explain xkcd - User contributions [en]

Talk:2467: Wikipedia Caltrops

2021-05-25T03:44:34Z

162.158.75.202:

seems more like flares (which distract) than caltrops (which physically impair) to me. [[Special:Contributions/162.158.222.122|162.158.222.122]] 16:31, 24 May 2021 (UTC)

I'd say "Well, I now know what I'm doing for the next few hours!", except that I suspect that this isn't even going to be the half of it... [[Special:Contributions/141.101.98.46|141.101.98.46]] 16:37, 24 May 2021 (UTC)
::👍 [[User:OhFFS|OhFFS]] ([[User talk:OhFFS|talk]]) 21:45, 24 May 2021 (UTC)

except 'caltrops' is a funnier word than 'flares' and we get the gist anyway. [[Special:Contributions/108.162.237.4|108.162.237.4]] 17:23, 24 May 2021 (UTC)

no WAY randall is a jon bois fan
[[Special:Contributions/173.245.52.175|173.245.52.175]] 17:38, 24 May 2021 (UTC)

Flares draw fire to prevent missiles from reaching their target. Caltrops impede the actual motion of the vehicle. If the links are as distracting as Randall implies, I think his choice makes sense!
[[Special:Contributions/108.162.215.92|108.162.215.92]] 00:34, 25 May 2021 (UTC)

Flares do " draw fire" but because they are more visible to heat seakeking missiles than engine jet engine heat. This seems like a solvable problem, missile and flare wise.[[Special:Contributions/162.158.75.202|162.158.75.202]] 03:44, 25 May 2021 (UTC)

Shouldn't the links be given as QR codes rather than plain text, which would have to be read and re-typed into a device with a suitable web browser? [[Special:Contributions/108.162.219.28|108.162.219.28]] 00:54, 25 May 2021 (UTC)
:Having to type the URL would be more distracting to driver of the car behind? And it's not like it is exactly easy to aim your phone camera to and read the QR code on a flying banner from the car in front of you, in addition to using smartphone mean traffic law violation. And text in URL also spoiler the link content a bit to invite interest. [[Special:Contributions/172.70.49.196|172.70.49.196]] 02:45, 25 May 2021 (UTC)

1475: Technically

2021-05-23T21:56:41Z

162.158.75.202:

{{comic
| number = 1475
| date = January 19, 2015
| title = Technically
| image = technically.png
| titletext = "Technically that sentence started with 'well', so--" "Ooh, a rock with a fossil in it!"
}}

==Explanation==
When the word "technically" is used to start a sentence, the remainder of the sentence tends to follow one of a number of patterns:

{| class="wikitable"
! Sentence pattern
! Example
|-
| An explanation which is far more complex than the listener needs/wants.
| "Technically, a {{w|Hemiptera|bug}} is a very specific order of insects, including aphids, cicadas..."
|-
| A justification of a particular (usually unpopular) viewpoint through an unusual technical definition.
| "Technically a tomato is a fruit, so there is no reason it shouldn't be used in a fruit salad."
|-
| A pedantic overapplication of rules or laws, often to avoid the inquiry through a technical and usually unrelated loophole.
| [http://factually.gizmodo.com/technically-american-flag-napkins-are-illegal-1599774198 "Technically, American flag napkins are illegal."]
|-
| The speaker repeating a 'little known fact', believing that he/she sounds incredibly knowledgeable. In many cases these 'facts' are actually false, as in the example to the right (see {{w|Ten_percent_of_brain_myth|the 10% of the brain myth}}).
| "Technically we only use 10% of our brains, so imagine what we could do if we used 100%"!
|-
| An attempt to disguise an outright lie as a simple misunderstanding in point of view.
| "Technically, we're not cows. We're aardvarks."
|}

[[Cueball]], possibly representing [[Randall]], has decided that any sentence beginning with the word "technically" is highly likely to be completely worthless for him to listen to; so whenever he hears it at the beginning of a sentence, he allows himself to be distracted by anything which happens to be around.

There are many cases where an item is classified in what appears to be an illogical way. Some fairly well known examples are 'Tomatoes are a fruit', 'Strawberries are not berries', 'Peanuts are not nuts' and so on. The reasoning behind these seemingly unusual classifications is typically down to the technical definition of the class, which may differ from the intuitive understanding that the general public have learned. It is not unusual for people to try and appear knowledgeable by demonstrating that they are aware of correct technical classifications.

[[White Hat]] starts to pedantically answer the typically incredulous rhetorical question “Are you on drugs?!” by explaining that according to the technical definition, food is classed as a drug. This classification is false due to his incorrect interpretation of the word "drug" and lack of understanding of the role of food in human physiology, and would fall under the fourth example in the chart above. Indeed, "drug" is defined as "a substance used to treat an illness, relieve a symptom, or modify a chemical process in the body for a specific purpose", followed by a secondary definition of "a psychoactive substance, especially one which is illegal and addictive". Food, on the other hand, is defined as "any substance that can be consumed by living organisms, especially by eating, in order to sustain life". In other words, food is consumed in order to sustain the normal, innate state of the body, while drugs are consumed in order to alter certain states. The Wikipedia {{w|drug|article}} for drug goes so far as to explicitly disqualify food from the definition of “drug.”

