Archived threads in /sci/ - Science & Math - 632. page
what sci-fi FTL concept comes closest to theoretical FTL with our laws of physics
>>7653091
why are there so many fucking FTL threads on this board?
>>7653095
because they just recently found a way to travel faster than the speed of light, read the news
>>7653091
none of them lol! Causality, relativity, FTL, pick two.
When talking about glueing in topology, are you allowed to stretch your object? If a square is glued like this, it should result in a sphere. Should I picture this square to be glued along its vertices, then "blown" up into a sphere?
Yes.
Any one body without a handle is topologically the same. Pic related is the Wikipedia pic for one body with one handle (demonstrating homotopy transformations)
related
https://en.wikipedia.org/wiki/Genus_%28mathematics%29#Topology
>>7653054
It sounds like you have a problem visualising the gluing process. Just see what happens as you pull the sides into the two corners while keeping the boundary connected. I think wikipedia has a gif of the process of making a disk into a sphere, probably on the quotient space page.
topology is the shit tho
How come higher Math is nothing more than alphabet soup? I started off with Elementary Algebra and at least it was understandable when taking notes. I'm now in differential equations and most of the concepts are written like alphabet soup that I don't even understand what's going on. It's only when the professor is doing the homework problems that I understand how to do the steps. I was looking at higher Math and they are using weird ass letters that I don't even know if those are suppose to be numbers or something. Why do we need to decipher what is...
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just because you don't understand it doesn't mean it doesn't make sense.
>complaining about greek letters and other symbols
>differential equations
>higher math
Why does anything exist? Why isn't there simply nothing, forever?
>>7652922
We just don't know
yet.
>>7652922
Because without something there can be no nothing. Without an ever there can be no never, nor forever.
The very logic you're using itself is based on existence. Non-existence probably isn't meaningful in the same way, as it's a consequence of the existing framework of logic you have available.
>>7652922
In the set of all possible complete mathematical representations of the universe, there is only one way in which nothing can exist, the empty set. There are however, one assumes, an infinite number of ways things can exist. So, it is infinitely likely things will exist, and infinitely unlikely nothing will exist.
It is a long shot, but someone might can point me to sources.
tldr, grapes, grape juice, wine
is wine superior to grapes and grape juice from a health pov?
Also I'm interested in the health benefits of wine without the drawbacks of alcohol. I know there are alcohol free wines out there, but it is almost impossible to buy them here. So I'm interested in making alcohol free wine by removing alcohol from it.
I guess I could achieve this by simply boiling it long enough (e.g. mulled wine), as ethanols boiling point is lower than water, but would...
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>>7652888
It's much better than grape juice, which is basically just sugar water, but probably worse than grapes.
However, it also lasts much much longer than grapes do because alcohol is a preservative.
All told, red wine is good for you in moderation.
>>7652888
>is wine superior to grapes and grape juice from a health pov?
No. Any benefit of wine can easily be found in myriad other sources.
Hey /sci/, have you ever independently discovered a math theorem or concept?
If so, what did you "discover"?
I realized last night after a Calc 2 lecture in sequences and series that you can use sequences to eliminate all non-prime numbers and consequently find all the prime numbers. Turns out this is called the Sieve of Eratosthenes. I guess I must be at least /greek/ tier.
I independently derived the fact that the "new thread" function is a projection from the space of 4chan users onto the space of faggots
When I was in kindergarten I figured out 10X10=100 when I barely knew what multiplication was. All the other babbies were impressed :^)
>>7652828
I guess this was pretty lame, but back when I was in physics 2, I was working through the derivation of the RC time constant, and thought the method used for analyzing the circuit was pretty cool.
So I went to a math instructor and said "Hey, this is pretty cool, given just a relationship between a function and its derivative, you can determine the function! Is there a way to generalize this, it seems really useful."
He told me "Yeah, it's called Differential equations..."
What is the difference between a Psychopathy and Sociopathy?
Often I've seen the terms used interchangeably, but on the other and I see some people stressing on the fact that are not the same thing.
>>7652810
one is a meaningless term used by the APA to bank on victims of a corrupt justice system
the other is a meaningless term used by the APA to bank on victims of a corrupt justice system
psychology would be almost as useful as astrology, except that gravitational waves produced by stellar objects is real and any purported objective description of what goes on inside your head that doesn't take into account external factors is not
>>7652810
Psychopaths are supposed to be more organized and harder to spot. Also they tend to be born with it as opposed to being a victim of child abuse or something.
>>7652836
>psychology would be almost as useful as astrology, except that gravitational waves produced by stellar objects is real and any purported objective description of what goes on inside your head that doesn't take into account external factors is not
i kek'd, thanks anon.
If gender can be changed in mice by silencing a gene and inserting chemicals, why haven't we don't it to humans already?
http://www.sciencealert.com/brain-gender-is-more-fluid-than-originally-thought-research-reveals
>>7652663
ethics, and the fact that doing it in mice doesnt mean they have figured it out, or even can, do it in humans.
>>7652694
What exactly are the dangers of doing this to humans?
