explain xkcd - User contributions [en]

Talk:3020: Infinite Armada Chess

2024-12-07T11:49:56Z

172.70.207.149: Chess clock

Did I do well? Added a very very basic explanation. [[Special:Contributions/172.68.147.132|172.68.147.132]] 04:25, 5 December 2024 (UTC)

Well, yes but I wonder if just one tiny fix is needed. If you replace the white side with a simplyfied artillery tower, you reinvented space invaders.{{unsigned ip|172.71.160.70|04:57, 5 December 2024 (UTC)}}

I was personally hoping for an explanation of the Infinite Armada thing, and I feel like a link to the TV Tropes page doesn't really. Explain that at all. So I would love a bit of an expansion on that part! Just want to be sure I didn't miss some reference or something. [[Special:Contributions/172.68.23.91|172.68.23.91]] 05:48, 5 December 2024 (UTC)
: Likewise. I get the comic, but I assumed the 'armada' part was a reference that I just did not get. But it seems it is just a word choice. [[Special:Contributions/172.71.102.105|172.71.102.105]] 09:39, 5 December 2024 (UTC)
:: The only "Infinite Armada" reference I can think of is ''[https://en.wikipedia.org/wiki/Star_Wars:_Knights_of_the_Old_Republic Star Wars: Knights of the Old Republic]'', which kind of makes sense because if you have a Star Forge to make chess pieces with, why wouldn't you make them all queens? [[Special:Contributions/162.158.167.159|162.158.167.159]] 18:47, 5 December 2024 (UTC)

I think that since the error was "out of bounds", not "out of memory", it's referring to indexing outside of the region of memory that the program allocated to deal with the board. This would happen since instead of addressing rank 1..8, you could address rank 9, 10, 0, or -1. Unless bounds checking is performed when converting the board coordinates into linear array indices, you'd get an out-of-bounds error (or worse, succeed in reading or modifying memory that you weren't intending to). --[[Special:Contributions/172.71.30.253|172.71.30.253]] 05:45, 5 December 2024 (UTC)
:It was "Out of Bounds memory access". That means it was trying to access a memory address that was out of the bounds of the computer, as if it were trying to access the ω-th index of the board array, which would put it out of the memory range of any computer [[User:Firestar233|guess who]] ([[User talk:Firestar233|if you want to]] | [[Special:Contributions/Firestar233|what i have done]]) 06:15, 5 December 2024 (UTC)
:: There is no hint that the bounds are those of the computer, the simplest explanation really is that the bounds are those of an array. The error message does come up. In addition, to try to access the memory at the ω-th index, you would need to construct the ω-th index itself first (which would fail or not terminate) [[User:Jmm|Jmm]] ([[User talk:Jmm|talk]]) 07:01, 5 December 2024 (UTC)
::: The specific message, "RuntimeError: Out of bounds memory access", is a WebGL error issuing from its WASM cross-platform browser implementation. This implies to me that an attempt to render an infinite chessboard failed in a fairly trivial way, because of a poor implementation. It's very unlikely that there had been a problem with the [https://github.com/official-stockfish/Stockfish/tree/master/src Stockfish playing algorithm] yet, which would have failed with a different message if it ran out of memory, such as "Killed", which is all that shells like Bash print when one of their job processes is killed by the kernel's OOM killer, or by anything else for that matter. [[Special:Contributions/172.70.215.21|172.70.215.21]] 12:58, 5 December 2024 (UTC)

Is this a reference to [https://youtu.be/rav29N0-h2c infinite chess by Naviary?] [[User:HaruruChanDesu|HaruruChanDesu]] ([[User talk:HaruruChanDesu|talk]]) 11:21, 5 December 2024 (UTC)

"it does not really need to consider the infinitely many pieces" => a chess Engine would need to consider the infinitely many pieces (or have a way to abstract them), even if some pieces are currently stuck because the engine recursively evaluates moves and counter-moves (i.e. evaluates the game up to some depth).

Is the cardinality of the set of all the pieces smaller than the cardinality of the set of all possible moves? My gut instinct says yes but I don't have the energy to muck around and see if I can prove it. If I did try I think that matrix diagonalization would be the first thing I'd try. Anybody less lazy than me on this? --[[User:Tomb|Tomb]] ([[User talk:Tomb|talk]]) 21:30, 5 December 2024 (UTC)
: The number of games is at least Beth one (cardinality of the continuum so uncountable). After some preliminary moves you can have a black queen on an otherwise empty row and a white queen in the black pawn row. Now on pairs of moves the black queen moves in its row so its column mode four is a base four digit while the white queen moves up one row to give the digits position. So we can map real numbers uniquely into games.
: The number of pieces is obviously countable.[[Special:Contributions/172.70.230.60|172.70.230.60]] 18:59, 6 December 2024 (UTC)

Can someone explain the linked joke with all the extra queens? I don't understand why it's a bad position. [[Special:Contributions/172.69.59.126|172.69.59.126]] 16:49, 5 December 2024 (UTC)
:Knight to d6. [[Special:Contributions/162.158.167.175|162.158.167.175]] 17:09, 5 December 2024 (UTC)
::...is checkmate by black. White can't capture the knight with either of the two queens that attack it because they're both pinned, by black's bishop and rook. (And we know it's black's turn to move because the colored squares indicate white just moved.) [[User:DKMell|DKMell]] ([[User talk:DKMell|talk]]) 17:54, 5 December 2024 (UTC)