Regardless of whether or not the classification was valid, Cueball has already allowed himself to be distracted by a passing bug.

The title text starts to pedantically over-apply Cueball's rule to the comic panel, noting that technically White Hat's sentence started with the word 'well' instead of the word 'technically', and thus Cueball is wrong to have ignored it. This would fall under the second or third example in the chart. Halfway through the sentence, this argument is cut off by the discovery of a rock with a fossil in it, correctly applying the rule to a sentence that began with the word "technically".

This comic is similar to [[1240: Quantum Mechanics]], in that they both suggest ignoring sentences containing a certain word or phrase indicating a pedantic attitude.

==Transcript==
:[White Hat talks to Cueball who looks at a flying insect.]
:White Hat: Well, technically, food is a "drug", since it's a substance that alters how your body works, so yes, I'm—
:Cueball: Hey, look at that weird bug!

:[Caption below the panel:]
:My life improved when I realized I could just ignore any sentence that started with "technically."

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Food]]
[[Category:Pedantic]]

Talk:2202: Earth-Like Exoplanet

2019-09-15T07:32:29Z

162.158.75.202:

I'm assuming this is in reference to exoplanet K2-18b? [[Special:Contributions/108.162.241.52|108.162.241.52]] 18:30, 13 September 2019 (UTC)
: I was thinking the same thing. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 18:41, 13 September 2019 (UTC)
: Note that K2-18b was actually "discovered" way back in 2015 by the Kepler Space Observatory. The recent news was the detection of water vapor in the atmosphere of the planet. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 04:36, 14 September 2019 (UTC)

I'm seeing the actual comic alt-text as "Fire is actually a potential biosignature, since it means something is filling the atmosphere with an unstable gas like oxygen. If we find a planet covered in flames, it might be an indicator that it supports lifeâ€”or used to, anyway, before the fire." Note the tab before "actually" and the odd characters after "life". But that's not what it has on this site. Is that difference intentional?[[Special:Contributions/172.68.70.70|172.68.70.70]] 19:07, 13 September 2019 (UTC)
: I've noticed a similar difference on other pages. For me, there are glitches in the title text on many XKCD pages, but here they appear as I assume they should. [[User:DanTheTransManWithoutAPlan|DanTheTransManWithoutAPlan]] ([[User talk:DanTheTransManWithoutAPlan|talk]]) 19:23, 13 September 2019 (UTC)
::AFAIS the XKCD-webserver claims incorrectly that the charset of the page is ''windows-1252''. --[[User:DaB.|DaB.]] ([[User talk:DaB.|talk]]) 19:49, 13 September 2019 (UTC)
::: Yes. If you change your browser's encoding to Unicode, it shows up properly -- though the tab before "actually" is still there. --[[User:Aaron of Mpls|Aaron of Mpls]] ([[User talk:Aaron of Mpls|talk]]) 00:24, 14 September 2019 (UTC)

A non-tidally-locked planet (like ours) needs to be firmly in a habitable zone (like ours) to allow the daily and seasonal cycles (like ours) to not send every square foot of the planet well outside any 'reasonable' range of conditions so that there's no possible adaptation possible by life (like ours).

OTOH, a tidally-locked planet probably sustains a belt of habitability upon it somewhere between the most sun-scorched face-centre and the most astronomy(-if-not-''astronomer'')-friendly area of the farside, and it may even let the lifeforms survive more extreme stellar 'seasons' than a swirling planet could, so long as that belt doesn't move so far as to 'lift off' either face, if there exist effective migration paths available for the mobile life and hibernation/aestivation states and hidey-holes for those that are forced/choose to be immobile.

There's the argument about a constant hurricane-force surface wind passing between hot and cold hemispheres, but that assumes a reverse upper flow in atmospheric cells (or a phase-cycle of liquid?) which would promote and reinforce elements of turbulance that might interact with 'surface' features (perhaps subsurface, in waterworld environment) to create areas that are lucuna in the chaos, 'islands' of calm.

Though with many theories of abiogenesis and evolution requiring some form of cycling conditions to filter out the unadaptable and promote the adaptable, so the actual 'interesting' zones are probably in habitable-edges surrounding the habital spots of constancy within the habitable belt upon the habitable-zone planet.

It's a bit moot how all this would work, though, given our knowledge based upon post-facto knowledge of a sample of one life-bearing planet. Hard to know how little or much Earth is typical compared with everyone else. At least until my people come back to rescue me, when I'll have to remember to catch up on the basic classes I've obviously missed. [[Special:Contributions/162.158.34.210|162.158.34.210]] 22:01, 13 September 2019 (UTC)

