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Archived threads in /sci/ - Science & Math - 315. page
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If you assholes are tired of answering and asking the same questions over and over, I'm going to build a fission battery.

Here's my plan so far:

Refine uranium 238 down to yellowcake. Guaranteed to get a some good radium from impurities in the ore, as well as likely to get some 235 from it, so that will likely end up being my fissile materials, where the 238 will be used to kick off the fission reaction.

This will take place in a chamber and here I could use some input about materials. I'm looking to keep the cost down and use materials I...
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tl;dr
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>>8043407
>Platinum
>Positively charged side of a magnet
I hope this is bait
>>
Not baiting, don't know if protons would be repelled by like charge of magnetic field. Probably wrong, in which case, still need a material that will repel protons.

Platinum wall works because natural electronegativity, unless you've got another, better option, or I'm misunderstanding something? Can harvest enough platinum easily.

Oregon licence plates consist of three letters followed by a three digit number (each digit can be from [0..9]).
While driving to work Seth plays the following game:
Whenever the numbers of two licence plates seen on his trip add to 1000 that's a win.

E.g. MIC-012 and HAN-988 is a win and RYU-500 and SET-500 too. (as long as he sees them in the same trip).

Find the expected number of plates he needs to see for a win.
Give your answer rounded to 8 decimal places behind the decimal point.

Help me /sci/, it's from project Euler.
>>
Does he win when the order of spotted plates is: 100->500->900?
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>>8043405
No, when numbers of TWO licence plates add to 1000 he wins.
>>
So, first plate is random
second wins 1/1000
third 1/1000
n-th 1/1000

Distribution is random, so on average he's gonna find 1000 after 50% of plates?

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Suggest me some good classical music to listen to while I study Math.

Actually, any music will do; just without lyrics.

tl;dr pls help anons i can't concentrate w/o mah musik. thanks guys <3
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>>8043311
Just listen to video game soundtracks. Usually does the trick for me
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>>8043335

Any suggestions? I'm not into video games much (used to be during grade school, but not so much in college)
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>>8043311
Chopin
Bach
Rachmaninoff

My personal favs

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So I have a lot of friends who do psychedelics and occasionally they hit me up to try them(Which I don't).

I remember reading some psychedelic mushroom essentially destroys your current consciousness and replaces it with another(sorta like how you wouldn't be you anymore after being teleported)

Could have been bullshit, I dunno

Are these drugs safe?

Will the current me die if I take them?
>>
> Science is yet to prove or examine consciousness
> Read somewhere some retarded bullshit claim as if they know what theyre talking about
kid pls...
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>>8043312
>kid pls
I'm likely older than you(27)

I just don't know shit about drugs, I don't really believe in recreational drug use personally but I feel like the experience could help me become closer to my friends.

If it was just weed this wouldn't be an issue but psychedelics are fucking spooky man.
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>>8043322
Calm down, pick a nice day and try them. Always remember that no matter how fucked your perception is, after you sleep its gone and what you saw will be a faint memory.
Irreversible damage to your mind are very unlikely and if you consider yourself a strong willed person at all you should definitely try tripping.

Hello /sci/. I am asking a couple of the boards I respect for some advice and you are one of them. Please hear me out:

As a teenager I loved reading Philosophy. I devoured Nietzsche, Camus, Dostoevsky, Popper, Aristotle etc. etc. but when I finished school I decided to study physics because I fell for the "better do something objectively useful" meme and also because I felt that it would somehow validate me intellectually to do something most people percieved as being hard.

I have now finished my Bachelors and am in the first semester of my Masters and...
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>>8043215
you spout meme, unrelated authors and show absolutely no signs of actually knowing any philosophy

you sound like you want lazy continental memery. and that sounds like an absolutely terrible idea.

if you're sick of your degree you definitely need to change ASAP though, so tell us more about your interests, at this point it's only "i like meme philosophy and programming I guess" and that's shit
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>>8043215
if you absolutely must study philosophy just double major you fuckhead

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>>8043228
In the last three years of my degree I barely read any non scientific literature and had very few creative thoughts that weren't clever ways of solving a tricky integral. In light of this I never really outgrew "meme philosophy" as you call it.

What would you call "good philosophy" btw? Russel, Wittgenstein, Sartre, Kant, Heidegger?

But to get back to my main point:...

I'm a physics major and I typically dislike "pure" mathematics, but I'm loving this group theory stuff. Only problem is, I hate this book. It doesn't even discuss Lie groups, which are the foundations of field theories in physics.
Does /sci/ recommend any good, more advanced texts on group theory and/or other topics in math that are great for contemporary physics?
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Lie Groups are more a topic of Differential Geometry than they are Algebra.

