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Archived threads in /sci/ - Science & Math - 28. page
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What are these reactions called and what should I look up to figure out how to do them?
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For those of you who are not owls :^)
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https://en.wikipedia.org/wiki/Carbonyl_group
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>>8514981
Carboxyl group reaction can move double bonds around when protons are present

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is not there a predefined path that will lead me to the solution of every math problem? if not, prove it.
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>>8514828
Yes anon it is time to realize your destiny is to solve all of the math problem and pull ridiculous engineer dick only to have them realize your social skills are sub par from being such a math experts that you can only have sex with the most autistic engineers.
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>>8514828
Does the set of all sets contain itself?

>ZFCtards btfo
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>>8514828
Yes and no.

Start with a set of axioms and a proof system. Enumerate all possible proofs until you find a proof of either A or ~A, where A is the proposition you want to examine. Thus method solves all solvable math problems.

However, by Gödel, not all math problems are solvable. There will be statements S such that you can neither prove S nor ~S.

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Who else doing nofap December?

How's it going it going if you're doing it and if you aren't, why?

>used to fap minimum of two to five times a day, every day
>usually,in order, using the following methods: pics, gifs or video
>over 1200 pics/gifs/videos saved
>quitesmug.jpeg
>decide nofap December
>almost a week in (started 2 days earlier)
>no...
>>
Nofap is shit and useless.

Do NoPorn, it actually is god for your brain.
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>>8514671
>no porn

Explain how it's good for the brain.

And how do I fap? Are nude pics, or pics of nice female faces good? Or do I use my imagination
>>
I've successfully conquered this last NFN, but couldn't last a week on NPN. I used to fap w/o porn quite often a few years ago, but now it's just not enough, and takes up to 30 mins. Got any info on those stuff?

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What's the significance of eigenvectors and eigenvalues with respect to real phenomena, /sci/?

I already have a degree and I still never made the connection between the mathematical and the physical and it still bothers me...

To keep a simple case, let's say I have a 2x2 matrix $A$ and a vector $\vec{x}$. If I assert that $A \vec{x} = \lambda \vec{x}$, I am saying that my matrix can be replaced by a scalar. If the determinant is then 0, it means my vectors, at appropriate eigenvalues, are linearly dependant.

But what does that mean for the physics?...
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>>8514469
Whelp that tex failed
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>>8514469
I recognize this slut.
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>muh physics
It's simply an interesting question to ask of a linear transformation.

What if I told you this was a density plot of the eigenvalues of random 5x5 matrices drawn from {-1, 0, 1}, and that we simply do not know why this pattern looks the way it does? Demands further investigation, don't you think?

Hello, is there a way to make wolfram calculate limits without using l'Hospital's (show step by step solution)? Or any other tool? We are not allowed to use l'Hospital's rule yet.
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Consider the function

[eqn] f(x) = \begin{cases}
\frac{1 - \cos(x)}{x} & \text{ if } x \neq 0 \\
0 & \text{ if } x= 0
\end{cases} [/eqn]

Then

[eqn] \lim_{x \to 0} \frac{x^2}{1 - \cos(x)} = \frac{1}{ \lim_{x \to 0} \frac{f(x) - f(0)}{x}} = \frac{1}{f'(0)} = 2[/eqn]
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>>8514457
How does this work? Sorry for not seeing it :(
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>>8514457
I assume he isn't allowed to use l'Hopital yet because the derivative hasn't been formally defined in class.

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What's up /sci/entists. I just heard a Muslim idiot claiming that Big Bang isn't real because nothing can only create nothing.
What are some of most plausible theories about where that dense point of singularity came from?
So far I heard it could be older universe shrinking into one point and that our universe could be part of multiverse that existed since forever.
What do you think? I have just basic science understanding.
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>>8514352
Huh, I recently had a muslim guy claiming all the great discoveries of the 19th and 20th centuries were from muslims (EM, relativity, quantum theory, computers). It is astounding how deluded people can be.

No one ever said "nothing" created the Big Bang. We don't actually know what started it, though some of the more wacky M-theorists and such claim it was the collision of higher-dimensional "membranes" that led to an explosive release of matter and energy, and the laws we observe are...
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>>8514352
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>>8514400

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Why don't scientists look for exoplanets from there? There could be one just 1 light year away from the direction of the south pole
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I can't tell if you're baiting or power-stupid.

