Search found 3636 matches

by PM 2Ring
Tue Aug 07, 2018 1:29 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2028: "Complex Numbers"
Replies: 48
Views: 3536

Re: 2028: "Complex Numbers"

Mathematicians used negative numbers for a long while, but they weren't considered to be proper numbers. They were just a bookkeeping trick that simplified calculation and algebra. But that's what numbers are . The lot of them! Jose Well, sure. But that's a fairly modern notion, and it took a lot o...
by PM 2Ring
Tue Aug 07, 2018 1:12 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2028: "Complex Numbers"
Replies: 48
Views: 3536

Re: 2028: "Complex Numbers"

Of course, another is the idea of negative numbers. Once you have negative numbers, complex numbers are a fairly small step... Oddly enough, the historical order was the opposite of that. Mathematicians used negative numbers for a long while, but they weren't considered to be proper numbers. They w...
by PM 2Ring
Fri Jul 20, 2018 10:53 pm UTC
Forum: General
Topic: Thoughts for ships
Replies: 90010
Views: 7787907

Re: Thoughts for ships

Not dumb. Saturn does have that photoshop look to it. I've seen lots of photos of Saturn, and saw it through a cheap telescope when I was a kid, but the first time I saw Saturn through a good scope I was blown away. Modern computer enhanced imaging techniques are great, and allow us to see high qual...
by PM 2Ring
Sat Jul 14, 2018 5:10 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2019: "An Apple for a Dollar"
Replies: 80
Views: 5647

Re: 2019: "An Apple for a Dollar"

When I was there in 2002-3, Australia had abandoned anything smaller than 5c - prices were still in any integer number of cents, but, at point of sale, if paying cash, the customer got to keep the odd cents (or the shop gave a few extra cents in change) to get to a multiple of 5c. I've heard someth...
by PM 2Ring
Sun Jul 08, 2018 2:31 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2013: "Rock"
Replies: 42
Views: 4291

Re: 2013: "Rock"

Soupspoon wrote:Everything was Created on Tuesday. Even this comic, and our memories of previously having read it…

Splitter. It was last Thursday.
by PM 2Ring
Mon Jun 25, 2018 9:42 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2009: "Hertzsprung-Russell Diagram"
Replies: 35
Views: 3693

Re: 2009: "Hertzsprung-Russell Diagram"

Surely an LED bulb has a lower effective temperature than a normal (incandescent) light bulb. They have about the same surface area, but an LED bulb emits less total EM radiation. LEDs only look "hot" because their spectrum is so different to that of a black body. It seems strange to me t...
by PM 2Ring
Mon Jun 18, 2018 12:25 pm UTC
Forum: Language/Linguistics
Topic: "Cactus plant"
Replies: 20
Views: 3051

Re: "Cactus plant"

I associate "cactus plants" with the song A Fine Romance composed by Jerome Kern with lyrics by Dorothy Fields, published in 1936. The song came from the popular Fred Astaire, Ginger Rogers movie Swing Time . A fine romance, my good woman My strong, aged-in-the-wood woman You never give th...
by PM 2Ring
Mon Jun 18, 2018 11:45 am UTC
Forum: General
Topic: Questions For The World
Replies: 2216
Views: 405282

Re: Questions For The World

Not to be confused with hyphae.
by PM 2Ring
Thu Jun 14, 2018 5:21 am UTC
Forum: News & Articles
Topic: In other news... (humorous news items)
Replies: 14779
Views: 2284582

Re: In other news... (humorous news items)

FWIW, a previous discussion on solar roads is here: viewtopic.php?f=7&t=123914
by PM 2Ring
Wed Jun 13, 2018 11:03 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2005: "Attention Span"
Replies: 78
Views: 6572

Re: 2005: "Attention Span"

I never encounter that "the reason being is" construction, and I really don't see why anyone would use it when they could just leave the "is" out and have something grammatically correct and shorter. E.g. "Unlike most people around here, Alice goes shopping every single day...
by PM 2Ring
Mon Jun 11, 2018 4:43 am UTC
Forum: Serious Business
Topic: Philosophy and science of gender and sex
Replies: 118
Views: 8030

