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Archived threads in /sci/ - Science & Math - 117. page
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File: dreamworld.jpg (425 KB, 1434x598) Image search: [iqdb] [SauceNao] [Google]
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Do we have free will?
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>>7779339
yes
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>>7779339
no
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more so if you iodize your 5-ht2a receptor

any advice on someone who's been out of school for years who is taking this course? i certainly have to brush up on calculus because i scarcely remember that.

any advice for p chem i? or as my school calls it - quantum mechanics and spectroscopy.

pic related is the book we're using.
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>>7779311
here's the syllabus.

http://chemistry.fas.nyu.edu/docs/IO/19766/CHEMUA651.pchem.quantum.turner.spr2015.pdf

There are chapters in the textbook that brush you up on some of the math. I guess I'll look at those rather than picking up and reading a whole calculus book.
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>>7779326
>It’s important that you read the textbook!
>Alternate texts
>Radically different famous textbooks that do not cover the same material at all or is an entirely different level

>Recommended software
>Like everything fucking high level software instead of just saying "I'm probably going to use Julia for the course so learn that if you want to read my...
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>>7779348
>Radically different famous textbooks that do not cover the same material at all or is an entirely different level

What? Introduction to Quantum Mechanics by Griffths and Physical Chemistry by Atkins are frequently recommended as supplement/main texts for Quantum/Physical Chem courses. Harris and Bertolucci's Symmetry and Spectroscopy is more geared towards an Inorganic/Spectroscopy/Group Theory course but it's not inaccessible.

>Like everything...

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To keep a long story short, I'm doing some bullshit maths right now.

Does anyone know how to factor (x-y) in a general way?
And don't tell me I can't do it; I just need a function that turns subtraction into division.
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>>7779258
Do you mean $x^2+y^2$ ?
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>>7779272
sorry, minus not plus.
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>>7779272
>>7779274
no I mean x-y
Maybe even x^n-y^m if I can do some real sorcery

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What language should I learn for Mechanical Engineering? For software development? For AI / al gore rhythms?
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>>7779257
MATLAB, Java and Lisp, respectively
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>>7779257
>>7779257
Did you like pure mathematical logic? ie, predicate, propositional, modal logics?
Do you like, and are familiar with a lot of mathematical notation?

If you answered yes, find a functional language like a LISP or Haskell that suits your needs.

If you answered no, hop on the bandwagon and use python. This is for AI of course, and that's basically the only one you have a choice with. Mechanical engineering(unless you are doing it yourself,...
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stata and matlab

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From Merzbach and Boyer's "A History of Mathematics" (good read by the way, heartily recommend) -
"The decimal system, common to most civilizations, had been submerged in Mesopotamia under a notation that made fundamental to the base 60"
>base
>60
Why? What would compel them to do this?
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>>7779247
What would compel you to do base 10? It's all arbitrary.
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>>7779247
Because fuck it, I made up a base 16 number system when I was little because I was bored. It has absolutely no effect on anything.
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>>7779256
You actually want the number to be as composite as possible, senpai.

Easy quantum physics.
If wave encounters a finite well does some part of incident wave reflect back on the edge of well ?
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>>7779246
A potential well, or an actual physical well?
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>>7779248
Sorry for not being clear enough, potential well of course.
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>>7779248
They are the same thing, really.

>>7779246
Yes, look up probability current. The sum of the reflection and transversing waves must be 1.

File: polymoly.jpg (57 KB, 1636x796) Image search: [iqdb] [SauceNao] [Google]
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can someone explain to me why it's so important that N!=NP? i don't get it. what's so different if something can be expressed as a polynomial? i read the implications on wiki but those seem weird, like cryptography breaking down etc.

pic sort of related, is that even a polynomial?
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>>7779201
If P = NP then that means problems that were before non-polynomial can now be solved in polynomial time. This has huge implications on cryptography in particular because modern day cryptography is based on prime factorisation which is currently an NP problem (a problem that cannot be solved in polynomial time). If it was proved that P = NP then these forms of cryptography would be "broken" and big problem would follow.
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>>7779201
it's obvious that you open the thread with something interesting that you may or may not already understand just so you can hide you homework question in the end

fuck off
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>>7779215
i read that and it seems silly because the algorithms required to break cryptography wouldn't magically appear out of thin air just because we've proven them to exist. or am i wrong about that?
>>7779217
k

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EE student here

this always puzzles me

I understand that the field on the left is strengthened and the on the right side its weakened. the result is a force

but why? does the field try to distribute itself evenly again?
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That's just a basic principle of physics. Without going deep into Maxwell and stuff,

Everything in physics "wants" to reach the lowest energy state, a state where no work is done.

