I am just having some trouble solving this. If somebody knowledgeable wants to help me out with this, some what thoroughly I'd really appreciate it.
"There are two balls traveling on a 2D plane. BallA is traveling at 10 degrees and the direction of BallB is unknown. BallA is traveling at 10km/h and BallB is traveling at 6km/h. BallA is located at point (2,7) and BallB is located at point (14,2). It is known that the two balls will collide perfectly; if they were just points they would meet perfectly. How can we locate the point of collision/the direction that BallB is traveling?"
So the knowns are:
Va = 10km/h
Vb = 6km/h
Da = 10 degrees
(Xa,Ya) = (2,7)
(Xb,Yb) = (14,2)
The unknowns are the direction of BallB and time. (Db and t)
We can infer that:
timeA=timeB
distanceA=(10km/h) * t
distanceB=(6km/h) * t
I imagine that some kind of vector addition and/or usage of trig sohcahtoa will be useful here. But this is where I'm stuck. I want to do this mathematically, not though the use of computers or guessing/brute force.
>>8073477
>BallA is traveling at 10 degrees
10 degrees with respect to what?
>>8073481
We can say that the positive X direction is 0 degrees or 360 degrees
I drew a picture to represent it.
I'm trying to think of a way to some how make a right triangle out of this
How can virtual particles just pop in and out of existence? Doesn't that violate the law of conservation?
If something can just suddenly appear out of no where, what prevents something larger from doing the same?
>>8073450
>As a consequence of quantum mechanical uncertainty, any object or process that exists for a limited time or in a limited volume cannot have a precisely defined energy or momentum. This is the reason that virtual particles — which exist only temporarily as they are exchanged between ordinary particles — do not necessarily obey the mass-shell relation. However, the longer a virtual particle exists, the more closely it adheres to the mass-shell relation. A "virtual" particle that exists for an arbitrarily long time is simply an ordinary particle.
>However, all particles have a finite lifetime, as they are created and eventually destroyed by some processes. As such, there is no absolute distinction between "real" and "virtual" particles. In practice, the lifetime of "ordinary" particles is far longer than the lifetime of the virtual particles that contribute to processes in particle physics, and as such the distinction is useful to make.
>>8073450
http://math.ucr.edu/home/baez/physics/Quantum/virtual_particles.
>>8073450
Virtual particles are just a mathematical tool. Each line tells you to write down some mathematical expression, and each vertex some other expression. What exactly depends on the theory and the kind of line/vertex. A quark line is different to a gluon line, and a quark/gluon/gluon vertex is different to a 3 gluon vertex.
That's all it is and thinking of them as actual particles is simply incorrect, despite what popsci might tell you.
What causes pineal gland calcification and how can it be stopped?
brain cancer
Fluoride in the water
Fibonacci in the water
What do you guys think?
>>8073159
it's as dumb as you are
>>8073196
B-but which part?
is the blue mist the singularity?
if I major in electrical engineering can I make and design stuff like bulbs, electric chargers, cheap toys for kids, meme shit like free energy and meme shit like tesla shit?
What else can I do with an electrical engineering?
I saw some robotic shit on youtube.
Also, can I do shit like making a lamp that uses biological shit like fireflies to charge with sun light and then on the darkness it shines?
It would be possible with an electrical engineering?
Also can I do wifi shit and work with arduinos?
You need to do ecological engineering for that
>>8073105
can't I simply take some classes or ask some bio and chemical dude for help?
I really want to study shit like batteries, wireless transmission of energy and information, shit like ilumination systems (lights and bulbs), design some cheap electronic toys for kids, some electronic shit for holydays, chrismass cards, arduino shit.
>>8073100
Yeah, you can do all kinds of shit with an EE degree. For more obscure/specific shit, you might need to do a doctorates or some shit.
Or some companies would be okay and be like shit, he could probably do this shit with just a BS or some shit.
So you can do pretty much any electrical/electronic shit with a shit E shit E shit degree. shit.
Can entropy be reversed, /sci/?
>>8073084
Of course.
entropy can never happen because of gravity
Yes
Its called life
Another question: should the criteria for a thing being life be changed to simply "something that actively resists entropy"? That whole 6 characteristics of life thing has too many exceptions for my autistic brain desu
Who /sliderule/ here?
>>8072999
no thanks i have an iphone
>>8072999
I have a pretty rare Gilson Binary 8.5"
>>8072999
I have one, have had it for about a decade, but I don't know how to use it as of yet. It's pretty similar to that one, except the end-bits are plastic as well.
I also got myself a nice compass kit recently. It passed the >draw a circle test. The trick is to keep the center pinned on a static spot, however. I may use it to go through the Elements the old-fashioned way.
I've been on a primitive kick lately, and I have the above two, and recently I've been looking for an abacus. Happily, this counting tool is not native to any particular culture, but instances have arisen and been standardized in much of the world, since ancient times. The below page is an excellent, brisk read on the topic:
http://www.ee.ryerson.ca/~elf/abacus/history.html
basically there's old sand-marble setups, later wood-plastic-metal things. the chinese have a version, the japanese have a version, and the russians have a version. But there have been European equivalents as well.
But when I think "abacus", all weeaboo accusations aside, I think of the Japanese soroban. I've flicked the beads on a few, so to speak, and I can't find just the right one, just yet. been antiquing, they all know what I'm talking about.