We have telescopes in space. We've mapped the local stellar neighborhood. The closest star to us, Proxima Centauri, is ~4.24 light years away.
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>>8514342
>What stars are only visible from Antarctica?
None of them.
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>>8514364

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>No dark energy
>No accelerated expansion

What is your thoughts on this recent PBS Space Time video?
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>>8514268
>What is your thoughts on this recent PBS Space Time video?

I think astronomers should do their thinking for themselves, instead of trying to get /sci/ to do it for free.

Fuckers are getting paid, after all.
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What I get from it is that apparently there may be less dark energy than previously thought.

I mean, constant expansion still requires a cosmological constant, i.e. dark energy
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I've read the actual paper and it's total crap. They're abusing the press release system. All they do in this papers is reanalyse a single cosmological data set (Supernova Union 2.1) using different methods than everyone else and find no acceleration is only rejected at ~2.8 sigma. (Convientently it doesn't reject their pet model and no it was not blinded). They have made a big fucking deal about this but it's nothing. Take a look at their main plot, no acceleration is the green line, the data favors acceleration. The major issue is that there are dozens...

What's the deal with antibiotics?
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China fed all our best ones to livestock and bred a superplague we can't cure, probs gonna b fine though lmao
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>>8514243
Antibiotics provide an evolutionary selective pressure that results in more resistant microorganisms.
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>>8514243
We should stop using them and save them for very serious illnesses, and get the public educated about how they DONT WORK on viral infections.

Since the cascade of new and more advanced antibiotics and further efforts to get better ones has been underway, we've noticed an improvement in the effect of the oldest antibiotics, Penicillin for example hasnt' been used widely since the late 80s and its starting to pay off.

If we reduce antibiotic use, they will become more effective because bacteria...

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Would it be possible in the near future to use a supercomputer to simulate and experience the past to a very fine detail? This of course would all just be a simulation and not actual time travel by any means
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basically no because the universe is a chaotic system.
The supercomputer pretty much have to be able to simulate the whole universe. he'd also have to know the current state of the universe and how each physical law can be reversed.
But to be more realistic, I think it woulf mostly be ebough to simulate the solar system backwards.
But that is still impossible.
What I could imagine are VR scenarios where you can experience a specific time with extremely high detail and historical accuracy. A computer could realistically place you in the 18th century and have...
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>>8514310
Well it would only really need to simulate what conscious observers are experiencing, it wouldn't need to simulate distant stars and galaxies
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>>8514215
Wouldn't it just be easier to timetravel?

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>>8514004

>>
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reading? i'm taking a full course load. how do you have time to read for leisure unless you're NEET

fucking when ?
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Why reinvent the wheel? Anyways, we're not even close. Check back in like a thousand years.
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>>8513878
k I will, thanks for the tip
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What's wrong with regular trees?

I want to learn calculus from the very basics,but i dont trust the internet. Recommend me a good calculus textbook or whatever book that can teach me everything
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>>8513747
Stewart Calculus?
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Easy as fuck: Calculus 1 by Stewart
Mid level: Spivak
Hard as fuck: Advanced Calculus by Lynn H Loomis and Sternberg
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>>8513747
Just read Apostol, nigga. You literally do not need any other calculus book. I mean if you really are autistic enough to want to learn absolutely everything about calculus (you shouldn't be).

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Hello, /sci/. What is the best precalculus book in your opinion? Cohen? Larson? Axler? Aiming at something for self-study
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>>8513673
What really is precalculus? Polynomials and stuff? You probably don't need a book, there are plenty of online materials
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>>8513677
fundamentals, functions (exponential, logarithmic, trigonometric), polynomial, limits, vectors, sequences and series
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>>8513686

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Why do cities remind me of circuit boards?
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pretty much autism
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>>8513597
because they're a similar shape? idk but this is a shit thread and you should feel bad.
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>>8513602
great post goym

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How the hell do people cope with going to one of innumerable the mediocre or bad universities in the USA? Their Wikipedia pages depress me. Why build giant campuses with giant buildings and pretend to care about the sports team when just standing there makes you look stupid in the eyes of society? The degrees are like dunce caps.

In the UK I went to University of [City Name] which was established before the USA existed, has old buildings, a history with a few Nobel prize winners... yet it was still a shithole with brain-dead easy classes and dumb normie students with...
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>>8513250
> The degrees are like dunce caps

You know how on /fit/, some people develop body dysmorphia and start saying ridiculous things because of their extremely skewed perspective?
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>>8513250
Science is built piece by piece. Groundwork is often done by those "shit" universities and then the final, more abstract pieces are put into place by the top tiers.

