## Search found 846 matches

Mon Mar 10, 2014 7:00 am UTC
Forum: School
Topic: Does anyone feel like previous levels don't prepare you?
Replies: 19
Views: 16375

### Re: Does anyone feel like previous levels don't prepare you?

The high school you go do does seem to make a pretty big difference (and probably what courses people take there if they have much choice too). I had a pretty awesome high school and the stuff I took advanced courses in during high school I feel like practically qualified me to teach first year univ...
Sat Mar 08, 2014 4:40 am UTC
Forum: The Help Desk
Topic: Excel 2000 formatting
Replies: 3
Views: 3042

### Re: Excel 2000 formatting

Thanks, the solution Deva found seems like it'll work nicely for my purposes. The way to force conversion by way of the special paste multiplication is also nice to know.
Sat Mar 08, 2014 3:43 am UTC
Forum: The Help Desk
Topic: Excel 2000 formatting
Replies: 3
Views: 3042

### Excel 2000 formatting

I have some data in excel from an external source that denotes thousands in terms of k, so '10100' is '10.1k'. Unfortunately this makes excel interpret it as just a string and not as 10100, which is bothersome as I want to do math with this data. Is there a straightforward way within excel I can con...
Wed Mar 05, 2014 7:31 pm UTC
Forum: Science
Topic: Double-Slit Experiment Question
Replies: 28
Views: 4803

### Re: Double-Slit Experiment Question

I don't think it'd be a huge leap to rename 'particle-wave' to 'wavefunction' if you want something more QP-y, I just figure particle-wave sounds more like a thing than a description of a thing as one might be inclined to treat wavefunctions as.
Wed Mar 05, 2014 7:04 pm UTC
Forum: Science
Topic: Double-Slit Experiment Question
Replies: 28
Views: 4803

### Re: Double-Slit Experiment Question

I'm happier to think of things as particle-waves rather than things that are one or the other depending on circumstances. Some experiments make the particle characteristics apparent, and other make the wave characteristics apparent, but it's still the same ole particle-wave in both cases. This may o...
Sat Feb 22, 2014 12:53 am UTC
Forum: Mathematics
Topic: A Multiple-Worlds Lottery
Replies: 17
Views: 3600

### Re: A Multiple-Worlds Lottery

It seems to me if you're thinking in terms of MWI that you're gonna do all the options anyway, since it's not really reasonable to conclude that things are classical right up until just after you made whatever investments and only then do things start branching a la MWI. Although to be fair there ar...
Fri Feb 21, 2014 7:27 pm UTC
Forum: Mathematics
Topic: Math: Fleeting Thoughts
Replies: 382
Views: 123320

### Re: Math: Fleeting Thoughts

I think the relevant wiki page is on logistic regression, but I was very tired and somewhat drunk when I looked into this last night, not to mention it's been ages since I did stats.
Fri Feb 21, 2014 7:23 pm UTC
Forum: Mathematics
Topic: A Multiple-Worlds Lottery
Replies: 17
Views: 3600

### Re: A Multiple-Worlds Lottery

I think there's problems with trying to deal with probabilities in many worlds, because everything (that can happen) happens with certainty. I think there's also some concerns with possible infinities of worlds where trying to think about the proportion of worlds with feature x is gonna spit out 0% ...
Fri Feb 21, 2014 6:02 am UTC
Topic: 1333: First Date
Replies: 117
Views: 25607

### Re: 1333: First Date

This phenomenon has reached xkcd? Man, my brother first casually referenced it earlier this week and I hadn't heard of it, and now pretty much every part of the internet I frequent has talked about it. I still have yet to actually watch the actual thing, but from what's been described it seems like ...
Sun Feb 16, 2014 5:26 pm UTC
Forum: Coding
Topic: Coding: Fleeting Thoughts
Replies: 9870
Views: 1781734

### Re: Coding: Fleeting Thoughts

It was being used as part of a normal english sentence along the lines of "Do I play *_game here" on a few scattered occasions so I doubt it's related to pointer shenanigans (and with multiples things following the *_ though, so there's not some game called "*_game" or anything)....
Sun Feb 16, 2014 4:54 am UTC
Forum: Coding
Topic: Coding: Fleeting Thoughts
Replies: 9870
Views: 1781734

