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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
15270

File 137740339172.jpg - (401.45KB , 1680x1050 , titanfalsecolor.jpg )

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:

http://ebookee.org/index.php?tag=7

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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Anonymous 13/09/17(Tue)06:00 No. 15308 ID: ba9e6c

bib.tiera.ru is back up - lots of math and physics texts are available there




Anonymous 14/04/18(Fri)01:45 No. 15631 ID: 0f9d09 [Reply]
15631

File 139777830659.jpg - (617.08KB , 575x1673 , exoearth-habitable-rocky-earth-kepler-186f-140416a.jpg )

So they found a new exoplanet that may be habitable, 490 light-years away. That is so great I guess Palestinians and Jews will stop killing each other now.


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Anonymous 14/08/30(Sat)18:54 No. 15848 ID: 3c414f
15848

File 140941768450.jpg - (492.29KB , 3000x1779 , 1289065983066.jpg )

The Habitable Zone hypothesis is kind of bullshit. It is bullshit. It DOESN'T take into account, atmospheric composition (which can be studied remotely) and more importantly, geologic attributes because this will determine the atmospheric compositions and give the possibility for tectonic warming of ices into liquids. The geologic attributes will also determine if there is a magnetic field, which would be protective against ionizing radiation and fags.
It also does not work for moons, moons of mah boys Jupe and Satty-nay-nay are evidence for this.

And as to the Jews and Palestinians, they NEED to kill each other until neither of either remain, for the betterment of us all.


>>
PlutoniumBoss!Y1SVQJ54eA 14/08/30(Sat)21:33 No. 15849 ID: c1bebf

>>15848

Why doesn't it work for moons? Are these moons somehow inside the sun's habitable zone when the planets they orbit are not?


>>
Anonymous 14/09/01(Mon)18:14 No. 15851 ID: 3c414f
15851

File 140958806962.jpg - (187.44KB , 1280x960 , 1236488156473.jpg )

>>15849


Gravitational tidal forces, yo. Take the vulcanism on Jupe's Io. Or the ice sheet cracking on Enceladus, cracks caused either or both by actual stress fracturing from flexing, or convection below from the melt caused by heating from flexing.
My point is, the heat to warm an environment can be derived totally independently from the energy output from a star.
We could be totally missing the moons of the hot Jupiters orbiting around the barely visible brown dwarf stars that have tidally flexed geovents that are sustaining worms and shit in a body of water that is miles under frozen ice.




Anti-Aging Anonymous 14/07/31(Thu)06:00 No. 15779 ID: 800849 [Reply]
15779

File 140677920234.jpg - (370.63KB , 850x565 , iStock_000010280186Small.jpg )

Can we get a thread on anti-aging and lengthening lifespans?

Any possibilities, and problems with those possibilities. And ways to get around said problems. And more problems. And repeat. Until we get to even a slightly plausible solution.

Then, maybe somebody like Qin Shi Huang will say, "Hey, maybe if we try to make this better, it will work in a few thousand years!"

First time on /sci/, so bear with me.
Anyway's, lets go?


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Anonymous 14/08/28(Thu)07:32 No. 15846 ID: f4d04e

>>15844
Also to add to your point, telomere shortening has been shown to have no effect on the ageing of the brain, which means you'll still get the neurodegenerative effects of ageing if you solve the telomere problem.
Besides, solving it is relatively easy with some gene therapy (never mind the ethics), but it does put you at risk of cancer so do watch out...


>>
Anonymous 14/08/29(Fri)20:00 No. 15847 ID: b52bee

Youtube - Toggle Video
  Aging is a lot more than just telomeres shorting, think of the thousands of age related diseases.
I did some research on this a while back, despite not knowing a lot about biology.
But this guy called Aubrey The Grey(see video) seem to be making some educated arguments on what aging is, what causes it, and how to 'cure' it. As well as some advancements he made in the field.

I think it's also worth noting that Google recently founded a company that does research in anti-aging (http://www.calicolabs.com/). With Google funding it it might go a bit faster.


>>
Anonymous 14/08/31(Sun)03:37 No. 15850 ID: 677e61

>>15805

Yea and that risk of accidents is still there but, I agree. Getting out of this more fragile bodies is prolly better.




Anonymous 14/02/23(Sun)14:05 No. 15550 ID: c4b814 [Reply]
15550

File 13931607112.jpg - (17.06KB , 500x390 , 10768_273185959499082_1150917839_n.jpg )

is .999...=1?


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>>
Anonymous 14/08/15(Fri)06:46 No. 15824 ID: c85029
15824

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But like, man, what if it's just how our puny human minds THINK the numbers work; but they don't actually work that way at all. There's probably like, aliens out there that say like, 1+5=blargnip. We could have it all wrong, man. There's absolutely no way to tell if our math is the right math because we're humans man.
Alien math could be like way different. Like, triangles with seven sides or something I don't know. There's just no such thing as a concept that exists independent of opinion and culture.

