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https://sites.google.com/site/scienceandmathguide/
>>
Reminder: /sci/ is for discussing topics pertaining to science and mathematics, not for helping you with your homework or helping you figure out your career path.

If you want advice regarding college/university or your career path, go to /adv/ - Advice.

If you want help with your homework, go to /wsr/ - Worksafe Requests.

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What are some interesting things you can do with Dry Ice?
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>>8305363
wow i can contribute something serious for once:

you can actually ring a metal-bell by evenly and gently pressing a piece of dry ice against it.

google it, its a really beautiful phenomenon
>>
>>8305363
use your rotovap
>>
You can kill people with dry ice weapons and your murder weapon will literally never be found.

Don't ask me how I know this.
>>
>>8305363

press a common coin against it. it makes a "screeching" noise, last I checked about 20 years ago.

some recent youtube russian has done same.

https://www.youtube.com/watch?v=nyE2Ipt6Wv0

Dry ice can also be used by grocery stores in the event of power outage, to try to salvage frozen inventory for the period of outage to keep a freezer cool and keep inventory saleable. it's an emergency measure though, and an asphyxiant, so it must be handled with caution in an enclosed environment.
>>
>>8305363
Throw a bunch of blocks in a pool then jump in afterwards.

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Is pic related a good idea? Which is more valuable, the existence of intelligent life or the existence of life in general?
>>
There used to be no life on earth.
Let us reduce everything to the old earth, i.e. no life at all.

Seriously though, saving the planet or not is meaningless, the planet actually doesn't give a shit.
People only want to save the planet for their own good (if the planet is inhabitable then everyone is fucked).
If someone finds a way to dumb on garbage and toxic gas to Mars, no one would have given a shit.
>>
>>8305610
No. There is no wealth but man. As we said the other day, it takes tens of thousand of people working to support one scientist and his lab equipment. Less people mean less technological progress.

And you can't just "be set forever by consuming less", it's not a thing. Sure, carrots grow back, but rare earths don't. Diminishing returns is a universal law. Getting resources can only get harder, not easier, no matter how much you save by having less people around. The only way to counterbalance that is to grow technology faster than you deplete resources.
You need people for that.

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So, what are we going to do about it? Plant tons of trees?
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>>8303270
>I was talking of forestation, not old growth.
It takes a lonnng time for clearcut forest
to restore itself, and the re-plantation done
by logging industry (here in USA) is a
monoculture of "tree farms", which are not
forest.
>>
>>8304999
How does that "good deal" of plants
obtain carbon for growth?
>>
>>8304999
What the fuck are you even talking about?

>co2 production
>>
>>8304992
>Or millions of tons of building material causing a coastal city to sink like 20 feet?

http://www.miaminewtimes.com/news/sorry-daily-caller-sea-level-rise-is-real-and-miami-isnt-just-sinking-because-of-too-many-condos-8594225

>Think carefully before you respond

Go back to bed, Steve Goddard.
>>
>>8303724
>the nukes will come out

it'll get going in the 2030's

https://youtu.be/Mc_4Z1oiXhY?t=39m15s

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what's the cure for premature eyaculation?
>>
Not being 13.

My girlfriend's family and my family are divided on this problem:
A man buys a horse for $500 then sells it for $600. He then buys the same horse back for $700 and sells it again for $800. What is his profit?
>My family and I say profit=$0
>Her family and herself say profit=$200
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>>8305607
Also the profit would not be zero because the market is not a zero sum game. People differ in tastes and hence there may be differences in utility functions and indifference curves (as well as cost functions for the producer) so each transaction creates value (or profit) greater than or equal to zero.
>>
>>8305559
if he could have bought the horse for $500 and sold for $800 and made a profit of $300 instead of $200 the opportunity cost would be $100
>>
>>8305607
>if you believe in efficient markets and rational actors,
Then you're an idiot.
Those things are abstractions used to build models, they don't actually exist.
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>>8305616
Depends, did the buyer do these transactions in this order? Or maybe she bought the horse for $500, used it, then no longer needed it, then sold it, then needed it again so bought it for $700, then no longer needed it again and sold it
Also there is no theoretical limit on how fast the indifference curves and utility functions could change over time. So $100 opportunity cost would be an educated guess. Not necessarily correct
>>
>>8305336
You are correct because it costs way more than nothing to feed and board a horse, so you probably lost money.

