explain xkcd - User contributions [en]

Talk:2962: President Venn Diagram

2024-07-25T23:06:55Z

ProfDigory: Added reply to comment.

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Another really timely comic. Biden just dropped out of the race and endorsed Harris yesterday. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 01:58, 23 July 2024 (UTC)

Forget Biden, Hillary and Obama. This is the endorsement that counts. [[Special:Contributions/172.68.23.199|172.68.23.199]] 01:58, 23 July 2024 (UTC)

I suppose no one is allowed to say that the upper right circle is mislabeled. It was supposed to say incompetent, dishonest and despicable. [[Special:Contributions/162.158.90.25|162.158.90.25]] 02:07, 23 July 2024 (UTC)
:You're allowed to say it, but then we're allowed to suggest (with rather more emperical proof) that her presumptive opponent better fits your rewording. How about we all just don't try to re-run the old arguments (or pre-run the upcoming election) in that sort of tone, eh?
:(To be clear, Randall has made positive comments to his favoured candidate, rather than stooping to arbitrarily attacking their opponent. If you can't at least be as positive in your own convictions then it's really not going to help your cause.) [[Special:Contributions/172.69.195.6|172.69.195.6]] 04:10, 23 July 2024 (UTC)
::First, Harris has more than one opponent, not just within her own party, but in the general election to follow if she’s nominated. Second, the many good qualities of my favo[u]red candidate are irrelevant to this comic, so I didn’t mention ''her''. Third, I didn’t start this political discussion; Randall did, by making a refutable claim in his comic. Lastly, there’s nothing arbitrary about a resident of California pointing out [https://truthout.org/articles/kamala-harris-has-a-distinguished-career-of-serving-injustice/ facts about the former attorney general of California] that people in other states, such as Massachusetts, might be completely ignorant of. [[Special:Contributions/162.158.186.253|162.158.186.253]] 05:45, 23 July 2024 (UTC)
:::Ugh, those abuses from the supposed party of police accountability. Politics in this country are so performative. [[Special:Contributions/108.162.216.75|108.162.216.75]] 13:58, 25 July 2024 (UTC)
: You could say it, but then the box which says 'Kamala Harris' is mislabeled and 'Donald Trump' should be placed in the box above the middle one. [[User:Jaap-Jan|Jaap-Jan]] ([[User talk:Jaap-Jan|talk]]) 07:19, 23 July 2024 (UTC)
::Also by saying the first circle is mislabeled you also say Randall is all those things. And if you feel that way, then remember you are free to NOT read his comics... I'm always on Randall's side in politics it seems, but I'm from another country, so I wont vote for any presidential candidates even if Randall was on the ballot ;-) I won't say more here now... --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 13:22, 24 July 2024 (UTC)
:::Note the difference between “upper right” and “upper left.” [[Special:Contributions/172.70.207.198|172.70.207.198]] 21:11, 24 July 2024 (UTC)

Well Kamala, you had a good run. Randall has the touch of death when it comes to picking political candidates. [[Special:Contributions/162.158.154.39|162.158.154.39]] 03:02, 23 July 2024 (UTC)
:You mean that no candidate endorsed by XKCD has ever won? ;) https://xkcd.com/2383/ [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 04:35, 23 July 2024 (UTC)
:Randall was smart enough to not make a comic endorsing Joe *before* he got elected like he did with Hilldawg and (now) Kamala.[[Special:Contributions/162.158.154.31|162.158.154.31]] 11:36, 23 July 2024 (UTC)
: Not so; Randall endorsed [https://blog.xkcd.com/2008/01/28/obama/ Obama in 2008]. [[User:-insert valid name here-|-insert valid name here-]] ([[User talk:-insert valid name here-|talk]]) 15:09, 23 July 2024 (UTC)
:Maybe Randall secretly wants Kamala to lose and is doing 5D chess. [[Special:Contributions/172.69.130.122|172.69.130.122]] 16:04, 24 July 2024 (UTC)

Randall angling for VP? [[User:Alcatraz ii|Alcatraz ii]] ([[User talk:Alcatraz ii|talk]]) 02:59, 23 July 2024 (UTC)

I think Randall would be good president. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 03:52, 23 July 2024 (UTC)
:Meh, he seems to at least not be good at public speaking. And from what he says about himself, he would be distracted way too easily. [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 04:35, 23 July 2024 (UTC)
:I, as an Epsilon Eridani native, think he would be a spectacular president, but his research priorities would swiftly result in [https://www.space.com/universe-end-false-vacuum-decay false vacuum decay], so please, for the sake of the universe, please do not elect him. [[Special:Contributions/172.70.214.218|172.70.214.218]] 20:55, 24 July 2024 (UTC)

The layout of this Venn diagram reminds me of https://xkcd.com/112/ {{unsigned ip|162.158.166.234|03:04, 23 July 2024}}

I think I would probably swap the two. [[Special:Contributions/162.158.174.23|162.158.174.23]] 04:03, 23 July 2024 (UTC)

I would be very interested in which non-Politicians Randall would put into the top middle section. [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 04:35, 23 July 2024 (UTC)
:People eligible to be president who would make a good president but aren't politicians? I would be much more interested in who he would list in the right middle section, that is, people who would make good presidents and love Venn diagrams, but are ineligible. --[[Special:Contributions/172.69.6.133|172.69.6.133]] 03:42, 24 July 2024 (UTC)

I guess Munroe has no issues with questions about ongoing U.S. backed genocides shrugged off with "shrimp and grits!"? {{unsigned|Markifi|05:39, 23 July 2024}}

What really strikes me is that the USA have a (de facto) 2-Party system and still go so much into personal attacks and endorsements, etc. which in my mind could be the decision-making bit between 2 similiar parties in a multi-party system, or 2 equally sympathic parties to me. But in my mind a 2-party system should at least have the upside of actually discussing policy, and voters deciding based on that... --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 06:30, 23 July 2024 (UTC)

If Randall was in charge he could stop supplying weapons to Israel probably [[Special:Contributions/172.69.195.63|172.69.195.63]] 10:16, 23 July 2024 (UTC)

:Randall sempai- we are targeted too. {{unsigned ip|172.70.131.52|15:37, 23 July 2024}}

Re: the mouseover text: "[[1062:_Budget_News|I am more of a deficit sugar glider]]" ought to be in the running. [[Special:Contributions/172.69.58.157|172.69.58.157]] 12:42, 23 July 2024 (UTC)

personally I'd put most candidates either the top left [[Special:Contributions/172.69.58.24|172.69.58.24]] 17:34, 23 July 2024 (UTC)

Neat. A Euler diagram (and no, Venn cannot just have this one). {{unsigned ip|172.71.158.226|18:18, 23 July 2024}}
:Quite! Venn called his diagrams "{{w|Euler diagram|Euler circles}}." [[Special:Contributions/172.71.151.137|172.71.151.137]] 22:09, 24 July 2024 (UTC)

I think the 'eligible' topic is related to a campaign against Harris saying she isn't eligible because she's not american enough. This (fake) news was reposted in France by french Trump's fans. {{unsigned ip|172.69.225.223|20:36, 23 July 2024}}
No, the topic of Constitutional eligibility, it is more nuanced than each said is represented to state it. Kamala Harris was undisputedly (I believe) born in the US. This makes her a native-born citizen. The Constitution calls for a natural-born citizen but doesn't define that. From writings at the time (I don't remember which) natural-born means born to two citizen parents. Apparently, neither of her parents were US citizens at the time of her birth, so once again (as with Obama, Ted Cruz, others) there are fair questions by thinking people. [[User:ProfDigory|ProfDigory]] ([[User talk:ProfDigory|talk]]) 23:06, 25 July 2024 (UTC)

_sigh_ I was about to come in here and suggest that we don't do the obvious political battle here but then I realized I'd be up all night because someone was WRONG on the internet [[386: Duty Calls]]! [[User:Tomb|Tomb]] ([[User talk:Tomb|talk]]) 21:21, 23 July 2024 (UTC)