You guys should take some liberal arts courses, it'll open your eyes.


>>
Anonymous 14/08/15(Fri)07:50 No. 15825 ID: c1bebf

>>15824

Numbers are based initially on the observation that you can count objects. Any alien entity so divorced from our frame of existence that they don't relate to solid objects in the same way we do will never observe us or be able to communicate with us in any way, so it's a moot point. In other words, you wrong, dude. Any alien being we could be able to encounter will be dealing with the same physical universe we do, and will necessarily be able to relate to concepts based on that physical world, like if you have a gooblatz with BINGBINGBING gobblefertzis growing on it, and BING falls off, there are still be BINGBING left.


>>
Anonymous 14/08/15(Fri)12:39 No. 15826 ID: 789203

>>15824
>>15825
And, more abstract mathematical objects (e.g. an infinite sum of increasingly small elements) are based entirely on axiomatizations of those initial intuitions. If the aliens axiomatize their perceptions the same way we do, they'll necessarily arrive at the same conclusions. If they don't, then their conclusions are not relatable to our own, in the same way that you can't use Pythagoras's theorem to prove or disprove the infiniteness of prime numbers.




Why competition? Anonymous 14/08/22(Fri)10:34 No. 15829 ID: 080683 [Reply]
15829

File 140869646585.jpg - (151.24KB , 600x781 , Discworld_Death_by_RobAnybodyFeegle.jpg )

This is most probably from complete lack of commonly accessible hard knowledge, but here's the question:
(1) If genes spanning individuals and species really do compete for survival as units of evolution,
(2) do the levels of competition seen in the natural world really benefit their survival?

They say, there's 1% genetic difference between humans and chimpansees, whatever that precisely means. Is intense competition between and within species not too counterproductive for genes' survival? May there be other, overriding controlling processes that steer genetic evolution from its optimal, maybe more cooperative behaviour?

--
Also, stupid philosophical crap for your amusement, because I have a psychological need to dump it somewhere: http://whitefielde.wordpress.com/


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Anonymous 14/08/23(Sat)14:17 No. 15841 ID: 080683

>>15837
TL;DR:
The function should evaluate not probability of individual passing genes, but gene pool's resulting survival.


>>
Anonymous 14/08/23(Sat)14:32 No. 15842 ID: e3000c

Of separate note is the fact (apparently) that competition is by no means the goal of evolution. The "goal" appears to be simply replication, and competition makes sense only when different genetic forces use same limited resources.


>>
Anonymous 14/08/24(Sun)01:07 No. 15843 ID: 789203

>>15840
>Thanks, that makes sense, although it is a behaviour observed in short-running, low count computer based genetic algorithms, no?
>This short-sightedness might not still be in effect in a superhuge pool like Earth's biosphere for very common and long-running traits, as there might be plenty of opportunity for evolution to go outside local maxima because of sheer number of attempts.
Depending on the maximum possible Hamming distance (given two bit strings, for each bit that's different to the counterpart bit in the same position, add 1 to the distance) between two generations of the algorithm after mutation and the slope of the function, it's possible to prove that some algorithms will never escape some peaks after reaching it.
In other words, if mutations are too conservative and selective pressures are too high, it's possible that once some peaks are reached, the only way out is extinction.
It's similar to the prisoner's dilemma. If just one player will cooperate, they'll get screwed. Either everyone cooperates or the one that does cooperate is much more powerful than all the other players combined.
A possible way out is by ignoring DNA. For example, the optimal thing for us humans to do would be to disregard any suffering that we may cause lab animals and just do whatever. Because of ethics, we don't do that.

>15841
>The function should evaluate not probability of individual passing genes, but gene pool's resulting survival.
That may kind of be what it does. What I was getting at is that the range of possible solutions that optimize individual success is a subdomain of the range of possible solutions that optimize general success (and average individual success as a side-effect).




Anonymous 14/05/16(Fri)14:05 No. 15669 ID: 1ac70f [Reply]
15669

File 140024190235.jpg - (10.83KB , 480x360 , hqdefault.jpg )

Any mathematical biologists here? I came across this post about mate choice and I'm not sure if it's a work of near-genius or complete stupidity. Are the arguments right?

----------------------------
The basic claim I'm making is that men have evolved to prefer young virgin girls because they have the greatest long term reproductive potential. You have argued that an adolescent girl would make a poor mate choice since she wouldn't be in her mating prime. I'm going to try to show to you that your position is wrong with a bit of mathematical reasoning.