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Is 0 considered a term in mathematics? I know it is considered a number and numbers are included in the definition of a term, but here's what happens if I consider 0 a term.

If I were to say 7 - 7 = 0 has 3 terms, then I should also be able to say that 7 - 7 = 0 + 0 has four terms, and in fact, despite not being able to see them, there could hypothetically be an infinite number of zero terms on either or both sides of the equation, meaning I could say that any equation, including 0 = 0, has an infinite number of terms in it.
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>>8305134
Talking to yourself?
>pls respond
>>
>>8305539
nice
>>
>>8304980

In the context of elementary algebra, which is the relevant context for the OP's question, "term" is not usually understood as a formal piece of language, but rather as a piece of human-understandable jargon which may connote monomials embedded in a larger expression, or other "bits" in a more complex formula of whatever sort.

In elementary algebra, or when manipulating complex formulas of whatever kind, "term" is commonly used to denote "that bit right there". the monomial, the thing in between the plus-signs, the number, the proposition, whatever that /bit/ is in the bigger thing, especially in this monomial-in-the-polynomial context. And so since term is commonly used in this vague, jargon-sense, I would be happy to say that "0 is a term", /depending on the context/, OP. For example. If I write " 0 + yz + x = q", then I might briskly describe this equation as having three terms on its left hand side, or LHS. Now of course, as-written, the same could be re-written by getting rid of that leading zero. But suppose for whatever reason that I want to keep it in the discussion. I might say that "the first term is zero.", or similar. Or in the re-write (getting rid of same per the rules of algebra), I might instead say that in the equation "yz + x = q", that there is no one term equal to zero, for all values of the arguments.

If I had an equation of three definite integrals which all summed to zero, then I might describe the last integral on the left hand side of the equation as "the third term of the LHS". This is imprecise, and to be done on a jargon-basis, as the speakers and doers of the math are comfortable with same jargon.

Now, it may of course happen that in a given algebraic expression, a given term assumes, for given values of the variables, parameters etc, that some particular term evaluates to zero. But a central point of elementary algebra is that expressions may assume different values as functions of their variables.
>>
This leads me to expand slightly on the same answer to the OP.

Shortest answer: "Yes, zero is (can be, and often is) a term. A term of an algebraic expression conveys numerical or algebraic information of some kind, even if that information can immediately prove to be disregarded, or discarded by a reasoning process, per the rules of algebra. For example, '0+1 = 1' conveys an equation with an LHS having two terms, say, and an RHS having one term. Here, we have an example of a situation where zero is regarded as a term."

Much better answer: "Zero is so commonly eliminated from consideration as a term in the course of doing elementary (and even intermediate, college-) algebra that depending on the context of a given algebraic expression, we may or may not need to consider whether zero is a term /in that context/. "Term" itself is a piece of jargon which pertains directly to the working process, where elementary algebra (and closely related calculus, etc) is concerned. It pertains to those bits which /are actually written down, at-the-moment/. When discussing x + y = z for example, I would not hold constantly in mind that there are an infinity of "zero-terms" on either side of the equation, for the simple fact that although they are feasible, they have yet not been written down. On the other hand, if I again write something like a + 0 + c = b, then such an expression has usually arisen in the course of an /argument/, a /narrative/, a /proof/, or a /problem/ of some kind. And so it is relevant to speak of the /middle term/ on the LHS, say, as being equal to zero /at a particular step/. And so we rewrite the thing as a + c = b (getting rid of something that is equal to zero, or goes to zero, is often spoken of as saying that the one thing /vanishes/), and then re-consider our new expression from this point forward.

