## Search found 150 matches

- Mon Sep 04, 2017 7:03 pm UTC
- Forum: Mathematics
- Topic: "multi-dimensional" analogy to linear orders?
- Replies:
**1** - Views:
**1034**

### Re: "multi-dimensional" analogy to linear orders?

by the '("preorder" might be replaced with a slightly stronger requirement? I am not sure.)' I think I mean that it might make sense to require it be a total preorder. The ones constructed from sets of points points in a finite dimensional vector space with the usual inner product all have...

- Thu Aug 31, 2017 4:40 am UTC
- Forum: Mathematics
- Topic: "multi-dimensional" analogy to linear orders?
- Replies:
**1** - Views:
**1034**

### "multi-dimensional" analogy to linear orders?

(If this post is tl;dr , the lines that just have a few underscores on them and nothing else are places that I think could be convenient to stop reading at, and I would appreciate getting a response to any portion of this post.) I was trying to either find an existing description of, or come up with...

- Sat Aug 12, 2017 9:05 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1875: Computers vs Humans
- Replies:
**24** - Views:
**3034**

### Re: 1875: Computers vs Humans

OK, but,

Computers not only do not care, they have not, as of yet anyway, been /able/ to care.

I don't see how "not caring" would be something that humans surpass computers at.

To the contrary, humans surpass computers at caring.

Computers not only do not care, they have not, as of yet anyway, been /able/ to care.

I don't see how "not caring" would be something that humans surpass computers at.

To the contrary, humans surpass computers at caring.

- Fri Jul 21, 2017 10:37 pm UTC
- Forum: Mathematics
- Topic: Help with a recurrence relation, related to partitions, and related to random infinite permutations
- Replies:
**6** - Views:
**2101**

### Re: Help with a recurrence relation, related to partitions, and related to random infinite permutations

First, thank you for your interest. In the distributions I am looking at, the probability that, given that the first m elements of the permutation form a permutation themselves, the probability that the next n elements after the first m form a permutation, is the same as the probability that the fir...

- Fri Jul 21, 2017 2:37 am UTC
- Forum: Mathematics
- Topic: Help with a recurrence relation, related to partitions, and related to random infinite permutations
- Replies:
**6** - Views:
**2101**

### Re: Help with a recurrence relation, related to partitions, and related to random infinite permutations

Oh wow, yes, that is very helpful! You have my gratitude. I am not really familiar with convolutions, but I have learned some about the laplace transform, and have some idea of what the fourier transform is like. Also I think I had seen that the product of two power series as a power series has the ...

- Thu Jul 20, 2017 4:18 am UTC
- Forum: Mathematics
- Topic: Determining line of sight over time
- Replies:
**30** - Views:
**4151**

### Re: Determining line of sight over time

I wonder if it might be possible to transform the problem into a version where they are stationary, but the location/movement of everything else gets warped. If we assign both of them a "mass" of 1, then the "center of mass" should be their midpoint, and because they are moving i...

- Tue Jul 18, 2017 6:41 am UTC
- Forum: Mathematics
- Topic: Help with a recurrence relation, related to partitions, and related to random infinite permutations
- Replies:
**6** - Views:
**2101**

### Help with a recurrence relation, related to partitions, and related to random infinite permutations

Hi, I am looking at defining a function a(n) in terms of another function f(n), with a(n) defined as: a(n) = f(n) - ∑ i=1 n-1 ( f(i)*a(n-i) ) I have noticed that for some functions f, the sum of a(n) over positive integers n goes to 1. I have proved this for f(n)=1/(n+1) , as well as for f(n) = c , ...

- Wed Jul 05, 2017 3:21 pm UTC
- Forum: Mathematics
- Topic: Looking for practice problems for algebra ?
- Replies:
**8** - Views:
**1872**

### Re: Looking for practice problems for algebra ?

Uh,

Which algebra?

Do you mean like, "solve for x" or like, "prove that the degree of x divides the degree of the group", or something else?

Which algebra?

Do you mean like, "solve for x" or like, "prove that the degree of x divides the degree of the group", or something else?

- Mon Jun 19, 2017 6:20 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1852: "Election Map"
- Replies:
**30** - Views:
**4949**

### Re: 1852: "Election Map"

What if, we took some political observer, with some set of positions, and checked how the average positions of each district compared to those of that observer, at 2 (or more) different times, and used that to determine some notion of "relative velocity", and then chose levels of red or bl...