I, too, have rather strong political opinions that absolutely nobody here cares about. But I also wanted to extend a heartfelt thank-you to the person who put the cautionary banner to not make the main article into a debate platform. I hope its presence becomes a staple of articles on all forthcoming controversial comics, as we commence our quadrennial plunge into the bubbling muck of American election season. -MeZimm [[Special:Contributions/172.68.34.59|172.68.34.59]] 21:41, 23 July 2024 (UTC)

Would it be a good idea to include a link to the actual United States Constitution in regard to the Presidential eligibility section? In other words, I'm wondering if it would be preferable to link directly to a primary source of information as opposed to a tertiary source like Wikipedia? Either way, I have a [https://constitution.congress.gov/constitution/article-2/#article-2-section-1-clause-5 link to the document on the Congress.gov website] for those who may want to have a read. [[User:OmniDoom|OmniDoom]] ([[User talk:OmniDoom|talk]]) 00:13, 24 July 2024 (UTC)

Does anyone have a longer version of https://www.youtube.com/watch?v=eWR2uTfrh-k&ab_channel=GOPWarRoom ? I want to see the diagram props! [[Special:Contributions/172.71.147.19|172.71.147.19]] 21:08, 24 July 2024 (UTC)
:"So many memes" https://www.youtube.com/watch?app=desktop&v=XOjRsJiBTF0&ab_channel=FoxNews [[Special:Contributions/172.70.214.129|172.70.214.129]] 22:00, 24 July 2024 (UTC)
:I see you are a netizen of exquisite taste. Might I suggest https://www.c-span.org/search/basic/?query=kamala+venn [[Special:Contributions/108.162.245.29|108.162.245.29]] 22:43, 24 July 2024 (UTC)
::Oh my God, infinite anonymous clipping! https://www.c-span.org/video/?c5125621/user-clip-venn-diagram [[Special:Contributions/172.71.150.3|172.71.150.3]] 23:03, 24 July 2024 (UTC)
:::[https://www.c-span.org/video/?c5125622/user-clip-circle-venn-diagram A fourth Eulerian circle emerges!] [[Special:Contributions/162.158.186.5|162.158.186.5]] 23:23, 24 July 2024 (UTC)

It has been decided. As per the [https://x.com/yashar/status/1815476912355205212 edict of the National Republican Senatorial Committee,] the problems with Kamala Harris are: (1) Her laugh is weird. And, (2) she loves Venn diagrams. Let the games begin! We shall [https://www.youtube.com/watch?v=xI_lxFv203I&ab_channel=SaturdayNightLive focus on the two issues Americans do care about: swine flue and fracking.] [[Special:Contributions/172.68.23.200|172.68.23.200]] 22:18, 24 July 2024 (UTC)

This is a really sad comic. Harris is a top cop and a corrupt one. America deserves better than either party is offering, and the supposed party of police accountability should not be running Harris. It's sad that Randall is telling himself otherwise. [[Special:Contributions/172.70.178.91|172.70.178.91]] 13:22, 25 July 2024 (UTC)
:I was not aware that Harris was ever in the police, herself, and cannot find any reference to it in a quick search. I know she advocated police bodycams, which only corrupt cops need to properly fear/avoid using, though obviously one can always be corrupt "in your spare time", or if you're not a uniformed officer/just sat at a desk. Anyway, you have an opinion, and feel free to make your own webcomic if you have better names, wish to add other names and/or want to change the basis upon which Harris's name is judged. It might well be that (of all likely candidates, as well as the unlikely one that is "me") Randall honestly sees Kamala as (one of) the better individual(s) for the role. If everyone agreed, there'd be no need to ask everybody and try to distil the resulting popularity contest into a close-fought result that maybe half the country won't like (but who ''would'' like a result that the other half(ish) of the country wouldn't like), give or take various statistical anomalies. [[Special:Contributions/172.70.85.103|172.70.85.103]] 15:15, 25 July 2024 (UTC)

Talk:287: NP-Complete

2024-07-10T01:07:25Z

ProfDigory: Found another solution

;Unique deciphering requires unique pricetags
Shame this only works in restaurants that price all their appetizers differently. [[User:Davidy22|Davidy22]] ([[User talk:Davidy22|talk]]) 03:18, 13 October 2012 (UTC)
:Not necessarily because the NP-problem allows for any equivocally competing sum certifying how the total can be reached. Shared pricetags as well as a nonpositive would add degrees of freedom and make it impossible to rule out surprise deliveries even through exponential pretesting. Unless the waiter is running into the exponential worst case, the six waiting tables can be attended to immediately upon finding the first feasible combination: [[User:Roman Czyborra|Roman Czyborra]] ([[User talk:Roman Czyborra|talk]]) 15:44, 15 May 2014 (UTC)

;Trivial solution first found
I have a hunch that the seven fruit cups are pretty intentional as the first item on the menu and the simplest solution possible.
I was about to write a script to solve the problem through random selections and was going to optimize for speed by limiting the maximum times an item could be order to floor(15.05/price). Thus, one could order up to 2 sample plates, 3 moz sticks, 5 of the hot wings/side salad/french fries or 7 fruit cups without going over budget. (side note: you can always with these prices squeeze in a fruit cup with the exception of the 7 fruit cups). I found the "trivial" solution on the first step of the "preliminary" work for that script and then took a catnap.
Of course, since the nontrivial solution involves the same item as the trivial solution, one could just pick a number, multiply by that number, subtract one unit, and pick two other items, whose prices were not set yet, and adjust their prices to add up accordingly just to ensure both trivial and nontrivial solutions lest anyone actually write a program to solve the problem through brute force as oppose to through wit. Why seed? Because to not have a nontrivial solution would be so much like Blackhat.
Note to self: try this sometime in the real world using a real menu. [[User:Katya|Katya]] ([[User talk:Katya|talk]]) 02:17, 23 November 2012 (UTC)

;Traveling Salesman Problem
Note: Traveling Salesman Problem ''might'' be mentioned ''also'' because both this problem and the Knapsack problem to be solved belong to set of '''[[wikipedia:NP-complete|NP-complete]] problems'''; a Knapsack problem can be transformed in polynomial time to Traveling Salesman Problem, and solution of Traveling Salesman Problem can be transformed in polynomial time to Knapsack problem solution. --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 16:00, 11 December 2012 (UTC)
:Yes, indeed! I think both meanings are intended to fully get the joke. The <code>TSP:={(n,d,M)∈ℕ×({0…n}²→ℕ)×ℕ|∃c∈{1…n}ⁿ:{1…n}=⋃{cₙ|n∈{1…n}}∧∑{d(cₙ,c₍ₙ₊₁₎)|n∈{0…n}}<M}</code> can both help to timely attend to the six waiting tables and to reduce the <code>ORDERSUM:={(a,b)∈ℕ*×ℕ|∃c∈ℕ*:∑{cₙaₙ|n∈ℕ}=b}</code> problem to. Plus, the "as fast as possible" pun seems to allude to the again six ridiculous inputs any trained human will rearrange to a near-exact solution quicker than they are entered into a computer who can quickly exhaust this tiny search space for an exact solution: [[User:Roman Czyborra|Roman Czyborra]] ([[User talk:Roman Czyborra|talk]]) 15:44, 15 May 2014 (UTC)

