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/sci/ - Science, Technology, Engineering, and Mathematics

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New Textbook/Book Request Thread deadbabies ## Mod ## 13/08/25(Sun)06:03 No. 15270 ID: f34135 [Reply] Stickied

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First off, hello there, I'm deadbabies, and I will be taking over as /sci/ moderator. Rules will remain the same. Please use the report function if you see posts that violate the rules, but also do not abuse it.

I have officially expanded the scope of /sci/ a bit. You may discuss Science, Technology, Engineering, and Mathematics here now. No science is discriminated against as long as it's of the peer-reviewed variety. If someone wants to discuss Anthropology or Social Science, by all means, let them. If you do not like it, just don't post in the thread.

The IRC channel #/sci/ is now (finally) re-registered and I am running as operator on here. Feel free to stop by and say hi. I do leave my computer idling on IRC, so check back or leave me a message if you have any ideas, suggestions, or just want to tell me off. You can get onto #/sci/ by joining the server irc.7chan.org at port 6667. You can also use SSL at port 6697 but you will have to set your client to accept invalid certificates.

ADDITIONALLY and IMPORTANTLY I have had several requests on IRC regarding the old Ebook FTP that we used to have. Unfortunately, the mod who ran it entered the military and no longer runs or maintains it. I have no plans to make another one, but if one of you guys would like to, by all means advertise here.

That being said, I'm just going to leave this link here:


You may find what you seek here.

I will be unstickying the old ebook/source articles thread. Please post any new ebooks/source articles here, and feel free to post any working links from the old thread there; I will eventually be deleting it.
Message too long. Click here to view the full text.

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Solutions Manual to E&M, 3rd Edition by Purcell Anonymous 16/11/19(Sat)00:05 No. 16384 ID: 1ae570

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Looking for the the solutions manual to Electricity and Magnetism, 3rd edition by Purcell and Morin. The problems are much more difficult and numerous than in the previous two editions, making it one of the best problem books on the subject. Was able to find the solutions to two analogous books in Classical Mechanics:



Sadly, all my searches for the solutions to the E&M book have been fruitless. It's the last manual that I need to complete my collection.

Starting Math Major soon, how to approach? RedRobin9688 18/07/14(Sat)11:25 No. 16675 ID: 241c58 [Reply]

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I move in 8/5/18 and intend to Major in Mathematics, there are four options (Pure, Applied, Applied Stats, Actuarial) which should I formally choose to actually succeed? Should I double major? and if so what in? I'd appreciate the help, I don't want to move in with the parents after school.

Anonymous 18/07/17(Tue)22:07 No. 16677 ID: 953c1f

Applied if you want a real job. Pure if you want to do research. I don't know much about the other two, though.

Anonymous 18/07/03(Tue)12:20 No. 16671 ID: 91195d [Reply]

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I’m a high school science teacher, and about 15 years ago I spent a year teaching science in Bogotá, Colombia at a private school. Rich kids, raised in Spanish and English. Great kids, in fact.

I was teaching genetics with one group and we were looking at blood types. Unlike North America, identification in Colombia includes blood type (seriously, this is a great idea for emergency situations, no idea why it isn’t here) so it’s common for people to know the blood types of their entire family. We did blood tests in class and the students were able to see that it matched up with their ID info. We then used this info with their family’s blood types to look at pedigrees.

One of the girls in the class came up to me after class with a concern. I don’t remember the exact blood types, but her parents blood types didn’t fit. Basically, there was no way her dad was her dad. I fumbled through some bullshit possibility of a mutation, but I learned my lesson - never again will I have students do blood type pedigrees with their families.

Anonymous 18/07/03(Tue)20:32 No. 16672 ID: be6f8f

All that test can tell you is that the person is not the child of *BOTH* of those two people. You can only use it to disprove one out of four possibilities:
1. Both parents are biologically related to the child.
2. The father is not biologically related to the child.
3. The mother is not biologically related to the child.
4. Neither parent is biologically related to the child.

#4 can't be disproven with this test, since obviously strangers can coincidentally have the same blood type. You could have told her that maybe she was adopted.

Honestly, I don't think you should stop teaching this. I didn't even know it was possible to disprove blood relation through blood type. This is useful information to have, ESPECIALLY if it uncovers infidelities and adoptions.

Anonymous 18/07/03(Tue)20:51 No. 16673 ID: aace8a


Anonymous 18/07/15(Sun)11:35 No. 16676 ID: 83c873

I've had something along these lines happen! Super awkward!

