/sci/ - Science & Math

[Anonymous No.5786682]

>be Swedish
>reading American textboox
>"We'll imagine that the box is made of a material that has no effect on any electric fields; it's of the same breed as the massless rope, the frictionless incline, and the free college education"
>mfw

[Anonymous No.5786689]

Textbook jokes thread? Textbook jokes thread.

>"One word of caution: All mathematicians and almost everyone else denote the imaginary number square root of -1 by the letter i. Electrical engineers use the letter i for the current (because "current" starts with "c"), so they use the letter j for the square root of -1"

[Anonymous No.5786692]

Here there can be no satisfying assignment, because <span class="math">v_1[/spoiler] must be false to satisfy the third clause, which means that <span class="math">v_2[/spoiler] must be false to satisfy the second clause, which then leaves the first clause unsatisfiable. Although you try, and you try, and you try, and you try, you can’t get no satisfaction.

[Anonymous No.5786697]

>>5786689
Brilliant

[Anonymous No.5786706]

>Then it is trivial to conclude that [completely non-trivial conclusion] is true.
I swear to this is how textbook authors have fun

[Anonymous No.5786728]

Anyone have the picture of the sheared sheep?

[Anonymous No.5786737]

>>5786728
Linear Algebra with applications book?
Sure I remember a sheared sheep from there

[Anonymous No.5786738]

I wish I could pay a bit of money for better education than the shit I recieve for free in Sweden.

[Anonymous No.5786742]

>>5786728

[Anonymous No.5786745]

>>5786706

Laplace wrote that whenever he misplaced a proof. Celestial Mechanics is pretty ripe with it.

[Anonymous No.5786752]

>>5786742
>>5786737
Yes, thank you

[Anonymous No.5787168]

>>5786742
Yeah lay's linear algebra. Loved thay textbook

[Anonymous No.5787215]

>>5787168
>loved that text book
The questions were fucking shit though. I did every in the book and most went perfectly fine, then when I started doing practice exams I realized I knew shit all.
Then again our exam turned out to be 100% theory while the book obviously focused on applications

[Anonymous No.5787236]

>>5786682

I remember seing that too. It's like he's justifying their system by misplaced argument that free education is somehow impossible, to the extent that it breaks the laws of nature.
In my country not only the higher education is free; every student gets 500 €/month student benefit and student housing (rent usually about 200-300 €). And our economy is among the strongest in Europe; of course because you didn't wisely join the Euro Sweden is doing even better.

regards, finnfag.

[Anonymous No.5787244]

>>5787236
>every student gets 500 €/month student benefit and student housing (rent usually about 200-300 €)
I get something similar, though 300€ rent is extremely cheap here and only student flats have that (at least in Stockholm).

[Anonymous No.5787248]

>>5786682
>>5787236
Your educations are not free, they are simply paid for by someone else. You simply do not understand the true cost of your educations, just as most Americans do not understand to true cost of food. Must be nice for you.

[Anonymous No.5787254]

>>5787248
>you didn't get it for free, you just didn't pay for it
Okay, sunny.

[Anonymous No.5787256]

all i have is a list of math article titles.

>Hodge's general conjecture is false for trivial reasons
>You Could Have Invented Spectral Sequences
>Can one hear the shape of a drum?
>A minus sign that used to annoy me but now I know why it is there
>How not to prove the Poincare Conjecture
>Ramanujan's association with radicals in India
>Is the null-graph a pointless concept?
>Everybody knows what a Hopf algebra is
>On O_n
>Free rings and their relations
>Six standard deviations suffice.
>The importance of being straight
>The homotopy category is a homotopy category
>Division by three
>A Group of Order 8,315,553,613,086,720,000
>Holey Sheets
>On groups of order one.
>K-Theory and Reality
>The Joy of Sets.
>Applied Mathematics is Bad Mathematics

[Anonymous No.5787261]

>>5787254
>reading comprehentiom
you got it for "free", but it isnt free.

[Anonymous No.5787265]

>>5787261
For me it's pretty damn free. Not sure why you think the fact that every service in the world is paid for by someone is somehow a revelation.

[Anonymous No.5787267]

>>5787254
I didn't say you didn't get it for free, I said the education itself isn't free. Or are you so self centered that a universe that doesn't revolve around you is inconceivable?

[Anonymous No.5787270]

>>5787256
>tfw you chuckled at almost every one
You'll never see these in a facebook 'lol im soooo nerdy XD' picture I bet.

[Anonymous No.5787272]

>>5787265
Jesus Christ, are you retarded? What was said, and what you apparently think was said, are two different things. Thus >reading comprehension.

[Anonymous No.5787283]

>>5787244

Yeah, 300 € rent is cheap here too, but I was talking about the rents of the student housing. The cheapest student flats are even below 200 €/month (+4 roommates), but you can live quite comfortably with 1 roommate for about 300 €/month. All of these shared student apartments have of course separate rooms for everyone. Private studio apartments are well over 500 €/month. Sorry for OT.