;Trivial solution was not intended
In [http://www.maa.org/mathhorizons/MH-Sep2012_XKCD.html an interview] with the Mathematical Association of America Randall said that the trivial answer to this problem was a mistake. [[User:Xrays Knock Charms Down|Xrays Knock Charms Down]] ([[User talk:Xrays Knock Charms Down|talk]]) 03:00, 6 May 2013 (UTC)
:I added this very interesting info to the explanation - at first as a trivia, but then I realized that it would not be seen by everyone - as you often do not read below the transcript. Why would you, you do not need to see what was in the comic again... So I moved it up to the solution part, because to me it is a very important fact about this comic. An error by Randall... But Dgbrt keeps moving this info away from the solution. I have understood now that the trivia should be below the transcript - although I cannot see why this should be so - as I have just described. But who says that this info should be a trivia item? It was I who put it there (by mistake?) at first. I will try not to start an editing fight here, but still think there should at least be a mention in the explanation that it was a mistake - in case you do not realize there is a trivia section below. I have used this page a lot lately, and had not found out before, that it was always below. There is not that many pages with trivia sections [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:02, 10 March 2014 (UTC)
::Cool reference, thanks! [[User:Roman Czyborra|Roman Czyborra]] ([[User talk:Roman Czyborra|talk]]) 15:44, 15 May 2014 (UTC)
:::How could Randall have missed that the '''first price''' was a solution, when drawing the strip? I know not everyone can do this kind of math in their head, but when I read the $15.05 and glanced over at the menu, that $2.15 was an even denominator of $15.05 was immediately apparent. I'm pretty sure that it'd be hard for him to miss, even if he actually has to use arabic notation to figure it out, which would take like three seconds. —[[User:Kazvorpal|Kazvorpal]] ([[User talk:Kazvorpal|talk]]) 16:23, 1 November 2019 (UTC)
::::Okay, reading the interview, all I can say is that this is a pitfall of taking longcut coding shortcuts. Speaking as a perl programmer, it'd take longer to write that algorithm than to quickly do at least the basic multiples of the prices in one's head, even if one has to do it through mental arabic notation (I have mental shortcuts I worked out before learning math notation in grade school, or in some cases simply "see" the answer).—[[User:Kazvorpal|Kazvorpal]] ([[User talk:Kazvorpal|talk]]) 16:28, 1 November 2019 (UTC)

;Complex solution found in a second
I was bored and tried to find a solution for fun. I found the more complex one quite fast by chance. It was actually the second combination I tried. I did not realize you could just add seven fruit cups because I was so set on starting with the sampler plate. Now I am not sure if I should be glad, because I was so lucky, or annoyed that my fight-the-boredom-idea did not work out, or even more annoyed that I never have that kind of luck in the lab where I could really use it for finding the one thing out of a thousand possible causes for "why-does-my-experiment-not-work" which actually will give me some usable data.
[[Special:Contributions/84.56.77.11|84.56.77.11]]

Did I find another solution or am I missing something (besides sleep)? I created a spreadsheet of prices and line totals and found a solution after 3 or 4 tries. Two mixed fruit, one mozarella sticks, and one BBQ sandwich. Once I found that, I realized the trival solution. Then saw in the explanation there are only two solutions but they didn't match mine with BBQ. Correct, no? Of course a general solution would be much more satisfying. [[User:ProfDigory|ProfDigory]] ([[User talk:ProfDigory|talk]]) 01:07, 10 July 2024 (UTC)

;Not the knapsack problem
This explanation is thorough, and I like being thorough, but it seems to be a bit of overkill. I copy-edited it a bit, but I have a couple qualms. This is not really the knapsack problem, as it does not attach values to the items (as mentioned). It is more of a {{w|subset sum}} problem, which admittedly could be considered a variant of the knapsack problem. Secondly, I don't see why we need to go into detail about the movie Office Space. --[[User:Quicksilver|Quicksilver]] ([[User talk:Quicksilver|talk]]) 18:34, 22 August 2013 (UTC)
:I did some clean-ups, but the the "In computational complexity theory" still needs a review.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 20:19, 22 August 2013 (UTC)
::The Wikipedia article on {{w|Karp's 21 NP-complete problems}} hints that Karp originally defined <code>KNAPSACK:={(a,b)∈ℤ*×ℤ|∃c∈𝔹*:∑{cₙaₙ|n∈ℕ}=b}</code> closer to today's shape of <code>SUBSETSUM:={Z⊂ℤ|∃s⊆Z:∑s=0∧s≠∅}</code> than that of the Unbounded Knapsack Problem <code>UKP:={(v,w,V,W)∈ℤ*×ℤ*×ℤ×ℤ|∃c∈ℕ*:{∑{cₙvₙ|n∈ℕ},∑{cₙwₙ|n∈ℕ}}⊆{V…W}}</code> with the former via <code>Z:={b,-a₁…-aₙ,-2a₁…-2aₙ,…}</code> and the latter via <code>(v,w,V,W):=(a,a,b,b)</code> coming close enough to what we really need here, namely <code>ORDERSUM:={(a,b)∈ℕ*×ℕ|∃c∈ℕ*:∑{cₙaₙ|n∈ℕ}=b}</code>. So Randall did hit it bull's eye after all! [[User:Roman Czyborra|Roman Czyborra]] ([[User talk:Roman Czyborra|talk]]) 15:44, 15 May 2014 (UTC)

;NP Food
Inspired by this comic, somebody has actually created an ordering site which tries to give you an order from a restaurant in your area (US only I think) totalling a specific amount [http://www.np-food.com NP Food]. Worth including above? -- [[User:Copito|Copito]] ([[User talk:Copito|talk]]) 20:43, 8 November 2013 (UTC)

That site doesn't work for me. —[[User:TobyBartels|TobyBartels]] ([[User talk:TobyBartels|talk]]) 10:07, 19 November 2013 (UTC)

:I do get more than nothing: a redirect to the HTTPS port whose certificate is signed only to .np-food.com without WWW and whose HTML and PNG and JS suggest that either solutions for San Francisco, Austin, Saint Louis, Miami, and New York menues have been memoized and that you may order by entering your credit card credentials or that only fools wait for a computer to calculate an NP-hard problem on too large a search space. [[User:Roman Czyborra|Roman Czyborra]] ([[User talk:Roman Czyborra|talk]]) 15:44, 15 May 2014 (UTC)

;Exhaustive Solution
[[user:Roman Czyborra|Roman Czyborra]] did post this at the explain:
;The Solution
… can be calculated as
let totaling total menu = if total == 0 then [[]]
else if total < 0 || null menu then []
else totaling total (tail menu) ++ map (
head menu :) (totaling (total - head menu) menu)
in totaling 1505 [215,275,335,355,420,580]
== [[215,355,355,580],[215,215,215,215,215,215,215]]
I don't think this is a helpful explain. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 19:11, 14 May 2014 (UTC)

Yes, I did.
Because I did think it was helpful.
Not just because an (effective if not efficient) general solution earns you a 50% on $15.05 tip.

Moreover to demonstrate that and how a complete search finds those two solutions.

And that the search tree can branch exponentially with each additional menu item.
Or with additional dollar bills to be spent.
Notwithstanding that any constructive proof of NP=P would let us replace this
straightforward bad NP-implementation with an equivalent better P-implementation.
Before Donald Knuth coined the name NP-Complete, the class was suggested to be named
'''PET''' for the (Probably(while NP?P)|(Proven(if NP>P)|Previously(if NP=P))) Exponential Time pet problems.

What is so confusing about the calculation?
The whole cent amounts instead of dollar floats?
My naming of variables?
Should <code>totaling</code> be renamed to <code>solutions</code> or <code>orders</code>?
Or <code>menu</code> to <code>menu_items</code> or <code>appetizers</code> or <code>pricetags</code>?
<code lang=haskell>
type Cents = Int
orders :: [Cents] -> Cents -> [ [Cents] ]
orders menu total =
total == 0 | [ [] ]
menu == [] | []
total < 0 | []
total > 0 | orders (tail menu) total ++ map (
head menu :) orders menu (total - head menu)

orders [215,275,335,355,420,580] 1505
== [[215,355,355,580],[215,215,215,215,215,215,215]]

calls menu total = if null menu || total < 1
then 1 else 1 + calls (tail menu) total +
calls menu (total - head menu)
calls [] 1505
== 1
calls [580] 1505
== 7
calls [420,580] 1505
== 25
calls [355,420,580] 1505
== 73
calls [335,355,420,580] 1505
== 181
calls [275,335,355,420,580] 1505
== 437
calls [215,275,335,355,420,580] 1505
== 1153
</code>
Or is it the committee language Haskell that is causing problems?
What other well-defined language would you formulate a general solution in?