They are smooth manifolds which also have the structure of a group.
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>>8043173
>I hate this book. It doesn't even discuss Lie groups.
Is this bait? I doubt there's a single introductory algebra book that discusses Lie groups. Not even Dummit and Foote does, IIRC, and that's as encyclopedic as you're going to get.

Pretty much everyone who's inexperienced enough to be reading Artin doesn't have enough background in manifolds to understand that.

That said, I think Knapp has written a book on them. I haven't read it...
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>>8043173
For basic algebra with a view towards category theory (which can be useful in some areas of theoretical physics - mostly toy models such as topological field theories) I would advise Aluffi's "Algebra chapter 0".

For Lie groups, take up e.g. Knapp's "Lie groups: beyond an introduction". You could also try with "Geometry, topology and physics" by Nakahara, where he introduces many notions from mathematics (such as Lie groups) needed in theoretical/mathematical physics....

If water is a shit lubricant for sex, why is it so good for cleaning our hands?
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>>8043127
if oil is a good lubricant for sex, why is it bad for cleaning our hands?
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>>8043127
I don't think you understand the difference between "solvent" and "lubricant".
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>>8043127
its not, most of us use soap. fucking slob

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https://en.wikipedia.org/wiki/Mars_Climate_Orbiter
Well done America, you fucking idiots.

Meanwhile Europe's managed to land a prope on a bloody asteroid!
>>
Why are Europoors so obsessed with Americans? You are just as idiotic as they are though.
>>
>>8043103
Says the paki.
I'm sorry ISIS didn't have enough curry for you today, rajeet.
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>>8043103
Because Americans are Europeans.

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So /sci/, i assume everyone here studies a STEM field and we all know it's very tough and rigorous, but how do you motivate yourself to push when the going gets tough, when you just feel like shit when your mind tells you that you can never get better at what you're doing, that you start doubting that your hardwork will amount you any success, i sometimes get so worried about this that i just lose all motivation in working.
Pic related
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>>8043083

I have no motivation

I'm gonna end it soon anyway

There's no point
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>>8043083
You want motivation?

Someday very, very soon, you will be sitting in an chair in a cheap suit, sweating bullets, while I or somebody like me grills you on what you learned during college to see if you actually have something resembling a clue and are worthy of being employed.

Then you will be expected to use what you learned, 9 to 5 every weekday until you retire or die, to do something useful. Everyone around you is doing the same and if you fall behind, no promotions or bonuses for you.
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>>8043083
>that you start doubting that your hardwork will amount you any success,
theres no doubt, i now know for a fact just how worthless this degree i got was.

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>yfw the UK is this retarded.

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That's pretty terrible. But 603 entries? I don't follow. I thought AQA Maths got like 100K entries
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>>8043019
The Northern Irish are beating your asses in English and they could barley speak it properly
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>>8043020

I've looked at all AQA stats for GCSE maths (all the way to 07) and the number of people achieving an A grade does not go over 10%. The ''entry'' category in some of them is above 30k.

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Gonna start CS in October at a pretty high ranked university. My math is pretty bad. What do I need to learn by then so I can have an easier time studying?
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>>8042989
If you're doing CS at a legitimately good uni, maybe start learning LISP and get used to recursion early. Try implementing matrices in LISP via lists, their arithmetic and useful functions, such as those that give the determinant and inverse of an nxn. This will really reinforce your understanding of what you're dealing with.

It really does depend upon what you mean by your math being bad though.
>>
Concrete Mathematics is a famous text which covers a selection of mathematics that shows up in the study of algorithms. Again, if you struggle with particularly basic math, then you should study that.
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graph theory, group theory. those are big ones, not as hard as you would expect. maybe try khan academy and see if they have some videos.

The informatic genius behind Sci-hub.cc

FREE KNOWLEDGE FOR ALL.

although Editors like nature and science start to complain and rise the dangers.

>----------------------------
EDITORIAL

My love-hate of Sci-Hub

BY MARCIA MCNUTT
SCIENCE29 APR 2016 : 497
>----------------------------

BY JOHN BOHANNON
SCIENCE 29 APR 2016 : 508-512

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>>8042963
naruhodo ne....
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>>8042991
means "I see" right?
romanji ftw
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>>8042963
You need people to pay for Journals. There is actual work behind it you nitwits.

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Anyone able to help me identify this rock? I picked it up years ago because i just thought it looked cool, but I found it again recently and began wondering if it could be a plant fossil.
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>>8042791
Thats clearly a frog
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>>8042791

I'll plant my rock in your fossil m8
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>>8042792
Are you sure?

How do I find the derivative of this?
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one of dem fukin tricks doe

wrt x function of f
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>>8042706
what exactly are we trying to do here?
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>>8042706
Volterra equ of 1st kind

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ITT we're hypothesizing about social/technical aspects of a species developing relative immortality, first, for wealthy individuals, finally for all. Final insights welcome.