This is the tactic all throughout elementary algebra. Speaking of zero "as a term" depends on /context/, and /process/.
>>
In first order logic, the recursive definition for terms is as follows, all constants and all variables are terms and if t_1,...,t_n are terms then for all function symbols, f, then f(t_1,...,t_n) is a term. 0 is a constant (distinguished) in the standard model of the natural numbers, thus it is a term.

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Will living forever be attainable in our lifetime? Will Biology be the future "engieneer" degree?

http://www.popsci.com/future-first-crispr-makes-biology-new-digital

http://www.bloomberg.com/news/articles/2016-06-23/crispr-wins-key-approval-to-fight-cancer-in-human-trials

https://www.youtube.com/watch?v=jAhjPd4uNFY
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>>
>>8305412
>It doesnt seem like there is a large demand for immortality
I never understood why this is
>>
>>8303640
delet
>>
>>8305474
Have you ever seen someone in there 90s? Most people don't want to spend an extra century in a nursing home slowly losing their mind.

Slowing aging is where the money is. If we could make a 50 year old look and feel like a 25 year old, THEN we would start to see demand.
>>
>>8305581
>If we could make a 50 year old look and feel like a 25 year old, THEN we would start to see demand

but that is the gist of most research on lifespan extension, isn't it?
>>
>>8305591
Mainly.

I remember reading an article 3 years ago where they altered the cells in mice with telomerase extension.

The end result was the age was reversed, but the mice gained cancers and tumors. Makes you think.

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Ready for mind blowing hires photos of Jupiter's atmosphere?
2 replies omitted. Click here to view.
>>
>>8303745
This really made me kekd
>>
>>8303746
"Coming soon, this week".
>>
>>8303745
This really made me think
>>
>>8303759
this
>>
Yeah man can't wait. It was a pain in the ass when juno arrived and they said we had to wait til end of august to see the first pics. But here we are!

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>its a brainlet doesn't do cardio for cognitive benefits but claims he's smart and enlightened episode
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>>
>>8300000
NIGGA WHAT'S IMPRESSIVE IS THOSE DIGITS
QUINTS DON'T GO UNCHECKED ON MY BOARD
>>
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>>8299019
That's it?
I work 80 hour work weeks and study. I still work out everyday, Heavy lifting 2 hours a day 4 times a week. Cardio 35 minutes a day 3 times a week.

I don't do stupid shit like 'browse /sci/' on the weekdays. If I'm on a bus, sure, why the fuck not browse sci. Walking to the gym? Sure. Why not.

Actually sitting down at home and burning hours browsing the internet? Fuck no. If you wanted to find exercise time and or exercise activities you like, You would have fucking found the time and activities to do. Stop making lame no time excuses. I guaran-damn-tee it's possible in your schedule. Question is whether or not you WANT to. It's ok if you don't want to. It really fucking is. Don't make the excuse, just say you don't want to. Are there benefits? Sure. Are there downsides? Yeah. But there's also benefits and downsides to what you're doing right now.

Weekends are when I do nothing for the sake of nothing. Lifting heavy things and putting them down is still part of that nothing.

Also, the "Frontloading" everyone keeps laughing at you for is your schooling and obtaining of a PHD. You're picking up a PHD at a pace that isn't allowing you any experience. In just about any of the sciences, there are ample opportunities to work in your field and go to school. The experience gained is invaluable accompaniment to your study. Both in application of concept, better room to 'think', time to actually ask and answer questions, future employer viewpoints, future business partner viewpoints.......

Could go on all day. Your PHD isn't worth shit. A company doesn't want a piece of paper, they want a PERSON. The piece of paper is just nice because it says that person might not be a piece of shit and should know x list of shit. That piece of paper could bar your entry, but you still need to be a person capable of social interaction.
Kind of up to you to determine if you can fulfill the other requirements other than what the piece of paper is saying you know.
>>
>>8305154
Sure, sure. You work 16 hour workdays, get home, eat, study, sleep for 5-3 hours per night, and still somehow work out 2 hours on 4 of those days.