:If anyone wants to implement this in Python: calculate in cents, use fixed-point arithmetic, or check if the absolute difference is under some tolerance, otherwise the 7 mixed fruit solution is missed. <tt>print(7 * 2.15 == 15.05)</tt> gives <tt>False</tt>.

Discussing all of this is helpful.
Leaving a "Thus" result without its afferent reasoning (and its deleted heading) is not, is it?
Cheers: [[User:Roman Czyborra|Roman Czyborra]] ([[User talk:Roman Czyborra|talk]]) 15:44, 15 May 2014 (UTC)

:Please let's keep this code at the discussion page. No common reader would understand; the explain is not only for programmers. I'm a programmer, knowing many languages like BASIC, Pascal, C, C++, Java, Bash, Perl... also HTML, JavaScript... RPG, Databases and SQL... and much more. And if you like to buy an IBM Power 8 I can tell you the proper configuration for your needs.
:But these details are not helpful to explain the comic. There is math that has to be explained. Findings on program codes do even not belong to a trivia section. Nevertheless it seems I have to take a closer look on Haskell, which is not used by many people. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:22, 15 May 2014 (UTC)

A 50% tip on a $ 15.05 order is not possible, is it? --[[Special:Contributions/108.162.231.186|108.162.231.186]] 21:08, 1 November 2014 (UTC)

If I were the waiter my response would, at best, be "I'll come back when you're ready to order". At worse it would probably involve burns. -Pennpenn [[Special:Contributions/108.162.250.162|108.162.250.162]] 04:27, 7 October 2015 (UTC)

---Easiest response: "Excellent, Sir. I'll raise the price of the french fries to $15.05 - [[User:Ruffy314|Ruffy314]] ([[User talk:Ruffy314|talk]]) 18:19, 21 November 2015 (UTC)

If we assume that "general solutions" implies that it's a polynomial-time solution, is a 50% tip $7.55, $500 000, or $500 007.55? [[User:Hppavilion1|Hppavilion1]] ([[User talk:Hppavilion1|talk]]) 02:32, 16 September 2017 (UTC)

;A similar situation in real life
Nobody would do that in real life, right? But look at http://www.numberphile.com/videos/43_nuggets.html . A guy orders 43 chicken nuggets, which come in boxes of 6, 9 and 20. It is also a Knapsack problem in a menu order. But in that case there is no solution.
:I tried solving what you described without of clicking the link (still didn't) and before reading the last sentence, and this one is very obvious and quick to find not solvable. As 43 is abviously not dividable by 3 (as one can see at first glance and which would be required to use only 9-boxes and 6-boxes) we need at least one 20-box. Leaving 23 nuggets. That's still not dividable by 3 so there is another 20-box, leaving us at 3 nuggets. Other approach sees that at first we need a package of 9, to get to an even number, and then 9-boxes can only be choosen in pairs at 18-boxes which is no benefit to 6-boxes, so it is only 6 and 20 left. 34 is not dividable by 3 and/or 6. So again subtracting 20 makes it 14, which is obvious to be unsolvable by using only 6-boxes. So "your" problem is quite more trivial. BTW: please sign your comments. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 10:42, 24 June 2019 (UTC)

TSP is NP-hard, not NP-complete [[User:Tembrel|Tembrel]] ([[User talk:Tembrel|talk]]) 00:19, 14 November 2019 (UTC)

If you guys like the knapsack problem and simplified stuff, then I've got the game mod for you! https://steamcommunity.com/sharedfiles/filedetails/?id=1844662069 along with https://ktane.timwi.de/HTML/Simon%20Selects.html

(I also tried solving this like I would that mod, but then I realized that this problem is not that.) [[Special:Contributions/172.69.34.24|172.69.34.24]] 03:05, 18 July 2020 (UTC)

;On general solutions
The explanation seems to assume that general solutions must be in polynomial time, but the comic does not mention that. It seemed to me that finding a non-polynomial general solution (which exist, obviously, with one even described in the explanation) *still* gets a 50% tip, which also means the 50% tip is a lot more reasonable now. While mentioning that no polynomial GS exists is probably still a good idea, it seems to me that the explanation should not assume one is neccessary for the tip. [[Special:Contributions/172.68.238.109|172.68.238.109]] 00:59, 24 October 2022 (UTC)

2929: Good and Bad Ideas

2024-05-09T00:06:02Z

ProfDigory: Typo

{{comic
| number = 2929
| date = May 6, 2024
| title = Good and Bad Ideas
| image = good_and_bad_ideas_2x.png
| imagesize = 595x522px
| noexpand = true
| titletext = While it seemed like a fun prank at the time, I realize my prank fire extinguishers full of leaded gasoline were a mistake.
}}

==Explanation==
{{incomplete|Created by a BLOOD FOR THE BLOOD GOD- Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This is a scatter plot comparing how good an idea sounds to how good the idea is. For example, leaded gasoline sounded like a good idea due to its anti-knocking effects, but is a bad idea due to lead toxicity. Fake prank fire extinguishers both sound bad and ''are'' bad, as they can make a dangerous situation worse. Putting mold on infections sounds like a bad idea, but some molds, like ones containing penicillin, have helpful antibiotic effects.

The title text combines leaded gasoline and a fake prank fire extinguisher into something worse than either. The fire extinguisher is fake and releases flammable material onto the fire, and there is additional lead toxicity.