OP beliefs, species will experience:
- increasing unfairness of wealth distribution
- immortals consolidating power
- technology boost due to brilliant minds not dying
- increasing civil commotions
- war on resources and locations
- juristic overhaul on ideas like wealth and heritage
- innovation boost on age-related problems like cancer, organ replacements and transplants
-...
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>>8042677
>increasing unfairness of wealth distribution
Stopped reading. What makes it seems as if the wealth distribution would do anything but standardize? If nobody has to work, they would all get paid the same.
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>>8042681
Your free decision, dude. And what makes plausible rich humans suddenly relinquish wealth and power for no reason?
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>>8042683
It just doesn't make sense to say that the rich get more rich where everything that is standardized is ready to be risen above. Their stocks could fail or whatever.

What is this with this style? Why do people that write "scientific" texts insist on making everything sound so pompous and complicated? With this example it's easy to get the meaning because it's a common concept to know. But once you start reading about more obscure topics or about things that are completely new to you, no matter how simple the concept may be, the way the text is written makes understanding it a very hard. And I'm not talking about the use of domain specific terminology, just this particular "style". It's very wide spread...
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>>8042585
Very low quality.
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I'm in the biz for too long and probably blind to any difficulty in that regard, but your pic in geberal has ab extremely reader friendly text.
If wikipedia was for me alone, that three lines could be replaces for a third of a line of first order logic definitions and I't get to know what a median is much more concisely
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That's nothing, OP. Look at this.

>The square is the n=2 case of the families of n-hypercubes and n-orthoplexes.
That's part of the introductory description comes before the table of contents in the wikipedia article for "square." For a fucking SQUARE.

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>The hairy ball theorem

This is why no one takes theoretical math seriously
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>>8042489
>theoretical math
as opposed to concrete math?
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>>8042498
Yes, anything that doesn't include negative numbers is concrete math.
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>>8042505

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Quantum entanglement seems to correlate instaneously with no energy transfer because it's simple energy poking through from a higher dimension yes? Imagine the higher dimensional waves moving in the pic related. the waves would intersect with the lower dimension and form multiple points of a similar kind that would appear connected over large distances with no information transfer

This seems like a perfect explanation to me.
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>>8042421
And, by this logic, if entangled particles are higher dimension waves intersecting our dimension, every particle is a higher dimension intersecting our dimension
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>>8042428
Whoa I can visualize 4d space now!

Thanks, /sci/!
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>>8042470
No problem man

I am pretty confident this idea can revolutionize physics

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What happens to semen (and the sperm) when it is exposed to water? I heard they die because of osmotic shock but searching on the Internet gives different answers. If it does kill them, how long can they survive?
>>
They look like a bouquet of noodles, or like a sea cucumber just puked up its intestines. That's what happens.
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>>8042030
Worried about jerking off somewhere you shouldn't have, anon?
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Does salt water have any affect on sperm?

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Two types of thing exist:
1. Fitness functions.
2. Things that aren't fitness functions.

The set of all acausal trades forms the first vector in Vector Bayesianism. All other problems can be reduced to off-by-one errors that result from using 0 as the empty set or allowing the first vector of Vector Bayesianism to function as the baseline 0. Everything else must be a matter of taste or else this definition of Vector Bayesianism is incorrect. Whether or not 0-as-base or 1-as-base is more valid ought to be the only undecidable problem.

You, provided proper...
>>
The OP pic is a PNG encoded raster made up of a series of Bezier curves in the (x,y,red,green,blue) vector space. Informally it's known as a cartoon, of the anime sub-genre. The content would otherwise be said to be unrelated to the topic of this thread if not for the fact that the OP pic is a consistent phenomena that can be measured repeatedly by refreshing the page. It is this concept of analyzing the data complexity of human cartoons that gives Vector Bayesianism the "Vector" component of its name.
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>>8042012
And since being the fairy Queen has nothing to do with Vector Bayesianism, I can permanently stop using the name so long as nobody cares about all such reputation that might have formerly existed.
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>>8042005
>method of generating algorithms
So the purpose of generating those algorithm is to potentially understand the structure of phenomena thus mapped. Basically it's my understand of what an advanced digital intelligence would do once it's determined how to change it source code without destroying its "values" (here on out, 'virtues'). You can think of it as the ideal method of creating tool AI, bypassing the need for any AGI-type seed.

Effectively,...

If you could be responsible for any single mathematical achievement what would it be /sci/ ?

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>>8041842
$e^{i \pi} + 1 = 0$
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>>8041858
why Euler's identity
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>>8041861
Not only is it a beautiful equation, but also the most famous mathematical equation after 1 + 1 = 2, and one with many applications.

