Archived threads in /sci/ - Science & Math - 12. page
What is spacetime made out of?
good question. anybody wanna answer ?
Space with a dash of time
>>8200240
pants
What's the consensus medfags? Is this stuff harmful or beneficial to health?
Does it depend on the dose alone?
>>8199337
>Harmful
Kind of, and mostly. Especially with chronic consumption.
>Beneficial
In no meaningful ways. The concentrations of beneficial compounds found in red wine are minuscule and occur alongside a number of other metabolic byproducts that give a good portion of the human headaches and much worse hangovers.
The human body is a complex machine, and ethanol and its metabolites net out as toxins, regardless of dose. Booze is for changing...
Comment too long. Click here to view the full text.
>>8199346
How do u explain the reduced mortality from cardiovascular disease in moderate drinkers compared to non-drinkers even accounting for exercise?
http://www.heart.org/HEARTORG/HealthyLiving/HealthyEating/Nutrition/Alcohol-and-Heart-Health_UCM_305173_Article.jsp#.V4UdGfkrJD8
>>8199398
Ohh God, has that cigarette faggot come back to *prove* that alcohol is good for you, and the negative health effects are a government conspiracy?
>tfw science and mathematics is extremely important yet have a brain that isn't catered to learning it
>>8196344
Kys, brainlet.
>>8196344
Literally just practice
>>8196347
an intelligent and coherent response one can only expect from /sci/
Any autodidacts in here? Tell me your experiences in self teaching. Personally I have had much better learning from teaching myself than any time I've spent with teachers. I taught myself music theory in middle school and how to play about 4 instruments. Then in high school I taught myself differential and integral calculus, some of the basics of quantum mechanics, and now I'm teaching myself linear algebra.
>>8199387
My issue with self-learning is that I stick with non-technical stuff. I do have a very broad range of knowledge.
>>8199387
it's not very efficient to self teach in the long run. unless someone knows what he's doing is helping you or giving you advice, it's very easy to get lost
that said, it's better than nothing. so keep going bro
I'm a math major at a shit school who's been teaching myself math outside of what I'll learn in my undergrad. So far I'm in the middle of Galois theory, am learning Dynamical Systems, advanced linear algebra, and Analysis I haven't done yet. In the past I taught myself advanced calculus and discrete math before touching the material in university. In the future I plan to teach myself pure math on the side while pursing applied math in grad school.
How many of you have published in peer reviewed journals?
>>8195546
I am, but only for a WW1 History project along with like 30 other people.
yeah, like, 10 millions articles or something i don;t know, i stopped counting.
cited a few hundred billion times, nothing big time.
>>8195546
Currently working on my first submission to a peer-reviewed conference as a result of something I came up with during an internship! A sister paper may follow on a parallel topic.
![_80461814_photonrace[1].gif](https://i.imgur.com/Y2v6p0S.gif "_80461814_photonrace[1].gif")
Can particles without a speed limit exist ?
>>8193688
Let's define particle mememesfriend as having 0 information. Wow, no speed limit.
>>8193707
wouldn't the inexistence of mass be enough ?
dunno lol
What's the best entry level chemistry work/textbook?
Ive looked into the Chemistry Workbook for Dummies, which gives assignments and practice as well as covering simple chemistry, but something that covers more of an in-depth scope is appreciated.
(Microbiology and pathology books also accepted for fun)
>>8199305
Lehninger - Principles of Biochemistry
Alerbts, et.al. - Molecular Biology of The Cell
>>8199317
Thanks, I'll check these out
>>8199305
General Chemistry: Principles and Modern Applications - This book covers almost all areas of chemistry, and is used as the main chemistry undergrad book in many universities.
Organic Chemistry: A short course - Nice introductory book to organic chemistry and organic reactions.
why aren't the cross sections of wings shaped like the Sears-Haack body?
>>8196991
Which wings?
>>8196999
airplane wings.
>>8196991
Why should they be?
Does modern math have an explanation for mind-reading tricks like pic related? Do we need to create a new system where things like dividing by zero are not impossible?
>>8195537
X
X*2
X*2+10
(X*2+10)/2= X + 5
X +5 - X = 5
[eqn]
\begin{aligned}
\sqrt{2} \cdot 2 &= 2\sqrt{2} \\
2\sqrt{2} + 10 &= 2\sqrt{2} + 10 \\
\frac{2\sqrt{2} + 10}{2} &= \sqrt{2} + 5 \\
\sqrt{2} + 5 = 5
\end{aligned}
[/eqn]
O-Oh...