Expected some discussion here already on the best opening moves given a infinite board or at least the board depicted.
1. e3 e6 2. Qh5 seems a logical start, but not entirely sure what would happen after that?
Any ideas? [[User:Flekkie|Flekkie]] ([[User talk:Flekkie|talk]]) 22:56, 5 December 2024 (UTC)
:I think games will generally end in a draw by perpetual check that's something like:
:1. Qxd7+ Qxd7
:2. Qxd7+ (etc)
:It's tricky to prevent a player at a disadvantage from repeatedly sacrificing queens from further and further away down some file. [[Special:Contributions/172.68.54.138|172.68.54.138]] 02:43, 6 December 2024 (UTC)
::However, the rules of chess wouldn't cause this game to end in a draw since there are captures every turn, and captures reset the 50-move counter that triggers a draw. The players could agree to a draw - or perhaps the player at a disadvantage could hope to win by exhaustion, that is, by following this strategy indefinitely and hoping the other player collapses from weariness first. [[User:DKMell|DKMell]] ([[User talk:DKMell|talk]]) 03:27, 6 December 2024 (UTC)

:::This assumes no chess clock. Alas, what I just wrote assumes a classic chess clock. Some games use time rules that require a modern electronic clock and add time every move, which in this case brings back the "recaptures go on forever" problem. [[Special:Contributions/172.70.207.149|172.70.207.149]] 11:49, 7 December 2024 (UTC)

;Hit me up when this becomes real.

I would like to try this out. [[User:CalibansCreations|'''Caliban''']] ([[User talk:CalibansCreations|talk]]) 12:29, 5 December 2024 (UTC)
:It should be easy enough. You will rarely get the queens out in play from deep in the array. So maybe just put two chess boars together and put some placeholder in for queens in the extra fields. If ever a queen in the bottom row is moved, place extra queens that can now be moved into the 2-3 squares that would be outside the board...--[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:39, 5 December 2024 (UTC)
:It might be something one could set up in Infinite Chess, although having limits on the chessboard may be difficult. [[Special:Contributions/172.68.150.67|172.68.150.67]] 14:01, 5 December 2024 (UTC)

: Here's a finite approximation in ChessCraft: https://www.chesscraft.ca/design?id=5KM4 [[User:Promethean|Promethean]] ([[User talk:Promethean|talk]]) 15:37, 5 December 2024 (UTC)

While I understand how to play chess, I don't get the bit about "having a bunch of queens doesn't go very well". At first glance, the linked chess layout looks pretty solid. Can someone please enlighten me? Also, what does the TV Tropes link about Title Drop have to do with Infinite Armada, aside from that being the title of the comic? [[Special:Contributions/172.70.230.77|172.70.230.77]] 13:10, 5 December 2024 (UTC)

:: ... Nd6. [[Special:Contributions/172.70.91.246|172.70.91.246]] 13:31, 5 December 2024 (UTC)

::: Ah, thanks. Moving the knight there puts the king in check, and moving either queen to take it exposes the king to the bishop or rook, so checkmate. [[Special:Contributions/162.158.63.38|162.158.63.38]] 15:05, 5 December 2024 (UTC)

::::<s>You are assuming that the opponent makes no moves while you spend at least three moves advancing your knight. Looks like either side can draw by always moving the king backwards whenever a queen has moved and made a hole he can move to and otherwise trying to make a new, deeper hole. Eventually he gets so far back that any attack turns into an infinite sequence of queens taking each other, with the attacker only having file attacks while the defender can retake from a rank, file, or diagonal. Any time the attacker breaks off the infinite sequence of queens taking each other to set up something else, the defender takes advantage of the break to move the king deeper and put more queens in front of him or to create more empty spaces to sidestep into when attacked. To me, this looks like a certain draw.</s> [[Special:Contributions/172.69.33.252|172.69.33.252]] 16:21, 5 December 2024 (UTC)

:::::They're talking about the linked layout at https://x.com/chesscom/status/1841540380363211164, not the layout in the comic. It only takes one move for the black knight to move to Nd6 and put the white king in checkmate. [[Special:Contributions/141.101.109.167|141.101.109.167]] 20:59, 5 December 2024 (UTC)

You might be able to get the developer of fairy stockfish ( https://fairy-stockfish.github.io/ ) to add this if you ask nicely. I have seen them add several reader requests. [[Special:Contributions/172.70.211.143|172.70.211.143]] 15:46, 5 December 2024 (UTC)

Could this be a reference to the meme about "eating an infinite armada of pizza"? The wording seems too similar to be a coincidence. [[Special:Contributions/172.70.114.46|172.70.114.46]] 14:46, 5 December 2024 (UTC)

Would this guarantee a draw between two competent players who'd played the variant before, or would there be more nuance to it than there appears to be?

Can someone explain the linked joke with all the extra queens? I don't understand why it's a bad position. [[Special:Contributions/172.69.59.125|172.69.59.125]] 16:48, 5 December 2024 (UTC)

The explanation of the linked joke is that the king appears safe at first glance, but in reality there is a simple move that wins the game for black. Moving the black knight to the top left corner of the queen square checks the king. The king cannot move to escape. Two queens are in position to take the knight and save the white king, but both of those moves expose the king to attack from other black pieces (the rook or the bishop).

Wow. Not only did White give Black a mate in one, they also blundered a mate in one. [[Special:Contributions/162.158.167.176|162.158.167.176]] 20:21, 5 December 2024 (UTC)

Really? This comic specifically references some obscure roblox game with like 350k visits? That can't be right. [[Special:Contributions/172.71.154.247|172.71.154.247]] 02:31, 6 December 2024 (UTC)

This was the variant played at the chess tournament held at David Hilbert's Grand Hotel. You'd think they would have struggled to fit infinitely large boards in the conference room, but they just kept moving the tables until they had enough space. [[User:RegularSizedGuy|RegularSizedGuy]] ([[User talk:RegularSizedGuy|talk]]) 08:01, 6 December 2024 (UTC)