[Anonymous No.5787286]

>>5787267
>I said education itself isn't free
Yes? I doubt there's anyone that doesn't get that. Why you are bringing that up in the context I do not understand though, for all intents and purposes education is free for the student, hence "free education". It's not referring to any utopian idea of teachers working without salary, it's about students not having to pay for their education.

[Anonymous No.5787290]

>>5787248
just as most Americans do not understand what their country would be like if it wasnt run by corporate interests

FTFY

[Anonymous No.5787292]

>>5787248
>>5787261
>>5787272

It's an investment by the state to the education of youth. It's better to educate everyone with ability than let people be hopeless because of their background ie lack of money. The investment pays itself back many times, since today almost all jobs require some sort of expertise.

[Anonymous No.5787295]

>>5787248
>just as most Americans do not understand what their country would be like if it wasnt run by corporate interests

FTFY

[Anonymous No.5787296]

>>5787292
>The investment pays itself back many times, since today almost all jobs require some sort of expertise.
It does, however I'm not too thrilled with a certain % of my taxes going to the game developer degree in shit tier university #4.

Sweden is too nice to shitty unis with shitty degrees not leading to jobs.

[Anonymous No.5787310]

>>5787256

These are great, thanks. Althoug I didn't get two of them, care to explain?
>Everybody knows what a Hopf algebra is
>Six standard deviations suffice

[Anonymous No.5787313]

>>5787296
> Sweden is too nice to shitty unis with shitty degrees not leading to jobs.


There are no non-shitty universities in Sweden. Went to one of the top 2, did one of the hardest programs, got bored cuz it was no struggle at all. Fuck this shit country and all it's commies.

[Anonymous No.5787314]

>>5787256
>On groups of order one.

Is that a real paper?

[Anonymous No.5787353]

>>5787314
yes.

[Anonymous No.5787366]

>>5787310
I havent read it, but from the abstracts i gather its:
>Everybody knows what a Hopf algebra is
He shows a very intuitive way to think about what a Hopf algebra is and its properties thus giving "meaning" to it.

>Six standard deviations suffice
He shows an approximation of something to prove a theorem, the error is very small and it is a reference to how in particle physics a particle is considered discovered if the error on the measurements is less than 6 standard deviations.

[Anonymous No.5787372]

>>5787296
Are you thrilled with a certain % of your taxes going to roads that can be used to quickly transport drugs?

[Anonymous No.5787376]

>>5787314
>On groups of order one
Given the generators and defining relations of a group G, it shows a method to determine if the group is trivial (G = 1)

[Anonymous No.5787381]

>>5786689
I don't get it

[Anonymous No.5787390]

>>5787366
The particle physics rule of thumb is 5 standard deviations, and it's not less than 5 standard deviations, it's more than 5 standard deviations from what you'd predict without the new particle.

[Anonymous No.5787395]

>>5787286
They don't pay directly, they pay through taxes.

[Anonymous No.5787392]

>>5787381
electrical engineers use i for current and j for imaginary unit.
physics and math uses j for current and i for imaginary unit.

[Anonymous No.5787396]

>>5787392
>physics and math uses j for current
wut

[Anonymous No.5787397]

>>5787392
From what I've seen, physics usually uses J for current density and (capital) I for current.
For example:
http://scienceworld.wolfram.com/physics/CurrentDensity.html
http://scienceworld.wolfram.com/physics/Current.html

[Anonymous No.5787398]

>>5787396
just look at the Maxwell equations.

[Anonymous No.5787403]

>>5787398
That's current density. Current per unit area. It's not the same thing.

[Anonymous No.5787416]

>>5787397
>>5787403
details, details.

[Anonymous No.5787452]

>>5787397
the vector quantity J is used for Current densities that vary in 3 spatial dimensions through a volume element. The vector K is used for surface currents, and the vector I is used for filamentary currents through a curve. Scalar I is used for total current.

[Anonymous No.5787451]

>>5787416
Not really

You wouldn't mix up mass and density

[Anonymous No.5787462]

[Anonymous No.5787466]

>>5787462
finland what are you doing

[Anonymous No.5787471]

>>5787451
just assume unit volume.

[Anonymous No.5787473]

>>5786689

I originally stood for "intensity" (but in french, it starts with an I so I don't feel like I have to look it up).

just a clearification for those who believe electrical engineers are stupid because of the previously mentioned.

> I'm not a electrical engineer
> I'm a nigger.

[Anonymous No.5787478]

>Read Intermediate Microecon textbook study guide
>"Total price" is spelt as "Towtow price"
>Obviously not a typo.

Dem thinly veiled Asian jokes in academia.

[Anonymous No.5787482]

On topic of units and letters
>High school
E_k = Kinetic energy
E_p = Potential energy
T = Temperature
V = Volume
>Uni
T = Kinetic energy
V = Potential energy
T = Temperature
V = Volume
v and <span class="math">\mu[/spoiler] is used for everything and often in the same equation (fuck you moles and velocities)

[Anonymous No.5787480]

>>5787292

>Swedish population: 9.449 million
>U.S. population 313.9 million

Do you not understand why free education doesn't work in America?