Etc. Just stop, and shut up. I didn't read the rest of your post, but if you have a point to make just do it strictly in the abstract so you don;t make a fool of yourself with what are at best blatant exaggerations and half truths.
>>
>>8305148
kek
>>
>take up cardio
>strain calf muscles
>can't run anymore
>been 3 weeks and it cramps when I try to run again
hmm

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Why do people question the Axiom of Choice? Banach-Tarski is nothing compared to what can do wrong without it.

[math] \bullet\ [/math] A real number can be in the closure of a set [math]X[/math] but not a limit of any sequence in [math]X[/math].

[math] \bullet\ [/math] There can exist a field with no algebraic closure. Furthermore, a field can have non-isomorphic algebraic closures.

[math]\bullet \ \ \mathbb{R}[/math] can be partitioned into strictly more than continuum disjoint subsets (!).

[math]\bullet \ \ \mathbb{R}[/math] can be a countable union of countable sets. Thus the theory of Lebesgue measure can fail totally (!!).

Math without choice is broken.
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>>8302168
that's not the only downside. many statements in math are equivalent to LEM, I think the intermediate value theorem for exmaple
>>
>>8304355
>equivalent
Maybe be more specific. A theorem in a theory about things that have a topology like the real numbers is not equivalent to a 4 symbol sentence in propositional logic.
To prove the intermediate value theorem, as classically formulated, you need LEM.

But (as I go in at lengths in that post) eve if you drop LEM, you can prove a statement that's classically the same as the intermediate value theorem:
You can't prove the intermediate value theorem in constructive analysis - you can "merely" prove any form of it that you could realize algorithmic ally.
But you can, in a classical logic, prove the intermediate value theorem USING JUST constructive analysis.
>>
>muh axioms
math is the most authoritarian shit I've ever seen
>>
>>8304766
How come? Everybody can choose his own?
It's rather like fashion, choose the clothes that you like.
>>
>>8304334
no not at all
intuitionist think that the powerset axiom [for any set, its power set exists] is fine
constructivist are predicative constructivist

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hmm... really makes you think huh?
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>>
>>8304679
actually the easiest way to find a brainlet is to test their iq.
t. brainlet
>>
>>8305070
speak for yourself brainlet.
t. high-iq physics major
>>
>>8304616
these IQ scores are extremely inflated for every major listed, even phd graduates don't average 130+
>>
>>8304971
Stop talking shit on me.
>>
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seriously though, why are physics majors smarter than other majors by all these metrics? I thought the physics master race thing was just a dumb meme.

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A few months ago an anon posted his book collection taken from the /sci/ wikia, and gave us the mega link. Since then, the mega link has been taken down. I've reuploaded it to torrent for others to peruse.

>>>/t/733182
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>>
>>8304043
>>Destroy eyes.
You're on /sci/, so please don't post momscience.
>>
Very nice torrent and very nice speed.
Will seed, thanks.
>>
>>8303980
bump
>>
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>>8303980
OP here, added the magnet link to the /sci/ wikia.
>>
>>8303980
thanks so much

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Let's talk about math education in the U.S. In particular, lets discuss high school math education.

Positives?
Negatives?
What are your thoughts?
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>>
>>8301623
Four classes from 7ish to 3 with an optional "zero hour"
>>
>>8298993
"u have 2 b smart"
They do though, otherwise they'll be dumb.
>>
>>8301936
>implying your IQ is relevant in highschool
>>
>>8298939
Physics 1 or whatever its called doesn't require calculus.
>>
>>8301756
>120 iq
>wasted potential
You can't blame the school system for your problems brainlet

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The other day I had a discussion with a SC student, said that Godel's incompleteness theorem showed that science was limited.

Why compufags and mathfags pretenten talk about science when they know almost nothing? Especially compufags.
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>>8299023
Godel's theorem is irrelevant to physics. Physics is not a formal system in the sense of Godel's theorem.
>>
>>8303351
too bad that the causal relation dreamed by physicists is exactly the material implication of the classical logic
>>
Godel's theorem proves the exact opposite in fact.

It provides an algorithmic method to produce new "facts" that were previously unknown.
>>
Bump
>>
>>8299769
>PhD in Physics
>Any job I want
>$300k starting


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