Archived threads in /sci/ - Science & Math - 33. page
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Hello, /sci/. This will be the first lecture in a series I will be giving here on Brave New Algebra. We will be starting from rudimentary set theory. This thread is meant to be a discussion place, so if anybody has any questions, feel free to ask. Shitposting is accepted but discouraged.
A set is naively a collection of things. We will start by imposing the axioms of Zermelo-Fraenkel set theory, coupled with the axiom of choice (sue me). But first, some definitions.
Two sets are equal, written A=B, if, given any element x, x is in A if and only if x is in B.
The...
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Now, the axioms.
1. Given sets A and B, there is a set AUB so that x is in AUB if and only if x is in A or x is in B.
2. Given any two sets A and B, there is a set C so that A and B are elements in C.
3. Given any set A, there is a set P(A):={S : S is a subset of A}.
4. Two sets are equal if they contain the same elements.
5. Every set A contains an element B such that A and B are disjoint. (That is, they have an empty intersection: they share no elements.)
6. (informally:) Given any formula p in the language of set theory defined over...
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Let's discuss ordinals.
Definition. An ordinal is a set S such that every element in S is also a subset of S, and so that set membership defines a strict well-ordering on S.
Exercise. Show that the empty set is an ordinal, and show that no element is less than the empty set (it is the minimal ordinal).
With {}=0 the smallest ordinal, we can inductively define the successor of an ordinal S(k) to be the powerset of k. Ordinals form a proper class, and they will probably turn out to be useful somewhere down the line. I figured we should have them under our belt.
Time to talk about functions.
Let f:A->B be a function. For any element b in B, the fiber f^-1(b) is the set of elements in a such that f(a)=b.
Exercise. Show that a function is surjective if and only if the fiber over every element in the codomain is nonempty. Show that a function is injective if and only if the fiber over every element in the codomain is isomorphic to either the point (the set {*}) or the empty set. Characterize a bijective function (one which is both surjective and injective) in terms of fibers.
Given a function f:A->B, the image...
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>speed is the change in position
>acceleration is the change in speed
what is the change is acceleration?
its derivative
/thread
>>8176764
>OP pretends not to know about jerking
>...on /sci/
0/10
http://lmgtfy.com/?q=what+is+change+in+acceleration
Ya jerk.
It's slow as fuck. Takes almost half a second to make a multiplication.
Can't do shit with it.
>>8171213
> half second to do multiplication
you need to upgrade your pentium 2 grandpa
>>8171218
I have Core i7.
>>8171213
Python is for kids. C# is the true programming language.
So I was playing some overwatch and some of the in game commentary got me thinking. I looked into the story a bit and it might actually be more realistic than you think. Basically there was a big fight over whether to give AI robots rights or not.
So I ask you /sci/, do robots with advanced enough AI deserve rights? We might not have the technology to create them yet but maybe one day we will. At what point do you think they deserve rights?
robots don't ever deserve human rights.
Define "rights"
As long as they abide by the 3 laws of robotics then everything should be fine. They have no more chance of becoming sentient than a toaster
>>8170326
This. Fuck """"AI"""" "sentience"
Why are most men clueless about how to impress and seduce women?
Most men don't seem to have a clue about how to seduce women and need to consciously learn these skills through trial and error, reading books etc. Isn't this a bit of an evolutionary paradox? Shouldn't we expect men to have evolved to instinctively understand what impresses women and how to talk to them etc?
To me, the fact that most men are pretty clueless about how to seduce women strongly suggests that this wasn't a necessary skill for prehistoric men to have. Prehistoric...
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ITT: projection
>>8169955
Not really. Even the best seducers and pickup artists all say that they weren't born knowing how to seduce women and that they've had to learn these skills through years of trial and error.
>>8169949
Why do you assume that cavemen didnt learn how to seduce cavewomen?
Is this the optimal food pyramid?
Optimal in regards to what?
Health wise, all that matters is water, kcals, essential fats, essential amino acids, and certain vitamins and minerals.
Where the above is derived from is not important.
>>8178173
>le vegetables are healthy xD
I want this meme to die.
>>8178184
Fat the good fat.
But it's right, red meat is at least 50% saturated fat.
You lied to me /sci/.
You told me science was something honorable and something that non-plebs pursue.
You promised me science would lead to lucrative careers
You told me science allowed freedom that other jobs don't.