- Fri Jun 09, 2017 8:24 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1844: "Voting Systems"
- Replies:
**83** - Views:
**8786**

### Re: 1844: "Voting Systems"

One idea which I had, which I assume is entirely impractical, but which I think might be good if it could be implemented in practice, is Assume that each person/voter has a vNM utility for each candidate. Normalize each voter's utility function such that their first choice has a utility of 1, and th...

- Thu Jun 08, 2017 6:14 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1844: "Voting Systems"
- Replies:
**83** - Views:
**8786**

### Re: 1844: "Voting Systems"

If you cannot (or will not) answer the question, then trying to decide on a voting system is just partisan politics, designed to promote whatever agenda you have at the moment. No, because the reason I will not answer the question is that you've sucked out all of the relevant details and oversimpli...

- Tue May 30, 2017 5:00 pm UTC
- Forum: Mathematics
- Topic: What would happen if $-1 bills were minted?
- Replies:
**20** - Views:
**4238**

### Re: What would happen if $-1 bills were minted?

Here is a variation on the idea: Imagine a world where anyone can create a dollar from nothing, but doing so causes a number associated with oneself to become $1 more negative, and this number can be observed by looking at the person, and any dollar created this way indicates what this number was wh...

- Tue May 23, 2017 6:41 pm UTC
- Forum: Mathematics
- Topic: Interesting question regarding Fermat nested radicals
- Replies:
**9** - Views:
**2422**

### Re: Interesting question regarding Fermat nested radicals

Are you looking to prove that it converges, efficiently calculate approximations to it, or find a closed form expression for it?

I think I've convinced myself that it converges (but I might have made a mistake in my reasoning).

I think I've convinced myself that it converges (but I might have made a mistake in my reasoning).

- Fri May 12, 2017 6:47 am UTC
- Forum: Mathematics
- Topic: ONAG: "Surreal Numbers" make a field?
- Replies:
**10** - Views:
**3279**

### Re: ONAG: "Surreal Numbers" make a field?

I'm still rather stuck on how the surreals are closed under multiplication, class or no. Does anybody have any advice? Theorem 8. (i) If x and y are numbers, so is xy. The proof is given in On Numbers and Games , by John H. Conway. What part of the proof is the sticking point? When they called the ...

- Thu May 11, 2017 10:30 pm UTC
- Forum: Science
- Topic: Why haven't any animals evolved wheels?
- Replies:
**22** - Views:
**4207**

### Re: Why haven't any animals evolved wheels?

How would these wheels generate motion? If you had another spinning wheel, you could use gears, of course, but that doesn't let you get started. It seems easier to combine many small parts that pull or push a little into a larger part that pulls or pushes more, than to take many small parts that cau...

- Sun May 07, 2017 3:38 pm UTC
- Forum: Religious Wars
- Topic: Is 1 prime?
- Replies:
**30** - Views:
**14439**

### Re: Is 1 prime?

I think the real question is whether the zero ring is a field, and whether 1 belongs with the prime powers. The characteristic of the field of size p^k is p. If 1 is a prime power, then it is p^0 for every p. So, if the field of one element were to exist, shouldn't it have every characteristic or so...

- Wed May 03, 2017 6:41 am UTC
- Forum: Fictional Science
- Topic: In scientific's definition, in a fantasy world would a beastman or an elf be considered the same species?
- Replies:
**24** - Views:
**5287**

### Re: In scientific's definition, in a fantasy world would a beastman or an elf be considered the same species?

(But, actually, the concept of Ring Species confuses things, too.) That article says "The textbook examples of ring species, including the circumpolar herring gull complex, the greenish warbler of Asia, and the Ensatina salamanders of America, have all been challenged, so ring species are at b...

- Mon May 01, 2017 8:29 pm UTC
- Forum: Mathematics
- Topic: Halting Problem
- Replies:
**208** - Views:
**17867**

### Re: Halting Problem

main(input: file) { if willHalt(program: file, data: file) { while true {} // infinite loop }} This program takes an input file, called “file”. Then it calls the “willHalt” program. The “willHalt” program takes two parameters which are both files. One is a program and one is a data fil...