Clarifying "Surprisingly little memory to analyze conventional Chess": Without trying to "golf" the memory requirements, a board can be represented in 64 bytes, a reversible move in three bytes (start square, end square, piece captured). 40 moves without a pawn move or a capture is a draw, so the search stack is less than 5,680 moves. Two copies of the board (current search position, a board for looking back for detecting repeated positions), a few pointers for searching for moves to try: 20K of memory is plenty to search the entire Chess tree. And a truly unimaginably huge finite amount of time. (Golfers, start your carts!) [[Special:Contributions/172.68.55.12|172.68.55.12]] 12:08, 6 December 2024 (UTC)

Queen to A9.56x10^14 -[[User:Psychoticpotato|P?sych??otic?pot??at???o ]] ([[User talk:Psychoticpotato|talk]]) 13:47, 6 December 2024 (UTC)

Seems like a trivial win for white? Start w/ scholar's mate 1. e5 ... 2. Qh6, and just keep throwing queens at the king. It's much easier for the infinite queens to attack than to block and defend. [[Special:Contributions/172.71.154.76|172.71.154.76]] 18:21, 6 December 2024 (UTC)
:The problem is 1. e5 h6 2. Qxh6 Rxh6, if you keep trying to win h6 you’ll run out of queens that can move diagonally and black has an infinite supply moving vertically. 2. Qg4 Ng6 3. Qce2 seem like the logical next three moves? Except now black has a free move and a knight out. So at least it doesn’t seem trivial. I do think these games will be shorter than regular chess if they lead to a result, because long series of moves will tend to release the infinite queens. 23:13, 6 December 2024 (UTC)

I cannot image this is not trying to reference https://www.youtube.com/watch?v=rSCNW1OCk_M , which recently resurfaced again.

2318: Dynamic Entropy

2024-05-30T04:54:36Z

172.70.207.149: /* Explanation */ quote entropy explanation

{{comic
| number = 2318
| date = June 10, 2020
| title = Dynamic Entropy
| image = dynamic_entropy.png
| titletext = Despite years of effort by my physics professors to normalize it, deep down I remain convinced that 'dynamical' is not really a word.
}}

==Explanation==
This is another one of [[Randall|Randall's]] [[:Category:Tips|Tips]], this time a [[:Category:Science tip|Science Tip]]. This time it is a bit special since it came less than three weeks after another Science Tip: [[2311: Confidence Interval]] (which was itself the first time that a non-Protip Tip type has been re-used). This is the first time a type of tip (that was not a [[:Category:Protip|Protip]]) has been used for two "tips comics" in a row.

This Science Tip suggests that if you have a cool new concept, you should call it ''dynamic entropy''.

{{w|Dynamic programming}} is a mathematical optimization method and computer programming method developed by {{w|Richard Bellman}} in the 1950s. The {{w|Dynamic programming#History|History section}} of the Wikipedia article contains the full paragraph from Bellman's autobiography that contains the quote that is in the comic strip. Bellman describes how he was doing mathematical research funded by the military at a time when the Secretary of Defense had a literal pathological fear of the word "research", and by extension, "mathematical". Bellman borrowed the word "dynamic" from physics as being both accurate for his work and as a word that in plain English has positive connotations and is never used in a pejorative sense (expressing contempt or disapproval). The word "dynamic" itself comes from the Greek ''dynamikos'', "powerful", which is a positive meaning in itself, and has been applied to topics in physics that are related to motion and forces and used in ordinary English to refer to things that exert power, force, growth, and change (dynamo, dynamite, and as an adjective). Even though those things aren't always good, when they're bad, we use other words instead (e.g. cancer undergoes {{w|metastasis}}, not "dynamism").

{{w|Entropy}} is a term from physics, specifically statistical mechanics, describing a property of a thermodynamic system. When {{w|Claude Shannon}} developed a mathematical framework for studying signal processing and communications systems, which became known as {{w|Information theory}}, he struggled to come up with a proper name for one mathematical concept in his theory that quantified amount of noise or uncertainty in a signal. Computer scientist {{w|John von Neumann}} noticed the similarity of the equations with some in thermodynamics and suggested, "You should {{w|Entropy (information theory)|call it entropy}}, for two reasons. In the first place your uncertainty function has been used in statistical mechanics under that name, so it already has a name. In the second place, and more important, no one really knows what entropy really is, so in a debate you will always have the advantage." (see {{w|History of information theory#Entropy in statistical mechanics|History of information theory}}). The following is an excerpt from the explanation of [[1862: Particle Properties]]:

<blockquote>
The term "entropy", which {{w|History of entropy|began}} as a {{w|Entropy (classical thermodynamics)|thermodynamic measure}}, has since been adopted {{w|Entropy in thermodynamics and information theory|by analogy}} into {{w|Entropy (disambiguation)|multiple seemingly unrelated domains}} including, for example, information theory. The table allows that the term "entropy" must mean something in the context of particle physics, but isn't certain whether it's the classical, Gibbs' modern {{w|Entropy (statistical thermodynamics)|statistical mechanics}}, Von Neumann's {{w|Von Neumann entropy|quantum entropy}}, or some other meaning.

In classical thermodynamics, entropy is a macroscopic property describing the disorder or randomness of a system with many particles. However, in statistical mechanics and quantum mechanics, the concept of entropy can also be applied to single particles under certain conditions. If the particle's position is not precisely known and can be described by a probability distribution, this contributes to entropy. Similarly, if the particle's momentum is uncertain and described probabilistically, this also contributes to entropy. A single quantum particle in a pure state (e.g., an electron in a specific atomic orbital) has zero entropy. This is because there is no uncertainty about the state of the system. If the single particle's state is described by a density matrix representing a mixed state (a probabilistic mixture of several possible states), the Von Neumann entropy can quantify the degree of uncertainty or mixedness of the state.