I thought "between the swinging blades" was just a metaphor - [[Special:Contributions/162.158.214.148|162.158.214.148]] 05:41, 14 September 2019 (UTC)
:it is and should be changed in the explanation. It is all the things mentioned by Megan that are the swinging blades--[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 07:42, 14 September 2019 (UTC)
::But anyone who can give some examples where this sentense is used in the real world? I could not find much using google. Would like it in the explanation, better than what I have done so far. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 21:25, 14 September 2019 (UTC)
::What came to mind for me is the blade-on-a-pendulum from Poe's short story "The Pit and the Pendulum", except that there were multiple ones that a life form would have to avoid being hit by. Do a google image search on "Pit and the Pendulum" to see what I am talking about. [[User:Redbelly98|Redbelly98]] ([[User talk:Redbelly98|talk]]) 22:30, 14 September 2019 (UTC)
:::That's what came to my mind as well. Not necessarily from this short story, but just a general depiction of a hellish place with fire and deadly (torture) devices. [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 07:10, 15 September 2019 (UTC)
:::I was reminded of the climax of Umberto Eco's novel "Foucault's Pendulum"... considering the previous comic, Randall may have been thinking the same.[[Special:Contributions/172.68.58.83|172.68.58.83]]
:I am not sure it's a metaphor. I thought it was Randall's first (of two) instances of something too ridiculous to actually be observed, the other being the screaming. The other stuff mentioned before the blades are all plausible observations. [[User:Redbelly98|Redbelly98]] ([[User talk:Redbelly98|talk]]) 22:30, 14 September 2019 (UTC)

Mentions of swinging blades is just a trope of an absurd life threatening hazard. Anyway, mentions of them always remind me of [https://ogn.theonion.com/video-game-characters-denounce-randomly-placed-swinging-1819565686?_ga=2.64683307.585344065.1568532178-1255070246.1556608491 this 19 year old joke article from the onion].--[[Special:Contributions/162.158.75.202|162.158.75.202]] 07:32, 15 September 2019 (UTC)

Talk:2045: Social Media Announcement

2018-09-12T12:00:11Z

162.158.75.202: Forgot to sign it, d'oh.

I doubt it's Wil-Wheaton-specific. I've seen a fair number of people talk about quitting some form of social media or another (though usually not ALL of it); Wheaton's just the biggest (that I'm now aware of). [[Special:Contributions/162.158.75.202|162.158.75.202]] 12:00, 12 September 2018 (UTC)

Talk:2045: Social Media Announcement

2018-09-12T11:59:31Z

162.158.75.202: Um, added a comment. First?

2039: Begging the Question

2018-09-03T05:36:02Z

162.158.75.202: /* Explanation */ Prescriptivist view is ahistoric

{{comic
| number = 2039
| date = August 29, 2018
| title = Begging the Question
| image = begging_the_question.png
| titletext = At least we can all agree on the enormity of this usage.
}}

==Explanation==
This comic makes fun of the constant battle between those who maintain a {{w|Linguistic prescription|prescriptive view of language}} and those who have a {{w|Linguistic description|descriptive view}}. In the prescriptive view, language has fixed rules and fixed usage, and any usage that does not adhere to established rules is incorrect. In the descriptive view however, language is malleable and any usage can be correct if it is common and understood by most people.

The comic specifically calls out two phrases which are commonly misused in the prescriptive sense, and whose meanings have changed in modern usage in the descriptive sense:

;Nauseous
''Nauseous'' in its supposedly 'proper' form means "causing {{w|nausea}}", while ''nauseated'' means affected with nausea.

Prescriptively speaking, it is only correct to use the word "nauseous" to describe the food item since that was the cause of Ponytail's nausea. Saying "the food made her nauseous" would be interpreted, by a prescriptivist, as meaning the food somehow caused her (her body, her appearance, etc.) to become so disgusting that she now causes other people to feel nausea. As White Hat states, the proper phrasing is that the "the food was nauseous", and it "made [her] feel nauseated".

Both historically and in modern usage, however, "nauseous" is a valid synonym of "nauseated". It is difficult, if not impossible, to cite an era of history when most people would not understand "she is nauseous" to mean she does not feel well.

;Begging the question
{{w|Begging the question}} originally referred to a logical fallacy where an argument assumed its conclusion. The phrase first meant to question (beg) the original question. In modern usage, it has come to mean to "raise a question or point that has not been dealt with". This is often a point of contention for prescriptivists. However, as the caption explains, Cueball has an entirely different meaning for this phrase that he created himself: "fight a losing battle against changing usage". This is actually a meta-meaning, as that is actually the common activity of prescriptivists who complain about incorrect usage; it's a losing battle, because language change is inevitable and unstoppable. And specifically, trying to preserve the original meaning of "begging the question" is a losing battle.

Ponytail might recognize that her exposure to nauseous food has both nauseated her and caused her to become nauseous to Cueball. The question is not merely begged it is missed.

The title text also plays on another word commonly argued over by prescriptivists. "Enormity" in its classical usage means either extreme wickedness or a monstrous offense or evil, though it is more commonly used in modern writing as a synonym for enormousness (i.e. largeness in size). The title text exploits the lexical ambiguity that this creates.

==Transcript==
:[Ponytail and White Hat standing next to each other talking. White Hat has raised his hand while Cueball stands behind him.]
:Ponytail: That food made me nauseous.
:White Hat: No, the ''food'' was nauseous. It made you feel ''nauseated''.
:Cueball: Come on, you're just begging the question.

:[Caption below the frame:]
:I annoy people on all sides by using "beg the question" to mean "fight a losing battle against changing usage".

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring White Hat]]
[[Category:Language]]

2035: Dark Matter Candidates

2018-08-22T04:24:10Z

162.158.75.202: /* Explanation */ There's more than one space western with cows.