Re: Philosophy and science of gender and sex

But none of that is enabled by definitions. We don't really need a precise definition of any subgroup to act appropriately towards someone we know. Well, sure. But clear agreed-upon definitions are useful if you're trying to have a technical discussion. Or if you just want to articulate your positi...
by PM 2Ring
Mon Jun 11, 2018 4:29 am UTC
Forum: Serious Business
Topic: Philosophy and science of gender and sex
Replies: 118
Views: 8030

Re: Philosophy and science of gender and sex

John Varley has several stories wherein bodies are adjustable. In one of the female protagonist first becomes male and then makes other changes. The collection is The Persistance of Vision, but I can’t remember the story title itself. The title of that particular story is Options . Several of Varle...
by PM 2Ring
Sat Jun 02, 2018 9:38 am UTC
Forum: Language/Linguistics
Topic: Language fleeting thoughts
Replies: 106
Views: 23087

Re: Language fleeting thoughts

"run through", as in "I'll run through the list", but also that thing with a sword.

Does "run by" fit the pattern?
by PM 2Ring
Sat Jun 02, 2018 6:57 am UTC
Forum: Language/Linguistics
Topic: Language fleeting thoughts
Replies: 106
Views: 23087

Re: Language fleeting thoughts

"pick down" is gibberish to me, but you could add "pick out" and "pick off". IIRC, English picked up this verb + preposition construction from the Vikings. Here's some support for that assertion Old English generally did not possess phrasal verbs as they are found in Pr...
by PM 2Ring
Sun May 06, 2018 8:10 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1989: "IMHO"
Replies: 111
Views: 12901

Re: 1989: "IMHO"

Ah yes, Jaffics Interchange Format. Giraffe-ics Interchange Format? Giraffics Interchange Format https://i.imgur.com/nCTjG87.gif Exactly. I've also heard of people pronounce JPEG as, "jay-peg," like Joint Potographic Experts Group. I thought it was Joyful Pornographic Entertainment Graphi...
by PM 2Ring
Sat Mar 31, 2018 7:40 pm UTC
Forum: General
Topic: Lucky Ten Thousand (TIL)
Replies: 13405
Views: 1477099

Re: Lucky Ten Thousand (TIL)

FWIW I'm looking for something like how a person with good attention is attentive, a person with good focus is focused, a person with good dedication is dedicated, a person with good memory is... memor... able? no... iful? that's not a word... what? How about memorious? https://en.wikipedia.org/wik...
by PM 2Ring
Sat Mar 17, 2018 4:38 am UTC
Forum: Science
Topic: Quantum Question
Replies: 110
Views: 14005

Re: Quantum Question

I read an article that suggested that quantum entanglement could be explained without spooky action if causality breaks down at the quantum level - i.e. a particle sends a message back in time to its twin about how it should spin, etc. If true, IYHO would this qualify as a major revision of QM or j...
by PM 2Ring
Tue Jan 02, 2018 10:41 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1935: "2018"
Replies: 66
Views: 7739

Re: 1935: "2018"

The mean tropical year is measured at 365.24219 days, but is gradually getting smaller because the slowing of the earth's rotation is making the days longer. This means that in the long-run my system would be more accurate than either of those proposals. In discussions like this one the mean Gregor...
by PM 2Ring
Thu Nov 30, 2017 8:49 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1918: "NEXUS"
Replies: 25
Views: 4274

Re: 1918: "NEXUS"

aaronb1138 wrote:Need to find some way of getting the alt-text in the printout.

The mobile view at m.xkcd.com can display the alt text.
by PM 2Ring
Thu Oct 26, 2017 8:29 pm UTC
Forum: Mathematics
Topic: What is a Euclidean Number
Replies: 13
Views: 3758

Re: What is a Euclidean Number

They forgot to mention that the number of repetitions is supposed to be finite. Of course there are infinite sequences whose limit is a constructible number, but in general that's not the case. If you permit infinite sequences then any real number can be constructed. I was going to say something abo...
by PM 2Ring
Wed Sep 27, 2017 12:39 pm UTC
Forum: Mathematics
Topic: Possible "Spot it!"-like decks
Replies: 30
Views: 7010

