Archived threads in /sci/ - Science & Math - 232. page
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Why are ice core data considered reliable?
If a warm period prevents ice formation or causes melting then past layers would mix and no new layers would form.
>>7985778
You are underestimating how thick the ice they gather data from is. It's literally miles thick. Can you even begin to imagine how deep that goes?
anyway, if the layers mixed together, they wouldnt look like pic related.
>>7985784
>ten thousand year of extreme heat.
>300 million years of ice core surface melts away. No new gets added during thouse ten thousand years because it's a melting period.
>2016
>"oh the ice is thick so I'm sure those hot years somehow ended up being recorded in there despite the heat!"
>>7985791
That's why it's important to choose sites which never go above freezing. Ice cores are only selected from extremely cold, well insulated sites. And we empirically know they are reliable because they agree with other proxies. If they were missing long periods of melt then we would see them skip in their agreement with other proxies.
Posted this on /adv/, but there aren't many academics that frequent that website.
So, /sci/, I've been incredibly lucky and incredibly blessed to have received two admissions offers to both Princeton's and Columbia's engineering MS programs with full financial support. I have to make a decision within the next few days, but I'm having a hard time choosing.
Columbia: I can transfer roughly half of the credits required for my degree program, finishing in about a year. During my graduate program (at whatever school I'm at), I want to take the opportunity to explore the theoretical side of my field more. Between the two schools, Columbia (says) that it offers more classes in this area, but it's somewhat unpredictable because the classes it claims to offer aren't always offered. I'm also quite familiar with professors at Columbia.
Princeton: I can't transfer any credits. The number of courses I have to take is similar, but there are more requirements in the way of TAing and doing a thesis, and I'd only be able to finish in 1.5 years if I severely push myself. According to the requirements, at least half of the courses will be spent taking analogs of courses I took during my undergrad, and the other half would be open to taking whatever variety I want (though the selection may possibly be more limited than at Columbia). Princeton's program has a better reputation (and ranking in my specific area of study).
Another confounding variable: I have two serious, competitive full-time offers at well-reputed and stable companies that will be there after my graduate program so long as I can start work in December of 2017. If I go to Columbia's program, I will certainly be able to finish in time, but if I go to Princeton's program, it will be a stretch, finishing within a week of having to start work.
What do, /sci/?
>>7985570
Also, would it impact potential PhD applications in any significant way having Princeton versus Columbia associated with my MS?
>>7985570
Columbia.
>>7985610
Thanks for the advice! Would you mind sharing your line of thought?
Have I found the cheat code to nature?
Psychiatrist threw these at me after I scored a borderline positive on a verbal ADD test which asked questions like, "do you often get distracted."
I use them to study and my concentration is through the roof and suddenly I find boring things interesting. Is this feeling going to last?
Apparently if someone with real ADD takes them they have a different effect on their brain. But does that just mean if your a retard and you take stimulants, they boost you to the level of a normie, and if your a normie, they boost...
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>>7985502
You are now a normie op, your old retarded self just thinks it's being a superman.
>>7985502
You write like you're a retard.
>>7985509
>>7985512
b-but I have a masters in creative writing and a bachelors in Architecture
hey /sci/, I'm a bit of an hypochondriac, but I want some peace of mind on the subject.
how can I be sure I don't have a brain tumor?
>>7984391
By getting an MRI
>>7984391
How are you sure you are not a robot?
>>7984397
Don't they cause brain tumours tho?
Is he right, /sci/? Will we see the Singularity in 2045 and be able to live forever, not work, and live with AI so smart that they solve all of humanity's problems? Part of me wants to believe and I do agree with some of his points, but once you listen to other scientists who disagree, it becomes harder to believe. What are your thoughts on Kurzweil and the Singularity?
>>7984362
>>7984372
Why do you believe technological progress will stagnate or even decline? I don't know how much I believe in the hard takeoff, but I think we'll always see some improvements through the years.
>>7984383
https://en.wikipedia.org/wiki/Diminishing_returns
Hi all,
In my numerical analysis class we have been discussing lagrange and chebyshev interpolation
my professor derived a bound for the chebyshev interpolation [math] Q_nf(x) [/math] that is
[math] |Q_nf(x)| \leq ... \leq ||f||_{\infty} \int_0^{\pi} |\frac{\sin((n+1/2)\theta)}{2\sin(\theta /2)} | d\theta [/math] where [ math] \theta = \arccos x [/math]
they then conclude that [math] ||Q_n|| = \int_0^{\pi} |\frac{\sin((n+1/2)\theta)}{2\sin(\theta /2)} | d\theta [/math]
So my question is how do you make the jump
obviously we can take...
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What is Q_n(f)(x)?That supremum norm is taken over what set?