Imagine two identical balloons filled with the same gas and heated from two opposite sides with identical heat sources, creating symmetric temperature gradients in both; because the distribution of temperatures is the same, the Gibbs statistical thermodynamic entropy 𝑆 of the gas molecule particles in each balloon will be the same. In contrast, if one balloon is heated by a low-power heat source and another from by an otherwise identical high-power heat source, the balloon next to the high-power heat source will have a steeper temperature gradient, increasing the number of [https://www.sciencedirect.com/topics/mathematics/accessible-microstates accessible] {{w|Microstate|microstates}}, so the Gibbs entropy 𝑆low power < 𝑆high power. Now consider electrons in two atoms excited by absorbing identical photons to a mixed state; if the mixed states have the same probabilities for different energy levels, their Von Neumann quantum entropy 𝑆 values will be the same. Conversely, if one atom has electrons excited to a {{w|Purity_(quantum_mechanics)|pure state}} and another to a mixed state by photons of different energies, the mixed state will have higher entropy due to greater uncertainty, i.e., 𝑆pure = 0 and 0 < 𝑆mixed ≤ ln(2).
</blockquote>

The naming of dynamic programming and of entropy in information theory are both examples of scientists choosing a name for what were at least partially very non-scientific seeming reasons. In one case because it has only positive and no negative connotations in plain English. In the other case because there is much confusion over the meaning of the word so Shannon would be free to adopt it in a new context. [[Randall]] is claiming that would make them great to put together to name some new concept; the combination will mean whatever the creator wants it to mean (even able to change mid-debate), and never sound bad the way that e.g. {{w|cold fusion}} has come to be.

Even though the caption implies that "dynamic entropy" would be available as a new name, it has actually been used in physics<ref>Allegrini, P., Douglas, J. F., & Glotzer, S. C. (1999). Dynamic entropy as a measure of caging and persistent particle motion in supercooled liquids. Physical Review E, 60(5), 5714, doi: 10.1103/physreve.60.5714.</ref>, probability<ref>Asadi, M., Ebrahimi, N., Hamedani, G., & Soofi, E. (2004). Maximum Dynamic Entropy Models. Journal of Applied Probability, 41(2), 379-390. Retrieved June 11, 2020, from www.jstor.org/stable/3216023</ref>, computer science<ref>S. Satpathy et al., "An All-Digital Unified Static/Dynamic Entropy Generator Featuring Self-Calibrating Hierarchical Von Neumann Extraction for Secure Privacy-Preserving Mutual Authentication in IoT Mote Platforms," 2018 IEEE Symposium on VLSI Circuits, Honolulu, HI, 2018, pp. 169-170, doi: 10.1109/VLSIC.2018.8502369.</ref>, and even the term "dynamical entropy" in physics<ref>Green, J. R., Costa, A. B., Grzybowski, B. A., & Szleifer, I. (2013). Relationship between dynamical entropy and energy dissipation far from thermodynamic equilibrium. Proceedings of the National Academy of Sciences, 110(41), 16339-16343.</ref><ref>Słomczyński, W., & Szczepanek, A. (2017). Quantum dynamical entropy, chaotic unitaries and complex Hadamard matrices. IEEE Transactions on Information Theory, 63(12), 7821-7831, doi: 10.1109/TIT.2017.2751507.</ref> and bioscience<ref>Chakrabarti, C. G., & Ghosh, K. (2013). Dynamical entropy via entropy of non-random matrices: Application to stability and complexity in modelling ecosystems. Mathematical biosciences, 245(2), 278-281, doi: 10.1016/j.mbs.2013.07.016.</ref>.

In the title text Randall mentions that, even though his physics professors have continued to use the word "dynamical", "trying to normalize it" by repetitive usage, he remains convinced that it is not really a word. Presumably he doesn't like that it has two suffixes used to make words into adjectives, -ic and -al, as if "dynamic" wasn't already positive enough. The [https://www.thefreedictionary.com/Commonly-Confused-Suffixes-ic-vs-ical.htm#:~:text=Words%20ending%20in%20%E2%80%9C%2Dic%E2%80%9D,are%20notoriously%20difficult%20to%20distinguish Free Dictionary] discusses how -ic and -ical suffixes are confused in many common words and explains their different uses.

The term "dynamical" in physics generally is used in "{{w|Dynamical system}}" or as an adjective to name a concept as applied to dynamical systems such as "dynamical entropy"<ref>Atmanspacher, H. (1997) "Dynamical entropy in dynamical systems," in ''Time, temporality, now'' (pp. 327-346). Springer, Berlin, Heidelberg, doi: 10.1007/978-3-642-60707-3_22</ref>.

==Transcript==
:[One panel only with text and a few lines and arrows. There are two columns each with a heading. Beneath each heading is a quote written on four lines. Below the quote, in grey font, and indented, starting with a hyphen, with the text aligned to the right of this are five lines of text. This explains who the quote belongs to and where it was stated (in brackets at the end). From the bottom of each of these two gray text paragraphs gray curved arrows goes down to two gray lines. Below each of these two lines are one large word per line. They are again in black text.]
:<big>Dynamic</big>
:"It's impossible to use the word 'dynamic' in the pejorative sense... Thus, I thought 'Dynamic Programming' was a good name."
::- Richard Bellman, explaining how he picked a name for his math research to try to protect it from criticism (''Eye of the Hurricane'', 1984)

:<big>Entropy</big>
:"You should call it 'Entropy'... No one knows what entropy really is, so in a debate you will always have the advantage."
::- John von Neumann, to Claude Shannon, on why he should borrow the physics term in information theory (as told to Myron Tribus)

:::<big><big>'''''Dynamic Entropy'''''</big></big>

:[Caption below the panel:]
:Science Tip: If you have a cool concept you need a name for, try "Dynamic Entropy."

== Trivia ==

Many of {{w|Buckminster Fuller}}'s designs and works were associated with the word "{{w|dymaxion}}", a combination of the words "dynamic", "maximum", and "tension", all words that Fuller himself used a lot in talking about his work, and which are words that simultaneously have use in science and positive connotations in lay English.