{{comic
| number = 2035
| date = August 20, 2018
| title = Dark Matter Candidates
| image = dark_matter_candidates.png
| titletext = My theory is that dark matter is actually just a thin patina of grime covering the whole universe, and we don't notice it because we haven't thoroughly cleaned the place in eons.
}}

==Explanation==
{{incomplete|Every section needs to be filled and explained. Do NOT delete this tag too soon.}}
{{w|Dark matter}} is a hypothetical form of matter used by the vast majority of astronomers to explain the far too high apparent mass of objects at large scales in our universe. In galaxies, stars are orbiting faster than the gravitational force of the sum of the masses of visible matter in the galaxy could cause, and entire galaxies are observed moving much faster around each other than their visible masses could explain. In galactic collisions, the mass can appear to separate from the visible matter, as if the mass doesn't collide but the visible matter does. A small handful of galaxies have been observed to not have this property, suggesting that it is a *thing* that a galaxy can have more or less of and is separable from. At scales of our solar system, those effects are too small and can't be measured. In cosmology, dark matter is estimated to account for 85% of the total matter in the universe.

This comic gives a set of possibilities for what dark matter could possibly be, charted by mass from smallest (given in {{w|Electronvolt#Mass|electronvolts}}) to largest (given in kilograms). Masses in the range 10-15 kg to 10-3 kg are given in grams together with appropriate prefixes, while the ton takes the place of 103 kg.

Only massive objects ranging from subatomic particles up to super massive ones are covered in this comic. There are also {{w|Dark matter#Alternative hypotheses|alternative hypotheses}} trying to modify general relativity with no need of additional matter. The problem is that these theories can't explain all different observations at once. Nonetheless dark matter is a mystery because no serious candidate has been found yet.

The joke in this comic is that the range of the mass of the possible particles and objects stretch over 81 powers of ten, with explanations suggested by astronomers covering only some portions of that range. [[Randall]] fills the gaps with highly absurd suggestions.

;Axion
An {{w|Axion|axion}} is a hypothetical elementary particle that might be a component of dark matter.

;Sterile neutrino
{{w|Sterile neutrino|Sterile neutrinos}} are hypothetical particles interacting only via gravity. It's an actual candidate for dark matter.

;Electrons painted with space camouflage
{{w|Electron|Electrons}} are fundamental particles which compose the outer layers of atoms. A large number of electrons in the galaxy would be relatively easy to detect, as they not only interact with light (which dark matter does not appear to), but also have a strong electric charge. Presumably, space camouflage is a positively-charged coating which prevents electrons from interacting with light. (Needless to say, this is not an actual candidate for dark matter.) The mass of an electron is about 0.5 MeV which fits well into the graph.

;Neutralino
A {{w|Neutralino|neutralino}} is a hypothetical particle from {{w|Supersymmetry|supersymmetry}}, it is an actual candidate for dark matter.

;Q-ball
In theoretical physics, a {{w|Q-ball}} is a stable group of particles. It's an actual candidate for dark matter.

(In billiards, a cue ball is the white (or yellow) ball hit with the cue in normal play. In addition, [[Cueball]] is the name explainxkcd uses for the most common xkcd character.)

;Pollen
{{w|Pollen}} is a joke candidate, though people with seasonal allergies may suspect that the universe is genuinely made up entirely of pollen in the springtime.

;No-See-Ums
{{w|Ceratopogonidae|No-See-Ums}} are a family (Ceratopogonidae) of small flies, 1–4 mm long, that can pass through most window screens. Another joke candidate.

;Bees
Insects of the clade {{w|Bee|Antophila}} are major pollinators of flowering plants. In recent years {{w|Colony collapse disorder|bees have been disappearing}} at an alarming rate; {{w|The Stolen Earth|Doctor Who explained}} that they are in fact aliens leaving Earth prior to a Dalek invasion.

;8-balls
In pool, the {{w|Pool (cue sports)|8-ball}} is a black ball numbered 8. It's a pun with Q-ball/cue ball. Unless undetected aliens have discovered billiards and become addicted to it, 8-balls are found only on Earth and are, hence, unlikely dark matter candidates.

;Space Cows
Cows are {{w|Bovinae|bovines}} extensively farmed on Earth for milk and meat. Although there is folklore concerning cows {{w|Hey diddle diddle|achieving circum-lunar orbits}}, not to mention their appearance on a {{w|Shindig (Firefly)|beloved space western TV show}} (and [https://tvtropes.org/pmwiki/pmwiki.php/Main/SpaceWestern others less-remembered]), they have yet to be found elsewhere in the Universe. In the television show "Too Close for Comfort", one of the characters is the cartoonist of a comic strip called "Cosmic Cow".

;Obelisks, Monoliths, Pyramids
While those human constructions are huge on a human scale, they're negligible at universe-scale. It would take a large number of such constructions, distributed through space, to replicate the effects of dark matter; while a scenario could be envisioned where enough such constructs existed, with properties and distribution allowing them to match observations, this is obviously not a likely explanation.
They often show up in fiction and pseudo-scientific literature as alien artifacts generating immense unknown power out of nowhere, with the most famous and influential example being the three monoliths from {{w|2001: A Space Odyssey (film)|2001: A Space Odyssey}} (with the largest having a mass of about 500,000 tonnes).

