makes it better

and write ASM-like C with GOTO and so on

@EmilioPisanty I haven't been in my best mental state

Emilio Pisanty

just sayin'

Bernardo Meurer

Today I even missed a "That's what she said" joke, and that's when you know I'm bad

Emilio Pisanty

@BernardoMeurer that's...

what she said =P

Bernardo Meurer

23:44

:(

LegionMammal978

And then you turn in the GCC-generated assembly and it still has the added metadata :p

Emilio Pisanty

@LegionMammal978 seriously, though, there's plenty of metrologists that will up and tell you that the concept of a base unit is only kept around for historical compatibility

10

Q: What is a base unit in the new SI, and why is the ampere one of them?

One question that comes up pretty much always in introductory electromagnetism courses is Why the base unit of electrical measurements is the ampere and not the coulomb, and the usual answer is that it is more accurate, and metrologically more useful, to build electrical measurements around measu...

units conventions si-units metrology

for an example

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