==References==
<references />

{{comic discussion}}

[[Category:Science tip]]
[[Category:Comics featuring real people]]
[[Category:Science]]
[[Category:Physics]]
[[Category:Programming]]

1862: Particle Properties

2024-05-30T00:33:14Z

172.70.207.149: /* Explanation */ clarify

{{comic
| number = 1862
| date = July 12, 2017
| title = Particle Properties
| image = particle_properties.png
| titletext = Each particle also has a password which allows its properties to be changed, but the cosmic censorship hypothesis suggests we can never observe the password itself—only its secure hash.
}}

==Explanation==
A table is presented comparing the range (maximum and minimum value) and scale (how big number increments are) of several measures. The table begins by listing properties pertinent to {{w|particle physics}} as the title suggests, but quickly devolves to other domains such as role-playing games (such as D&D) and sports after failing to provide a good definition of {{w|Flavour (particle physics)|flavor}}.

{| class=wikitable
! Property
! Scale
! Explanation
|-
| Electric charge
| [-1,1]
| The {{w|electric charge}} is shown in increments of a third from -1 to +1 which are the only known charges of fundamental particles (leptons, quarks and gauge bosons); however there are some exotic composite particles with twice integer charge, e.g. the recently discovered {{w|Ξcc++|double charmed Xi baryon}} with a charge of +2.

Quarks are the only particles with charges of ± ⅓ or ± ⅔, but cannot exist individually; below the {{w|Hagedorn temperature}}, they are only found within hadrons. To date, all hadrons (particles composed of quarks), leptons, and bosons have integer charge, and current models indicate that this must be the case.
|-
| Mass
| [0,∞) in kg
| Mass (specifically {{w|rest mass}}) is the measure of an object or particle's resistance to force, as well as its ability to distort {{w|spacetime}} (its gravitational attraction).
Theoretically, any object's mass could approach infinity, but mass cannot be below 0 (as far as {{w|Negative mass|we know}}). The mass units shown (kilograms) are, however, far too large for particles. Some particles, such as photons, have zero rest mass and are therefore massless.

All particles with rest mass obtain it through confinement, either by the {{w|Higgs field}} (the quarks; leptons; and W, Z, and Higgs bosons) or the strong nuclear force (hadrons).
Particles with no rest mass (photons and gluons) can only move at lightspeed.
|-
| Spin number
| (-∞,∞) (Intervals of ½)
| {{w|Spin (physics)|Spin}} is an intrinsic property of particles, a relativistic form of angular momentum. The spin of a particle determines what statistics the particle follows, half odd integer spin particles are classified as fermions and integer spin particles are bosons.

Two fermions cannot have exactly the same state, an observation known as the Pauli exclusion principle. Thus, for fermions to exist in the same position, they must have opposite spins, of + ½ and - ½. It follows that a maximum of two fermions of the same flavor (e.g. two electrons) may exist in the same position.
|-
| Flavor
| Misc. quantum numbers
| Flavor is a series of {{w|quantum numbers}} that do not fit neatly onto a set of dimensional axes.

The most general theory breaks flavor down into four distinct conserved values, the electric charge, the weak isospin, the baryon number and the lepton number, but more specific models increase the number of distinct values. Quarks, for example, add five more flavor numbers: isospin (upness vs. downness), strangeness, charm, topness and bottomness (the last four are literally just the number of strange, charmed, top and bottom quarks, minus the corresponding anti-quarks).
|-
| Color charge
| Coordinate system with R, G and B axes
| The primary {{w|strong nuclear force}} has six mutually attractive charges, arranged in three perpendicular axes each analogous to electric charge. These charges are commonly referred to as "{{w|Color charge|color}}" and the three axes are given the names of the three primary colors of light: Red, Green and Blue. The black dots in the diagram represent the actual colors while the white dots are the anti-color charges: anti-Red (colored cyan in diagrams), anti-Green (magenta) and anti-Blue (yellow). To complete the analogy, a color charge of zero is referred to as "White". The names of these charges are purely allegorical, but they do make it convenient to refer to them, especially in diagrams.

The color of a particle not confined by the strong force must be White, either as the sum of a color and its anti-color (as in a meson), as the sum of RGB or anti-RGB (as in a baryon), or as a sum of those sums (As in tetra-, penta- or hexaquarks). The attraction of the strong nuclear force is so strong that attempting to separate two quarks from each other creates enough energy to create two new quarks, which then bind to the original quarks. This property is known as "confinement" and means that color charge can never be observed directly.

Randall is incorrect in stating "Quarks only", since {{w|gluon}}s (the particle that carries the color force) are themselves colored. However, the colors of gluons are much more complicated, with a total of eight distinct superpositions of every possible color-anticolor pair. The fact that gluons are subject to the force they mediate also means that the strong force has a defined radius of effect, unlike the electromagnetic force, whose gauge bosons (the photon) are uncharged.

This is the last entry currently used to describe particles by particle physicists.
|-
| Mood
| 5 emojis on a number line ranging from angry to joyful
| Particles are not considered to have mood, even in the allegorical way they have color or flavor, but Randall implies that there is a quantized 5 point scale (from "angry" to "ecstatic") which would have some effect on the properties of the particle. This would be more appropriate for measuring customer satisfaction. Charts such as this are also sometimes used in medicine to indicate levels of pain, and in some psychiatric treatments as a quick way to track changes in the patient's condition.