### Re: Coding: Fleeting Thoughts

Is *_ some sort of indicator or part of syntax for any languages? I saw someone on the interwebs use *_ in a similar manner as I would use \$ in \$example in casual text, but it turns out that it's really hard to search for *_ and get potentially relevant results instead of emoticon things. Might just...
Fri Feb 14, 2014 3:09 am UTC
Forum: Mathematics
Replies: 32
Views: 8219

### Re: quarkcosh1's math coincidences thread

I'm mostly going to try to not be involved in this, but as a reader, I'm not terribly ok with the use of = to mean approximately equal, particularly with the sorts of comparisons you're inclined to make. I know you put a warning so that's better than nothing, but it could get confusing if you ever s...
Sun Feb 09, 2014 11:02 pm UTC
Forum: Mathematics
Topic: almost homework, a system in 3 unknowns
Replies: 11
Views: 2752

### Re: almost homework, a system in 3 unknowns

There's definitely a real root. Really, just think about the graph of a cubic (with real coefficients anyway), on one side it's going off to positive infinity and the other it goes down to negative infinity, and cubics are continuous so theres definitely a crossing somewhere. Actually finding it ana...
Sat Feb 08, 2014 5:42 pm UTC
Forum: Mathematics
Topic: One divided by Zero (1/0)
Replies: 44
Views: 7397

### Re: One divided by Zero (1/0)

Most things have already been addressed, but for ways positive infinity behaves differently from negative infinity (in the context of real analysis at least) is that x< ∞ for all real x, but x>- ∞ for all real x.
Sat Feb 08, 2014 4:45 am UTC
Forum: Mathematics
Topic: One divided by Zero (1/0)
Replies: 44
Views: 7397

### Re: One divided by Zero (1/0)

I feel like you've used a number of properties that when stated more carefully, explicitly exclude 0, and so aren't valid properties to be using (such as x^-1=1/x for x=0). Even overlooking things like that, I'm fairly sure you could construct a near identical argument showing that 1/0 is negative i...
Fri Feb 07, 2014 1:27 am UTC
Forum: Mathematics
Topic: Axiomatic mathematics has no foundation
Replies: 158
Views: 32725

### Re: Axiomatic mathematics has no foundation

I'm pretty sure physics is basically just math with extra assumptions about the nature of the universe and measurement errors, rather than the other way around, so if you're dissatisfied with the state of math, physics is apt to be far worse off.
Thu Feb 06, 2014 9:52 pm UTC
Forum: Mathematics
Topic: Axiomatic mathematics has no foundation
Replies: 158
Views: 32725

### Re: Axiomatic mathematics has no foundation

Aren't you trying to reason using logic, which itself boils down to some axioms? If you want to argue that use of axioms is a fallacy, then you shouldn't use axioms in your argument. I'm also pretty sure that an axiom free argument would amount to you saying nothing, as there's assumptions/axioms de...
Tue Feb 04, 2014 7:32 pm UTC
Forum: Mathematics
Topic: almost homework, a system in 3 unknowns
Replies: 11
Views: 2752

### Re: almost homework, a system in 3 unknowns

Isn't the traditional route just taking one of your equations, solve it for one of the unknowns (e.g. x=6/(yz)), plug that into another equation which now has only 2 unknowns, solve for one of those in terms of the other, and then plug that into the final equation to solve for a value? Then backtrac...
Mon Feb 03, 2014 8:30 pm UTC
Forum: Science
Topic: Can you (passively) heat an object hotter than your source?
Replies: 98
Views: 23305

### Re: Can you (passively) heat an object hotter than your sour

This isn't quite the same thing I don't think, but it seems similar enough to add here. My intuition keeps on wanting to tell me that if you had one object with a massive heat capacity, one object with a tiny heat capacity, and heated them both to the same temperature, the high heat capacity one wou...
Thu Jan 30, 2014 10:58 pm UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2870
Views: 644333

### Re: RELATIVITY QUESTIONS! (and other common queries)

So, regarding the implications of causality breaking FTL travel... It's been awhile, but I gather relativity basically says that given the means to go FTL, one could arrange that in some frames messages could be received before they were sent, so that's bad and this is a pretty strong reason to beli...
Sat Jan 11, 2014 1:06 am UTC
Forum: Mathematics
Topic: Idea for using pi approximations to get close to 1
Replies: 24
Views: 5779