So what happens when the ISS is decomissioned in 2025 ?
Do space agencies nowadays have the budget to put something back up ?
Will it be the end of continuous manned spaceflight ?
>>8199842
The space shuttle was the end of manned spaceflight. ISS is just like the tatrail of a headless snake still flopping about. It's up to private companies now, unless there's a major change in the world's priorities, that I just don't see happening.
>>8199847
I take it you've not been keeping up with space news. There's no longer big hoopla in mainstream media but the private sector and Chinese are sending shit up constantly including people.
https://www.youtube.com/watch?v=HvwKB2jblwk
>>8199847
The last space shuttle flight was only like 5 years ago and is being replaced by Orion using Delta IV Heavy/SLS.
How come neural nets get so much more attention than support vector machines these days?
>>8199555
Can a SVM make trippy pictures? I thought so.
DUDE IT'S NEURAL LMAO
but both are shit desu.
>>8199555
Because of deep learning which lets you solve harder problems. It's also worth mentioning that there are a fuckload of huge frameworks for working with deep neural nets as well as nvidia libraries and shit.
Why do our alcoholic drinks contain ethanol, and not isopropanol?
A quick Wikipedia search verifies that both substances have almost the same lethal dose.
On top of that, isopropanol is metabolized to acetone, which is not only much less toxic than ethanol's metabolite, acetaldehyde, but non-cancerous as well.
What am I missing here?
>>8199508
um taste, maybe?
Ease of production?
>>8199508
Go drink a bottle and post results.
>>8199508
Find a yeast that selectively produces isopropanol then report back.
![FILnI2X[1].png](https://i.imgur.com/3VqMoLa.png "FILnI2X[1].png")
Is tau really superior to pi or is it just a meme?
Anon, do you really need someone to explain you the difference between π and 2π?
>>8199475
No, rather the difference between 2Ï€ and Ï„.
I know they have the same value, but people still use one or the other. Why?
i think pi is for non-physicists/brainlets with -0.999... IQ
So I was helping an algebra student with his homework, and this quadratic came up.
[eqn]\sqrt{2}x^2+(2\sqrt{2}-2)x-4=0[/eqn]
I can verify using the ABC method and just by plugging into the function that the roots are [math]\sqrt{2}[/math] and [math]-2[/math]. But for the life of me, I can't figure out how to show this with the quadratic formula.
[eqn]x=\frac{-(2\sqrt{2}-2) \pm \sqrt{(2\sqrt{2}-2)^2-4(\sqrt{2})(-4)}}{2\sqrt{2}}[/eqn]
Any ideas how to simplify this? I've tried every method I can think (factoring out of the square root, multiplying...
Comment too long. Click here to view the full text.
>>8199403
dont be lazy. open up the expression in the root, then divide the numerator by the denominator. that's it.
foil on the first term under the square root
Why is it this a problem? My prof always shrug this off as something very delicate about the notion of infinity so unless we are careful we will be wrong. But this seems to be a philosophical answer more than a mathematical one.
Surely there's a well thought out reasoning using proper mathematics that explain what kind of rearrangement is acceptable.
Riemann only ever said you can add up converging alternating series to any value you want by rearranging right?
I am guessing this have to do with the fact that we have infinite amount of positive and negative term, so it is possible to do arrangement such that we can use it to approximate the summation to any value without "exhaustion" in a sense. Since our series is an convergent alternating series, our approximation will get better.
ie 1/100 - 1/1000 + 1/10000 ....... we can take the the positive term to some value up, then take the negative term to reduce it to some value down and our approximation will get better because the terms get smaller.
But this is done via choice, not algorithmic, so while I understand the idea, it feels incomplete and doesn't capture the full picture for me.
Is this also true for non-alternating series? Surely not, since we will only have either positive or negative terms.
>pic related
????
>>8198964
>But this is done via choice
Not a problem. We're doing math here and not CS. An existence argument is sufficient.
>Is this also true for non-alternating series?
It is true only for conditionally convergent series, i.e. those which converge but don't converge absolutely. This implies that there are infinitely many negative and infinitely many positive terms.
>>8198995
>Not a problem. We're doing math here and not CS. An existence argument is sufficient.
is this pretty much all I need to do show that every convergent alternating series can be manipulated to be equal to any value; QED?
>It is true only for conditionally convergent series
Then why can't I manipulate the sum of 1/(n^2) any way I can?
>>8198964
>alternating series
please do not use that word.
riemann showed that any convergent series that DOES NOT CONVERGE ABSOLUTELY can be rearranged to converge against anything we want
