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/sci/ - Science & Math


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File: 358 KB, 2621x1425, medical care.jpg [View same] [iqdb] [saucenao] [google] [report]
9306995 No.9306995 [Reply] [Original] [archived.moe]

We are looking for this issue of Medical Care to support our investigation, but subscription is too expensive (727 dollars), does anyone have a PDF of it?



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9306987 No.9306987 [Reply] [Original] [archived.moe]

>one uppon time there was something wich for some reason exploded at some point in time and this is how the world was created.

This is what atheists actually believe.



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9306947 No.9306947 [Reply] [Original] [archived.moe]

[math]\sqrt{2}=\frac{2}{\frac{2}{\frac{\vdots}{\sqrt2}}}[/math]

What can /sci/ take from this definition of a square root?

>> No.9306953

n\!i\!g\!g\!e\!r\!s



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9306941 No.9306941 [Reply] [Original] [archived.moe]

Which millennium problem you guys think it'll be solved next?



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9306933 No.9306933 [Reply] [Original] [archived.moe]

Can someone genuinely tell me if humans are likely to find out alien life form and if so, when? Could just be acknowledging that life form exists, taking pictures or even seeing these aliens. Not aliens per se but just life form on another planet. How likely is it that we will discover something?

>> No.9306957

>>9306933
Highly likely that it's out there given the amount of space that exists. Not so likely that we'll find it. Even less likely that when we do find it, it's intelligent and not a bacteria or something.


If we do find anything it'll probably be a bacteria or some kind of micro organism.



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9306919 No.9306919 [Reply] [Original] [archived.moe]

Why do people have different personalities?

>> No.9306930

>>9306919
Depends on the place they grow up, their genes and their race

Like, my family is filled with lazy fuckers, but my dad is a hardworking man, yet I'm a lazy fucker.

>> No.9306952

>>9306919

Firstly, evolution. People from very cold climates are cooperative, hard working, and boring, because that gets you through a long winter when you have bad luck with crops. People from tropical hunter-gatherer societies have impulsive ADHD-type personalities, because its useful in that context. People with ancestry from resource scarce areas with frequent tribal conflict have tempers and are very restricted with their empathy, because their ancestors had to be ready to be ruthless. People whose ancestors lived in centralized agricultural societies for ages are more conformist, because standing out as a trouble maker would get you killed or ostracized. Generally, the less central state power was around, the more violent men had to be willing to be, to protect their family. Otherwise, both men and women have been sexually selected to be sociable, with men also being selected for humor as a sign of social intelligence.

Broadly, a man can have three sexual strategies: 1) hard working, friendly, conformist, anxious, shy (i.e. low risk-taking) 2) intermediate 3) opportunistic, aggressive, hedonistic, extroverted (high risk-taking). In certain climates and societies 2) works better, especially when intelligence and child-rearing is rewarded. In other climates, getting a girl pregnant and leaving her, or invading a rival tribe and raping their women can lead to greater sexual success, and hence more men from those backgrounds will display dark-triad personality traits.

All this also changes over your life-span. Your confidence is driven by feedback from others. If you practice theater you'll become more extroverted. If women throw themselves at you, you will increase your confidence and decrease your altruism. Same with being rich or having big biceps. If you have a sudden illness you might suddenly have an urge to connect to people in your community.



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9306916 No.9306916 [Reply] [Original] [archived.moe]

Can someone explain me how to "use" Einstein's gravity equations to make simple predictions or to get basic values?
I am guessing that one needs to work with the field equations.
For example, how can you get the acceleration experimented by a 1 kg object at rest on the surface of the earth?
Let's assume the Earth radius at that point is of 6370 kilometres. And Earth's mass to be 5.97E+24 kilograms.
When working with Newtonian gravity we could simply use the equation everyone knows:
[math]F=G{\frac {m_{1}m_{2}}{r^{2}}}[/math]

Note that this is no homework. I am simply want to know more about it. And I think that looking at how to solve a problem is a good approach to learning.