### Re: Idea for using pi approximations to get close to 1

I was about to compare you to scratch123, but I see someone beat me to it over in the linguistics thread. Is there compelling reason to believe you're not the same person? Anyway, there's infinitely many mathematical constants, so being able to find some to relate to physical ones isn't surprising. ...
Tue Dec 17, 2013 9:08 pm UTC
Forum: The Help Desk
Replies: 16
Views: 6770

How significant would things like folding@home be on that? On one hand, the point of it is perhaps to always keep your computer hard at work for the glories of protein folding (or seti or whatever other distributed computer thingummywhatsits people might be using), but at the same time I don't feel ...
Wed Nov 27, 2013 12:45 am UTC
Forum: Science
Topic: Can someone explain more about the Higgs Boson and mass?
Replies: 24
Views: 5301

### Re: Can someone explain more about the Higgs Boson and mass?

Susskind did an hour and 15 minute long lecture on what the higgs boson is on Stanford youtube page. I'm fairly sure the first time he even says anything directly about the higgs boson was in the final 10 minutes, which is probably a sign that it's being explained right rather than throwing analogie...
Tue Nov 26, 2013 5:02 am UTC
Forum: Mathematics
Topic: I have a drinking problem.
Replies: 4
Views: 1873

### Re: I have a drinking problem.

DCBDADCBCD is a handwavey non math derived version that's kinda close to what you want, but that's just me kinda squinting at it and not doing anything rigorous. There's probably a number of equally 'good' solutions too based on the 'evenly distributed' part, but avoiding the same thing twice in a r...
Thu Nov 14, 2013 6:58 pm UTC
Forum: Science
Topic: Combining Volumes don't add up?
Replies: 25
Views: 6133

### Re: Combining Volumes don't add up?

Another aspect that hasn't been mentioned (that is probably relevant in circumstances where you're supposed to be using volumetric glassware), is that the 'if' part of "if you mix 5 mL of A with 5 mL of B..." can be pretty important, as theres uncertainties involved with all measures of vo...
Mon Nov 11, 2013 8:15 pm UTC
Forum: Mathematics
Topic: Question bisection method
Replies: 4
Views: 997

### Re: Question bisection method

Regarding the first question, it seems more like a clarification for your prof/grader to make, rather than something for random forum folk.

As for the second, I suspect that wikipedia has all the answers, although I haven't checked.
Fri Nov 08, 2013 4:13 am UTC
Forum: Mathematics
Topic: Dogma in Math
Replies: 98
Views: 12514

### Re: Dogma in Math

Give a man a program and he'll be frustrated for a day. Teach a man to program and he'll be frustrated for life.
Thu Nov 07, 2013 6:00 pm UTC
Forum: Science
Topic: What is the smallest object that has gravity?
Replies: 65
Views: 17873

### Re: What is the smallest object that has gravity?

Well, how 'big' is a photon, and do they count as an 'object' for the purposes of the question? I'm fairly sure it's been shown light has gravity, although I don't know if that's theory or experiment at work. What gravity 'is' might not necessarily be the same as what someone thinks it is, be it alo...
Thu Nov 07, 2013 6:07 am UTC
Forum: Science
Topic: What is the smallest object that has gravity?
Replies: 65
Views: 17873

### Re: What is the smallest object that has gravity?

Yeah, small objects attract things too. Since they're small it's not a very big attractive force, but it's still there. It's hard to tell what your physics experience is, but it falls out of newtons 3rd law if you're ok with classical theory. Perhaps more intuitively, 'big' things are just collectio...
Wed Nov 06, 2013 3:51 pm UTC
Forum: School
Topic: Presentation Preparation Philosophy
Replies: 17
Views: 10559

### Re: Presentation Preparation Philosophy

In theory, I would imagine the best way to prepare is to give a bunch of improvised mini-presentations to a smaller audience, so you get a sense for the overall flow of your presentation, but since it's improv you're still not falling into the trap of having rigid memorized lines that could mess you...
Wed Oct 30, 2013 9:56 pm UTC
Forum: Mathematics
Topic: Question-Sum!!
Replies: 7
Views: 1583