;Black Holes ruled out by:
{{w|Black hole|Black holes}} are known to occur in sizes of a few solar masses (about 1030-1031 kg) as remnants of the core of former big stars, as well as in quite large sizes at the centers of galaxies (millions or even billions of solar masses). But recent gravitational wave detections indicate that black holes at 50 or 100 solar masses also exist, though their origin is still not understood. Randall doesn't mention this but some astronomers hope that these could fill at least a part of the gap. Regardless, they have been ruled out as a candidate for dark matter for various reasons Randall has listed. He rules out all black holes in the range of approximately 1010 kg to 1033 kg even when below some gaps at the bars appear.

Except the last item, all range below the mass of the sun (2x1030 kg) while the smallest known black hole is about four solar masses.
* Gamma rays: If dark matter were black holes of this size, the black holes could be evaporating by the predicted {{w|Hawking radiation}}, and we'd see a buzz of gamma rays from every direction if many of those objects would exist. Nonetheless this radiation is still hypothetical and not been observed on any known black holes. Further more those objects would very small because the Schwarzschild radius of a 1012 kg black hole is approximately 148 fm (1.48×10−13 m), which is between the size of an atom and an atomic nucleus.
* GRB lensing: {{w|Gamma-ray burst|Gamma-ray bursts}} (GRBs) are the brightest events in the universe and have been observed only in distant galaxies. While gravitational microlensing (see below) is an astronomical phenomenon, it doesn't make much sense here. GRBs are short (milliseconds to several hours) and are often detected only by space-borne sensors for gamma-rays -- rarely at any other wavelengths. Measuring lensing effects would be very difficult. This [https://arxiv.org/abs/1406.3102 paper] discusses the probability of detecting lensing effects caused by {{w|Dark matter halo|galactic halo objects}} among the known GRBs given sufficient objects to represent the missing mass.
* Neutron star data: {{w|Neutron star|Neutron stars}} aren't black holes, but they're also very small highly compact objects at about 1.4-2.16 solar masses. While black holes can't be observed directly, neutron stars are detectable in many wavelengths. The number of them gives a clue about the number of black holes close to the mass of the sun, a number which is far too low to make up dark matter.
* Micro lensing: {{w|Gravitational microlensing}} is a gravitational lens effect, (the path of radiation is changed by passing through space bent by nearby mass). This was predicted by Einstein's {{w|General Relativity|Theory of General Relativity}} and was first confirmed in 1919 during a solar eclipse, when a star which was nearly in line with the sun appeared more distant to the sun than usual. Astronomers have found many so called {{w|Einstein ring|Einstein rings}} or Einstein crosses where a massive object in front of other galaxies bends the light toward us. Those massive objects may be black holes, but the number is far too low to explain dark matter.
* Solar system stability: Our {{w|Solar system|solar system}} is 4.5 billion years old and has been very stable since shortly after its formation. If not, we wouldn't exist. If dark objects at 1024 kg - 1030 kg (mass of Earth up to mass of Sun) accounted for dark matter and were distributed throughout galaxies, there should be many of them in the vicinity of our solar system and the system wouldn't be stable at all.
* Buzzkill Astronomers: Black holes above a certain size would be impossible to miss, due to the effects they have on nearby matter. But at the mass of some 1030 kg there must be many supernova remnants we still haven't found.

;Maybe those orbit lines on space diagrams are real and very heavy
Diagrams of our solar system (or any planetary system) often show lines representing the elliptical paths the planet takes around its sun. These lines don't show real objects, though. Astronomers just draw them on pictures of the solar system to show where the planets move. If you draw a line on a map to give someone directions, that line isn't an object in real life; it's just on the map. If these lines were real, they would be ''huge'' (Earth's would be 940 million km long (2π AU) and Neptune's would be 28 ''billion'' kilometers long). [https://www.youtube.com/watch?v=0fKBhvDjuy0 Powers of Ten (1977)] gives a good sense of just how large these orbit lines need to be in order to be visible in space diagrams. If these orbit lines were also very dense, they would have a huge mass and could possibly account for the missing 85% of the mass in the universe. But they would also constantly be impaling the planets, including the Earth, which would be a problem. Their mass would also affect planetary motions in ways which we would detect. A related worry about space travel was expressed in previous centuries; it was thought that the planets were embedded within {{w|Celestial spheres|crystal shells}} (spheres or Platonic solids), and a rocket into space could smash the shells and send planets plummeting to Earth. Another joke candidate.

;Title text
The title text refers to the fact that space is just vast emptiness where a little bit of dirt could be overlooked. Actually the mean density of detectable matter in the universe, according to NASA, is equivalent to roughly [https://map.gsfc.nasa.gov/universe/uni_matter.html 1 proton per 4 cubic meters]. And because this matter is mostly located in galaxies -- and inside there in stars and clouds -- the space between is even more empty. For comparison, one gram hydrogen consists of {{w|Avogadro constant|6.022 x 1023 atoms}}. Like at home wiping with a cleaning cloth in which we can see the dirt that wasn't clearly visible on the surface we have wiped, Randall believes that some few atoms more per cubic meter could stay undetected in the same way. This isn't true because in the space between galaxies astronomers can detect matter as it spreads over thousands or millions cubic light years. Atoms can't hide; there is always radiation.