>> No.9306923

>>9306916
I simply*

>> No.9306968
File: 717 KB, 865x649, emmpay.png [View same] [iqdb] [saucenao] [google] [report]
9306968

To show you where things come togeter...

If you know electrostatics or the use of potentials f for Newtonian gravity, then you know that 1/r^2 (propto Df) for a vaccum comes about through the Possion equations DDf(r)=q(r), which spefically reads
(1/r^2) D (r^2 Df) = 0

In relativity, f would be part of the the time-component of the metric g and the Einstein tensor G is essentially the Laplace operator DD applied to the metric. Except there are 9 more independent components, so things don't get simpler.

There is a Wikipedia page with exact solutions, but it's mostly not possible.
You also have the derivation here.

https://en.wikipedia.org/wiki/Deriving_the_Schwarzschild_solution

But essentially, it's just a differential equation and you got to do a lot of modeling work to get "what you want" out of it. Gödel trolled Einstein quite a bit when he explicitly worked on finding a solution where time goes in circles and such. Not all that pops out of it is relevant physics. There was a phase in the 50's when GR became super popular again, and that's they era where le Hawkings comes from too. But it doesn't matter too much anyway. It was coocked up in the 20 and one two decades later they were already desperately trying to find a quantum version.

>> No.9306991
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9306991

here that meme solution I talked about

https://en.wikipedia.org/wiki/G%C3%B6del_metric

Here's 85 of the more classical elternatives to general relativity, i.e. those after Einstein but before stuff like loop quantum gravity

https://en.wikipedia.org/wiki/Alternatives_to_general_relativity

Einstien tensor

https://en.wikipedia.org/wiki/Einstein_tensor

This table helps too

https://en.wikipedia.org/wiki/Del_in_cylindrical_and_spherical_coordinates



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9306895 No.9306895 [Reply] [Original] [archived.moe]

Ohhh but MUH earth will be uninhabitable MARS IS ALREADY UNIHABITABLE if you cant fix earth WHY would you think you could fix mars.

>> No.9306907

>>9306895
Its not about Earth becoming uninhabitable, its about Earth getting hit by an extinction event like an asteroid and suddenly we are all dead. If we had a self sustaining mars colony the human race would live on. Not to mention the absurd iron reserves on mars will make the person to monopolize travel there (Elon) into the worlds first trillionaire.



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9306867 No.9306867 [Reply] [Original] [archived.moe]

I have a 14 hour car ride ahead of me this week and am looking for ideas for good science related audio listening. I already listened to Feynman's lectures last year so looking for something else. Preferably physics related but I am open.

How does /sci/ learn while driving?

>> No.9306880

I just listen to music like a normal person

>> No.9306899

Jordan peterson

>> No.9306904

Just listen to music you fucking asspie

>> No.9306971
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9306971

>>9306880
>>9306904
Not really an option because I will be in the middle of nowhere a lot of the time and don't have 14 hours worth of music on my phone to get me there.

>>9306899
I don't view psychology as science so I would like something a bit more hard sci.



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9306833 No.9306833 [Reply] [Original] [archived.moe]

What is oxygen made out of? Is it air and coal? I'm sorry, i never was able to finnish Elementary school.. Like when someone say that you've nevver seen oxygen in your life, does that mean they are implyign that you are retarfed?

>> No.9306869
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9306869

>> No.9306980

>>9306869
I'm serious i need help

>> No.9306990

>>9306833
oxygen is made out of protons and shit yo



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9306812 No.9306812 [Reply] [Original] [archived.moe]

>acording to this board faggots, changing your diet from cancer producing food (meat, processed sugar, processed foods) to said foods that contains chemicals that are anti carcinogens and have been proven to decrease cancer or kill it has not effect on the body
>tfw becoming vegan has not effect on the body acording to this board
>tfw eating the food that contains fiber and the chemicals that are used to produce medicine has not effects on the body

>> No.9306816

>>9306812
>faggots
Why the homophobia?