Everyone is all like hurr durrr sweeden #1 murica sux xD until you realize that America has 35x more people than Sweeden.

Also, hows that multiculturalism working out?

[Anonymous No.5787485]

>>5787482
µ*

[Anonymous No.5787488]

>>5787482
<span class="math">\nu[/spoiler]*

[Anonymous No.5787489]

>>5787473
Something like intensité I assume

[Anonymous No.5787492]

>>5787482

[Anonymous No.5787494]

Some of us went to college on academic scholarships.

[metric !1tensorX8Q No.5787498]

>>5787492
Peskin and Schroeder I see?

[Anonymous No.5787512]

>>5787480
>Also, hows that multiculturalism working out?

You tell me.

[Anonymous No.5787535]

>>5787498
Yes. It's a good book, and that notation doesn't cause any real ambiguity, but it's still a bit funny.

[Anonymous No.5787548]

>>5787492
>done maths up to calc 3
>this might as well be a different language
What am I looking at?

[Anonymous No.5787553]

>>5787548
Seriously? That's just babby quantum physics.

[Anonymous No.5787560]

>>5787553
Oh of course, forgot about the third order derivative of p with respect to.. I mean divided by 2pi
what

[Anonymous No.5787561]

>>5786742
that fucking textbook.

I think I still have it.

[Anonymous No.5787566]

>>5787553
Oh of course, forgot about the third order derivative of p with respect to.. I mean divided by 2pi.. what

Or it just happens to look like some kind of derivative and it isn't that fucked after all

[Anonymous No.5787574]

>>5787548
It's talking about the relationship between quantum fields and particles. x is position and p is momentum. <span class="math">\phi(x)[/spoiler] and <span class="math">\pi(x)[/spoiler] are quantum-mechanical operators (okay, operator-valued distributions) giving the value of the field and the canonical momentum (which in this case works out to be the rate of change of <span class="math">\phi(x)[/spoiler]). <span class="math">a_p[/spoiler] and <span class="math">a^\dagger_p[/spoiler] remove and add particles of momentum p from/to a quantum state. The <span class="math">\dagger[/spoiler] means Hermitian conjugate. <span class="math">\omega_p[/spoiler] is the angular frequency that you'd calculate using classical mechanics for waves with wave vector p.

[Anonymous No.5787579]

>>5787566
<span class="math">\int d^3p[/spoiler] is just a volume integral over the three-dimensional space of values that p may take.

[Anonymous No.5787584]

>>5787579
Ah, not too out of this world then.
>>5787574
Thanks for the explanation.

[Anonymous No.5788684]

>>5786689

[Anonymous No.5788689]

>>5787248
>You simply do not understand the true cost of your educations, just as most Americans do not understand to true cost of food

Is that why Europeans are overdosing on education while Amerifats are overdosing on cheeseburgers and sticks of butter?

[Anonymous No.5788704]

>>5787480
Are you really an American who just used multiculturalism as an argument against another nation?

[Anonymous No.5788707]

>tax the hell out of your citizens to pay for schools
>then call them free
>too stupid to know you're swindling them because you run the only source of education

You couldn't think of a better grift

[Anonymous No.5788713]

>>5788707
>tax the hell out of your citizens to pay for schools

I feel like this should be part of a SimCity "meme" picture.

[Anonymous No.5788720]

referencing the existence of continuous functions with divergent fourier series

[Anonymous No.5788721]

>>5788704
I think he is. It makes sense, considering the many immigrating families that go to america from countries like Sweden and other European shitholes. America has a very diverse cultural spectrum in fact.

[Anonymous No.5788725]

>>5787256
>can one hear the shape of a drum
is there something i dont get about that one? the geometry people in my department study that all the time, i hear it constantly in their talks

[Anonymous No.5788777]

>>5787482

this shit, using v, nu and capital V in the same equation where you have shitty hand writing

[Anonymous No.5788782]

>>5788777
my first physics course was thermodynamics, it's what taught me to write clearly

[Anonymous No.5788806]

>Needing textbooks
I thought you guys were smart or something, the lectures and classes should be more than enough.

[Anonymous No.5788833]

>>5788707
Yet somehow Europeans generally end up without the massive student debts. Weird.

[Anonymous No.5788841]

>>5788806
Maybe in your communications class it's good enough.

[Anonymous No.5788882]

>>5788806
Even top tier universities have some less than stellar lecturers.

Like the ones who can' speak English

[Anonymous No.5788889]

This may sound weird but, am I the only one who never ever gives a shit about theory and can work my way through only using the class notes (examples) and a formula sheet/quick review ?

[Anonymous No.5788890]

>>5787392
i is the imaginary number
I is current
Trust me I'm a chemist.

[Anonymous No.5788894]

i is the current
I is the phasor current
j is the imaginary number
J is the current density

[Anonymous No.5788896]

>>5787480
Wow. Waving around a large population size like that somehow invalidates an idea. You realise you have to prove or at least show that something doesn't scale up, right?