Not everyone can be the best. We need average workers, too. A Ph.D. in EE from MIT isn't going to be satisfied maintaining a power plant but a bsce in EE from state university will be.

You're welcome, faggot.
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>>8513250
It's 2016 and all information is freely available on the internet. There's no advantage from a geographically centralized building of learning, no matter how "prestigious" it is. All knowledge is the same and expensive/competitive unis only exist for the purpose of perpetuating this elitist classist system we all are unfortunately forced to live in.

Fuck off OP you conceited ass. Science has no use for you.

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There is no future.
Prove me wrong faggots.
>protip You can't.
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Yeah, because it only "exists" in the finite present as a construct that most people predict poorly.
>sage in all fields
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>>8513202

we dont know the future because it doesnt exist
we can only know the past
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i predict the end of this post will be 7

Chemistry really soothes my autism, but I don't really like not understanding the physics behind a lot of it. What books or more general things should I look into to understand physics, with the goal of applying that to chemistry?
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>>8513058

What's your math level, chem level, and physics level?
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>>8513058
quantum chemistry by mcquarrie is bretty good
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>>8513092
0 in all 3, well HS level math

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and I guess I never will.

>I understand Planck's Constant
Its why it takes a radio transmission 40 seconds to reach earth from the moon
>I understand nuclear fission
heat and pressure cause atoms to split and release energy
>I understand gravity
the more mass an object has, the greater its attraction to other objects
>I understand nuclear fusion
a stars gravity converts hydrogen into helium, producing energy

But for the...
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>>8512865
Radio transmissions are delayed due to the finite speed of light, not Planck's constant.
Heat and pressure do not cause nuclear fission, being hit by neutrons does.
>>
Imagine you have two clocks that measure time using photons. They stand upright and the photons move on the y-axis and get reflected by mirrors. Every time a photon hits a mirror the time count of the clock that registrated it goes up by one. The numbers of photons and the lspeed of light are always the same. Now one clock remains where it is and the other one moves by the distance x while its photons (photons b) move by the distance y on the y-axis. The photons b now have moved by sqrt(x^2 + y^2). If time went by the same pace everywhere this wouldn´t be possible because the...
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>>8512865
>I don't understand relativity

What's to understand? It's bullshit.

The only reason anyone "Agrees" with relativity is to keep their job.

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...
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>>8511878
Take a 10mg daily cycle of sunifiram for about a year.
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>>8511878

Obviously you just need to forget how to speak.
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>>8511948
Mind you, I'm willing to do it if it really works.

Post unis, discuss your major etc
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>>>/soc/
>>
> University
Universitat de Girona, Spain

>Major
Computer Engineering

98% males, the only female is an ogre. Teachers are high school tier. Everyone is a normie.

For example doing the four color theorem someone raises their hand:

"Sir, do we have to bring pencil colors in order to study this theorem?"

Everyone laughs.

Doing Data Bases:

"I connected the TRUCK entity to the INTERNET entity"
"But trucks don't have wifi!"

Everyone...
>>
>University

>Major
Chemistry

We all make drugs all day and spend the time using carbon tetrachlorure on all guys lolz

Jk we all fail exams and go on parties drinking all the alcohol we can

everyone's happy

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F
>https://www.nasaspaceflight.com/2016/12/roscosmos-progress-ms-0465p-to-station/
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>>8509701
f
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>>8509701
Not that long since the last time this happened, right?
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>>8509701

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as u can see i make a 5 second clip enjoy
<iframe width="560" height="315" src="https://www.youtube.com/embed/IDeyAFlp1ac" frameborder="0" allowfullscreen></iframe>
what to fuck do u see there is simple a spaceblimp
the total information why it is better than a spacecraft is on my side-for sure not u side
http://nwgg.de/index.html
yes that why nwgg is there and yes it is german-come on u know only stupids fly with rockets-that is suicide-the only way is with a blimp pulled by a satellite into space

and...
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>>8503663
that was terrible goes wrong cause i embedded wrong-anyway it was my first try-how can i delete
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What the fuck?

Most people would consider basic English literacy a prerequisite for posting here.
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>>8503663
>a spaceblimp is better then a spacecraft
Error: You must wait longer before posting a new thread.

how long is wait

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why is this true? I can't comprehend how he can just replace xI with a similar matrix

is this really easy and I am just being retarded or what
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>>8515054
Multiplying by a matrix then multiplying by it's inverse yields the original result. You're basically doing a transformation to a different coordinate system then transforming back.
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>>8515061
but that would mean that all similar matrices are just the same matrix, right? That's obviously not true.