- Sun Apr 23, 2017 12:59 am UTC
- Forum: Science
- Topic: Lay question about entropy
- Replies:
**29** - Views:
**4430**

### Re: Lay question about entropy

I think they meant something like (and I'm going to say this very poorly) that even if the "time progressing" function is a bijection, that if some macrostates have more possible microstates than others, that the output of the function will be a microstate of a macrostate with more possibl...

- Fri Apr 21, 2017 9:43 am UTC
- Forum: Science
- Topic: Why do humans see themselves as different from animals?
- Replies:
**35** - Views:
**6331**

### Re: Why do humans see themselves as different from animals?

Humans ask why humans see themselves as different from animals. "It is customary to insist that man resembles the other creatures. Yes; and that very resemblance he alone can see. The fish does not trace the fishbone pattern in the fowls of the air, or the elephant and the EMU compare skeletons...

- Sun Mar 19, 2017 5:11 am UTC
- Forum: Computer Science
- Topic: A Category of problems
- Replies:
**1** - Views:
**2105**

### Re: A Category of problems

Alright, so apparently ~217 people have viewed this, but none have decided to respond. I am not sure if this is because what I said was uninteresting, or because it was unclear. I don't know which one to hope for. __ A reduction of a problem to the empty problem would be a solution to the problem. I...

### Re: Free Will

Err, Wouldn't the standard response to that be that the soul is what we are referring to as "Fred" when we say that "Fred has/doesn't-have 'free will' " ? Then we just examine the soul's mechanism. It's funny how susceptible the soul's decisionmaking process is to the external w...

- Fri Mar 17, 2017 4:10 am UTC
- Forum: Science
- Topic: Science-based what-if questions
- Replies:
**530** - Views:
**49806**

### Re: Planet's spin

in 4d space I think there can be 2 axes of rotation which are at independant speeds. Idk how many dimensions you need for 3 axis. I'm guessing 6 spatial dimensions? The idea of an axis of rotation only works in 3D space. That's because if things are moving round in a circle in 2 of the dimensions, ...

### Re: Free Will

If this putative soul were "outside" (not part of) the entity, then the soul would be a puppetmaster, and Fred would just be dancing to his soul's strings. Fred himself wouldn't have free will. Err, Wouldn't the standard response to that be that the soul is what we are referring to as &qu...

- Thu Mar 16, 2017 8:56 am UTC
- Forum: Science
- Topic: Science-based what-if questions
- Replies:
**530** - Views:
**49806**

### Re: Planet's spin

in 4d space I think there can be 2 axes of rotation which are at independant speeds.

Idk how many dimensions you need for 3 axis. I'm guessing 6 spatial dimensions?

Idk how many dimensions you need for 3 axis. I'm guessing 6 spatial dimensions?

- Wed Mar 15, 2017 12:54 am UTC
- Forum: Computer Science
- Topic: A Category of problems
- Replies:
**1** - Views:
**2105**

### A Category of problems

I'm not sure if this goes here or in the fleeting thoughts section, or maybe even in the math subforum, but this is my best guess. As always, I expect that this is either not useful, or is already known about, or a more useful version is already known, but I don't know where to find it. I'm not sure...

### Re: Free Will

So, is it just me not understanding, or does many worlds seem rather like modal realism?

- Wed Mar 08, 2017 7:02 am UTC
- Forum: Science
- Topic: What is the Biggest Non-Repeating Molecule?
- Replies:
**39** - Views:
**7160**

### Re: What is the Biggest Non-Repeating Molecule?

[Edit: I am writing this in order] To try to get at the idea of "repeating" which is [edit: maybe] meant, I get the impression that they don't want the molecule to be a chain of "blocks" where each "block" is from some structured family. (By a "block" I mean s...

- Fri Jan 06, 2017 11:10 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1782: "Team Chat"
- Replies:
**84** - Views:
**11940**

### Re: 1782: "Team Chat"

That'd mean limiting the total feature set to whatever you included in your federated standard. There's no incentive to do that, and no compelling incentive for a user to prefer your service on the basis of your choice to do so. Then, of course, your universal standard is still only as universal as...

- Fri Jan 06, 2017 8:17 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1782: "Team Chat"
- Replies:
**84** - Views:
**11940**

### Re: 1782: "Team Chat"

Aren't Skype and Slack proprietary though? This seems to be acting like switching to them is progress in some way, but I don't see what would be better about skype or slack? Is it the voice chat, or sub-topics or something? They have a bunch of nice features that IRC doesn't provide out of the box....