==Transcript==
:Dark matter candidates:
:[A line graph is shown and labeled at left quarter in eV and further to the right in g together with some prefixes.]
:[The labels read:]
:µeV, meV, eV, keV, MeV, GeV, TeV, 10-18kg, ng, µg, mg, g, kg, TON, 106kg, 1012kg, 1018kg, 1024kg, 1030kg

:[All items are shown in bars ranging between two approximately values:]
:< 1 µeV - 10 meV: Axion

:1 eV - 10 keV: Sterile neutrino

:0.5 MeV (exactly): Electrons painted with space camouflage

:10 GeV - 10 TeV: Neutralino

:100 TeV - 10-17 kg: Q-ball

:1 ng - 100 ng: Pollen

:0.1 mg - 1 mg: No-See-Ums

:10-1 g (exactly): Bees

:10 g - 100 g: 8-balls

:100 kg - TON: Space cows

:TON - 109 kg: Obelisks, monoliths, pyramids

:109 kg - 1033 kg: Black holes ruled out by:
::109 kg - 1013 kg: Gamma rays
::1013 kg - 1017 kg: GRB lensing
::1015 kg - 1022 kg: Neutron star data
::1021 kg - 1030 kg: Micro lensing
::1024 kg - 1030 kg: Solar system stability
::1030 kg - 1033 kg: Buzzkill astronomers

:1033 kg - >1036 kg: Maybe those orbit lines on space diagrams are real and very heavy

{{comic discussion}}

[[Category:Science]]
[[Category:Physics]]
[[Category:Astronomy]]
[[Category:Line graphs]]

2034: Equations

2018-08-17T16:42:45Z

162.158.75.202: /* Explanation */ title text explanation

{{comic
| number = 2034
| date = August 17, 2018
| title = Equations
| image = equations.png
| titletext = All electromagnetic equations: The same as all fluid dynamics equations, but with the 8 and 23 replaced with the permittivity and permeability of free space, respectively.
}}

==Explanation==
{{incomplete|Created by an EQUATION. Do NOT delete this tag too soon.}}
This comic gives a set of equations supposedly from different areas of science in mathematics, physics, and chemistry. To anyone not familiar with the field in question they look pretty similar to what you might find in research papers or on the relevant Wikipedia pages. To someone who knows even a little about the topic, they are clearly very wrong and only seem even worse the more you look at them.

;All kinematics equations
:<math>E = K_0t + \frac{1}{2}\rho vt^2</math>
{{w|Kinematics}} describes the motion of objects without considering mass or forces.

This equation here literally states: "Energy equals a constant <math>K_0</math> multiplied by time, plus half of density multiplied by speed multiplied by time squared". The first term here is hard to interpret: it could be correct if <math>K_0</math> is a constant power applied to the system, but this symbol would more normally be used to denote an initial energy, in which case so multiplying by <math>t</math> would be wrong. The second term looks similar to the traditional kinetic energy formula <math>\frac{1}{2}mv^2</math> but with a density instead of the mass. This is then wrong without some accompanying volume term (on either side of the equation). This appears to be a play on the forumula: <math>s = ut + \frac{1}{2}\ at^2</math> where distance travelled (s) in a constantly accelerating environment, is determined by initial velocity (u), time (t) and acceleration (a)

;All number theory equations
:<math>K_n = \sum_{i=0}^{\infty}\sum_{\pi=0}^{\infty}(n-\pi)(i-e^{\pi-\infty})</math>
{{w|Number theory}} is a branch of mathematics primarily to the study the properties of integers.

Taken literally the equation says: "The nth K-number is equal to: for all i in 0 to infinity, for all pi in 0 to infinity; subtract pi from n, and multiply it with i minus e to the power of pi minus infinity". A twofold misconception can be seen here. The first is the reassignment of pi as a variable instead of the constant (3.14...). This might be a jab at how in number theory letters and numbers are used interchangeably, but where some letters are all of a sudden fixed constants. The second misconception is the use of infinity in the latter part of the formula. Naively this would signify that (with the reassigned pi values) the part in the power would range from minus infinity to zero. However, infinity is not a number and cannot be used as one without using a limit construct.

;All fluid dynamic equations
:<math>\frac{\partial}{\partial t}\nabla\cdot \rho = \frac{8}{23}
\int\!\!\!\!\!\!\!\!\!\;\;\bigcirc\!\!\!\!\!\!\!\!\!\;\;\int
\rho\,ds\,dt\cdot \rho\frac{\partial}{\partial\nabla}
</math>
{{w|Fluid dynamics}} describes the movement of non-solid material. In particular for gases, the density <math>\rho</math> is often the most interesting quantity (for liquids, this is actually just constant). A unique feature of fluid-dynamic equations is the presence of {{w|Advection|advection terms}}, which take the form of often strange-looking spatial derivatives. This equation turns this up to a new level by differentiating with respect to a differential operator <math>\nabla</math>, which does not make any sense at all. Also it has a contour integral which seems reminiscent to a closed-circle process like in a piston engine, but this does not really fit in the context (differential description of a gas), and it has a pair of {{w|Magic number (programming)|unexplained numbers}} <math>8</math> and <math>23</math>, probably alluding to the {{w|Heat capacity ratio|specific heat ratio}} which is often written out as the fraction <math>\tfrac{7}{5}</math>, whereas most other physics equations [[899: Number Line|avoid including any plain numbers higher than 4]].