A is similar to B if there exists an S for which the following holds true

A = S^-1 B S
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>>8515080
>but that would mean that all similar matrices are just the same matrix, right? That's obviously not true.
No, that would mean that all similar matrices have the same set of eigenvalues, which is true (the original image is the proof of that).

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LMAO

Sucks to suck assholes

How do you non-canadian/russian/scandinavians feel to be getting cucked?
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>shitskins going to all starve

We're gonna need a bigass wall to keep them back
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>>8515034
>China
West is fucked
>>
It's all bullshit anyway. Imagine how much agriculture can change by 2080 if there's any pressure to. We're just starting to get good at genetic modification and robots.

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Duke and Young jumped in their moon rover and drove 5km to House Rock. They find a pyramid rock. It has a Maltese Cross on the side. Below this is an ornate "shrine". On the top shelf of the shrine is a box. I had noticed Young touch something as he walked by. Duke actually grabs the box, rips it out with all those wires attached, then struggles to get it in a sample bag. Young ask, "did you get it"?"., Duke says," I can't believe this ". Young wants to leave immediately, which they do. Since I first posted this find NASA has removed that...
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>>8514686
>ITT Things that never happened.

Also, complaining about video cleanup quality while presenting photograph of another screen...

Go to /x/ or some other containment board please. Your question is in no way scientific.
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>>8514693
The question is whether even with poor quality image and my poor resources for sharing, I asked posters if they have an idea what this wired box may be on the moon in 1972. How in the hell could a wired box on the moon, recovered by NASA, not be science?

Is it a lunch box? or could it be electronics, considering the wiring, that may have something to do with science.
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>>8514693
Just realized you are a geek that doesn't believe we landed on the moon, several times!
At least say if you saw anything?

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How to make an algorythm that replaces some amount of 1s with other amount of 1s, divided by space symbol? Look at the pictures to understand it better
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This must be the result
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It must work for any amount of 1s
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I will bump for... 10 days, maybe?

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Is it true that cathode rays can cause decomposing of the atmosphere through which they pass? The theory is that under the action of these rays, the elements of the atmosphere revert to their etheric state. Thus creating a pressure difference and making the aircraft 'lift' off the ground.

Is this realistic?
>>
I think with a 'Lenard Window' (small window made of thin aluminium) the cathode ray can escape the tube. Don't know it does anything to the air surrounding the aluminium though...
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don't know if troll or not.

"cathode rays" are just electrons. They don't really travel very far in air, and they can't really do anything but ionize it.
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>>8514587
Get an accurate scale and a CRT television (the old timey fat back ones). Post results.

As a CS grad who has already wasted two years of life/career working in a non CS-intensive although CS-related field as he failed to understand the thin blur difference between IT and CS, and as someone who has ALMOST GIVEN UP on programming (reading/writing/thinking code)

.....

How much of CS depends on math and if I wanted to start now,where would be a good place(or book) to begin in computational math/Algorithms?
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>>8514548
not a very intelligent post on your part, as you do not state your current math skill level or your completed math courses
you call yourself a cs grad but then you ask how much of cs depends on math

at most schools you would take calc 1-2, linear algebra, discrete math - this is the minimum
normally you would also take any calc based prob/stats course
if you have taken all this then any relevant math is covered in the cs courses

you can start...
>>
>>8514600

>Outside enginerring, I have not done any math courses

>My math skill level is probably zero

but, I do have the time ahead of me to change,

>Excellent links by the way,although finished the third book(DAA) in college
>>
you sound like a massive faggot
you will still be a basement dweller it guy because you cannot express yourself in a clear manner
these are all online

http://stanford.edu/class/ee364a/

http://www.crypto-textbook.com/

complex variables - any book will do

numerical linear algebra - watkins fundamentals of matrix analysis is good

any...

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Are lucid dreams /sci/ ? What do you think of pic related and the dream research?
>>
They are cool as fuck. That's what I know.
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>>8514521
>dream research
Please go on. Bumping for interest.
>>
After I had written the theme I continued to be curious, and I kept practicing this watching myself as I went to sleep. One night, while I was having a dream, I realized I was observing myself in the dream. I had gotten all the way down into the sleep itself!

In the first part of the dream I'm on top of a train and we're approaching a tunnel. I get scared, pull myself down, and we go into the tunnel-- whoosh! I say to myself, "So you can get the feeling of fear, and you can hear the sound change when you go into the tunnel." I also noticed that I could...