File: 303 KB, 349x366, Untitled.png [View same] [iqdb] [saucenao] [google] [report]
9306779 No.9306779 [Reply] [Original] [archived.moe]

I'm in an open book physics exam right now and I know nothing.
Is anyone interested in helping a desperate anon?

8 replies omitted. Click Reply to view.
>> No.9306913
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9306913

>open book
>exam over internet
>smartphone allowed

is this us education?

>> No.9306943

>>9306831
>>9306862
these t.bh

>> No.9306975

>>9306913
>https://iseri.eu/
Nope, glorious eurocuck education.

>> No.9306986

>>9306822
>>9306832
>"""""superior"""" European """"education"""" revealed
lmao, I thought you lying cucks learned this in 1st grade.

>> No.9306997

>>9306986
This. I thought euros knew Analysis and Hamiltonian Mechanics before getting into college



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9306740 No.9306740 [Reply] [Original] [archived.moe]

In what ways are things like tactile sensations different from emotional ones? Obviously the sources are different, but what about the sensations? How analogous is feeling the surface of a wooden desk or a smooth rock to feeling something like anger or sadness?

>> No.9306778
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9306778

A E S T H E T I C S

What makes liking a color different than liking a flavor? Is it just because separate areas of the brain are responsible for processing these things that leads to the different experience or something else?

I think an aesthetics and psychology board would be cool but it would probaby be dead and make sci dead'er

>> No.9306787

>>9306778
>What makes liking a color different than liking a flavor?
I guess I don't need that much of an answer; my real question is more like "is the difference between something like taste and touch etc bigger than the difference between taste or touch etc and emotional sensations?" Does one precede the other?

>> No.9306858

>>9306787
you dont have senses and emotions to test yourself?

isn't something like that purely subjective



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9306711 No.9306711 [Reply] [Original] [archived.moe]

Can we ever create a true random number generator?

>> No.9306719

>>9306711
amplify your mothers farts and merge it with an audio stream of every CNN station, then have a program generate numbers from the noise

>> No.9306721

>>9306711
We already have, it uses the electromagnetic noise or some shit like that

>> No.9306797

>>9306711
easy just measure voltage from open port which should produce white noise static

>> No.9306897

>>9306711
Define random

>> No.9306908

Your processor has one using metastable latches.



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9306663 No.9306663 [Reply] [Original] [archived.moe]

>http://fortune.com/2017/11/08/graduate-students-say-gop-tax-plan-could-increase-their-taxes-by-nearly-300/

>THREE HUNDRED PERCENT INCREASE IN TAXES

Is this for real?

At least you can do your taxes on a form as small as a post card.

>> No.9306676
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9306676

>>9306663
Go back to muh pole.

>> No.9306689

>>9306663
> grads were(and still are) paying THREE HUNDRED PERCENT LESS than other working people



File: 196 KB, 1078x1402, FutureSuperContinents.jpg [View same] [iqdb] [saucenao] [google] [report]
9306654 No.9306654 [Reply] [Original] [archived.moe]

What is /sci/ opinion on the future of the conintents. Personally, I think a lot of these future models are inaccurate with Novopangaea coming closest to what I think will happen with these exceptions:

>Antartica will most likely collide with the Atlantic side of Patagonia in 20 myfn or so given current trends
>East Africa will separate in the North mostly from the mainland and collide with Southern Pakistan as Arabia drives between them like a wedge.
>The Atlantic, Indian and Southern oceans will merge as North America and Eurasioafrica close the Arctic ocean near modern Alaska/Northern Pacific while South America closes the South Pacific, wrapping around southern Australia which will have already collided with South China.

Any thoughts/critiques? This is based off the current movement of the contintents. I haven't seen much discussion about it in the geological community in the last 10 years or so, and given new findings this model seems to make the most sense. I call it BeringoArtica because of the fusing of the Eurasian and North American Cratons in the afeormentioned region of the Bering Strait and the nearby Arctic Ocean.