===Table of the entries===
{| class="wikitable"
|-
! Idea !! What it means !! How good it sounds !! How good it actually is !! Explanation
|-
|{{w|Leaded gasoline}}||Adding {{w|Tetraethyllead|tetraethyl lead}} as an antiknocking agent to allow for increased performance||++||---||Leaded gasoline was introduced in the early 1920s to allow higher pressures and temperatures in an engine without causing {{w|Engine_knocking|detonation (knocking)}}, allowing for increased fuel efficiency and engine performance; it also works to prevent engine valve wear. In essence, it artificially raises the {{w|octane rating}} of the fuel, reducing the need for fuel refinement, thus reducing waste and/or expense. Lead, however, is both toxic and bioaccumulative, meaning that lead released into the air over decades built up to harmful levels in people (as well as other animals) and almost certainly contributed to a host of health issues. Some scientists even suppose that {{w|Lead–crime hypothesis|crime levels are influenced by lead exposure}}. (It should be noted that this only "[sounded] like a good idea" due to deliberate campaigns to obscure the known dangers).
|-
|{{w|Bloodletting}}||Releasing "bad blood" from the veins||---||---||You need (most of) your blood. Losing [https://www.ncbi.nlm.nih.gov/books/NBK542273/ more than 15%] of a person's total blood volume results in adverse effects. Bloodletting was performed as a medical procedure for at least 2000 years until the 19th century. The idea was to withdraw blood to balance the body's "humors". Despite this long history, the notion that bleeding someone is bad now seems like basic common sense, and it's now well-understood that blood-letting (outside of {{what if|98|certain rare and specific cases}}) does no good, causes significant harm and quite certainly causes many deaths.
|-
|{{w|Asbestos}}||Mineral which does not burn, tolerates extremely high temperatures and forms small fibers. These qualities make it excellent for insulation and fire protection||+++||---||Asbestos was used extensively in ships and buildings throughout most of the 20th century. Unfortunately, the microscopic fibers that make up asbestos greatly increase the risk of {{w|Asbestosis|lung disease}} and cancer when inhaled, causing its use to be banned in most countries.
|-
|Extension cords with prongs on both ends||allows easy connection between 2 female connectors||0 (neutral)||---||Prongs on both ends would make it easier to plug the extension cord in on either side. But once plugged into an outlet, the other end becomes a serious shock hazard, as seen in [https://www.youtube.com/watch?v=L08LjkN1k70 this Backyard Scientist video]. Short circuits (both ends connected to outlets supplying power) would be much more likely, resulting in more sparks, fires, and damage to wiring.
|-
|Stair kayaking||Riding down a flight of stairs in a {{w|kayak}}||--||---|| Stair kayaking is a stunt where a person positions a kayak at the top of a flight of stairs and then, using their paddle to push off, [https://youtu.be/46BjHAxgddU?t=154 rides the kayak down the stairs]. This poses significant easily foreseeable risks of injury or death, as well as being very bad for the kayak, which is designed to ride on {{w|Kayak|water}}, not stairs.{{Citation needed}}
|-
|Fake prank fire extinguishers||Intentionally placing empty or otherwise non-functional {{w|fire extinguisher|fire extinguishers}} as a {{w|practical joke}}.||---||---|| The idea of placing fake fire extinguishers as a prank, presumably so that a person who thinks they are grabbing a real fire extinguisher will instead find a decoy, sounds very dangerous and potentially life-threatening for many people, and it would be highly dangerous. In the United States, (and presumably most countries), this would also be a felony in most, if not all, jurisdictions. An example of a similar situation, although not intended as a prank, can be found [https://twitter.com/ThatSamWinkler/status/1657154071051239424 here].
The title text expands this idea by having the prank fire extinguishers filled with (leaded) gasoline. This is literally adding fuel to the fire.
|-
|Always saying what you think||...regardless of the feelings of others or other considerations||++||--||Openness and honesty are seen as positive character traits in people. However, taking it to the extreme of ''always'' telling people what you think, can lead to awkward, unpleasant or dangerous situations. It may harm your relationship with the other person if they don't like what you think, or they may reply without concern for ''your'' feelings or other considerations. Keeping negative thoughts to yourself or telling "white lies" can be considered a better alternative in some situations. Saying what you think to somebody in power (a boss, soldier, dictator, drunk) can negatively impact your earning potential, health, or freedom. [https://quoteinvestigator.com/2010/05/17/remain-silent/ "Better to remain silent and be thought a fool than to speak and to remove all doubt."]
|-
|Replying to spammers||Clicking on the "Reply" button from {{w|spam email}}s and writing (and sending) a reply (or worse, clicking on the links in these emails)||--||--||At best, you confirm your email address and identify yourself as someone likely to respond to such messages and so encourage the spammers to deluge you with more messages. At worst, the spammer may extract sensitive information about you, make you a victim of a scam, or gain control of your computer.
|-
|{{w|Solar car}}s||Having {{w|Solar panel|solar panels}} on the car's surface (mostly hood and roof) for power generation||+++||-||Powering electric vehicles with solar panels seems like an excellent idea: it would provide power with no increased land use, and theoretically could allow a vehicle to operate indefinitely without being fueled or charged. However, such vehicles would require power storage (due to power requirements, weather conditions, shade from roadside features and nighttime driving), adding significant weight. Adding solar panels to a plug-in or hybrid vehicle would add cost, weight, manufacturing complexity and maintenance requirements. Solar panels on moving cars are less efficient than in stationary installations, where they can be aimed at the sun, and subject to damage from both collisions and road debris; even without these problems, the size of automobiles relative to their power requirements would sharply limit the car's range (unless it was a normal electric vehicle with supplemental solar panels). Solar cars do exist (the {{w|World Solar Challenge}} is a competition for such cars), but as a practical form of transportation, the negatives likely outweigh the positives.
|-
|{{w|Heelys|Heelies}}||Heelys are shoes with an inline skate wheel built in to the sole, at the heel. ||+||-||Heelys allow the wearer (usually children) to shift between normal walking and rolling like being on skates. This sounds like fun but [https://abcnews.go.com/Health/Exercise/story?id=3242181&page=1 has been suggested] to be a potentially significant injury risk.
|-
|{{w|Prequel|Prequels}}||A work of fiction (often a movie) telling the "story before the story" of another work.||+++||-||More of a good story sounds great on the surface, and audiences who are invested in a set of characters and/or a setting often love the idea of finding out what led up to certain events. But there are several pitfalls. Spin-offs of a popular property are often low-quality cash grabs. Prequels, specifically, are constrained by the fact that they have to lead to the story that's already been released, which can lead to contrived storytelling. There's less room for suspense, since the future of the storyline has already been established. There's a tendency to invent or fill in detailed backstories, which can undermine character arcs, and/or destroy the mystery and nuance of certain characters. And, since they tend only to be made where the original is already well-received, regression to the mean tends to mean they are more likely than not to fail to live up to expectations. Prequels can be good, but there are a lot of ways they can go wrong.
|-
|Transitions® lenses||A brand name for {{w|Photochromic_lens|photochromic lenses}} in glasses or contacts, which get darker (like sunglasses) in bright light.||+||-||Photochromic lenses are clear lenses that darken when exposed to UV light, then turn clear again when the UV is removed. The advantage is that wearers of glasses don't need to have separate (prescription) sunglasses or contacts. However, the process is relatively slow (about a minute) so not so useful when there is a quick succession of shade and bright light, as in a forest or when driving. If used in a car, the windscreen filters out UV light to some degree, which prevents the glasses from darkening as required. Finally, the process is temperature dependent, so in hot weather the glasses don't become as dark, and in cold weather they might stay dark for too long.
|-
|Cutting pizza in squares||Cutting (a presumably round) pizza in squares||-||-||Most people cut pizza into wedges and hold it by the crust. Cutting it into squares could allow for more pieces to be shared, if the resulting wedges would be too thin to be practical. However, pieces near the center will have no crust to hold it by, getting cheese and sauce all over your fingers. Cuts around the edge will probably leave smaller leftover scraps which are mostly crust. While hardly a disaster like the other items in its quadrant, square pizza pieces are just not very useful and rather inefficient. Cutting a rectangular pizza into squares might not suffer from the problems above, but, unless the pizza itself is square and cut only into four squares, some people will end up with a higher crust-to-topping ratio than others. Cutting a round pizza into squares is popular in Chicago and is sometimes called tavern-style or party-cut and some<nowiki>[</nowiki>''{{w|Wikipedia:Manual_of_Style/Words_to_watch#Unsupported_attributions|who?}}''<nowiki>]</nowiki> [https://www.bonappetit.com/story/real-chicago-pizza-tavern-style consider it the real Chicago style pizza] [https://destinationeatdrink.com/the-real-chicago-style-pizza-isnt-deep-dish/ rather than deep dish pizza].{{Dubious}}
|-
|{{w|Project Orion (nuclear propulsion)|Project Orion}}||Study by the U.S. government looking into nuclear pulse propulsion for spacecraft.||---||-||Using repeated nuclear explosions to generate motion sounds bad for both the spacecraft and everything else, especially with a ground launch, but there are ways to address a lot of the concerns, so it isn't as bad as it sounds. Project Orion's theorized specific impulse and thrust would also be far higher than anything chemical rockets can accomplish. The efficiency of Project Orion is extremely low, however, and the {{w|ablation}} issues are extremely difficult to overcome.