In grammar, {{w|Grammatical particles|particles}} are a nebulous class of words, usually defined by a lack of declension or conjugation (such as prepositions in English). Some languages use particles instead of or in addition to "standard" declension/conjugation, much like auxiliary verbs are used in English. These particles may well carry "{{w|Grammatical mood|mood}}" as an attribute, as well as tense and aspect.
|-
| Alignment
| 3x3 grid with varying shades (columns Good-Evil, rows Lawful-Chaotic)
| A reference to the tabletop RPG ''{{w|Dungeons & Dragons}}'', where characters have an {{w|Alignment (Dungeons & Dragons)|alignment}} that is either Good, Neutral, or Evil (describing whether they have a propensity to help or harm others) and either Lawful, Neutral, or Chaotic (describing how much they care about organizations, social norms, and the status quo). Common examples of these alignments include Darth Vader (Lawful Evil), Superman (Lawful Good), Robin Hood (Chaotic Good), and the Joker (Chaotic Evil). This may be a reference to the now defunct names of the two heaviest known quarks ("truth" and "beauty").
|-
| Hit points
| [0,∞)
| Games (videogames, board games, CCGs, RPGs, etc.) often have values for players and other entities that represent {{w|Health (video game)|health}} (also called hit points or HP). Generally there is not necessarily a limit on this value, but it does not often go below 0 as the zero value is considered "dead" (or some equivalent).
|-
| Rating
| 5-star scale
| The five-star rating system is often used to rate films, TV shows, restaurants, and hotels. Randall has previously criticized this system in [[937: TornadoGuard]] and [[1098: Star Ratings]].

Interestingly, unlike the "Heat" rating with the chili peppers below, this scale doesn't have a creatively labeled number line, merely a rating (3.5, in this case). Considering [[1098]], could Randall be subtly self-deprecating here?
|-
| String type
| Bytestring-Charstring
| In computer science, this denotes what type of data is stored subsequent set of elements or a {{w|String_(computing)|string}}. This is likely a pun on {{w|String_(physics)|string}} types that appear in {{w|string theory}} and particle physics, and may also be a reference to {{w|Python (programming language)|Python}}, in which the difference between a byte string and a (Unicode) character string is a cause of difficulties for some programmers.
|-
| Batting average
| [0,100] in %
| In {{w|baseball}}, a player's {{w|batting average}} is calculated by dividing their hits by their at-bats. Instead of using the percent sign (%), it is usually presented as a number between 0 and 1 (inclusive) expressed as three decimal places with no leading zero: [.000, 1.000]. It is pronounced as though it is multiplied by 1,000: A batter with a batting average of .342 (which is very good) is said to be "batting three forty-two." A perfect batting average (unattainable except in very small samples) gives rise to the expression "batting a thousand." The 0-100 scale would be a better match for the batting average statistic in {{w|cricket}}, although percents would still not be used.
|-
| Proof
| [0,200]
| This refers to {{w|alcohol proof}}, which is the measure of the amount of ethanol in a beverage by volume. In the United States, 100 proof correspond to 50% alcohol, so the proof of a beverage is two times the percentage of ethanol, so the maximum value is 200.
|-
| Heat
| No jalapeño icons - 3 jalapeño icons, increasing
| Spicy dishes are sometimes measured by the intensity of the spicy flavor, usually ranging from values like "mild" to "hot". The gray jalapeño likely represents negligible or no spicy taste in the food. However, as an objective scale it is largely meaningless, since there is no reliable consistency in how these ratings are applied - what may be considered a 3-chilli dish in one establishment may only be a 1-chilli dish in another (as restaurants rarely if ever intend their dishes to be rated on the {{w|Scoville scale}}). The scale being unlimited may be a reference to the practice of some restaurants where a fourth or fifth chilli may be added to exaggerate the heat of their dishes.
|-
| Street value
| [0,∞) in $
| The value of an illegal good or a legal/controlled good when bought or sold by illegal means usually by or to the end user.
|-
| Entropy
| ''This already has like 20 different confusing meanings, so it probably means something here, too.''
| The term "entropy", which {{w|History of entropy|began}} as a {{w|Entropy (classical thermodynamics)|thermodynamic measure}}, has since been adopted {{w|Entropy in thermodynamics and information theory|by analogy}} into {{w|Entropy (disambiguation)|multiple seemingly unrelated domains}} including, for example, information theory. The table allows that the term "entropy" must mean something in the context of particle physics, but isn't certain whether it's the classical, modern {{w|Entropy (statistical thermodynamics)|statistical mechanics}}, Von Neumann's {{w|Von Neumann entropy|quantum entropy}}, or some other meaning.
|}

The title text says that in addition each particle has a password, but only hash of the password can be observed. This is a computer science reference. In computer science, properties (e.g. of an object or program) often can be changed with a single command. In physics as we observe it, properties can locally change with the environment. There are several {{w|Time-variation_of_fundamental_constants|experiments}}, whether physical constants are really time-const. Password hashing is the practice of hiding the password itself by storing only an irreversible representation of the password. Since the password itself is not stored, the password cannot ever be viewed by the user or a hacker (outside of the login page). This method is considered to be safest way of storing passwords. Password hashing using some {{w|key derivation function}} makes it impossible to steal passwords even if the server that stores hashes is cracked, unless the hash function is also broken, which should be a task which cannot be completed in any feasible time for sufficiently strong passwords. The title-text claims this is predicted by the {{w|cosmic censorship hypothesis}}, which in reality claims that a {{w|gravitational singularity}} must always be obscured by an event horizon (i.e.: there can't be a {{w|naked singularity}}). There is also a hint of quantum mechanics in the statement, as observation is one of the central concepts of the field, and {{w|Heisenberg's uncertainty principle}} actually states that it is impossible to observe (measure) some property of a particle with arbitrary precision when another one is known (e.g.: you can't determine the momentum and position of a particle). This makes the title text a mix of several domains, as was the above table.