The first thing I want to show you is that girls who started reproducing in their teens were reproductively more successful than those who started later in their 20s or 30s. It's going to take a bit of mathematical thought so get ready.

Let's imagine there was some ideal age, X, for the females in a species to start reproducing. Females who start reproducing at about this age leave behind the most surviving offspring. Females who start reproducing significantly later that age X leave behind fewer surviving offspring on account of having a shorter reproductive lifespan (since they started reproducing later) and those who start reproducing significantly earlier than age X also leave behind fewer surviving offspring due to them suffering more pregnancy complications and the like. The details don't actually matter that much. It's the principle that reproductive success is dependant on age of first reproduction and forms some kind of peaked distribution centred on the ideal age X that counts. Something like this:

http://img.ie/oka82.png

So, what's going to happen under these conditions? If you think about it, it's really simple. Females who start reproducing later or earlier than age X will leave behind a suboptimal number of offspring and over time become a minority in the population. While females who start reproducing at about age X will leave behind the most surviving offspring and therefore come to dominate in the population. The typical age that the females start reproducing will automatically stabilise around age X, since, by definition, females who start reproducing at age X are the reproductively most successful! In a species that is adapted to its environment, the average age and the optimal age of first reproduction will be the same thing.

Follow?

Message too long. Click here to view the full text.


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Anonymous 14/08/21(Thu)13:04 No. 15828 ID: 597595
15828

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Matchbox Prince 14/08/22(Fri)23:26 No. 15835 ID: 2f260d

>>15828

1. Source?
2. Doesn't take into account that the only people stupid enough to google-search for childporn are preteens, themselves.


>>
Anonymous 14/08/23(Sat)03:10 No. 15838 ID: 597595

>>15835

1. The book "One Billion Wicked Thoughts".
2. I think young boys generally prefer older women, at least I did when I was young.




Meteorite Anonymous 14/08/18(Mon)20:37 No. 15827 ID: 040c46 [Reply]
15827

File 140838707141.jpg - (104.25KB , 960x741 , Lunar Meteorite.jpg )

Kickstarter campaign to purchase Lunar Meteorite

https://www.kickstarter.com/projects/1141594225/lunar-meteorite-boxes




help wer 14/06/27(Fri)00:24 No. 15749 ID: ad7ee9 [Reply]
15749

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What the fuck is this!!!


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Anonymous 14/07/25(Fri)13:24 No. 15764 ID: 52a81c

>>15749
what is 'flying materials?'


>>
Anonymous 14/08/14(Thu)13:52 No. 15823 ID: 9c94f7

>>15749
i dont even study chemistry and this is pretty obvious, even to me


>>
Anonymous 14/08/22(Fri)13:55 No. 15830 ID: 943f0d

Sorry, is this a scientific board or a school board?




jdawg 14/08/12(Tue)06:23 No. 15817 ID: 18c102 [Reply]

Youtube - Toggle Video
  Somebody stole my phone at Walmart in Angleton, TX.... It is vital for my work. My number is 9792858654 through Verizon. There will be a reward to anyone that can help me find it.




Cryptoforums.net Technology Forum Cryptoforums.net Technology Forum 14/05/13(Tue)10:25 No. 15656 ID: 288b60 [Reply]
15656

File 139996955137.png - (8.43KB , 82x77 , CF-logo.png )

Hello chans of the internet. We at https://cryptoforums.net have created a MyBB forum dedicated to the discussion of things like Bitcoin, Privacy, Security, Cryptography, GNU/Linux, Philosophy, Politics, Freedom, Cryptocurrency, Hacking and many other general subjects. We are currently in our early stages and we want to invite more members. If you like any of those subjects you should come check us out! We also respect anyone's opinion even if negative so give us all your positive/negative support/criticism!


7 posts omitted. Click Reply to view.
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Anonymous 14/07/31(Thu)05:04 No. 15773 ID: 800849

>>15746
Legally, the government can't catalog information about all the peoplez of the world. But, they found a way around that.
Then, they made it look like everyone was against it. And, more than likely, kept doing it.


>>
Anonymous 14/08/11(Mon)18:38 No. 15815 ID: d9f5aa

>>199869
the joke's getting old, shillfag.

OP your forum would be a lot more appealing if it didn't require an email.
trashmail makes it easy but waiting for the email to arrive is a fucking dealbraker.
I'd probably rather enter a fucking google recaptcha and have my everchanging dynamic IP logged by some useless waste-of-money agency than wait for a shitty activation mail (and possibly still get logged if my ISP or trashmail provider is sharing data as much as google does).


>>
Anonymous 14/08/11(Mon)18:39 No. 15816 ID: d9f5aa

>>15662, not 199869 obv.




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