Archived threads in /sci/ - Science & Math - 250. page
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So /Sci/
What do you think will be the best fuel source for cars in the future?
dark matter
>>7971571
tachyons
>>7971571
Mongolian Enchanted Talismans
Help a calculus babby out.
I don't see where Feynman gets this extra "v" from. What am I doing wrong?
I've never done calculus outside of a pure math context before, and im finding it pretty tough.
d/dt v^2 = 2dv/dt * v
>>7971539
Sorry to be so stupid, but like I said I have only done differentiation in pure maths before.
In maths, I would do pic related. Why can't I do the same for Physics?
>>7971542
Because you aren't applying the chain rule properly
D/dx of f^2 = derivative of outer function times derivative of inner function = 2 f . Df/dx
D/dx x^2 = 2x = 2x .1 because d/dx of x = 1
how much weight can a concrete ceiling hold?
thickness: 2 inch
Can i hang about 25Kg from it?
can i walk on it or id better move onto loadbearing beams?
>>7971490
'concrete'
So many factors just in concrete, let alone the whole picture
> Cement used
> Sand used
> Aggregate used
> Mixture of Aggregate and Sand
> Any additives into the concrete
> Reinforcing - Fibre, rebar, mesh, strips etc..
not that I can answer the question at all, but its very complicated.
But...
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Do FEM analysis
>>7971522
fair.... but i dont have these data.
For what ive seen it seems just concrete (i mean without reinforcement) i know it's impossible to answer this question exhaustively but even a estimate would be helpufl.
Thanks in advance
Can /sci/ explain why it isn't a load of bullshit- that is, why it isn't purely neurological? The passing of time could be set at a constant imaginary speed faster than time, because time doesn't exist, right?
I'm probably just a dumbass that doesn't understand it, so a simple explanation would be nice too
philosophy board when
>>7971478
whoops, meant faster than light, not time
because of einsteins law of electric divulsion particles cannot subside equidistant between electrons. That is to say that time cannot be represented as two prefixes of a particle.
>tfw you realize life is just a slightly more efficient energy gradient than non-life
we're just the universe trying to be lazy
>>7971497
made me kek
>>7971497
How is life in a lower energy state than non-life ? Genuine question.
Can someone convince me that singularity is a dumb meme?
It's the only thing that computer """""""science""""""fags have about their field of study that is even mildly interesting. Please tell me why its bullshit so we can get cuck sci posters off of our borad.
>>7971230
>meme
>cuck
Upvoted xD Nice to see another meme conissieur from reddit :)
>>7971230
Except there are many interesting things in Computer Science. The singularity to computer science is like Schrödinger's cat to Physics, something that people spout after watching the Big Bang Theory to make themselves look smart.
>>7971239
How's your first month on 4chan, ex-redditor?
How come in the reaction H2SO4 + HCOOH -> CO + H2O the S disappears?
>>7971218
It gets annihilated by the small biting demons that live on organic acids
>>7971218
The equation isn't balanced.
If this is acid catalyzed dehydration of formic acid, then the H2SO4 is catalytic.
>>7971233
No, its demons
>Tau is better than Pi
>>7971214
Its more elegant though
>>7971219
>>7971231
Autism causes vaccines
Hey /sci/,
Can you please recommend good primer into machine learning.
It would be nice to some something that includes at least pseudocode examples, however that is not critical. What is critical though that book goes is more or less entry-level at the start, but goes at least up to and including recurrent neural network theory.
Please don't post "AI Modern Approach" meme.
Thanks in advance.
My University is a meme, so I really need your help.
>>7970827
I did my neural net implementation based on this pseudo-book:
http://neuralnetworksanddeeplearning.com/chap1.html
It focuses on implementation rather than theory, and frankly I think I'd be better off if I treated it as a black box and used someone else's library, but it gets the very entry-level stuff out of the way. From there, you can look for something more intermediate.
I have realized that I have basically forgotten all of science. I feel that the best way to remedy this is to go all the way back to elementary school science and learn my way back up. What are the best online resources to help me do this?
>>7970777
There are none. School was your one in only chance.
>>7970777
KhanAcademy
>>7970780
I've already been teaching myself math again on there. The science doesn't really go back far enough for me. I mean I really forgot EVERYTHING.