- Fri Jan 06, 2017 6:54 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1779: "2017"
- Replies:
**71** - Views:
**9894**

### Re: 1779: "2017"

Oh! See these "frozen peaches" and "wet knees", As we all drink down those sweet <outgroup> tears. What truths can be found from barbs such as these? No comedy will calm these restless fears! _____ But the important thing is I've found a way to feel superior to both of them.

- Fri Jan 06, 2017 5:27 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1782: "Team Chat"
- Replies:
**84** - Views:
**11940**

### Re: 1782: "Team Chat"

Aren't Skype and Slack proprietary though?

This seems to be acting like switching to them is progress in some way, but I don't see what would be better about skype or slack?

Is it the voice chat, or sub-topics or something?

This seems to be acting like switching to them is progress in some way, but I don't see what would be better about skype or slack?

Is it the voice chat, or sub-topics or something?

- Fri Dec 09, 2016 11:15 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1770: "UI Change"
- Replies:
**56** - Views:
**11280**

### Re: 1770: "UI Change"

Or he does and doesn't care, because the actual point of the comic is to be smug toward people who don't like UI changes. Yes, curse that smug Randall, reminding us all that we're growing old while he stays young and beautiful forever thanks to his Elven heritage You're very bad at understanding th...

- Wed Nov 30, 2016 11:44 pm UTC
- Forum: Mathematics
- Topic: Misunderstanding basic math concepts, help please?
- Replies:
**338** - Views:
**58527**

### Re: Misunderstanding basic math concepts, help please?

When people are saying that nonwellfounded sets don't exist, they mean that they don't exist in ZFC, right? I don't think Aczel's anti-foundation axiom has been shown to cause a contradiction or anything like that. I'm somewhat fond of mathematical platonism, and I personally find non-well-founded s...

- Tue Nov 22, 2016 10:45 pm UTC
- Forum: Science
- Topic: Quantum Mechanics over Finite Fields?
- Replies:
**3** - Views:
**2021**

### Re: Quantum Mechanics over Finite Fields?

I know there are some books on this. Or at least, I know there are one book on this. And this is a thing: https://en.wikipedia.org/wiki/P-adic_quantum_mechanics Oh! Thank you! I had briefly looked at that page, but didn't read it in depth, and didn't notice it had a section on finite fields. I've n...

- Tue Nov 22, 2016 8:46 am UTC
- Forum: Science
- Topic: Quantum Mechanics over Finite Fields?
- Replies:
**3** - Views:
**2021**

### Quantum Mechanics over Finite Fields?

Sorry if this isn't a good place to put this. This thread is about me wondering how much it would make sense to try to do quantum mechanics type calculations except over finite fields instead of the field C . I am under the impression that the Bekenstein Bound (and related things) suggest that the n...

- Mon Jul 18, 2016 6:41 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1708: "Dehydration"
- Replies:
**109** - Views:
**12234**

### Re: 1708: "Dehydration"

You are evil, and wrong. [Citation Needed] Evil and Wrong are independent sets, the statement was an intersection of the two self-evident examples (harmful manipulative doubt is equivalent with evil, "Actually, this is by far the most common bit of pop hydration advice you will get from friend...

- Fri Jun 10, 2016 7:17 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1692: "Man Page"
- Replies:
**51** - Views:
**9474**

### Re: 1692: "Man Page"

ahaha its the page on true bugs.

- Mon May 23, 2016 4:00 pm UTC
- Forum: Computer Science
- Topic: Fleeting Thoughts (CS Edition)
- Replies:
**99** - Views:
**60797**

### Re: Fleeting Thoughts (CS Edition)

Since then, a machine with, 1920 states has been found which also cannot be shown to never halt under zfc (but which can be shown to never halt under zfc+"zfc is consistent"). Also, wrt the large cardinal thing: As I understand it, ZFC + large cardinal is the thing that they used to show t...

- Wed Apr 13, 2016 4:25 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 1667: "Algorithms"
- Replies:
**49** - Views:
**9034**

### Re: 1667: "Algorithms"

My primary intent was to have an instant riposte whenever some dope says "I can do [this weird thing] in Excel." I boot up Pong and say "You can but that doesn't mean you should." That's obviously something you definitely should have made, then, to prove that there's such things...