Which is more eco-friendly? Lithium Mining or Oil sands?
nuclear
>>8949861
>this thread again
I'm gonna respond with this article again
https://cleantechnica.com/2016/05/12/lithium-mining-vs-oil-sands-meme-thorough-response/
thorium
Why is the side opposite to an obtuse angle always the longest? i have been brushing up on my geometry and cant really come up with it. obviously you can measure it but without measurements, how is it possible to tell?
gee I dunno use the fucking cosine theorem maybe
>>8949155
angle sizes correspond to opposite side lengths
sorry for the bump, have a CAT scan of my skull
>>8949164
handsome, mf
https://www.youtube.com/playlist?list=PLbMVogVj5nJSxFihV-ec4A3z_FOGPRCo-
In the second video of this series at 24:34, the professor claims that a relation cannot simultaneously be both symmetric and antisymmetric, which is very obviously false.
https://youtu.be/jZXHzpq-vmM?t=1473
The fact that the professor could make such a simple and horrendous mistake makes me wonder how much of the information provided in the course might be complete bullshit. Before I commit to watching any more of it, I would like to know if the lectures are generally good otherwise, or if I should look elsewhere for videos on real analysis.
did you not even bother scrolling down to the comments?
>>8948564
The comments don't address this.
>>8948567
>Are these Real Analysis lectures worth watching?
>Thanks alot !!! Best real analysis MOOC in entire globe as of now.
>The best lecture organization for real analysis, especially for first learner :)
>All the lectures are very useful. Please upload lectures on "Algebra" also
>very useful lecture series. Thank you sir.
do you not know how to read brainlet?
I've heard that gum doesn't decompose but I've also heard that it does.
So, does chewing gum decompose?
>>8947434
I don't know, test it and find out for yourself.
>>8947434
Short answer,yes.
>>8947457
Ok. Good.
I felt bad about throwing old ones away because I thought they would sit in a landfill forever.
>97% Of Climate Scientists Agree
What did they mean by this?
That if you take 100 climate scientist, 97 of them agree with each other.
>>8947147
Not this, but this at the same time.
>>8947143
>Argumentum ad populum
This is how we die.
https://www.sciencealert.com/google-is-improving-its-artificial-intelligence-with-artificial-intelligence
If anyone hasn't read it yet I highly recommend the Metamorphosis of Prime Intellect. It's a short story that shows in detail what life would be like with a superintelligent AI ruling the world
>>8946592
No.
>>8946592
>fiction
>showing what life would be like
Right, bud.
Question: Is it true that engineers spend their entire time in university studying math but then when they have to work in real life they only use high schiool level math?
>>8943229
For the most part, but I've used calculus a few times in optimization problems, FEA and Monte Carlo simulations. Graduated a year ago
>>8943235
So for the most part of the time you use high school math and a few times you used a few ''complicated advanced math for super inteligent people'' ?
>>8943249
Make no mistake, high-school math is part of it, albeit in incredibly large volumes that often require analyses to put the data into physical context. It's just that the higher maths are usually reserved for design, optimization, and experimental analyses.
Are trig tables supposed to be intuitive, or does everyone just memorize them?
what's a trig table, just standard trig function values?
x 0 30 45 60 90
sinx sqrt(0)/2 sqrt(1)/2 sqrt(2)/2 sqrt(3)/2 sqrt(4)/2
cosx sqrt(4)/2 sqrt(3)/2 sqrt(2)/2 sqrt(1)/2 sqrt(0)/2
The only shit you need to memorize it's what's on the unit circle. Or really just one quadrant of the unit circle, since you can just flip the appropriate signs for their multiples.
>>8949832
Just solve the first three or four elements of the taylor series if you don't have a calculator to do it for you ffs
Is a wireframe mesh like this a topology?
You often see in computer graphics and such that people will refer to some specific mesh as "the topology", but by the actual mathematical definition of a topology, I don't see how thats true.
You can think of a mesh a set containing many sets of connected points (the sets of connected points are the edges). A topology should contain any arbitrary union of subsets though, and obvious a wireframe doesn't have a structure that links two edges.
A space is not a topology. You put a topology on a space.
>>8949327
Wouldn't the rabbit be the space, and the wireframe mesh be the topology?
>>8949325
Mesh is a example of Topology.
Many sets of connected points (aka Graphs) are also a example of Topology.
But there are many other objects that can be mathematically modeled as a topology or considered a topology.
I'm going to visit the CERN tomorrow with my physics school group, what should I see in priority ?
>>8949324
>implying they let you choose where you go
cern trips are a fucking meme load of loud american tourists speaking over the guide when i went. Saw the antimatter facotry and some compters
>>8949324
there are like 2 tours, is nothing spectacular.
The United Nations visit is more fun.