Science is literally a meme.
Science is underpaid
Science is spending countless hours searching for knowledge that will never be directly applied.
Science as it's portrayed is lie.
PhDs are overrated.
mfw chemistry phd since 500 BC and still on 4chan
>>8177429
>math PhD
>300k starting
>any job I want
>>8177429
>Science is spending countless hours searching for knowledge that will never be directly applied.
Where does it say science needs to be applied. Go do engineering.
![[CBM]_Cowboy_Bebop_-_Session_08_-_Waltz_for_Venus_[720p]_[CA767F28].mkv_snapshot_10.37_[2016.07.03_00.52.36].jpg](https://i.imgur.com/MNrPvJh.jpg "[CBM]_Cowboy_Bebop_-_Session_08_-_Waltz_for_Venus_[720p]_[CA767F28].mkv_snapshot_10.37_[2016.07.03_00.52.36].jpg")
Will humans be able to colonize other planets and galaxies?
>>8181287
Planets, yes.
Galaxies, no.
>>8181358
why not, really?
if we go by the notion that the existing scientific endeavors will develop further, it could be anyone's guess.
cryogenics is still a debated thing, uploading consciousness to preserve a mind is also a viable method.
Why would you think we couldn't simply fling an inert spore-like ship to estimated trajectories of other galaxies?
Not galaxies, other than Andromeda, Triangulum, and the surrounding dwarf galaxies unless we invent FTL travel.
Planets, definitely.
>"The Speed of Light"
Today I learned Light doesn't have an absolute speed and changes depending on your reference frame.
So Light can be emitted from a star that's traveling at 1 million mph and then Light's speed is C + 1 million mph.
Why did Science lie to me?
that's called blueshifting. You can't add up colinear velocities when dealing with waves.
>>8182177
> plebs on this board
> sum the velocity when dealing with relativity
seriously do some research before posting.
>>8182177
>blaming science for your idiocy
But hey, I'm no better, replying to a shitposter and all.
I got this question from my professor for homework and I want to see what some /sci/tards get. Explain your reasoning. I got 5000 +/-500
>The following type of question is called a Fermi question, and you are to do it without using anything except your pencil and paper: How many average-sized sewing needles will fit into an average-sized coffee mug?
no takers?
>>8181992
No this Fermi problem is boring.
>>8181994
pussy
Hey /sci/.
What would it take to breed sapience into a non sapient species?
are you retarded?
just pick the smartest animals from the litter, and breed on with that, and so on.
it's not that fucking hard.
god
>>8181464
total shitpost
>>8181408
get the ones that communicate to bang eachother
Can math notation be improved?
>>8181209
Yes, the current notation is shit and difficult to understand for people new to it. Notation should give hints to what it's underlying symbols mean. I think we should all take just take a hint from programming and use natural language followed by an arguments list. E.g.
Integrate(LeftBound, RightBound)
Union(Set1, Set2)
>>8181342
>notation
>art
what
>>8181209
yeah, computers
hover mouse over notations, get explains
How about a proof thread? No matter if babby math, advanced math, CS theory or logic. Post your proofs here. Ill start.
>>8181015
IF a halt function exists then:
void halting_troll( void (*funfun)(void*) ){
if(halt(funfun, (void*) funfun))
while(1){}
return;
}
would be valid but what is the result of >halt(halting_troll, (void*) halting_troll);
QED
>>8181015
>Look at me, I'm so [eqn]smart[/eqn]! I wrote a proof in [eqn]latex[/eqn]!
Shinichi Mochizuki has written a new paper:
>http://www.kurims.kyoto-u.ac.jp/~motizuki/Alien%20Copies,%20Gaussians,%20and%20Inter-universal%20Teichmuller%20Theory.pdf
Pic related: it's an excerpt from the paper.
Discuss.
>>8180994
His writing is horrible, is this even peer reviewed or just a rant?
2deep4me
>>8181006
Please don't shitpost. I know that it's funny that his developments are very complicated and indecipherable, but he actually makes an effort to make it more accessible. He just made a 115-page survey of his theory.
My stats professor told me that the larger the sample size the more trustworthy the data.
I guess the N's justify the means.
>>8180531
No well respected scientist uses a mean. You meant to say the N's justify the medians.
Youre not remotely funny
>>8180540
Fuck you it was a bit funny.
Fucking critics.