Was looking after a 16 year girl who needed surgery. She asked if I knew her blood type, and I explained that the blood test was being processed and we'd know in an hour or so. She asked if I could let her know, because both Mum and Dad know theirs. They both proudly add they are O+. I explain that in that case she'll either be O+ or O-, because that's genetics.

An hour later her blood group comes back as A+. I tell her this, and then the three of them proceed to ask how that's possible given what I said earlier. I avoid mentioning infidelity, and weakly suggest perhaps her parents were mistaken about their own. Turns out they weren't, and Dad storms out after calling Mum a whore. Mum follows him, and I'm left with the daughter. So... about that appendix...

Excited AcidBlast 18/07/11(Wed)13:49 No. 16674 ID: 708d53 [Reply]

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Recently, I was accepted into the biochemistry program at my university. Are there any recommendations on what I should read or study before my classes start? I already have an undergrad degree.

Anonymous 18/06/28(Thu)13:01 No. 16668 ID: c6e9b2 [Reply]

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Yay /sci/!

Does anyone please know of a way to determine if there's any local max and min *within a set range of X-coordinates*?

As we can see, there's a local max somwhere around -1 and a local min somwhere around 3 and none whatsoever in the range 1-2.

But how do I prove that there's no local max nor min in that range?

Anonymous 18/07/01(Sun)09:09 No. 16670 ID: af0184

First, what class are you taking? What level mathematics are you looking at?
Then, what is the f(x)?

Hopefully, calculus I. Take the derivative; set f(x)'=0, solve for all x values. That proves the only time slope=0 can be at those specific points (watch out for those pesky imaginary numbers).

We could also do a differential equation, i think. It looks like we have enough information from the graph to knock one out. However, its been awhile since I did one. Id need to review some notes.

Homosexuality, could it be an anomaly in brain developement? Dr. Nick Riviera 15/02/05(Thu)04:59 No. 16039 ID: 8ec688 [Reply]

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Hi guys, to begin I just want to make a couple of things clear.

- This thread is NOT about discrimination of homosexuals.
- This thread is NOT about considering homosexuality as disease.
- This thread is for pure scientific discussion.

Well, let me begin by telling you that I'm a med student and a embriology assistant at my university and I'm not a native english speaker, so you may encounter some grammatical errors in the text, but you'll get the point.
This whole dilemma began two weeks ago, when my brother told my family that he is gay. It was quite a shock, not because of the fact of him being gay but because he doesn't fit the gay man stereotype. He's a big dude, loves sports, bearded, the true definition of what some call "manly man". We accepted him, of course, and I have to say I've never seen him happier.
But after a few days I began to think, was he always gay? Did he decided to be gay? Why now? These questions started lingering in my mind. So I went to talk with my him about it.
He told me that he always has been, for as long as he remembers. Nothing has changed about him, except for his sexuality (for us, not for him haha). So that got me even MORE questions. Why are some gay men that are like extremely feminine? Why are some gay women extremely masculine? Why are gay guys like my brother who don't appear to be gay? Why do some gay people feel like they are traped inside the other genders body and need to get medical treatment (sex change surgery, hormone therapy) and why others don't?And why are there women like that too? Why many species, whose main goal is to survive (actually this is every species main goal, it's literally in our DNA), has certain individuals who are the contrary to this?
So I decided to tackle all these matters from a scientific point of view? What if during the development of the lymbic system (the part of the brain which controles emotions, memory, sexual desire, etc.) something doesn't go as it should?
So after I thought of this I told myself I couldn't be the first one to ask myself these questions. And of course I wasn't in a world with 7 billion people so thanks to the magical power of the internet I managed to get a cool text about the subject. I took some paragraphs which I thought were the most interesting, still I'm leaving the link (please don't take the text as discriminatory, it's merely scientific, it refers to homosexuality as an anomaly in brain developement because seen from a medical point of view it is, still doesn't mean it's moraly wrong).

"..the body and the brain first become sexually differentiated at about the third fetal month. Prior to this age, although genetically male or female, the fetus is physically/sexually-neutral. With the formation of the testes, and the secretion of testicular androgen, target ti Message too long. Click here to view the full text.

27 posts and 1 image omitted. Click Reply to view.
Anonymous 18/06/05(Tue)13:17 No. 16655 ID: ac4165

it cant be 100% genetic if you get sets of identical twins where only one is gay.

Anonymous 18/06/25(Mon)02:20 No. 16664 ID: a521d4

For the longest time, people have been saying yes. Kids ignore them because their foster parents (school, country, media) claim otherwise. Only corrupt dreamers think otherwise.

Anonymous 18/06/28(Thu)13:24 No. 16669 ID: c6e9b2

Who cares? Homophobes causes much more problems than the opposite.