![libros1[1].jpg](https://i.imgur.com/faHfheS.jpg "libros1[1].jpg")
Hi guys
any of you know pages to download academic books or scientists journals specifically of botany, plant physiology or microbiology
loltrain.com
>>7970769
Libgen for books
Sci-hub.io for scientific journal papers
>>7970806
do not know another is that already knew
Im a med student and I have to say, health care system in the US can be pretty bad. Obviously not all doctors are going to be money grubbing, but a lot of them are. I mean they keep the number of resident slots low so that they suppress internal competition, they always opt for expensive procedures and a whole list of unnecessary tests for extra dosh, they over-specialize in the fields, and they are terrible when it comes to patient interaction. We really do need to shake things up in the medical field because this kind of stuff needs to stop. Any thoughts?
>pic...
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>>7970738
You have a career that should only be occupied by people who are selfless and want to care for others. The thing is most people that really want to help others go into social services. Why study for 10 years to help people if I can go out and join a charity instantly?
So naturally due to the large obstacle of obtaining a medical license and proper training, good people who dont care for that stuff are turned away.
Because of this though wages are high due to the rigor of becoming a doctor so naturally...
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>>7971077
But they are better doctors for offering more money right?
I always thought our state sponsored education would improve if we offered higher teacher salaries and increased competition.
>>7971077
That is some great insight, and it makes sense when you think about it.
Its kind of depressing when you think about it. And I can definitely see it in my classmates. They pretend to be altruistic but really they care about prestige. I suppose I'm guilty of playing the game too to an extent.
I'm just hoping that technology will eventually start phasing out the need for such a high education and rely more on sociable and empathetic people.
What effect would injecting massive amounts of morphine into the bloodstream have on a person?
Use Google faggot
https://en.wikipedia.org/wiki/Morphine
>>7970606
The "joke" is that the guy in OPs picture killed people by causing morphine ODs
>>7970609
Still faggot OP asked a real question not implying sarcasm
Even if it was he should GTFO with his shitposts
Hope someone could help me.
How can you obtain the eigenvalues of a matrix which has trigonometric functions as elements?
For example the matrix I show in the image (matrix A)
| cos(x), sin(x), 0 |
| -sin(x), cos(x), 0 |
| 0, 0 , 1 |
According to the equation
det(A - E*y) = 0
where A is the matrix above, E is the identity matrix, and y is the eigenvalues
if I get the determinant established by that equation then I got a cubic polynomial from whose roots I can get the three eigenvalues for the matrix A.
I already...
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>>7970565
it is apparent from just looking at the equation that y=1 is a root because
[eqn][-2*cos (x) -1]*y^2 + [2*cos (x) +1]*y[/eqn]
clearly cancel.
I don't think there is a general rule to easily this kind of polynomial but I do think you're expected to be able to see obvious roots like this. The other two innolve solving a quadratic which is simple enough.
If worst comes to worst there is also the cubic formula for the roots of a polynomial but I'd avoid that.
Or you could just use a CAS...
>>7970565
You should be able to read of the first eigenvalue, just from the characteristic equation
(1-y)((cos(x)-y)^2+(sin(x)-y)^2)
And from expansion note that the polynomial is equivalent to
2y^2 - 2(cos(x)+sin(x))y +1 = 0
so if we calculate the quadratic formula we see that
[math]
\frac{2cos(x) + 2sin(x) \pm \sqrt{ 4(1 + 2cos(x)sin(x)) - 4(2)(1)}{4}
[/math]
and using some trig identities you can find that this should equal the other two eigenvalues.
Alternately you could observe that for any fixed...
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>>7970602
Actually, the second method is surely the easiest. Since a rotation matrix has eigenvalue a+/-bi where a is the entry in the first column and b is the entry in the second column of the first row.
How could evolution explain such a complex metabolic extremely linked pathways
>not implying creationism OFC just having a critical view
I mean how could enzymes be created in the SAME moment and generation to make mutated said individuals have an advantage over others.
We know enzimes are proteins made of AminoAcids
The odds to create a full functioning CHAIN of enzymes are ZERO. Im sure of it?
What do you think /sci/ ?
*enzymes
>typo
>>7970448
>I mean how could enzymes be created in the SAME moment and generation to make mutated said individuals have an advantage over others.
Environmental changes.
>>7970457
But in order for example for glucolysis to work, you have to make ALL the enzymes of said pathway to be there, in same individual at the same time . Mutated in the right places at the right moment.
Wich is impossible if you ask me.