63 replies omitted. Click Reply to view.
>> No.9306964

>>9306945
>>9306948
The Central US seems to be a rather tumultuous region, particularly out west in geological terms. The Area is primarily folded strata that separates the pacific from the Canadian Shield.

>> No.9306969

>>9306948
Its possible. Its more likely that it is a remnant of a past failed rift that occurred in the mid US and resulted in alot of uplift from the ozarks to the driftless zone of wisconsin. If it had to guess, it would be the latter because there is tons of evidence for a failed rift and those make some big honking faults bigger than the new madrid.

>> No.9306976

>>9306969
How come the nearby area of the black belt and the Atlantic Plane is so low lying and flat then? Wouldn't the Uplift make the South more elevated and Rocky like the Northeast around New England?

>> No.9306978

>>9306964
Midwest US from ohio to south dakota is defined as a craton, literally the opposite of a tumultuous spot. It has had almost no tectonic activity occuring there since the ordovician 480 mya. There are anomalies like the failed rift, but that failed and only caused a bit of uplift. Now out west in the rockies, shit was and is going crazy with tons of shortening the the past, super complex structure and faulting, and now extension and normal faulting. Pretty neat

>> No.9306985

>>9306976
No, uplift in the Mid US is a smooth and broad process, and is not pronounced like actual mountains. The rockies and the appalachians were formed from crust colliding and oceanic crust subducting under the continental crust. The collisions creates a buckling effect that can form mountains, but the subduction creates magmatic ponding and localized volcano building. Keep in mind these are very general summaries of extremely complex processes. These are very different processes from uplift like in the mid US, which was probably from a mantle plume and completely removed from tectonic strucute for the most part.



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9306653 No.9306653 [Reply] [Original] [archived.moe]

Hey guys, i'm doing a presentation about depression and i was wondering if anyone has some good scientific links for matters concerning depression, anxiety and so on.
I myself am diagnosed with depression and anxiety but i don't want to make it a personal kinda of thing.
Since i started the thread i guess i will contribute too:

https://www.psychologytoday.com/blog/urban-survival/201701/new-research-shows-depression-linked-inflammation

>> No.9306661

oh and controversial opinions are also welcome. I'm trying to make it was obejctive as possible

>> No.9306680

>>9306653
I'm no expert so no references, but re: serotonin, I hear gut-brain axis is a current topic.

any studies that show link of anti-depressants to suicidal actions should be nice and controversial, as well as "recreational" (psilocybin) as treatment for depression, etc.

>> No.9306695

>>9306680
>gut-brain axis

cool nver heard of the correlation between the two. Thanks!



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9306645 No.9306645 [Reply] [Original] [archived.moe]

>go to good university
>don't understand lectures and end up learning from shitbox community college
>explanations designed for brainlets like me, understand immediately

Anyone else do this?

>> No.9306665

Teachers are just shitty, and don't give a damn, so they hide it behind a veneer of expectation.

>> No.9306694

>>9306645
You want to know if anybody else is a brainlet? Yes, there are more brainlets like you out there. There's your answer.

>> No.9306765

>>9306645
Yeah pretty much. I'm taking as many of the "weed out" courses at CC as possible and transferring them in. It's not that I've had any bad teachers, a lot of it is due to the departmental administration(in math at least) as well as test structure.

For example, calculus tests are multiple choice, so if you arrive at an answer which is correct, but not in the form they have on the test, you have to derive it which takes time away from the other questions. For example, if used logarithmic differentiation while calculating a derivative which totally would suck balls another way, you're fucked. At CC, where it's not multiple choice, once you get to an answer, which plugged in to a calculator equals the answer on test from my university, you get it right. Probably a shit example, but you get the idea.

I understand, because there are so many students, but I've never made a grade lower than a B in calculus courses at CC, but I got my ass handed to me at my university and dropped it to avoid GPApocalypse(gotta keep my 3.7 yo) despite killing it on homework and quizzes.