>>8949324
Ah, you are going to see the main base of the Grant Chasers. Nice.
Why is nobody building greenhouse towers?
>build towers that produce ethanol
>cheap, clean, reliable energy for everyone
Seems quite simple, why is there no serious approach for it?
I have found in the internet that a square meter of greenhouse costs around 20 dollars. Lets say building it in a tower structure is significantly more expensive, so lets say 50 dollars. that puts the square kilometre price at 50.000 US-$. So building 1 million square kilometres of ethanol producing greenhouse costs only 50 billion. 1 km2 allows for around 500.000 litres of ethanol production per year, so we are speaking about 500 billion litres a year. lets say the towers have an operating time of 20 years before they need full replacement. then you could generate 10 trillion litres for the price of 50 billion US-$, or 0,05 cents per litre. That does not include operating cost yet. Lets assume those are very high and say they are 10 cents per litre. Thats still just 10,05 cents per litre of ethanol. A barrel would cost around 16 US-$. So even if we double all the cost we would still end up with 32 US-$, which is still significantly under oil prices.
So why isnt it happening?
>>8948912
infrastructure that is already inplace
>>8948912
>So even if we double all the cost we would still end up with 32 US-$, which is still significantly under oil prices.
Isn't the more important question the energy density? If you only get a quarter of the energy from your barrel of ethanol then hey, maybe there isn't such a big price difference. I'm not saying you have a bad idea, but maybe you should look into this too.
>>8948912
Consider the plants on the lower floors near the middle of the structure. A majority of those plants aren't receiving sunlight.
By your logic, a 200 meter tall building that has a footprint of a meter squared costs 10000 dollars. Bullshit it's 50 per cubed meter.
How do you support its weight and the weight of the irrigation system used the water the plants? More structural support reduces sunlight penetration and increases costs.
>hurr, durr why don't we coat all the roads in solar panels to save the planet
Imagine your a critic and criticise your own work. 90% of ideas are dead on arrival.
So what is actually happening when you're bitten by a critter? Pic very much related. This doesn't even itch, it just hurts like a bruise and is pretty sensitive.
But why does the skin react this way to bites? Any possible remedies?
>Inb4 is OP Australian?
>>8948297
>why does the skin react this way to bites
venom
>Any possible remedies
time
>>8948300
>venom
I thought only snakes had venom?
>>8948297
>Growing nipples on your arms
It just means you're becoming a man
Why is analysis so easy? Seriously. I always hear how hard it is online but it has not been much of a challenge so far.
>Freshman
>Was non brainlet in high school so taking advanced multivariable calc and linear algebra first quarter
>next quarter pdes and set theory
>this quarter real analysis
>mfw it's not that hard
>mfw some things take a bit of work but nothing is actually confusing
>mfw brainlets have lied to me about analysis all these years
>mfw I'm a year younger than everyone else in the class but I'm one of the top students
When did /sci/ realize that they had been lied to?
you're probably just using an easy textbook, there's plenty of challenging textbooks with hard problems if you want them
>>8948011
Do tell senpai
>>8948061
pugh's book labels the more difficult problems,
>One star is hard, two stars is very hard, and a three-star exercise is a question to which I do not know the answer.
Can we have a thread just for people to practice Tex? There have been a lot of times where I wanted to post in Tex but was afraid to because I don't want my Tex to be fucked up. It seems certain commands don't render properly on /sci/ and there is a lot of goofed up latex in replies.
Also, ask general questions about Latex formatting.
in the quick reply box there's a tex sandbox
[eqn]m \frac{dV^\mu}{d\tau}=\frac{e}{c}F^{\mu}_{\nu}V^{\mu}[/eqn]
Test
>>8947940
Fact:
[eqn]\pi = \lim_{n\to \infty}\frac{e^{2n}n!^2}{2n^{2n+1}}[/eqn]
I have a lot of free time.
Should I dedicate myself to only one thing or do different things?
Say, I like math.
But at the same time I love playing basket, practicing the guitar, videogaming, etc...
Are these activities taking room away from my math brain centers?
Most likely I shouldn't worry much about this in my case but suppose I'm a professional mathematician.
This kid is deaf and seems like his brain has allocated more room for math, even though basic.
there is no evidence to suggest you have a "brain limit"
>>8947907
>there is no evidence to suggest you have a "brain limit"
But areas of your brain do grow in size in relation to your skills, right?
Then if a person is blind, part of his visual cortex is allocated to processing sounds.
>>8947881
your brain specializes in what you spend your time doing. You really won't get great at something unless you spend the majority of your awake time doing that thing.
your "math centers" won't be degraded by doing other stuff, but they will by lack of use. You can maintain as long as you dont go too long not using them. But they do take away in a sense from the potential that they'd have as the opportunity cost of spending time on other things is not have as specialized of a brain.