See also [[2423: Project Orion]].
|-
|{{w|Soup}}||Soup||0 (neutral)||0 (neutral)||Soup is probably one of the oldest foods created by prehistoric cooks. Many people enjoy it, though some consider many soups somewhat lacking as a meal on their own, or boring.
|-
|{{w|Washer-dryer|Combo washer dryers}}||A device that combines a washing machine and laundry dryer||+++||+||Better at space efficiency, but worse at each task than separate devices, and unable to do both tasks in parallel (useful when you have more than one batch of laundry).
|-
|Cutting sandwiches diagonally||Cutting sandwiches made with rectangular sliced bread diagonally||+||+||[https://www.popularmechanics.com/science/math/a32690399/triangles-rectangles-best-way-cut-sandwich-math/ Generally] [https://www.npr.org/2009/11/28/120914097/rectangles-vs-triangles-the-great-sandwich-debate regarded] as the superior way to slice a sandwich, providing more aesthetically pleasing display of the contents, better support in the hand and fewer all-crust bites. Required in the assembly of a club sandwich,{{actual citation needed}} where the diagonal components are stacked again.
|-
|{{w|Diverging diamond interchange}}s||Road junction where the two (sets of) lanes cross over to switch sides (so if you normally drive on the right, now you drive on the left), then switch back to normal after the junction||-||+||Highway engineers believe the shape improves safety and traffic flow through the interchange because switching to the other side facilitates merging to and from the other road in the junction. However, the shape appears to be insanity to an unfamiliar driver, so where they are rare, driver confusion may lead to increased accidents.
|-
|Toasting sandwiches||Making a sandwich first and then cooking it, as in a dedicated {{w|Pie_iron|sandwich toaster}}, a {{w|toaster oven|toaster oven}}, frying pan or under a grill.||++||++||The grilled cheese sandwich is a familiar form to most people, and many other sandwiches are improved by toasting as a final step. Others, such as the {{w|western sandwich|Western}} or {{w|club sandwich|club}} are prepared using toast. The {{w|peanut butter, banana and bacon sandwich|Elvis}} is a specific case of a sandwich that normally wouldn't be toasted, but is improved by it - peanut butter, bacon, banana, and jelly, with the assembly lightly fried.
|-
|{{w|Crumple zone}}s||Areas of a car that are designed to deform in a controlled way in case of a crash. ||--||++||Most people's intuition would be that stronger cars are safer, and intending parts of a vehicle to collapse ''by design'' might seem crazy. But engineered crumple zones are designed to gradually absorb the kinetic energy in a vehicle collision and protect the passenger cabin. The result is that the occupants experience less intense deceleration and ideally without the damage significantly compressing the shell around them. This significantly reduces the danger of injury or death from higher speed crashes.
|-
|{{w|Sliced bread}}||Bread, sliced by the baker before packaging for sale||+++||++||It's far more convenient for making sandwiches or toast, but unfortunately pre-sliced bread will go stale faster and some applications may be better off thicker or thinner than the slices provided. Sliced bread is often used as a comparator for how good something is, using the phrase 'the best thing since sliced bread'.
|-
|{{w|Pizza}}||Pizza - a toasted sandwich made on thin bread, so doesn't need slicing, usually cut diagonally||++||++||Pizza is a widely popular dish throughout much of the world, uncontroversial {{w|Anchovies_as_food|except}} {{w|Pineapple|certain}} [https://www.taste.com.au/recipes/nutty-choc-pizza-fresh-berries/2c0220a4-8463-45ff-b2ba-ac7e5012a006 toppings].
|-
|Eating citrus fruit while at sea||Having a supply of {{w|citrus fruit}} on long sea journeys, especially during the {{w|Age of Sail}} ||0 (neutral)||+++||For a long time, {{w|Scurvy|scurvy}} was a danger to sailors, who generally subsisted on a monotonous diet of shelf-stable foods with low vitamin content while on long voyages. Most citrus fruits are rich in vitamin C, which prevents scurvy. Eating orange or lemons doesn't seem like a significant activity one way or the other, but it's an easy way to prevent a disease that causes serious ill-health and possibly a painful death.
|-
|Putting mold on infections||Seemingly a reference to the ancient practice of pressing moldy bread against infected wounds||---||++||While this sounds like a good way to get a fungal infection, with the correct mold this is a primitive way to obtain an antibiotic. Certain fungi naturally produce antibiotic substances, and this is where humans discovered {{w|penicillin}}.
|-
|Wheels on luggage||Some luggage bags have small wheels inset on their frame and a carrying handle.||+++||+++||A relatively simple fitting for rigid or semi-rigid luggage that substantially eases its transport over long distances on flat surfaces such as travel terminals.
|-
|{{w|Heat pump}}s||A technology that moves heat energy from a cold area to a warm area, most familiar as the technology that keeps a refrigerator cold. It can be used to heat a home interior in winter or cool it in summer.||++||+++||Unlike traditional furnaces, heat pumps do not generate heat (beyond a small overhead). Instead, they move existing thermal energy from a coolable environment across to a warmable one. This allows a space to be heated with significantly less energy use than a furnace or resistance heater that generates heat directly from chemical or electrical energy. Because these units are usually operated by electricity, they can provide heating with renewable energy (potentially using {{w|thermal energy storage}} for load-shifting), reduce or eliminate the need for natural gas connections, and prevent several risks that come with traditional furnaces (such a carbon monoxide leaks and fires). In addition, heat pumps can operate in the reverse direction as air conditioners, so a single unit can be designed to both heat and cool a building. It sounds like a good idea and works out better than expected in real life.
According to [https://www.technologyreview.com/2023/02/14/1068582/everything-you-need-to-know-about-heat-pumps/#:~:text=Heat%20pumps%20today%20can%20reach,today%20reach%20around%2095%25%20efficiency. MIT Technology review]:
<blockquote>Heat pumps today can reach 300% to 400% efficiency or even higher, meaning they’re putting out three to four times as much energy in the form of heat as they’re using in electricity. For a space heater, the theoretical maximum would be 100% efficiency, and the best models today reach around 95% efficiency.</blockquote>

See also [[2790: Heat Pump]].
|-
|{{w|Laser eye surgery}}||Surgical techniques using lasers for precision cutting in the eyeball.||-||+++||In the popular imagination, lasers are often thought of as something used for destroying their target. Firing them into people's eyes, then, does not sound like a great idea. However. this technology has substantially improved the eyesight of millions of people worldwide by allowing the treatment of eye problems otherwise only corrected by lenses or entirely untreatable. Randall has previously commented on laser eye surgery, amongst other ideas both good and bad, in [[1681: Laser Products]].
|-
|{{w|Fecal transplant}}s||Transfer of portions of the {{w|Gut microbiota|gut microbiome}} of a healthy person to the sterilized gut of an ill person.||---||+++||The gut microbiome is a collection of organisms that lives in our guts. It can influence our health. It is responsible for the last stages of digesting our food. It can also produce neurotransmitters that are carried by blood to our brain influencing our behavior. A healthy microbiome can be destroyed by bad eating habits, unhealthy lifestyles, infections, or the use of antibiotics. Sometimes it may be beneficial to completely sterilize the gut and then take a sample of a healthy biome from another person. A sample is enough, as the organisms will multiply. As long as the patient eats correctly, the microbiome after transplant should develop correctly.

It sounds bad because we tend to think of our feces as something gross, to be discarded, and other people's bacteria as infectious. It is called fecal transplant as our feces contain about 50% of gut bacteria, but nowadays the sample usually takes the form of a coated pill that is applied rectally.
|-
|}

==Transcript==
:[Two axes with double arrows cross each other in the middle. At the end of each arrow, there are labels. Scattered over the chart are 28 entries. Below these entries are given for each of the four quadrants, plus three that are on the Y-axis. For each quadrant the entries are listed in reading order, top to bottom left to right.]

:[X axis from left to right:]
:Sounds like a good idea
:Sounds like a bad idea

:[Y axis from top to bottom:]
:Actually a bad idea
:Actually a good idea

:[Top left quadrant (sounds like a good idea, actually a bad idea):]
:Leaded gasoline
:Asbestos
:Always saying what you think
:Solar cars
:Heelies
:Prequels
:Transitions® lenses

:[Top middle (actually a bad idea):]
:Extension cords with prongs on both ends

:[Top right quadrant (sounds like a bad idea, actually a bad idea):]
:Bloodletting
:Fake prank fire extinguishers
:Stair kayaking
:Replying to spammers
:Cutting pizza in squares
:Project Orion

:[Center (neutral):]
:Soup

:[Bottom left quadrant (sounds like a good idea, actually a good idea):]
:Combo washer dryers
:Cutting sandwiches diagonally
:Toasting sandwiches
:Sliced bread
:Pizza
:Wheels on luggage
:Heat pumps

:[Bottom middle (actually a good idea):]
:Eating citrus fruit while at sea

:[Bottom right quadrant (sounds like a bad idea, actually a good idea):]
:Diverging diamond interchanges
:Crumple zones
:Putting mold on infections
:Laser eye surgery
:Fecal transplants

==Trivia==
*A much leaner version of this comic appeared in the first [[What If? (book) | "What If?" book]], chapter "Weird (and Worrying) Questions from the What If? Inbox, #9".

{{comic discussion}}

[[Category:Charts]]
[[Category:Scatter plots]]
[[Category:Rankings]]
[[Category:Food]]

1221: Nomenclature

2024-05-08T22:35:06Z

ProfDigory: Replace Abbott & Costello image link which is now 404 to archive.org version.

