[Boards: 3 / a / aco / adv / an / asp / b / biz / c / cgl / ck / cm / co / d / diy / e / fa / fit / g / gd / gif / h / hc / his / hm / hr / i / ic / int / jp / k / lgbt / lit / m / mlp / mu / n / news / o / out / p / po / pol / qa / r / r9k / s / s4s / sci / soc / sp / t / tg / toy / trash / trv / tv / u / v / vg / vp / vr / w / wg / wsg / wsr / x / y / ] [Home]
4chanarchives logo

Archived threads in /sci/ - Science & Math - 404. page


File: sad pepe.jpg (88KB, 900x877px) Image search: [Google] [Yandex] [Bing]
sad pepe.jpg
88KB, 900x877px
>tfw in college
>study environmental science/biology
>want to be wildlife biologist
>taking out shitload of student loans
>will have to go to grad school and take out more loans
>currently in environmental activism internship not extremely related to what i want to do
>will earn next to no money in target field

I will be a scientist on welfare checks
6 posts and 1 images submitted.
>>
>>7804913
>loans.

Stop. If your scholarship doesn't cover enough then don't fall for the college Jew, go find work.
>>
>>7804927
my scholarship covers about half. I want to become an RA so room/board is paid for, then I go for basically free. but some damage has already been done
>>
>will have to go to grad school and take out more loans

wut

File: dank meme.jpg (69KB, 600x422px) Image search: [Google] [Yandex] [Bing]
dank meme.jpg
69KB, 600x422px
how would you explain to someone with little math knowledge that the probability of picking a particular real number between 0 and 1 is exactly 0 and not "infinitely small" ?

the latter kinda make sense in real life, i guess
22 posts and 3 images submitted.
>>
>>7804865
Well, infinitely small has no meaning, in the first place.
Ask them to construct an infinitely small number, and if they say "0.0000.....1" then explain to them that the number they constructed cannot exist, since it's paradoxical-
Either it terminates in 1 after a finite number of 0's, or it's infinitely many 0's; it cannot be both.
>>
Number of digits after decimal point of any given real number is infinite. Probability of being able to enumerate infinite number of digits = 0. QED.
>>
>>7804865
The hang-up here is that the only number than can fit any reasonable definition of "infinitely small" magnitude is zero.

If infinitely small is taken to be "smaller than any positive real number", then it's obvious it can't be positive since else you could take the average of it and zero.

File: em_spectrum.png (89KB, 1000x593px) Image search: [Google] [Yandex] [Bing]
em_spectrum.png
89KB, 1000x593px
Can any of you study when you're high? I'm doing electrical engineering and all of my years of studying come together when I'm baked and its awesome. Wireless communication is fucking awesome. We can pick up invisible waves of energy that oscillate from place to place and make the internet.
3 posts and 1 images submitted.
>>
>>7804859
Everything but math and physics.

Although discrete structures for me was a blast when I smoked.
>>
Depends how high you get and what the context is.

Vaping 0.5g of a nice sativa when you're just having a casual fun study session during the semester and learning new things is awesome. I highly recommend investing $200 in a good vaporizer because the high is so much more cerebral, if that makes sense.

Massive bong-rips 4 days before your final or project deadline looming? Fuck that shit.

File: 1451727252542.jpg (82KB, 650x650px) Image search: [Google] [Yandex] [Bing]
1451727252542.jpg
82KB, 650x650px
You guys are masters of conspiracy theories, the occult, and the secrets of the universe. Tell me the most incredible thing you know right now.
31 posts and 2 images submitted.
>>
>>7804742
OP is a faggot.
>>
>>7804755
This
>>
We can make an EM device that can remotely effect people's brainwaves and thought patterns,

It really mostly makes people hallucinate or gives them a bad headache, but still.

File: WRudin.jpg (64KB, 515x678px) Image search: [Google] [Yandex] [Bing]
WRudin.jpg
64KB, 515x678px
What is with this board's obsession over this man?
5 posts and 2 images submitted.
>>
Because he made good books Baby Rudin and Papa Rudin
>>
>>7804705
He wrote some books that have deeply entrenched themselves in math undergraduate culture.

He also wrote some books that are not for undergraduates. They are probably good (ie like Dieudonne/Bourbarki level).

Honestly I never read any of his books.
>>
>>7804718
I've read two of his books but it's become a psuedo-meme around here to recommend them to people that are just coming out of single variable calculus

File: modern_human.jpg (158KB, 395x450px) Image search: [Google] [Yandex] [Bing]
modern_human.jpg
158KB, 395x450px
Hey /sci/, /v/ here, I have a coupe of questions about anthropology!