==Transcript==
:<big>Particle Properties in Physics</big>
{| class=wikitable
! Property
! Type/scale
|-
| Electric charge
| [Scale with -1, 0 and +1 labeled and markings dividing the units in thirds. The endpoints are both dots.]
|-
| Mass
| [Scale with 0, 1kg and 2kg labeled and markings dividing the units into thirds. The endpoints are a dot on the zero end and an arrow on the other end.]
|-
| Spin number
| [Scale with -1, -½, 0, ½ and 1 labeled and no additional markings. The endpoints are both arrows, pointing out.]
|-
| Flavor
| (Misc. quantum numbers)
|-
| Color charge
| [Coordinate system of three axes labeled R, G and B clockwise from the 10 o'clock position. Endpoints are arrow-dots on all ends, with black dots for the labeled ends and white dots for the unlabeled ends.] (Quarks only)
|-
| Mood
| [Scale labeled with 5 emoticons, from angry to happy, and markings dividing the units in thirds. Endpoints are both arrows, pointing out.]
|-
| Alignment
| [3x3 grid with varying shades] Good-Evil, Lawful-Chaotic
|-
| Hit points
| [Scale starting from 0, markings but no labels other than zero. Endpoints are a dot at zero end and an arrow at the other end.]
|-
| Rating
| [Star rating of 3.5/5 stars.]
|-
| String type
| Bytestring-Charstring
|-
| Batting average
| [Scale from 0% to 100%. Endpoints are dot at 0% end and arrow-dot at 100% end.]
|-
| Proof
| [Scale from 0 to 200. Endpoints are dot at 0 end and arrow-dot at 200 end.]
|-
| Heat
| [Scale labeled with pepper icons, from 0 (a grayed-out pepper) to 3 black peppers. Endpoints are a dot at zero end and an arrow at the other end.]
|-
| Street value
| [Scale with $0, $100 and $200 labeled. Endpoints are a dot at zero end and an arrow at the other end.]
|-
| Entropy
| (This already has like 20 different confusing meanings, so it probably means something here, too.)
|}

{{comic discussion}}

[[Category:Charts]]
[[Category:Physics]]
[[Category:Baseball]]

2920: Survey Marker

2024-04-17T01:18:36Z

172.70.207.149: /* Explanation */ Citation needed for claim

{{comic
| number = 2920
| date = April 15, 2024
| title = Survey Marker
| image = survey_marker_2x.png
| imagesize = 740x272px
| noexpand = true
| titletext = Fun fact: The standard North American NAD83 coordinate system is misaligned from the actual Earth, off-center by about 7 feet. Someone knows where I am, and I'm in the wrong place.
}}

==Explanation==
{{incomplete|Created by a GUIDED MISSILE THAT MISSED THE TARGET DUE TO COORDINATE DRIFT - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
Cueball and Megan have found a {{w|survey marker}} on the ground. Survey markers such as these are used as reference points for the {{w|North_American_Datum|NAD 83 and NAVD 88}} geodetic reference systems, and the {{w|U.S. National Geodetic Survey}} has a database storing the coordinates of these markers. However, those two systems are being replaced by the {{w|National_Spatial_Reference_System#Datum_of_2022|New Datums of 2022}} (delayed to 2024-2025), which is primarily based on satellite systems and gravimetric models.

When they update the database, in the comic Cueball's altitude changes to compensate (as well as moving his horizontal location) leaving him panicking in mid-air. In reality, updating a database to change the coordinates of a location would not physically move items at the location{{citation needed}}. Arguably, if they did, no-one would much notice, since everything surrounding them should similarly move simultaneously to its corrected position as well. However, this shifting does not seem to apply to Megan, still standing next to the survey marker, perhaps due to being prepared for the update unlike Cueball.

The title text refers to NAD 83 being around 7 feet off. This is in reference to both {{w|World Geodetic System|WGS84}} and presumably the New Datum.

Absurd outcomes from differing survey standards was also the topic of [[2888: US Survey Foot]].

==Transcript==
:[Zoomed in view of a round marker on the ground, with small specks of dirt around it. There is one line of text going around the central part in the outer rim of the marker, with the first three words written around the top, and the last two words written around the bottom (thus not text that are going all the way around in one single line). Inside this rim there are more text on three lines. In the center there is a small cross in a triangle pointing up in relation to the central text. There are more unreadable text below the last line of text and around the inner part of the rim. And off panel voice, which in the next panel turns out to be Cueball, is written above the mark.]
:U.S. Geological Survey bench mark
:Elevation above sea 447 feet
:Cueball (off-panel): I love finding these survey markers. It's somehow reassuring.

:[Cueball and Megan are shown as they look down on the marker. Cueball has one leg on either side of the marker and Megan stands to the right.]
:Cueball: I like that someone, somewhere, knows where this spot is.
:Cueball: If I stand on it, they know where '''''I''''' am.

:[Cueball and Megan looks up at each other.]
:Megan: But the NAD83 and NAVD88 datums are getting replaced soon. That marker's coordinates could shift by like 5 feet.

:[Megan is looking down at her phone in her hand, standing in the same place in relation to the marker. Cueball is now floating in the air behind her 5 feet above the ground, while flailing with his arms and legs (as shown with three small curved lines at the end of either arm and above and below him.)]
:Megan: Oh look, it just got updated.
:Cueball: '''''Hey! Put me back!'''''