### Re: Question-Sum!!

What do you mean? Order of the sum as in "double x = 5.3+4.7;" is giving you a different number than "double x = 4.7+5.3;"? It might be worthwhile to post an example of the code that's giving odd results. (Also, I suspect this is gonna end up being more of a coding type question ...
Mon Oct 21, 2013 10:56 pm UTC
Forum: Coding
Topic: Basic Q about compiled executables
Replies: 11
Views: 3124

### Re: Basic Q about compiled executables

Hmm. That was helpful, although I almost feel like I know less than before given all the abbreviations I don't know what are (and even if I did, they probably still wouldn't mean much to me), as well as various other tidbits related to the under-the-hood stuff. Still, what I'm getting is that differ...
Mon Oct 21, 2013 7:46 pm UTC
Forum: Coding
Topic: Basic Q about compiled executables
Replies: 11
Views: 3124

### Basic Q about compiled executables

So, I just realized I don't know something that is probably extremely basic. Namely, under what circumstances can I write code, compile it into an executable file, and then just copy that exe to other computers and have it still work? Does it depend specifically on what the code is/does? (e.g. if it...
Sat Oct 19, 2013 4:03 pm UTC
Forum: Coding
Topic: Superuser: "What are the Windows A: and B: drives used for?"
Replies: 38
Views: 12998

### Re: Superuser: "What are the Windows A: and B: drives used f

I'm only 20 something, why do I keep discovering I'm old?

Man, when I'm actually old relative to the overall population I'm gonna feel like I've been dead for almost a century at this rate.
Thu Oct 17, 2013 4:56 pm UTC
Forum: Science
Topic: electron degeneracy, neutron degeneracy, and pressure?
Replies: 11
Views: 4217

### Re: electron degeneracy, neutron degeneracy, and pressure?

The hydrostatic equation that describes neutron-degenerate stuff is the Tolman–Oppenheimer–Volkoff equation, which is analogous to the hydrostatic equation derived by Chandrasekhar for electron-degenerate matter. This gives rise to the Tolman–Oppenheimer–Volkoff limit to the maximum mass of a neutr...
Wed Oct 09, 2013 5:12 pm UTC
Forum: Mathematics
Topic: Solving Polynomial Equations
Replies: 15
Views: 5122

### Re: Solving Polynomial Equations

Well, some quartics are quadratics in disguise, so if you have ax^4+bx^2+c, you can solve them fairly easily by setting X=x^2 so you have aX^2+bX+c which you can use the quadratic formula on to get two solutions for X, and then it's a simple matter to go from X to x so you have all 4 solutions.
Wed Oct 09, 2013 4:30 pm UTC
Forum: Mathematics
Topic: Is this ambiguous? Is it fallacious?
Replies: 92
Views: 18116

### Re: Is this ambiguous? Is it fallacious?

So, you believe you're presenting a set of axioms?

I seem to recall you saying you'd demonstrated that your set of axioms was consistent? Do you still believe you've done that (even if you haven't done so here)? Or have you since retracted that claim?
Sat Oct 05, 2013 6:46 pm UTC
Forum: Science
Topic: How does light work/how do we see? [stupid question]
Replies: 5
Views: 1991

### Re: How does light work/how do we see? [stupid question]

Yeah, that sounds familiar. There's extra hiccups coming from the fact that even 'white' light sources aren't necessarily radiating at every wavelength equally, and also our eyes are more sensitive to some colours than others, so I imagine there's a whole variety of light combinations that would be ...
Sat Oct 05, 2013 3:46 pm UTC
Forum: Science
Topic: How does light work/how do we see? [stupid question]
Replies: 5
Views: 1991

### Re: How does light work/how do we see? [stupid question]

Most things reflect light (and absorb the rest), and it's that reflected light that then reaches your eye (and it's the fact that some wavelengths are absorbed/reflected better than others that results in things appearing to be different colours, so something 'green' is mostly reflecting green light...
Tue Sep 24, 2013 3:21 am UTC
Forum: Mathematics
Topic: Geometry: A line is defined?
Replies: 16
Views: 3081

### Re: Geometry: A line is defined?

...Does "defined" mean something different from the usual definition in the context of geometry? I have a hard time imagining any sort of math being done with undefined things, since by my reckoning math is pretty much all about carefully defining things and seeing what those definitions i...