{{comic
| number = 1221
| date = June 5, 2013
| title = Nomenclature
| image = nomenclature.png
| titletext = [shouted, from the field] 'Aunt Beast hit a pop fly to second! Dive for it, Mrs Whatsit!'
}}

==Explanation==
Nomenclature can be defined as the devising or choosing of names for things. Here [[Randall]] connects three pop culture references that each contain one or more instances of ambiguous nomenclature based on pronouns: the "{{w|Who's on First?}}" skit, the "{{w|Doctor Who}}" television series, and in the title text also the novel "{{w|A Wrinkle in Time}}" by {{w|Madeleine L'Engle}}.

The comic references the famous "{{w|Who's on First?}}" skit by the American comedy duo {{w|Abbott and Costello}} in the 1930s. This [http://youtu.be/airT-m9LcoY video] is one of the original performances. Costello is the shorter character, with a round brimmed hat and baseball bat, while Abbott is taller and wearing a baseball cap. This reflects the [https://web.archive.org/web/20151226210855if_/http://www.ramsheadgroup.com/files/2013/04/abbott-and-costello-whos-on-first.jpg most common image] associated with the skit. In the routine, Costello is confused by the nicknames the {{w|Baseball|ball}} players go by. The man playing first base goes by the name "Who", the man on second base goes by "What", and the one on third calls himself "I Don't Know". Costello asks "Who's on first?", inquiring the name of the first-baseman, and Abbott replies "that's right", affirming that the first-baseman's name is Who. Both parties become confused within a matter of seconds.

{{w|Doctor (Doctor Who)|The Doctor}} from the long-running British television series ''Doctor Who'' is often referred to as "Doctor Who" by people who [http://tvtropes.org/pmwiki/pmwiki.php/Main/IAmNotShazam think the series' name and their name are the same] (although it should be noted that the name "Doctor Who" is not entirely incorrect; the character [https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcSipAqHqoHH-Ma04kMV_d0rmCVD7p6co_iItlcmSXfOqt6BiCmGDQ was referred to as such in the end credits for several seasons], as well as in the spin-off theatrical films starring Peter Cushing). In-universe, the character often introduces themself as "The Doctor", which elicits the response "[http://tardis.wikia.com/wiki/The_%22Doctor_Who%3F%22_running_joke Doctor who?]". Their response to this question is: "Just 'The Doctor'". [[Megan]] appears to have interrupted the "Who's on First?" skit to clarify the confusion that the person on first is not called "Who", but just "The Doctor".

The title text references the Madeleine L'Engle novel {{w|A Wrinkle In Time|A Wrinkle in Time}}, which has characters with similarly ambiguous names. Mrs. Whatsit appears to be on second base (like What in the original sketch). Aunt Beast is the batter and hits a {{w|pop fly}} towards second base, while Mrs. Whatsit is being encouraged to dive to catch the ball before it hits the ground, to get the batter out. Another character in the book, Mrs. Who, may also be on the field; Megan may be pointing out that she should be the player referred to as "Who" rather than The Doctor.

==Transcript==
:[Mrs. Whatsit, a woman drawn as Megan, holds her hand out and talks to Abbott (a tall guy with a baseball cap) and Costello (a short guy wearing a round brimmed hat and holding a baseball bat in his right hand.)]
:Mrs. Whatsit: You're both confused.
:Mrs. Whatsit: He's just "The Doctor".

==Trivia==
The names are from the [http://xkcd.com/1221/info.0.json original transcript].

{{comic discussion}}

[[Category:Comics featuring Megan]]
[[Category:Comics featuring real people]]
[[Category:Fiction]]
[[Category:Doctor Who]]
[[Category:Baseball]]

Talk:2493: Dual USB-C

2021-07-28T23:53:19Z

ProfDigory: Adding a comment.

Is "USB-AC" in the title text a reference to the fact that this looks like an AC power plug, or is that a legitimate variant of USB-C? [[Special:Contributions/172.68.55.65|172.68.55.65]] 18:09, 27 July 2021 (UTC)

I guess this is how connector vendors maintain backwards compatibility for USB-C. ----DaveK

I would have thought it was cursed more from what would happen if you plugged it into a standard ac outlet. [[Special:Contributions/162.158.74.107|162.158.74.107]] 04:49, 24 July 2021 (UTC)
:Does USB C actually fit inside an outlet? (As I live in europe, I really have no clue...) [[Special:Contributions/141.101.105.7|141.101.105.7]] 07:42, 26 July 2021 (UTC)
:: i'm pretty sure it doesn't (should be wasy to test for any american who owns a USB-C plug), and the third point in the list mentions that currently, which actually renders the first two points immaterial. [[Special:Contributions/162.158.88.188|162.158.88.188]] 14:41, 26 July 2021 (UTC)
:::This does not fit into a standard AC outlet. However, I have seen plenty of outlets, especially on extension cords, which might allow one of the USB-C plugs to touch the live contact.[[User:Geek Prophet|Geek Prophet]] ([[User talk:Geek Prophet|talk]]) 18:16, 26 July 2021 (UTC)

Looks good. But I'll obviously need a BS 1363/Type-G converter! [[Special:Contributions/141.101.99.211|141.101.99.211]] 09:14, 24 July 2021 (UTC)

It's worth noting, Dell already does this with the WD19DCS... [[Special:Contributions/141.101.99.211|141.101.99.211]] 09:23, 24 July 2021 (UTC) Gargravarr

Is it worth pointing out that "cursed X" is a meme, c.f. /r/cursedimages? I think this is the first time xkcd has referenced it. --[[User:Esogalt|Esogalt]] ([[User talk:Esogalt|talk]]) 14:59, 24 July 2021 (UTC)
:No I do not think so. That something is cursed is not special to a meme. This reminds more of the bad map projections series. Wonder if more will follow. Have added this similarity in title to the explanation. Starting with a very high number just like that series. In that series number 4 comic just came out, so interesting to see if he has planned more of these. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 14:32, 25 July 2021 (UTC)

This comic yet has no categories. And I cannot think of any suitable? Something with electronics that is not a category yet? I mean it can be used with smart phones and computers, but is not only used for one of these? --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 14:32, 25 July 2021 (UTC)
:I was thinking something like 'Spurious Series(es?)'. It could encompass My Hobby and Map Projections as child-categories (they're self-categorised, I'm fairly sure without checking) but any lone "Something-Or-Other #xyz" like this is added as a direct example. And then if "Something-Or-Other #pqr" ever happens and is so categorised it ''highlights'' the need to create a Something-Or-Other category and reassign membership to this instead. If it never gets any direct companions, it can stand out as a spurious to the extent of never being partnered by up to ''xyz-1'' other later examples.
:Non-spurious serieses (xkcdphone, e.g.) that start with example #1 (or even un-numbered, but clearly item 1 in hindsight) might be better to be dealt with as is. But anything pretending to be just one of dozens/hundreds of as-yet-untold examples, especially out of index order (#1 is unlikely to be referenced, for reasons of refusing to establish a truly comprehensive catalogue that doesn't even exist, but would not necessarily disqualify such a leap-frogging/randomly-sampled series if it appeared anyway, after the original asynchro ous+gappy impressions) is probably an intentional Spurious Series.
:Or find an even better term. Or supercategorise Series with subcats of Storytelling/Chronicalling/Chronological (Journal), Upgrades/Revisiting (xkcdphone, also Internet Map?) and Spurious/Ad Hoc (as above), allowing room for future additions to revisit the true nature of the series concerned.
:Would need a proper editorial policy discussion, of course, especially to find better terminology (of whatever form of grouping(s) the final conclusion recommended). But perhaps you can see some glimmer of (a different?) solution in what I have just suggested. Putting it out there so at least it's there to be ignored or dismissed as overthinking the matter. [[Special:Contributions/141.101.99.183|141.101.99.183]] 16:43, 25 July 2021 (UTC)

