Search found 3644 matches

by PM 2Ring
Sat Sep 15, 2018 2:35 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2046: "Trum-"
Replies: 38
Views: 2914

Re: 2046: "Trum-"

I'm waiting for The Trump Show, starring Drew Carey. Or Mariah.
by PM 2Ring
Mon Sep 10, 2018 3:52 am UTC
Forum: Science
Topic: Laser recoil, relativistic momentum and whether mass counts
Replies: 4
Views: 621

Re: Laser recoil, relativistic momentum and whether mass counts

Right, then. Momentum does not, in fact, equal mass times velocity. Wow. Thank you, chenille. Exactly. p = mv is just a Newtonian approximation. OTOH, momentum is velocity times relativistic mass, but in modern treatments of SR relativistic mass is a deprecated concept because it can be misleading,...
by PM 2Ring
Mon Sep 10, 2018 3:40 am UTC
Forum: Science
Topic: Half full or half empty?
Replies: 41
Views: 1947

Re: Half full or half empty?

But for a given volume/radius of black hole, you cannot add anything more without it becoming greater in volume/radius, so in that sense any size black hole is “full”. Sure, but that's just talking about the event horizon, which is a mathematical surface, it's not a physical object. Inside the EH, ...
by PM 2Ring
Sat Sep 08, 2018 3:31 am UTC
Forum: Computer Science
Topic: a neat picture based on recursive number
Replies: 10
Views: 1646

Re: a neat picture based on recursive number

Also see Dyck words . In the theory of formal languages of computer science, mathematics, and linguistics, a Dyck word is a balanced string of square brackets [ and ]. The set of Dyck words forms Dyck language. Dyck words and language are named after the mathematician Walther von Dyck. They have app...
by PM 2Ring
Tue Sep 04, 2018 8:28 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2040: Sibling-in-law
Replies: 52
Views: 4475

Re: 2040: Sibling-in-law

Wikipedia says The Serbo-Croatian standard languages (Croatian, Serbian, Montenegrin and Bosnian) have one of the more elaborate kinship(srodstvo) systems among European languages. [...] There are four main types of kinship in the family: biological aka blood kinship, kinship by law (in-laws), spir...
by PM 2Ring
Thu Aug 30, 2018 1:07 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2038: "Hazard Symbol"
Replies: 39
Views: 3422

Re: 2038: "Hazard Symbol"

For extra fun, make the chlorine trifluoride using 36 Cl, which is a beta emitter with a half-life of around 300,000 years, and a maximum decay energy around 709 keV. I guess you could just get some regular ClF 3 and put it inside a fission reactor to irradiate it with neutrons, but the reactor peop...
by PM 2Ring
Mon Aug 20, 2018 12:35 pm UTC
Forum: Mathematics
Topic: Cross-continuousness in higher dimensions,
Replies: 4
Views: 560

Re: Cross-continuousness in higher dimensions,

Did someone say rhombic dodecahedron? I'm rather fond of those, as you might be able to tell from my avatar. :) The spoilered image shows the relationship between the cube, octahedron and rhombic dodecahedron (ray-traced using POV-ray). http://i2.photobucket.com/albums/y43/PM2Ring/RhombicH3S.jpg As ...
by PM 2Ring
Sun Aug 19, 2018 5:50 am UTC
Forum: Science
Topic: Gravitation 'Beach'
Replies: 11
Views: 1022

Re: Gravitation 'Beach'

Could gravitational waves not be slowed by passing through masses interacting with them, much like light itself can be slowed moving through a medium? A "gravitation beach" would then be some kind of ginormous wall of mass, somehow? I don't think so, because matter is essentially transpar...
by PM 2Ring
Tue Aug 07, 2018 1:29 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2028: "Complex Numbers"
Replies: 48
Views: 5297

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: 5297

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: 90035
Views: 7947990

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: 6539

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: 4969

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: 4843

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: 3534

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: 409862

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: 14876
Views: 2326175

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: 7377

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: 10032

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: 10032

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: 134
Views: 26071

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: 134
Views: 26071

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: 14437

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: 1502488

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: 15562

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: 8032

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: 4487

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: 3981

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: 7250

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: 287213

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: 5981

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: 4592

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: 3222

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: 8231
Views: 1286068

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: 3222

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: 3222

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: 9077

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: 33525

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: 7630

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: 7630

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...

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