Re: Possible "Spot it!"-like decks

I've been following this thread since it started but I apologize that I'm a bit late in posting to it; I got caught up learning about finite projective geometry . ;) As Soupspoon noted, it's easy enough to solve the cases with R=2. And as mentioned on Stack Exchange, we can use finite fields to qui...
by PM 2Ring
Fri Aug 25, 2017 5:12 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0936: "Password Strength"
Replies: 893
Views: 284822

Re: 0936: "Password Strength"

@morris But why do you want to eliminate doubled letters? All else being equal, the total number of passwords when doubles are allowed is larger than the total number of passwords with doubles banned. So eliminating doubles makes password generation more complex and makes it easier to crack the pass...
by PM 2Ring
Fri Aug 25, 2017 5:00 pm UTC
Forum: Science
Topic: American solar eclipse
Replies: 44
Views: 5733

Re: American solar eclipse

Shadows under trees look strange during an eclipse. All the little gaps in the foliage act like pinhole cameras, and normally they project circular images of the Sun, creating the familiar dappling. But during an eclipse that dappling pattern is modified because the Sun images become crescents. You ...
by PM 2Ring
Thu Jun 01, 2017 1:17 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1843: "Opening Crawl"
Replies: 19
Views: 4486

Re: 1843: "Opening Crawl"

Seriously, though, I probably gave you one of the big two reasons for me to still use it, i.e. "telnet http://www.dodgyserver.cz 80", or 8080 or 8000 or..., then something like "GET /shared/docs/banknamelogin.html HTTP/1.1 <enter><enter>" (then again with a HOST: line, etc), to ...
by PM 2Ring
Wed May 31, 2017 10:35 am UTC
Forum: Mathematics
Topic: Interesting question regarding Fermat nested radicals
Replies: 9
Views: 3092

Re: Interesting question regarding Fermat nested radicals

I've done some more work on estimating the tail term of the transformed nested radical. To estimate the tail of the i'th term we can use https://i.stack.imgur.com/xbAw6.png Here are the a j 0: phi, 1: -2 + 2 * phi, 2: 14 - 8 * phi, 3: -72 + 44 * phi, 4: 410 - 250 * phi, 5: -4340 + 2680 * phi, 6: 447...
by PM 2Ring
Fri May 26, 2017 1:02 pm UTC
Forum: General
Topic: [SAFESPACE] LGBTIQQA Thread - Queer Support!
Replies: 8230
Views: 1267809

Re: [SAFESPACE] LGBTIQQA Thread - Queer Support!

Right on. So my read of the situation is that gender queer people are neutral in terms of gender. Neither male nor female. Or do you (general "you") choose a gender you like more that day and go with that? Sounds like the possibly related term gender fluid. I might be in the T spectrum of...
by PM 2Ring
Fri May 26, 2017 11:35 am UTC
Forum: Mathematics
Topic: Interesting question regarding Fermat nested radicals
Replies: 9
Views: 3092

Re: Interesting question regarding Fermat nested radicals

here's the corresponding OEIS page and it provides a an alternate equivalent formula which looks much easier to work with and also a efficient algorithm https://oeis.org/A273580 and a lookup in https://isc.carma.newcastle.edu.au/advancedCalc gives no results ;( Nice! I like that transformation. In ...
by PM 2Ring
Wed May 24, 2017 1:33 pm UTC
Forum: Mathematics
Topic: Interesting question regarding Fermat nested radicals
Replies: 9
Views: 3092

Re: Interesting question regarding Fermat nested radicals

My guess is that it converges, or if it diverges it does so extremely slowly. ;)

A brute-force calculation (using mpmath) of 500 terms with 1000 decimal digits of precision yields

3.398589439226157032953566735957045
by PM 2Ring
Mon May 22, 2017 9:58 am UTC
Forum: Coding
Topic: var == 'value' vs 'value' == var
Replies: 20
Views: 8595

Re: var == 'value' vs 'value' == var

by PM 2Ring
Sat May 20, 2017 8:38 am UTC
Forum: Science
Topic: Bad science jokes!
Replies: 100
Views: 33143

Re: Bad science jokes!

Here's one for the chemists, and physicists interested in atomic orbitals.

