Archived threads in /sci/ - Science & Math - 161. page
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Any idea what mineral this might be?
It seems to have formed over a layer of quartz. It is grey and finely crystalline.
Hey I saw this on shark tank and I'm trying to figure out how you come to the answer. Is it just plugging in random numbers till something works, or is there a faster way?
>>8060311
divide the two equations
>He does math with numbers
x^5 = a/k
x^2 = b/k^2
x^3 = x^5 / x^2 = (a/k) / (b/k^2) = a*k/b
How do I get into organic materials?
I'm finishing up my 3rd year as a chemistry major currently. Should I look into taking a materials science class next year? Is materials science the area I would be looking into for graduate study?
start with biomaterials, from biotech. Pretty much everything related to organic materials come from biotech related investigations.
Also food engineering has a lot to do with organic materials and is an interesting, funny and always hired area to work in, specially if you live in a processed food producer country such as murica
>>8060381
thanks for the response
my university only offers biomaterials as a high level ME course, I have none of the prereqs for it as a chem major
Right now my schedule is looking like
Advanced Organic Chemistry Lab
Materials Science
Quantum Mechanics
Pchem 2
what else should I take? i only have taken up to calc 3 do i need more maths if I'm trying to get into this?
>>8060412
Reported.
I have a theory on what could cause gravity that may go against popular science and I was wondering what people may think about it.
Gravity is caused by the sun. It is a condensed ball of molecules that has a reaction happening that need to be fed. It does not burn like a fire because it is an intense chemical reaction, but like a fire it needs to be fed to continue "burning". It pulls matter, including planets, towards it, and as these planets are pulled towards it it is spiraled around the sun, sort of like a toilet flushing. The sun pulls these planets towards...
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So then why do planets have moons? CHECKMATE ATHEISTS!
>>8060248
Please be kidding
But in case you're not, /saged
Also, planets don't spiral towards the sun, they fall towards it, the spinning comes from them already having tangent velocity. The sun's reaction is not chemical, its fusion. The whole "sun's gravity create's the earth's gravity" thing doesn't make any sense.
Ever stopped to think about it through?
God, we get these kinds of stoner theories all the time. People need to start considering how real physics work, at least read some introductory textbooks, rather than rely in mere intuition.
I mean, seriously, if you're going to theorize at least try and have it make sense.
>The sun needs matter to feed it so it pulls it from the environment
By virtue of what principle exactly? The issue is how come gravity exists as a large scale phenomenon with such a weak force, as in particles interacting...
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So, /sci/, what is the superior engineering degree?
>>8060087
me fucking your mom's cunt, that degree.
>>8060087
Knowing that engineers only do it for the money, the one that has the highest average salary.
Therefore petroleum engineering.
Or the one with the most job openings, which is probably civil engineering.
So civil engineering if you are average, petroleum engineering if you are a genius.
>>8060108
Civil engineers are idiots that don't even know how to make a road in a straight line. Chemical engineering master race.
How do I solve this?
>>8060064
If you wanted to brute force it you can use double integration, but there are better approaches.
I would try integration in polar coordinates.
The ratio of the area of the top right square within the larger circle to the area outside is probably the same as the ratio of the smaller circle bounded by the larger circle to the area that isn't.
I say probably cause I cant be fucked to check.
Working mathematicians thread.
How do I evolve from a student into a professional mathematician? I've been researching "heavily" in philosophy of mathematics, yet I cannot find still the secret sauce that makes up a good mathematician.
People who are undergrads or haven't published a maths paper need not reply.
Pic related is an image of how I currently perceive philosophy and practice of mathematics. The math world (Platonic or otherwise) is split into two groups - objects and properties. And then proofs are derived from conjectures, and...
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Better picture
bump! :-)
>>8060024
You need to figure out where theorems start to break down, implications of theorems that no one thought of yet, equivalences over different branches of mathematics, etc.
Learn about methods of mathematical proofing, you either want to expand the current tools of mathematics, bridge gaps between current ones, make corrections, or simplify things. This is easier to do at the "limits" of complicated or new theorems. Essentially, if you have an idea, write it down, disregard if it's good or bad at...
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Dumb newbie question, but because I just learnt about electronic circuit analysis, and I haven't found the answer to this on search engines:
So... You can short circuit a battery. Right? Obvious: Connect the positive to the negative, and the electrons will flow to the positive part, evening the voltage and fucking up your day.
But... Connect the positive end of a battery to the negative end of an IDENTICAL other battery, and do they short circuit between the batteries? Nooo... You're just increasing the voltage! Batteries can stay like that for years...