The force exists to distribute it evenly again (= lowest energy state) just like you said

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If the fundamental bits of energy in the universe (those "vibrating strings") are non-divisible and thus homogeneous how it is that they are understood to vibrate differently from one another? How is such a difference brought about?
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>>7779112
bump
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>>7779112
The picture of a vibrating string is better suited as just an analogy when dealing with the quantum mechanical behavior.

I will try to show what is going on with a toy model, bosonic string theory.

So what we mean by the vibrating is the different levels of energy excitations of the string states.

So if we take a look at closed string world sheet model, we describe the string by functions which embedded the worldsheet into the background spacetime.

${X_R}^\mu \left( {\sigma ,\tau... Comment too long. Click here to view the full text. >> >>7779657 ** Fixed code lines: [math] a_n^{\mu \dagger } = \frac{1}{{\sqrt n }}\alpha _{ - n}^\mu$

and

$\left| S \right\rangle = a_{{n_1}}^{{\mu _1}\dagger }...a_{{n_m}}^{{\mu _m}\dagger}\left| 0 \right\rangle$

does anyone have a ForumBiodiversity login? (registration closed.) can they repost the pictures?

has anyone seen other direct-to-consumer DNA test data from Australian aborigines?
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>>7779069
Bump for interest.
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>>7779696

There's very little published genomic data from Australians at present. Intredasting that the best fitting models were all Papuan + SE Asian. were there migrations into Australia that bypassed New Guinea?
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>>7779069
>23andMe

Aren't those guys frauds?

How does one get a good understanding of preprocessing data before starting to think about neural network architecture, etc?

Is there a checklist or something? I guess there's imputation if needed, converting categorical to numerical, then... I look for correlations (correlation matrix) and maybe for mutual information (to check for non-linear correlations) but what else? I don't know, is there a complete guide for this?

Also, computer science general
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>http://blog.kaggle.com/2016/01/04/how-much-did-it-rain-ii-winners-interview-1st-place-pupa-aka-aaron-sim/

>mfw random physics guy jumps into ML and gets #1
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>>7779060
fuck NNs, bayesian program learning BTFO deep learning: http://science.sciencemag.org/content/350/6266/1332.full
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>>7779090
nice paywall kike

>he thinks he can be a good scientist
>yet he struggled in English class

Kek. Good luck with all of the writing you'll have to do.
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>>7779038
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>>7779038
Writing a scientific paper on a topic you love is a whole lot different from writing a paper on some socialist propaganda in the form of a book which was shoved down your throat by a cultural marxist professor.
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>>7779044
thanks for sharing

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Would aliens create the same mathematics as us?
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Probably not.
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YES

>>7779033
gnorts pls.
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>create

different notation at the least

Will it be delayed, blow up, crash on landing, or work perfectly.
Or, if the comments on NASA's facebook-page are true and space is just a carped made by the government to fool us for some reason and rockets dont work in vacuum, what will happen?
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>>7778994
>Or, if the comments on NASA's facebook-page are true and space is just a carped made by the government to fool us for some reason and rockets dont work in vacuum, what will happen?

>no satellites have ever been launched before.
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>>7779059
i shit you now, those comment sections are full of people rambling on about how everything from how Apollo was fake to the Van Allen belts being gods way of stopping people from leaving.
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>>7779068
And with an amazing amount of crappy English/spelling as well.

File: K_htbw_immune-cells1[1].gif (15 KB, 436x158) Image search: [iqdb] [SauceNao] [Google]
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Why is the immune system so unbelievably retarded?
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It's actually very complex, but microorganisms are too good at adapting.
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>>7778993
>Giving personality traits to what is literally a process.

Go back to /b/, someone already got the get. You can leave now.
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>>7778998
No, I'm saying why is it so fucking stupid it attacks the body like ALL of the time?

I have several autoimmune diseases and holy shit evolution sucks if it can't figure this shit out.

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