The title text stating that the electromagnetism equation is the same as the fluid dynamics equation, but with the arbitrary 8 and 23 replaced with the permittivity and permeability of free space is likely because electromagnetism equations often have relations to fluid dynamics, and because those two constants appear in the vast majority of electromagnetism equations.

;All quantum mechanic equations
:<math>|\psi_{x,y}\rangle = A(\psi) A(|x\rangle \otimes |y\rangle)</math>
{{w|Quantum mechanics}} is a fundamental theory in physics which describes the nature at scales of atoms and below. It typically uses the {{w|Bra–ket notation|bra–ket notation}} in its formulae.

This equation takes a state psi in the dimensions of x and y and equates it to an operator A performed on psi multiplied by the same operator performed on the tensor product of x and y. Seeing as the state psi is already the tensor product of the states x and y, this is equivalent to performing the same unknown operator twice on psi, and unless this operator is its own inverse such as a bit-flip or Hermitian operator, this equation is therefore incorrect.

;All chemistry equations
:<math>\mathrm{CH}_4 + \mathrm{OH} + \mathrm{HEAT} \rightarrow \mathrm{H}_2\mathrm{O} + \mathrm{CH}_2 + \mathrm{H}_2 \mathrm{EAT}</math>
A {{w|Chemical equation|chemical equation}} is the symbolic representation of a chemical reaction in the form of symbols and formulae, wherein the reactant entities are given on the left-hand side and the product entities on the right-hand side. The number of each element on the left side must match them on the right side, the equation is balanced. The energy produced or absorbed in this process is not included in that formula.

This here is a modification of the combustion of methane. The correct form is often taught and a good example problem but obviously there are more chemistry problems.<math>\mathrm{HEAT}</math> is normally shorthand for {{w|activation energy}}, but in Randall's version it's jokingly used as a chemical ingredient and becomes <math>\mathrm{H}_2\mathrm{EAT}</math>, taking the hydrogen atom freed by the combustion equation shown. To deliver the punchline while maintaining proper stoichiometry, <math>\mathrm{OH}</math> (which should be <math>\mathrm{OH}^-</math>, since the oxygen keeps a free electron when it combines with a single hydrogen) is shown instead of <math>\mathrm{O}_2</math>. The proper methane combustion equation would be: <math>\mathrm{CH}_4 + 2 \mathrm{O}_2 \rightarrow 2 \mathrm{H}_2\mathrm{O} + \mathrm{CO}_2</math>

;All quantum gravity equations
:<math>\mathrm{SU}(2)\mathrm{U}(1) \times \mathrm{SU}(\mathrm{U}(2))</math>
This is more similar to experessions which appear in {{w|Grand_Unified_Theory|Grand Unified Theory}} (GUT) than general quantum gravity. Unlike some of the other equations, this one has no interpretation which could make it mathematically correct. This is similar to the notations used to describe the symmetry group of a particular phenomena in terms of mathematical {{w|Lie_Group|Lie Groups}}. A real example would be the Standard Model of particle physics which has symmetry according to <math>\rm{SU(3)\times SU(2) \times U(1)}</math>. Here, <math>\rm{SU}</math> and <math>\rm{U}</math> denote the special unitary and unitary groups respectively with the numbers indicating the dimension of the group. Loosely, the three terms correspond to the symmetries of the strong force, weak force and electromagnetism although the exact correspondence is muddied by symmetry breaking and the Higgs mechanism.

Of course, an expression missing an "=" sign, is difficult to interpret as an "equation", because equations normally express an "equality" of some kind. Nobody knows whether Randal refers to a horse here (equidae)

Randall's version clearly involves some similar groups although without the <math>\times</math> symbol it is hard to work out what might be happening. A term like <math>\rm{SU(U(2))}</math> has no current interpretation in mathematics, if anyone thinks otherwise and possibly has a solution to the quantum gravity problem they should probably get in touch with someone about that.

;All gauge theory equations
:[[File:All gauge theory equations.png]]
In physics, a {{w|Gauge theory|gauge theory}} is a type of field theory which is invariant to local transformations. The term gauge refers to any specific mathematical formalism to regulate redundant degrees of freedom.

This equation looks broadly similar to the sorts of things which appear in gauge theory such as the equations which define {{w|Yang–Mills_theory#Quantization|Yang-Mills Theory}}. By the time physics has got this far in, people have normally run out of regular symbols making a lot of the equations look very daunting. The actual equations in this field rarely go far beyond the Greek alphabet though and no-one has yet to try putting hats on brackets. The appearance of many sub- and superscripts is normal (this links to the group theory origins of these equations) and for the layperson it can be impossible to determine which additions are labels on the symbols and which are indices for an {{w|Einstein_notation|Einstein Sum}}.