>>7652702
Pick a bad genetic mutation...any of em. That's the risk you run.
With the rise of DNA sequencing facilities for the public like 23andme has anyone here bit the bullet and checked out their raw data? If you did have your raw data would you even want it looked at?
Also just curious if there are any geneticists here as I looked at mine and I had some mutations that popped up that are supposedly in very important areas. Such as:
MAO A R297R rs6323 T +/+
COMT V158M rs4680 AA +/+
VDR Bsm rs1544410 TT +/+
COMT H62H rs4633 TT +/+
>>7652621
Also opinion on the ethics of passing such genetics on if I have a daughter since male wouldn't inherit.
>>7652621
Having a daughter would be more ethical than having a son with these mutations. While the COMT muts would only affect a female its probably the case that the mother would have non mutated genes that would compensate for the mutations present. Also 23andme only does extremely basic shit so the data is most likely reliable. Also males would inherit. Look up x linked diseases in males. All of these genes (except the last, I didn't. check that one) are x linked
>>7652621
Also, you wouldn't want the info released. One of the guys who worked on the human genome project switched a sample containing donor DNA with his own and got caught when geneticists were using basic tools (I think ncbi) to look at some of his genes
I want to work with robots in the future. Not the ones in factories that build cars together for example, but humanoid robots.
I want to be involved in the "general design" of them, but I'm not sure what subject I have to get into to do that.
Would it really be robotics? Because that just seems like a mixture of informatics and mechatronics.
Should I study mechanical engineering instead?
>>7652620
either could allow you to work with robots, but i recommend the mechanical engineering approach as it tells you everything you need/ want to know about robots, and then some
![CRlIPqeVEAAbC4X[1].jpg](https://i.imgur.com/JxRLNIv.jpg "CRlIPqeVEAAbC4X[1].jpg")
>>7652620
Why do people always want robots to look humanoid??? Unless its for sex, there is literally no reason to spending time on how to design such a thing. A robot with a simple form cna perform most tasks just as good if not better than one with a humanoid form.
>>7652620
>Not the ones in factories that build cars together for example, but humanoid robots.
good fucking luck. every engineer out of college wants to do that. 99% of everyone that gets into robotics does the " boring" stuff. if you go to a top tier university and just BTFO every course, maybe you could get into it, but i'm pretty sure that if you are posting on 4chan about it, you won't be able to pass the cut.
why is it when we look into a mirror, the reflection is reversed, but only on the horizontal axes (x,z) but not vertically (y)? (see second pic related)
2nd pic
>>7652533
because our eyes are aligned horizontally, not vertically.
>>7652534
also your 3D axes do not form a direct trihedron
what's the most cutting edge in cancer treatments?
oncolytic viruses?
gene therapy/editing?
something I haven't read about?
which one, in your opinion, shows the most promise, and why?
I have no idea if it shows the most promise, but metallic nanoparticles are probably something you haven't heard of.
>grow hollow gold spheres to precise dimensions and therefore precise optical properties
>attach proteins that bind only to cancer cells
>inject and wait for to collect around tumors
>see tumors easily because they're loaded with gold
>shoot them infrared lasers that pass harmlessly through...
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>>7652523
Why gold? And would they remove the spheres afterwards? Could you just have bi-yearly check-ups using this?
>>7652529
because gold is really conductive.
How will modern civilization end?
>>7652434
the answer starts with n
>>7652437
Nukes?
>>7652440
the second letter is i
good people of /sci/ i need some coding help. i'm working on a project and i will be using trees, but i have some problem in my code i can't debug
typedef char labeltype;
typedef struct __celltype {
labeltype label;
struct __celltype *first_child;
struct __celltype *next_sib;
struct __celltype *last_child;
int zadnji;
} celltype;
typedef celltype *node;
typedef celltype *Tree;
node lambda;
lambda->zadnji=100; //ERROR
#define LAMBDA lambda
my compiler says that there is an error in the above...
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>>7652405
Have you tried moving the define to above where you first use it?
>>7652415
yeah :/ exact same error
>>7652405
>i
loser
>node lambda;
>lambda->zadnji
lambda is struct, not a pointer to a struct. To access data use "lambda.zadnji" or "(&lambda)->zadnji" not "lambda->zadnji"
Let's scientifically discuss logistics.
What math/algorithms are used? How do they predict arrival times? What do they do to handle fluctuations in demand (Amazon easily gets 10x normal orders around Christmas)?
how can you predict when you land at airport XX although you've changed flights 5 times?
>scientifically discuss logistics
>scientifically discuss
>scientifically
honestly there are just factories of people that sort shit for trucks 3-4 times a day, and then a preload in most places, some nodes along the way are automated, some are post air mail, the point is each mode of transportation is a puzzle piece with a logical numeric value, and useing all of your pieces you
A. Have a computer plot out the best possible route( UPS implemented this for small brown trucks), and international node transfers alike.
B. You operate in a more domestic capacity, and have each mail truck play zone defense on the mailboxes.
>>7652344
Also theres a fucking ton of auto scans along the way so your logistics division can just mainline data livefeed, generate a plan of action based on the past, and future trends.