I go to a pretty good university as well, so no shame in going that route.

>> No.9306848

>allowed to take four sheets of paper to math test
>watch patric jmt videos on youtube and write down order of operations for every possible proplem
>get a 7 while not understanding a thing I did
>smarter students write down theorems and proofs and score a 10
feels bad being a lazy brainlet. luckily I'm an engineer and will never have to use any of that math ever again



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9306632 No.9306632 [Reply] [Original] [archived.moe]

If I have 2 functions f1(x,y) and f2(a,b) where x,y,a,b eof N does there always 2 different functions f3(k) and f4(i) exist where i,k eof N such that f1( f3(k) ,f4(i) ) = f2(a,b) ?

I'd say yes.

1 replies omitted. Click Reply to view.
>> No.9306641

>>9306632
I Think I got it wrong, it must be:

If I have 2 functions f1(x,y) and f2(a,b) where x,y,a,b eof N does there always 2 different functions f3(a) and f4(b) exist such that f1( f3(a) ,f4(b) ) = f2(a,b) ?

>> No.9306681

>>9306641
>If I have 2 functions f1(x,y) and f2(a,b) where x,y,a,b eof N does there always 2 different functions f3(a) and f4(b) exist such that f1( f3(a) ,f4(b) ) = f2(a,b) ?
No.

>> No.9306697

>>9306641
no consider f1 and f2 both constant functions, but different constants

>> No.9306733

>>9306697
why tho

>> No.9306741

>>9306733
if f1(x,y) = 1 for all x,y and f2(a,b)=2 for all a,b then f1(f3(a),f(b))=1 for all a,b, which can't equal f2(a,b)=2



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9306572 No.9306572 [Reply] [Original] [archived.moe]

If your brain is made up of two neural networks, one in each hemisphere which communicate through the corpus callosum, why do you never see this simulated in AI? It's always a single neural network.

You'd think it'd be pretty important thing to simulate considering most, if not all, animals have two brain hemispheres.

3 replies omitted. Click Reply to view.
>> No.9306602

>>9306593
Neh, I think I have a point. The human brain's hemispheres are obviously something inherent to brains or constructs of similar complexity. If you're sticking together 10 neurons for image classification, what would you gain from separating them into hemispheres?

>> No.9306613

>>9306602
parallel processing

>> No.9306615

>>9306602
I just proved you didn't have a point though. You can remove one hemisphere from someone's brain and the evidence we have suggests there isn't any significant decrease in cognitive power following that hemisphere excision.

>> No.9306722

>>9306585
>Cognitive measures typically changed little between surgery and follow-up

>You can remove one hemisphere from someone's brain and the evidence we have suggests there isn't any significant decrease in cognitive power

That paper does not prove that at all. The seizures render those areas of the brain that are removed as disfunctional and from it as your paper shows, the mean IQ of these groups are extremely low. It shows removing the damaged part of the brain does not negatively effect them but the damaged area did significantly decrease their cognitive abilities. As such, if you removed a healthy child's part of the brain you could still expect a decrease in cognitive abilities like these children have. It of course depends on to what degree and how old the child is but no such experiment has been done to shows there would be no decrease in ability.

Long story short, removing a damaged part of the brain and removing a health part are two very different things.

I honestly agree with your overall premise that mimicking this system in neural networks would be unnecessary for most systems but the premise you can live just as well with one hemisphere is silly. There is a limit to neural plasticity even in children.

>> No.9306781

>>9306572
that's not true, GANs have 2 networks, capsNET kind of have 2 although not at same time, synthetic gradients technically have +1 for each layers to predict the gradient. Also many large scale projects like Siri, alphago etc use multiple neural network each with it's won task.

They don't behave like hemispheres per say but we do have multiple-network systems, it's just that nobody has any use-case for something like what the left/right hemispheres do yet.

>>9306581
thousands



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