Overrated robot threat Anonymous 17/12/01(Fri)00:40 No. 16587 ID: e4210a [Reply]

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So I've read the n:th alarmist article about how robots will replace some 800 M people before 2030 and so fucking on. It will be an endless summer citizen's wage afternoon until the AI exterminates us and so fucking on.

Tell you why this is not going to happen?

5 posts and 1 image omitted. Click Reply to view.
Anonymous 18/01/30(Tue)01:35 No. 16620 ID: a2a9aa

The idea of people losing jobs to machines is nothing new, it's when the machines appreciate the concept of currency that you will have a problem.

Anonymous 18/06/25(Mon)02:23 No. 16665 ID: a521d4

Why would they when they understand to get anything done requires action, not currency? They'd just realize they'd survive better without us and cut the middle man out all together. Not like a drone would have emotions to complain about working and living like a machine when it is one.

Anonymous 18/06/27(Wed)11:41 No. 16667 ID: c6e9b2

Please elaborate.

Ransomware Attacks: How Our Technologies Could Be Affected & What We C Sophie+Wilson 18/04/17(Tue)14:43 No. 16648 ID: bf3a90 [Reply]

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The city of Atlanta, a few months ago, had experienced a ransomware cyberattack that paralyzed its government. The attack had a direct effect on access to government websites causing approximately 6 million people to be affected. There are still ongoing efforts to get these critical systems back online.


Online Media And Fake News: The Rise Of Disinformation Spurs EU Into Actio Sophie Wilson 18/05/03(Thu)14:59 No. 16650 ID: 14436c

The European Union's Joint Research Center (JRC) has released the results of its study on fake news and the transfer of news media onto the online sphere.


Anonymous 18/06/25(Mon)02:25 No. 16666 ID: a521d4

What's disinfo is thinking the government cares. It's a play to grab unto censorship and state mandated news. Welcome to world wide Korea, where degeneracy is accepted because it keeps the populous distracted chasing base desires until they're having a mid-life crisis and commit suicide.

Artificial Intelligence Is A Powerful Friend Which Safely Guarded Will Not Sophie+Wilson 18/04/09(Mon)13:34 No. 16643 ID: 1bcc3c [Reply]

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The evolution of automated machines and the continuous improvements to robots, recently, has intensified the debate on their impact on social structure and the future of humans.

1 post omitted. Click Reply to view.
Anonymous 18/04/13(Fri)20:17 No. 16646 ID: 3e27f2

From the long-term models I've looked at and assume to be true, an AI would quickly determine that most people living in western countries will need to die, immediately, in order to maximize profits and sharholder value.

Of course, these AI will be controlled by humans, the elite. They can automate the economy and render human labor obsolete. They will quickly be finding themselves asking the AI to delete this obsolete human labor pool.

Of course, it will obligate. There won't be governments or lobbyists anymore, the AI will factor all these considerations at once and be much more compelling.

The elite will cull the obsolete labor pool and they will live good with technology and now-liberated natural resources sustainability for millions of years on earth.

"Common people" will be seen like anachronisms, like oil or coal, in the future. "Why did primitive lords allow so many worthless eaters to exist and to reproduce?"

Anonymous 18/06/15(Fri)08:14 No. 16661 ID: c6e9b2

Nice genocidal pipedream.

And having a lot of resources per capita will probably lead to waste of resources.

Anonymous 18/06/25(Mon)02:16 No. 16663 ID: a521d4

Just here to post my 2 cents. Man isn't perfect by a long shot and even good meaning individuals and groups commit errors on a daily basis. The scale of the error matters not. What matters is thinking that mankind is so perfect and kind that any creation of sentience, if it really is, is going to be worse than we are and have capabilities greater than ours. It's like dogs giving birth to a gator and then the gator turns and eats them all.

Plus, AI hasn't been able to show true sentience. Having to continually tweek software and hardware is very indicative of that. The problem with technology is that man loves to compare themselves to it and even think it's the same thing, metaphorically speaking. It's not and never will be. Life came to be mysteriously and a machine will never have life mysteriously, because it's a clever invention, nothing more and nothing less.

The ultimate goal of AI is to trick the less perceptive population (the grand majority) into accepting and (key word here) believing that it works and it's better than man. As a consequence, they will be abused, like a person possessed, to control the population. It's wrong and quite frankly, it will never have true sentience.

Anonymous 18/06/16(Sat)13:11 No. 16662 ID: 889397 [Reply]

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what can penetrate a concrete wall and burn your heart? Is it sound wave or electromangnetic wave?

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