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In scenario 2 you aren't creating a closed circuit. Why would you expect anything to happen?
>>8060058
because he's an idiot.
>>8060071
I'm not creating a closed circuit between ALL battery poles, no.
But if you accept the fact that the positive and the negative is seperated inside the battery, I am creating a short circuit between the positive of one, and the negative of the other.
Think of it this way:
I have 1 battery. For the sake of simplified argument, let's say the negative reservoir is in the left half, and the positive is in the right half of the battery, or something like that. So it's easy to physically...
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This is why classical physics is best physics.
Cosmologists don't have "no clue" , we know dark matter can't be hot via various probes and the Lyman alpha forest points to masses > 2 keV, that puts very tight constraints on warm dark matter.
>>8059913
I keep reading these anti matter/energy posts and wonder what they would have said when Brown suggested that Brownian motion was caused by little particles that you couldn't see, even with a microscope.
>>8059929
>falling for the brownian motion meme
>typical pure science wankery with no real world worth
>he just wants to sit around doing meme math all day instead of science
>great mathematician; awful scientist
>how are we supposed to do experiments with these invisible particles? nice falsifiable "theory"
Something like this, I imagine.
Fusion when?
>>8059813
Not until after the Day of The Rope, friend. You know what I mean.
>>8059813
some think it may be soon anon
https://en.wikipedia.org/wiki/High_beta_fusion_reactor
working prototype not until 2040
>everything is made of atoms
>atoms are 99.9999999999999% empty space
>everything is made of empty space
Very interesting discovery! But did you find out how magnets work?
*Everything is made from condensed Energy which exists within the space/Time field, my ninja.
>>8059817
alignment of electrons in relitive posistion to one another
is carl sagan a meme?
>>8059781
Depends on your outlook on the world
He was a drug addict.
>>8059803
this he was just a degenerate, spewing new age astronomy BS
no better than Terrence McKenna
How come all the signals in the air are not interfering with each other? Say you have 3 sine waves as an example (pic related) the resultant would be gibberish. How does a router/reciever understand what is the information that is meant for it?
Because each receiver is tuned to a particular frequency.
And then e.g. you have things as
http://ham.stackexchange.com/questions/137/what-frequencies-am-i-not-allowed-to-use-north-of-line-a-in-the-usa
(I should add that in frequency space, your pic would be 3 functions that are very seperated from each other)
>>8059672
Could you elaborate on how it is tuned to that particular frequency? In the example (take sine of 1Hz, 2Hz, 4Hz together) if you sample at 1Hz you'll be incapable of seeing wether it went down or up right? (As the others add their energy to the wave?)
>>8059677
Seperated how? As in in/out of sync?
Here's something that's been on my mind lately with all the mars colonization talk...
On mars, water boils away easily, correct? How exactly does that play out with planetary heating and atmospheric thickening? What would be the proper order of events to ensure retention of as much moisture as possible? It'd be incredibly counterintuitive if we boiled away the ice caps in the process of heating the planet, turning it into even more of an uninhabitable desert than it already is.
>>8059609
It's not really boiling like we think of it. More like evaporation.
>>8059893
Is the moisture held by Mars' atmosphere or does the vapor escape into space? I would think water's escape velocity is high enough that Mars should be able to hold onto it, but I might be missing something.
>>8059609
>On mars, water boils away easily
It boils because of the lack of atmosphere. You can see a similar, but less dramatic, effect on earth at high altitude. I've no idea how to answer the rest of your question.
Hey /sci/, I know jack shit about astronomy.
How come we can observe other galaxies and shit but we apparently can't see this theoretical tenth planet?
Is it because its so dark?
Yes. its much more distant and its not lit by a lightsource like our sun. we only discovered it because cassini recieved EM signals from the planet X
>>8059597
Galaxies radiate light. Planets ... well ok planets do to but at a much much lower frequency and power.
https://en.wikipedia.org/wiki/Stefan–Boltzmann_law
That's the energy everything radiates at according to temperature. Apply that to any planet you want in the solar system. Remember the Sun's energy drops off significantly with distance because of the inverse square law. A planet at that distance will receive very little solar energy and emit extremely little.
Compare that to Earth...
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>>8059608
Eh, sorry, here's a simpler energy balance equation that removes the greenhouse effect. In this case we can probably ignore it because Icy bodies like Pluto and further Kuiper Belt Objects will have no significant atmosphere.
It's also already solved for T