So I've been reading a lot about various diets, but specifically: Paleo. Occasionally the authors of articles against Paleo mention that we have evolved a great deal since the stone age, also that our digestive system is different, but then they just leave it at that and don't bother explaining what has changed. Obviously, the lactase persistence mutation here in Europe and also Africa was one thing, but I can't recall any other difference related to digestion.
That said my questions are:
1. How is our digestive system different from people who lived in the stone age? Do we have specific adaptations for our industrialized diets? High quantities of sugar for example.
2. If we put a person from 10.000 BC and someone from today next to each other, what kind of differences would we see? Obviously we're taller and have a wider range of hair/eye/skin colors but what about bone structure? Brain size?
3. Intelligence. I assume we're smarter than our ancestors, but just by how much? Is this due to genetics and evolution, or rather, is it our accumulated knowledge over thousands of years and more efficient teaching methods that give us the advantage over them?
I thirst for knowledge /sci/.
2 posts and 1 images submitted.
>>
>>7804392
>If we put a person from 10.000 BC and someone from today next to each other, what kind of differences would we see

Not much if any
Modern Humans are like 200,000 years old

>Intelligence. I assume we're smarter than our ancestors

Not really. We have the same level of intelligence, but only our collective knowledge is much greater than theirs was.

File: Mirror.jpg (62KB, 320x320px) Image search: [Google] [Yandex] [Bing]
Mirror.jpg
62KB, 320x320px
Why don't mirrors reflect smell?
15 posts and 1 images submitted.
>>
Report threads that ask these childish retarded qustions
>>
Production units are made imperfect.
>>
>>7804326
In order to self reflect it'd need its own light source, and its own perspective to view the reflection.

Mirrors works because you see light bounce off of things, bounce off of the mirror and into your eyes. This requires the mirror, the observer and the thing to observe.

File: smetana.jpg (97KB, 800x800px) Image search: [Google] [Yandex] [Bing]
smetana.jpg
97KB, 800x800px
Special snowflake students BTFO
https://www.youtube.com/watch?v=LjN8xP0i6Ak
37 posts and 5 images submitted.
>>
>>7804062
Man, I fucking love that cat. I have it as a wallpaper
>>
>>7804064
fuck I came here to say exactly that lel
>>
>>7804064
>>7804071
>le funny cat pictures on le internet
Literally reddit.

File: 1451332320669.jpg (51KB, 540x429px) Image search: [Google] [Yandex] [Bing]
1451332320669.jpg
51KB, 540x429px
What background knowledge in math do I need in order to learn PDE's, Complex Analysis, Finite Element Method, and Numerical Methods.
19 posts and 1 images submitted.
>>
>>7803705
Functional Analysis
>>
My mathematical knowledge is up to calculus 1.
>>7803722
what background do I need to be able to pick up this topic?
>>
>>7804489
Read
>Principles of Mathematical Analysis by Rudin
>Real and Complex Analysis by Rudin
>Functional Analysis by Rudin
in that order.

File: formula.png (2KB, 352x55px) Image search: [Google] [Yandex] [Bing]
formula.png
2KB, 352x55px
A formula I created. Can any anon tell me if it's original? I only used my math notebooks, pencils (pens too) and calculator and never learned this in school so I don't know if it's original. I don't even know if it's in proper format actually. Anyway, that's the factored form I guess. (That's just the smallest formula I've made.) Also, if unoriginal please link me to where I can learn more about it.
29 posts and 3 images submitted.
>>
>>7803525
Where's the proof?
>>
>>7803535
in the pudding
>>
I guess I'll give a quick example of it in the case that I wrote the formula wrong

Lets say you wanted to add 4 numbers together (each with the same amount of numbers between them). So lets say 7 and every 8th number after that. 7, 15, 23. 31, all squared. A would be 8 (Since that's the difference), B would be 1 (Since we want 7, and 8-1 is 7), and N would be 4 (since there are 4 numbers).

i increases by 1 every time the function happens.
(8(1) - 1)^2 + (8(2) - 1)^2 + (8(3) - 1)^2 + (8(4) - 1)^2
Is the same as 7^2 + 15^2 + 23^2 + 31^2

So you plug it into the formula.