Q: Where do you find 2d electrons?
Spoiler:
A: In flat batteries.
by PM 2Ring
Sat May 20, 2017 8:30 am UTC
Forum: Coding
Topic: Basic Question Involving Functions (Python)
Replies: 18
Views: 7271

Re: Basic Question Involving Functions (Python)

I'm trying to learn a programming language, and after some research decided to explore Python. Given the conceptual difficulties that you've had in your Mathematics threads http://forums.xkcd.com/viewtopic.php?f=17&t=122713 and http://forums.xkcd.com/viewtopic.php?f=17&t=122712 I really don...
by PM 2Ring
Mon May 08, 2017 4:51 pm UTC
Forum: Coding
Topic: Basic Question Involving Functions (Python)
Replies: 18
Views: 7271

Re: Basic Question Involving Functions (Python)

I'm trying to learn a programming language, and after some research decided to explore Python. Given the conceptual difficulties that you've had in your Mathematics threads http://forums.xkcd.com/viewtopic.php?f=17&t=122713 and http://forums.xkcd.com/viewtopic.php?f=17&t=122712 I really don...
by PM 2Ring
Sun May 07, 2017 10:05 am UTC
Forum: Mathematics
Topic: Halting Problem
Replies: 208
Views: 30595

Re: Halting Problem

Can someone help me figure out what happens next? Does Oracle itself get stuck in an infinite loop, or does Devious actually get to the do-the-opposite stage with respect to Oracle? Oracle does NOT run Devious, it analyzes it to see how it would behave if passed the given data, which just happens t...
by PM 2Ring
Fri Apr 14, 2017 4:52 pm UTC
Forum: Site/Forum issues
Topic: Incorrect encoding on JSONP API
Replies: 5
Views: 7031

Re: Incorrect encoding on JSONP API

It's still there. In https://xkcd.com/1824/info.0.json we have

Code: Select all

alt": "Be careful—it's breeding season, and some of these can be *extremely* defensive of their nests.",


BTW, this bug was mentioned on Stack Overflow Meta.
by PM 2Ring
Tue Apr 11, 2017 9:22 am UTC
Forum: Coding
Topic: Getting the most recent comic
Replies: 24
Views: 86131

Re: Getting the most recent comic

FWIW, I just posted a Python 2/3 script in the General thread Date for a comic? which fetches the JSON of a comic and prints its title and publication date.
by PM 2Ring
Tue Apr 11, 2017 9:14 am UTC
Forum: General
Topic: Date for a comic?
Replies: 3
Views: 4463

Re: Date for a comic?

You can get the date of a comic from the JSON feed. For that comic, the JSON is at http://xkcd.com/1425/info.0.json . Your browser may have an extension that formats JSON data nicely. Or if you have Python and you aren't afraid to use the command line, you can use the following script to fetch the J...
by PM 2Ring
Mon Apr 03, 2017 4:13 pm UTC
Forum: General
Topic: Lucky Ten Thousand (TIL)
Replies: 13405
Views: 1477099

Re: Lucky Ten Thousand (TIL)

WibblyWobbly wrote:Sorry, don't mean to harp on typos, but this one might cause confusion - it's "Verlet", isn't it?

Oops! Thanks for that!
by PM 2Ring
Mon Apr 03, 2017 12:47 pm UTC
Forum: General
Topic: Lucky Ten Thousand (TIL)
Replies: 13405
Views: 1477099

Re: Lucky Ten Thousand (TIL)

[edit]good news everyone, with RK4 implemented it is wonderfully stable. Even if I drop the plane from 1km, it just sinks through the ground (the spring really is more like a rubber sheet at 1m height and the ground is just a hologram) and comes back up.[/edit] Yay! You might also like to take a lo...
by PM 2Ring
Thu Mar 30, 2017 5:40 pm UTC
Forum: Science
Topic: The Reverse of how colors work: how would it look?
Replies: 6
Views: 3068

Re: The Reverse of how colors work: how would it look?

Here are a pair of images that approximately illustrate what you're asking about. The colours of one image are the RGB complement of the other image, so the hues of corresponding pixels are 180 degrees out of phase, but they have the same saturation and value (brightness). Well, sort of :) for the r...
by PM 2Ring
Wed Mar 22, 2017 5:16 am UTC
Forum: General
Topic: Whetstones and Sharp Knives
Replies: 12
Views: 4022

Re: Whetstones and Sharp Knives

You may find this recent Cooking Stack Exchange question of interest: Do magnets dull knives?

Go to advanced search