Something that is true on several models, slightly annoying to me, is that the back is closed in or fenced off by wooden back-strips. I always had a vague idea that an abacus could be turned on either side, but apparently this is not the case, for practical reasons.
phenylalanine is it safe?
yes, so long as you don't have phenylketonuria
That's quite rare though, isn't it an allergy? has there been a study on the long-term effects. I drink zero sugar drinks all the time. Statistical correlations?
>>8072945
structure in pic isn't phenylalanine, it's L-DOPA
What is the voltage at point A? How would you calculate it?
88 Volts
>>8072817
I know for a fact the peak voltage is around 21.9V
What I'm really looking for is how to get there
>>8072815
24V - 2 diode drops so 23~22.6V
So now that it's settled that [s4s] is the smartest board, seeing that that is where eccentric geniuses flock to when they're on their creative downtime, what's next?
/lit/ or /sci/?
probably something like
lit > pol > sci
and 6+ years ago
sci > everyone
>Humanities & Arts
>Other Humanities & Art
what's the difference?
>>8072738
probably specific majors at particular colleges that wouldn't generally be classified under what's colloquially thought of as humanities
Are successful/famous mathematicians more talented than their colleagues, or they just simply got lucky? Were these guys seen before their achievements who will further mathematics? Are there any counter examples? Guys with great expectation living up to their potential regarding their impact?
john von neumann would be a good example of a prodigy living up to expectations
although he is probably the smartest human being to ever live, so i don't know if its fair to count him
>>8072715
>i don't know if its fair to count him
absolutely
>>8072715
>von neumann
i hate this reddit tier obsession
shut the fuck up or fuck off
What's the difference between boolean algebra and propositional logic? Are they isomorphic to each other?
I fail to see the difference between them.
boolean algebra, propositional logic, and predicate logic are all pretty similar
the different names are used to refer to distinct subtle differences between them between each field (e.g. you wont find sets in propositional, but will in predicate)
tl:dr their the same for all intents and purposes and even if you mix them up in your PhD thesis, no one will care and even if they do you are still technically correct
Its all jargon from a leftover era
>>8072305
who cares? the real question is why anyone would study this nonsense
>>8072337
lol go back to /b/
Today I opened this book in the library and got scared.
probably not much, just watch a few documentaries on physics.
anything by stephen hawking, neil degrasse tyson, coral sagan, brian greene, michio kaku, brian cox, or morgan freeman would be fine
ofc the tryhards here will tell you you need some shit 4 year physics degree but they are just trying to justify their own shit life choices.
morgan freeman explains the double slit pretty well
his thoughts on how it might relate to god are also interesting
>>8072205
you still think of god as a person rather than a concept? huehuee
So, how many classes do all engineering classes share in common?
So, following that logic, how many engineering majors can I get (the degree paper) in 10 years of study?
Also, what engineering major is best for making electronics, plastic crap, electric bulbs and so on.
>>8072145
A lot more than you think
>2 years of history, english, and lit classes
>gen ed bio, chem, and phys
>math through at least DiffEqs
Really just the last half of your junior year and senior year, or 36 or so credit hours are your engineering specialty.
>>8072159
This is true. I know a guy who switched from Chem E to Biomedical Systems E at the end of his junior year and is still graduating on time w/o too much effort.
Google is your friend mate, learn to use it.
Suppose f is a polynomial with complex coefficients. Is there a way to test if there are polynomials g and h with degree(h)>1 such that
f(z)=g(h(z)) identically? Is there a way to characterize such f and find the "factors" h and g?
Clearly the degree of f can't be prime. Also, for any complex c, h must map the solutions of "f(z)=c" to the solutions of "g(z)=c" so, for
example, h would need to map the roots of f to the roots of g, respecting multiplicities.
Any other thoughts?
My thoughts are that you can pass to an algebraic equation via
https://en.wikipedia.org/wiki/Fa%C3%A0_di_Bruno's_formula#Formal_power_series_version
and going from small to high exponents (the higher use the smaller ones too),
maybe the solutions can be parameterized by h's coeffieints.
>>8071970
Yes, I you could (once you pick degrees for g and h) multiply out g(h(z)) and equate coefficients. This looks like it would be a mess though. I was wondering if there were a necessary condition based on examining the roots of f. For example, must every root of f have the same multiplicity which is >1 ? If b is a root of f with multiplicity m, then c=h(b) must be a root of g of multiplicity k that divides m, and b must be a root of h(z)-c of multiplicty m/k.. or some such. Seems like there should be a way to make this sharp.
>>8071943
it feels weird.
I feel like f and g can't contain as much information as f.
In fact I'm pretty sure that's key to the problem.
say f, g and h are of degree n, p and q with n=pq
f has n+1 independent coefficients.
g has only p+1, h has only q+1
so I would say a strong condition for f=g(h) would be that (p+1)+(q+1)>=n+1 (basically you need to have more degrees of freedom to be able to fit the resulting polynomial).
this results in p+q+1>=n, or p+q>n.
given pq=n, it's pretty hard to accomplish.
p+q>=pq implies 1/p+1/q >= 1, which is impossible unless p=q=2 and n=4
Is it possible to formalize this? I think the main tool would be that h has to map a certain number of complex numbers on the set of roots of g. But h only has so many roots, meaning a restriction on the degree of f.
also from n=4, p=q=2, the other constraints should be expressed pretty easily.