2(8)^2(4)^3 + 3(8)^2(4)^2 + (8)^2(4) - 6(8)(1)(4)^2 - 6(8)(1)(4) + 6(1)^2(4)
then divide it all by 6.
8192 + 3072 + 256 - 768 - 192 + 24
The answer would be 10584
Divide that by 6 to get 1764.

49 + 225 + 529 + 961 = 1764

File: crop.jpg (135KB, 626x650px) Image search: [Google] [Yandex] [Bing]
crop.jpg
135KB, 626x650px
Okay, so an MRI aligns all the hydrogen protons' axes with some EM coils, then RF pulses pull them out of alignment. Then when the RF is gone, the axes move back to being aligned. Axes re-align in different tissues at different speeds, creating a signal. This movement is measured by other EM coils and an image is made.

I've got a few questions I'm having trouble with.

A. I thought MRIs captured a 3d image all at once, but I've been reading that it builds it by taking cross sections. So it's just capturing a number of planes? What orientation, or can they modify that?

B. How do the 'other' coils measure the changes? Don't the coils creating the field interfere?

C. I thought atoms were at a scale too small to be affected by tissue differences. How is it that some re-orient more slowly than others at that scale?

Are there any good papers that describe the functioning of an MRI in more detail than wiki or howstuffworks? I'm kinda using this interest as a catalyst for learning calculus/vector calculus.

Pic related, it's my spine.
9 posts and 2 images submitted.
>>
one bump
>>
BTEC Applied Science?
>>
>>7803437
A. The planes are usually three: Coronal, sagittal and horizontal.

Also, your spine is too straight and lacks lumbar lordosis.

File: image.jpg (23KB, 400x293px) Image search: [Google] [Yandex] [Bing]
image.jpg
23KB, 400x293px
What do you think of him ?
21 posts and 5 images submitted.
>>
>>7802599
Yes
>>
>>7802599
He is based. People don't give Hamilton enough credit though, the Ricci flow was the pivotal concept in the proof.
>>
He is cool, just a heart breaker.

File: pepes.jpg (104KB, 500x500px) Image search: [Google] [Yandex] [Bing]
pepes.jpg
104KB, 500x500px
Do you remember the time when you weren't a PhD student?
>lots of free time
>girls
>shitposting about barnett on /sci/
33 posts and 3 images submitted.
>>
As an undergrad I was a drug addict. Can't do that anymore. I still think about it every day.
>>
>>7802785
I thought drugs were only okay in grad school. A little bit of crystal meth but just don't bring it to class?
>>
i thought PhD students just wrote shit like once a week. what's the big deal?

How should I make use of the Feynmann Lectures?

I plan on making detailed notes on it, but I dont know if that will really give me the best learning experience. This is my first extracurricular textbook and i am unsure about how to assimilate this type of resource.
7 posts and 2 images submitted.
>>
learn maths instead... those are glorified popsci books
>>
Read them.
>>
>>7802510
Great for insight. Also get a book with some exercises to help it sink in.

What is time anon?
28 posts and 3 images submitted.
>>
>>7802199
a coordinate axis in spacetime.
>>
>>7802199
The duration of an event
>>
>>7802200
How comes a coordinate axis makes a clock's hands move?
>>7802203
>Bootstrap definition
Time is duration is time

Pages: [First page] [Previous page] [395] [396] [397] [398] [399] [400] [401] [402] [403] [404] [405] [406] [407] [408] [409] [410] [411] [412] [413] [Next page] [Last page]
[Boards: 3 / a / aco / adv / an / asp / b / biz / c / cgl / ck / cm / co / d / diy / e / fa / fit / g / gd / gif / h / hc / his / hm / hr / i / ic / int / jp / k / lgbt / lit / m / mlp / mu / n / news / o / out / p / po / pol / qa / r / r9k / s / s4s / sci / soc / sp / t / tg / toy / trash / trv / tv / u / v / vg / vp / vr / w / wg / wsg / wsr / x / y / ] [Home]

All trademarks and copyrights on this page are owned by their respective parties. Images uploaded are the responsibility of the Poster. Comments are owned by the Poster.
If a post contains personal/copyrighted/illegal content you can contact me at [email protected] with that post and thread number and it will be removed as soon as possible.
If a post contains illegal content, please click on its [Report] button and follow the instructions.
This is a 4chan archive - all of the content originated from them. If you need information for a Poster - you need to contact them.
This website shows only archived content and is not affiliated with 4chan in any way.
If you like this website please support us by donating with Bitcoin at 1XVgDnu36zCj97gLdeSwHMdiJaBkqhtMK