>>7984381
[math] Q_n f(x) = \sum_{k=0}^n <f,\phi_k> \phi_k(x) [/math] where [math] <g,h> = \int_a^b g(x)h(x)w(x) dx [/math] where [math] w(x) [/math] is some weight function on given fixed points [math] x_0 \leq x_1 \leq ... \leq x_n, x_i \in [a,b] [/math]
>>7984381
so the sup is taken over [math] x \in [a,b] [/math]
>WHATS WRONG WITH MY CODE?
its a simple problem to invert the order of a vector (C language), but somehow the return values are totally wrong:
>#include <stdio.h>
#include <stdlib.h>
int main ()
{
int vet[3],i;
printf("give 3 numbers:");
for(i=0;i<3;i++){
scanf("%d",&vet[i]);
}
printf("\n reverse order is: \n");
for(i=2;i>=0;i--){
printf("%d ",&vet[i]);
}
return 0;
}
>>7984181
>printf("%d ",&vet[i]);
you're printing the address of the ith element of vet
now delete your thread and fuck off back to /g/
>>7984185
holy fuck, thanks
>>7984181
>Background looks like it's moving
Wew lad
I am looking for books about 1800-1900 era physics, that aren't 100% popsci - a little bit of actual physics would be nice!
Any reccs?
Albert Einstein's book on relativity.
Physics for engineers
Actual books from that era
<<<We're on the edge.
>>7983999
When? Within the year.
Why? Global warming.
T H I N K A B O U T I T
>>7983999
The day after we create true Ai. We're fucked dude...
I hope it's not tomorrow lol !
I have a date haha !
Okay, so my retarded-ass college course isn't actually teaching me anything at all, it's all on computer and the book resource is useless. I have seen multiple people solve problems like this, and it isn't helping me solve THIS one. I only have one more chance to answer this problem before it locks me out, what the fuck do I do?
>>7983908
Not even gonna bother to TeX pre-school maths
1 = 16x2/(x4 + 64)
16x2 = x4 + 64
16x2 - x4 - 64 = 0
find the roots of that polynomial, then plug in numbers into the x4 + 64 part because if it equals 0 then the function isn't defined for that number, so you can disregard those points in your answer set.
After that you are done and can then proceed to kill yourself, faggot. Learn 2 fucking math.
You just replace f(x) with 1, and solve.
sqrt(8)
Favorite fields of math?
CS major here, quite fond of algebra, combinatorics and graph theory.
Algebraic geometry mostly.
Math Bachelor here, I'm liking probability stuff
>>7983885
>Last name Cox
>Be in high school
>just realized what sex is and sex jokes are 10/10 the best comedy out there
>Meet my friend Zucker
>Go to college together
>Graduate
>Go to grad school in same field
>Struggle to get our PhD
>Find something,...
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Hi /sci/, im working to reverse engineer this induction heater i got, and i think i have the right schematic (pic related).
Does this make sense? I find it particularly odd that the work coil doesn't seem to directly interact with the ground/negative terminal.
Those Schottky diodes are probably Schottky, they are model FR307. Feel free to assume that the values of all the components are reasonable.
Bump. Parallel thread in
>>/g/53903548/
>>7983838
Are the values of L1 and L2 different? If they are, it looks like they are meant to create two resonant circuits that have different resonant frequencies. It is probably meant to generate a higher frequency AC voltage for the load to use than just straight mains voltages.
>>7983980
A higher frequency would make sense seeing as it would result in larger eddy currents being induced in the material.
>I fell for the Noopept meme
I kept seeing great stuff on here and reddit about it, so I decided to order 5g from a reputable supplier. I just measured out 10mg and poured it under my tongue and held it for 10 min. It didn't dissolve very well. I washed the rest down with a glass of milk.
I definitely don't feel sharper or smarter at all. In fact, I feel more retarded for falling for the Nootropics meme.
>>7983782
Just believe in it until the placebo effect kicks in :^)
>>7983782
Just use caffeine
Isn't it supposed to be a gradually manifesting effect? Don't be hasty.
Do you think they'll ever catch up to piston engines before ICE becomes replaced with electric altogether?
Mazda recently patented a new design, see >>>/o/14781432
>>7983758
What's a rotary engine and why should I care?
>>7983763
Wankel engine.
>>7983758
>ICE
>Ever being replaced with electric
Tesla shill pls go. Also Mazda is the only company that has ever believed in the Wankel. Despite achieving great things no-one else can be bothered to retool. this is why the Wankel has failed to make an impact, the industry is simply too set in it's ways.
>>7983784
>Wankel engine.
In japan its called a wanker engine.
Not sure where else to post this, I figure there might be a few medical professionals on this board. This isn't serious enough to actually go bug a doctor down at the clinic so I figured I'd ask you guys.
The outside of my right thigh is numb. Like, not the kind of numb you get when your arm falls asleep or something. It's the kind of numb you feel when your skin gets really, really cold or something. It's been like this for a few hours now. I've tried stretching it and massaging it to push blood around, and I've tried applying a hot wet...
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You should probably go to the emergency room. If not,take the largest safe dose of aspirn you can and try to move around as little as possible while laying flat.
>>7983590
Emergency room? This hardly seems like that big of an issue. I am a 20 year old man, a little overweight but nowhere near the point where my arteries are plugged up with grease and cholesterol or anything. I can't see how it could be anything very serious.
>>7983583
I'd cut it off if I were you.
It sounds like your symbic nerve has been caught between your trachin and quinia. If that persists there's a very large chance that the electric pulses from your spine that are being blocked by the trappage will enter straight through your groin.
I've seen this happen before and it's very messy.
Don't try to drive to the hospital - it will only make it worse. Self amputation is the only option. Make sure you have aspirin lined up.