I seem to recall at least one other xkcd strip that was "Cursed". I think it was cursed office chairs. That would make at least two comics in the "Cursed" category. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 14:45, 26 July 2021 (UTC)
:There is also the cursed store that beret guy gets all his stuff from, only to find out later that the item is cursed but when he goes back to the store it's gone. Maybe this is one of the items he recently purchased and couldn't return? [[Special:Contributions/127.0.0.1|127.0.0.1]] 21:51, 25 July 2021 (UTC)

:Not sure if you mean [[2332: Cursed Chair]] or [[2144: Adjusting a Chair]].
:--[[User:FrankHightower|FrankHightower]] ([[User talk:FrankHightower|talk]]) 19:05, 28 July 2021 (UTC)

The need of dual plugs could also be a result of the increasing power consumption of some devices, as suggested with the Macbook-compatible high-performance dongles in the explanation. USB-C is limited to 100 W, what is not bad for this tiny pins - [https://en.wikipedia.org/wiki/USB-C#Power_issues_with_cables Wiki USB-C power issues]. So crude soft- and hardware design, e.g of high performance laptops, leads to dual plugs or an additional power plug next to the dock connector. [[Special:Contributions/162.158.134.94|162.158.134.94]] 11:47, 27 July 2021 (UTC)

"Cursed Connectors #187" - Section 187 of the California Penal Code covers murder. [[User:ProfDigory|ProfDigory]] ([[User talk:ProfDigory|talk]]) 23:53, 28 July 2021 (UTC)

1737: Datacenter Scale

2016-09-23T23:20:18Z

ProfDigory: /* Explanation */

{{comic
| number = 1737
| date = September 23, 2016
| title = Datacenter Scale
| image = datacenter_scale.png
| titletext = Asimov's Cosmic AC was created by linking all datacenters through hyperspace, which explains a lot. It didn't reverse entropy--it just discarded the universe when it reached end-of-life and ordered a new one.
}}
==Explanation==
{{incomplete|The paragraph explaining the final panel needs a grammar check.}}

{{w|RAID}} ("redundant array of independent disks") is a technology that splits data across several hard-drives as if they were one. RAID comes in several levels (varieties) which have different applications, but one of the big applications of RAID is creating mirrored hard disks that back each other up. If one disk drive in such a RAID fails, no data is lost.

However, RAID is complicated to configure, so you don't want to be constantly setting it up. An alternative technique for data centers is therefore to simply send the data to several servers at once. This makes maintenance easier, but without RAID, one hard disk crash basically breaks the server. However, this is what the woman with a bun's (possibly an adult [[Science Girl]]) data center is doing since their scale is so large that fixing individual servers does not make sense, and instead of fixing the drive they throw away the machine.

From here, the comic starts to exaggerate. Nowadays, servers can be made extremely small ("{{w|Blade server}}s") and dozens of servers can be attached to one {{w|19-inch rack}} in a data center. Rather than going to the effort of unplugging and unscrewing one blade from the rack, when a blade fails at [[Cueball]]'s data center they just throw away the rack, and [[Ponytail]] agrees and kinda mocks the woman with a bun for replacing one server.

[[Hairy]]'s goes one step further - they have so many servers that they would constantly have to be throwing away and replacing racks, so instead they just build a new room when one rack fails. This would be currently possible with small modular data centers that are built in shipping containers for easy transport and can be linked together to expand capacity. Here the cargo-container "room" with the failure would be quickly swapped with a fresh one. Cueball adds "like Google!" - [[Randall]] previously mentioned {{w|Google|Google's}} approach to hard drive failures in the [[what if?]] ''{{what if|63|Google's Datacenters on Punch Cards}}''. Back in [http://static.googleusercontent.com/media/research.google.com/de//archive/disk_failures.pdf 2007] they had one failure every few minutes - that might have increased hugely since then.

Finally [[Megan]] appears and her company of course breaks the scale of silliness in exaggeration. She says that they don't have any fire extinguishers (neither {{w|Fire sprinkler system|regular sprinklers}} nor the {{w|Gaseous fire suppression|inert gas systems}} that flood the room with gases like argon which force out oxygen and stop fires - these are better for computers than traditional water or powder systems, but are lethal to people trapped in the rooms!). Rather, they just rope the center off, thus letting the data center burn down. Then they simply move a town over and build a new one. This may indicate they are so big that the entire town will burn down if their center catches fire, for else they did not have to skip town. Alternatively, they just leave the center burning and this may cause problems in that town, so they simply flee the premises.

Most big internet companies do have multiple redundant data centers around the world, in order to increase speeds for users in different countries, but Megan's idea would be very expensive, increase in {{w|Latency (engineering)|latency}} and possibly also kill people, either in their company or other people in the town and since they do not try to turn out the fire, at least cause severe destruction of properties, not only their own.

Still Hairy thinks that it makes sense, whereas Cueball wonders what difference the roping off does. This could again be a reference to the fact that they just let the buildings burn without bothering about the local consequences, and the next step is just one more step towards the extreme of the title text.

This comic references how, as data requirements expand, the cost of time eventually outweighs the cost of hardware at ever increasing scales (drive, rack, room, building). While this comic takes this to the extreme, with whole buildings being destroyed for simple flaws, the concept is not as far fetched as it seems if "thrown out" is taken to include being sold to equipment refurbishers. It could indeed be cost effective for a large data services provider to resell racks or even whole data center modules at some significant fraction of their "as new" price as opposed expending the time and effort to attempt a repair. The equipment refurbisher would then rely on a {{w|competitive advantage|cost advantage}} like cheaper labor to repair the flaw and sell it back to Google or another company with less demanding requirements. Equipment rental firms already operate on this model and with the added incentive customers preferring to rent newer models, this means that the equipment is often ''preemptively'' replaced before failures even occur.

The title text refers to {{w|Isaac Asimov}}'s science-fiction short story "{{w|The Last Question}}", where humanity asks, at different stages of its spatial and technological development, the same question to increasingly advanced computers: "How can the net amount of {{w|entropy}} of the universe be massively decreased?". At each point, the computer's answer is that it does not yet have enough data for a meaningful answer. Ultimately, the computers are all linked through hyperspace, outside the physical boundaries of the universe, and make up a single computing entity named AC which keeps pondering the question even as the {{w|heat death of the universe}} occurs and time and space cease to exist. When AC finally discovers the answer, since there is nobody left to report it to, it decides to demonstrate it and says "{{w|Let there be light|LET THERE BE LIGHT!}}", which are the first words said by God during the Creation, according to the {{w|Book of Genesis}}. Here, the title text implies that, as the universe died, AC no longer had a use for it as a physical support and, taking the comic's logic to the next extreme, chose to discard it and get a brand-new one instead of bothering to "fix" it by reversing its entropy.

This comic's concept of taking a real world phenomena and exaggerating it to levels currently considered implausible for comic effect closely mimics an earlier comic which describes progressively more "hardcore" programmers in [[378: Real Programmers]].

==Transcript==
:[Zoom in on a woman with a bun holding her hand palm up in front of her taking to people off-panel right.]
:Woman with a bun: RAID controllers don't make sense at our scale; everything is redundant at higher levels. When a drive fails, we just throw away the whole machine.

:[In this frame-less panel it is revealed that the woman with a bun talked to Cueball and Ponytail who is looking her way.]
:Cueball: Machine? We throw away whole racks at a time.
:Ponytail: Yeah, who replaces ''one server''?

:[Hairy has appeared from the left and holds one hand palm up towards the other three where also the woman with a bun has turned towards him.]
:Hairy: We just replace whole rooms at once. At our scale, messing with racks isn't economical.
:Woman with a bun: Wow.
:Cueball: Like Google!

:[Megan walks in from the left, and everyone including Hairy now looks towards her. Cueball has taken a hand up to his chin. The replies to Megan are written with clearly smaller font.]
:Megan: We don't have sprinklers or inert gas systems. When a datacenter catches fire, we just rope it off and rebuild one town over.
:Hairy: Makes sense.
:Cueball: I wonder if the rope is really necessary.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Science Girl]]
[[Category:Computers]]
[[Category:Fiction]]