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Geography]]
[[Category:Fun fact]]

Talk:2892: Banana Prices

2024-02-09T19:12:31Z

172.70.207.149: Context

Is it a linear extrapolation? Or does it only appear so because the Y axis is logarithmic? Inflation is logarithmic, since it's expressed in percentages. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 17:04, 9 February 2024 (UTC)
:Well, the lines of extrapolation are (invoked as) linear, by dint of the height above the baseline being preconverted to a logarithmic function of the represented axial value. Rather than taking exponential-style extrapolation of data and 'happening' to linearise it through the subsequent transformation, it is almost certainly going to have been merely establishing some trend point(s) through which such an exponential would pass and using that to directly guide the linear plot that (on the converted scale) is the functionally equivalent result to doing it with ''every'' point. [[Special:Contributions/172.71.178.77|172.71.178.77]] 17:26, 9 February 2024 (UTC)

OK, so... my reading of the comic after studying it for a while is that Randall is making a sophisticated meta-joke about 'lying with data" and unreliable precision and how easy it is to be fooled. He knows, of course, that this graph's "prediction" is completely arbitrary and is likely to be VERY wrong. He is intentionally breaking a whole set of statistical best practices in this graph. If so, I think this comic is one of the most-layerd and subtle he's ever done. You have to know a lot about statistical best practices to see what he's really doing here. .. What's so interesting to me is him using the voice of the caption-writer -- usually good ol' reliable Randall -- to actually be the butt of the joke. ... If someone wants to claim that this is more sarcasm than "unreliable narrator," I guess that's a reasonable interpreation, but the use of the word "probably" in the caption makes me think we're supposed to take the caption-writer seriously. [[User:Laser813|Laser813]] ([[User talk:Laser813|talk]]) 18:38, 9 February 2024 (UTC)

Bananas are a special case: Basically we have a monoculture. With no genetic variations, bananas are highly vulnerable to the emergence of specialized pathogens and currently Panama 4 is threatening the Cavendish banana: https://www.theguardian.com/food/ng-interactive/2022/apr/14/climate-crisis-food-systems-not-ready-biodiversity So trying to fit this question of "will it go extinct soon?" into a smooth inflation price increase might be another butt of the joke [[Special:Contributions/172.71.246.88|172.71.246.88]] 18:49, 9 February 2024 (UTC)

Randall is way off-base here, by about an order of magnitude. The episode is about Bluth frozen bananas, which require refrigeration, chocolate, and custom labor; they also do not have the economies of scale of fresh bananas. The AD wiki says the prices are >$1; in "Top Banana," Maeby says they cost at least $1. This is a joke similar to the Pulp Fiction $5 milkshake; milkshakes have been much more expensive than that for years. --[[Special:Contributions/172.70.207.149|172.70.207.149]] 19:12, 9 February 2024 (UTC)

Talk:2872: Hydrothermal Vents

2023-12-26T16:52:48Z

172.70.207.149:

Current text: "... but could theoretically repopulate the surface if there were ever extenctions in the real world, as there have been in prior times." Should extenctions be extinctions?
[[Special:Contributions/172.69.195.176|172.69.195.176]] 12:01, 26 December 2023 (UTC)
:I was the one who (somehow mis)typed that, and indeed it should. If it hasn't been corrected by the time I get there, I'll do it. (Related, or not, but my on-screen keyboard appears to have updated over the last day or so. I had to reset it back to how I like it (no drag-to-type, no 'suggestions' bar above, remove the emoji button) and I'm sure it's also resized vertically, meaning I may mis-hit 'keys' on different rows, but not sure how I got 'e' instead of 'i'. Put it down to an inexicable Thinko, perhaps?) Also, I might change to make clear that (e.g.) hydrothermic crustacea might (re)redevelop 'regular' phototropic versions (or those atuned to photosynthesis-rooted food webs, or something), instead of being chemosynthesis-rooted. But that could be too difficult to summarise.
:...darnit, where's the tilde on this changed OSK? (Ah, there it is. Looks like they added a 'handy' numberpad setting, which I need to switch away from to get where the ~ still resides!) Yet another bothersome 'improvement' that I'll have to see if I can deal withn in the settings... Sheesh... [[Special:Contributions/172.69.194.225|172.69.194.225]] 14:18, 26 December 2023 (UTC)

Regarding the ethology of the benthic species of ''Rangifer tarandus'', the May-Marks natigational hypothesis has now been largely supplanted by the idea of the "angler deer", in which the low-frequency luminescence around the covering of the turbinate bones is used used as a lure, attracting abyssopelagic subspecies of ''Daucus carota'' that would ordinarily avoid regions of such extreme temperature. [[User:Yorkshire Pudding|Yorkshire Pudding]] ([[User talk:Yorkshire Pudding|talk]]) 12:23, 26 December 2023 (UTC)

This may well be the most dark Christmas comic ever in the history of xkcd! And not even really funny. Don't get my wrong I can still be amused but find it a bit out of the ordinary for saying Merry Christmas ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 13:36, 26 December 2023 (UTC)
:Oh, don't worry, this only traps ''benthic'' santas. As you'll have noticed, your own Julemanden has remained unaffected... As you can tell by the lack of charboiled reindeer ''or'' nisser, just beyond the 'chimneys' themselves. [[Special:Contributions/172.69.194.225|172.69.194.225]] 14:18, 26 December 2023 (UTC)

The link to an article explaining ''Buffy the Vampire Slayer's'' slayer replacement system, is humorous & mostly apropos, but I feel that a link to ''The Santa Clause'' would be much more directly relevant?

The ecology and behavior of "benthic santas" (putative taxon Abyssosanta bathytroglodyta) may have been [ahem] profoundly different from the extant species. The clues are few, but they support the hypothesis that A. bathytroglodyta sought out chimney-like structures and other crevices for shelter and food, to which they were perhaps guided by a symbiosis with Rangiferpisces rubrum, the red-antlered reindeerfish. Predation pressure from hydrothermal vent chimney mimics (Nigroventus abyssosantavorus) would have driven A. bathytroglodyta to the surface. In a possible analogy, the Atlantic clawed lobster, Homarus americanus, initially a deep-water species, was driven to the intertidal zone by predation from Gadus gadus (cod) and other large fish - only to be confronted with intolerable predation pressure from humans, to which they eventually adapted. By this model, the modern Santa (Santa donator evolved from its precursor species under strong human selection pressure. At least S. donator was, from its precursor's traits, preadapted for a high-pressure existence, and for the cold and dark of the Arctic. [[Special:Contributions/172.70.214.80|172.70.214.80]] 16:51, 26 December 2023 (UTC)