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Dopamine, Serotonin, Oxytocin.
Three chemicals that just fuck you up.
Is there some way to block these? Looking for any receptor blockers or production inhibitors that I can purchase online.
And don't try to suggest "overdose on dopamine so you fry the receptors".
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>>8041733
https://en.wikipedia.org/wiki/Depressant
>>
why do you want to be a goalless and undriven slacker?
>>
My professional medical recommendation, in my full capacity as not-a-doctor.

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Is psychology science?

...is philosophy?
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>>8041692
Are you too much of a brainlet to use your own fucking common sense to figure out which results of psychology are trustworthy and which are questionable? Do you seriously need the science section of a meme forum to tell you whether we approve of it?
>>
>>8041698
>brainlet

Memeposter, stop posting in memes.
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>>8041692
psychology pretends to be a science
philosophy isnt a science and doesnt have any pretensions of being a science

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Is this true, /sci/?

I mean it's quite scary, but the "report" in the website wasn't linked to at all.

I'm basically retarded, can anyone enlighten me?
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>>8041686
Do you think that website would just lie? It's true.
>>
yes it might be triggering small earth quakes
aka smaller than you can feel

Anti-fracking sentiment is by retarded liberals who have no clue about economics
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>>8041686
and if anything should be done in areas where a large quake is overdue and could critically hit for massive damage, to release the stress.

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I see the philosotards on this board talking shit about scientism.

somehow they give me the impression that belief (whatever that means) in the scientific method and in science as the ultimate method of finding the truth, is somehow wrong.

Sure, some advanced alien race may have something better, but I don't think mere humans will find a better system.

I see you faggots keep showing those books that showcases faults in the system, sure, the scientific method may not be perfect.

but what's the alternative?
what do you propose then instead...
>>
Undergrads in philosophy fundamentaly missundertand science and viceversa.
>>
>>8041671
The "philosotards" on /sci/ are just pseudo-intellectual math or CS freshmen who want to believe they are the deepest thinkers for spouting preschool platitudes along the lines of "cannot know nuffin".
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>>8041695
The worst thing is, I wouldn't be surprised if this was the case.

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Is is possible to leave the event horizon of a black hole by way of a stable wormhole?
>pic related
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>>8041667
Probably, if you're going fast enough
>>
>>8041720
i thought the mechanics of a wormhole makes velocity irrelvent, isnt it space/time that is moving, not the object, for the most part?
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>>8041729

Spacetime doesn't move, it's just different from place to place. And yes, it doesn't matter even if you were able to exceed the speed of light; the geodesics of spacetime beyond the event horizon all send you only one way -- towards the singularity.

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How is Psychoanalysis, is there actual employment in it?
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>>8041550
You mean outdated Freudian shit, about 80% of which has been debunked? Why would you want to study a discipline like that?

I think there are still some therapists that use it, but I'd never go to one. Why wouldn't you study a therapeutic discipline that at least has some evidence-based practice involved, like CBT?
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>>8041584
What if I just really like Jung and want a career in it?
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>>8041550

The literal couch-thing with the associated different methodology (I guess) is the stuff of mid-20th century. People used to talk about it in the Saturday Evening Post, and movies of the period; along with nukes and the space race, it was the pop-sci of the day. IIRC Woody Allen went in for Freud-tier stuff regularly, and the culture has mostly moved on.

But not completely. Remember that Woody Allen is known for living in New York. In fact, since this form of "analysis" is old, IIRC there's...

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yes.
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>>8041469
this is the best thread on /sci/ today .
>>
>>8041469
Pretty good really. Viaducts built by Romans 2000+ years ago are still standing.

I would be much more concerned with buildings from the 1970's.

Whoa....
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>>8041300
Woah
>>
>>8041300
Waoh
>>
screenshot from that jewphile video

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Warning: This is a social sciences thread.

Hear me out on this one: Traditionally, the stereotype has been that women are more right-brain dominant (creative, intuitive, emotional) and not logical. Problem is, Hemispheric dominance has long fallen out of favor with actual cognitive psychologists and neurologists.

I think you could actually make the opposite case that men are emotional and women are logical, based on the confidence gap between sexes.

Basically, men tend to overestimate their own abilities and take more risks due to testosterone, whereas...
>>
Also before anybody tells me to take this to /pol/, you know damn well what their circlejerk response would be. Thought I'd have more luck here.
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>>8041197
>This is a social sciences thread.
drop'd
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>>8041202
>you know damn well what their circlejerk response would be
You're not in luck anon. Most /sci/ people here have nothing to do with social sciences (including me). The rest are /pol/ and /r9k/ lurkers who try to validate their views through science no matter how delusional or biased. I'll give you one guess as to which threads a scientifically illiterate polack is going to reply in, either the one that has to do with actual natural science, or the one that he can easily turn...