The left-hand side <math>S_g</math> is the symbol for some {{w|Action_(physics)|action}}, in Yang-Mills theory this is actually used for a so-called "ghost action". On the right-hand side we have a large number of terms, most of which are hard to interpret without knowing Randall's thought processes (this is why real research papers should all label their equations thoroughly). The <math>\frac{1}{2\bar{\varepsilon}}</math> looks like a constant of proportionality which often appears in gauge theories. The factor of <math>i = \sqrt{-1}</math> is not unusual as many of these equations use complex numbers. The <math>\eth</math> symbol looks similar to a <math>\partial</math> partial derivative symbol especially as the {{w|Dirac_equation#Covariant_form_and_relativistic_invariance|Dirac Equation}} uses a slashed version as a convenient shorthand.

The rest of the equation cannot be mathematically correct as the choice of indices used does not match that on the left-hand side (which has none). In particle physics subscripts (or superscripts) of greek letters (usually <math>\mu</math> or <math>\nu</math>) indicate terms which transform nicely under Lorentz transformations (special relativity). Roman indices from the beginning of the alphabet relate to various gauge transformation propetries, the triple index seen on <math>p^{abc}_v</math> would likely come from some <math>\rm{SU(3)}</math> transformation (related to the strong nuclear force). Since <math>S_g</math> has none of these (and is thus a scalar which remains constant under these operations), we would need the right-hand side to behave in the same way. Most of the indices which appear are unpaired and so will not result in a scalar making the equation very wrong. For those not familiar with this type of equation, it is a similar mistake messing up units and setting a distance equal to a mass.

;All cosmology equations
:<math>H(t) + \Omega + G \cdot \Lambda \, \dots \begin{cases} \dots > 0 & \text{(Hubble model)} \\ \dots = 0 & \text{(Flat sphere model)} \\ \dots < 0 & \text{(Bright dark matter model)} \end{cases}
</math>
This is a parody of equations defining the {{w|Hubble's_law#Derivation_of_the_Hubble_parameter|Hubble Parameter}} <math>H(t)</math> although it looks like Randall has become bored and not bothered to finish his equation. Such equations usually have several <math>\Omega</math> terms representing the contributions of different substances to the energy-density of the Universe (matter, radiation, dark energy etc.). In this context <math>G</math> could be Newton's constant and <math>\Lambda</math> is the cosmological constant (energy density of empty space) although seeing them appear multiplied and on the same footing as <math>H</math> is unusual (the dot is entirely unnecessary). Choosing to make <math>H</math> a function of time <math>t</math> and not of redshift <math>z</math> is also unusual.

The second section looks like the inequalities used to show how what shape the Universe, based on the value of the curvature parameter <math>\Omega_k</math>. A value of 0 indicates a flat Universe (this more or less what we observe) whilst a positive /negative value indicates an open /closed curved Universe. Randall's choice of labels further makes fun of the field as both a flat sphere and bright dark matter are oxymoronic terms which would involve some rather strange model universes.

;All truly deep physics equations
:[[File:All truly deep physics equations.png]]
<math>\hat H</math> is the Hamiltonian operator, which when applied to a system returns the total energy. In this context, U would usually be the potential energy. However, there is also a subscript 0 and a diacritic marking indicating some other variable. Much of physics is based on Lagrangian and Hamiltonian mechanics. The Lagrangian is defined as <math>\hat L = \hat K - \hat U </math> with K being the kinetic energy and U the potential. Hamiltonian mechanics uses the equation <math>\hat H = \hat K + \hat U </math>. The Hamiltonian must be conserved so taking the time derivative and setting it equal to zero is a powerful tool. The principle of least action says allows most modern physics to be derived by setting the time derivative of the Lagrangian to zero.

==Transcript==
:[Nine equations are listed, three in the top row and two in each of the next three rows. For the bottom equation to the left, there are three equations in one, the part that is different in each equation is given on three lines and a bracket encompassing all three points to three dots indicating the equation continues. Below each equation there are labels:]

:E = K0t + 1/2 pvt2
:All kinematics equations

:Kn = ∑i=0∞∑π=0∞(n-π)(i-eπ-∞)
:All number theory equations

:∂/∂t ∇ ⋅ p = 8/23 (∯ ρ ds dt ⋅ ρ ∂/∂∇)
:All fluid dynamic equations

:|ψx,y〉 = A(ψ) A(|x〉⊗ |y〉)
:All quantum mechanics equations

:CH4 + OH + HEAT → H2O + CH2 + H2EAT
:All chemistry equations

:SU(2)U(1) × SU(U(2))
:All quantum gravity equations

:Sg = (-1)/(2ε̄) i ð (̂ ξ0 +̊ pε ρvabc η0 )̂ f̵a0 λ(ℨ̆) ψ(0a)
:All gauge theory equations

:H(t) + Ω + G⋅Λ ... > 0 (Hubble model) ... = 0 (Flat sphere model) ... < 0 (Bright dark matter model)
:All cosmology equations

:Ĥ - u̧0 = 0
:All truly deep physics equations

{{comic discussion}}

[[Category:Science]]
[[Category:Physics]]
[[Category:Math]]
[[Category:Chemistry]]
[[Category:Astronomy]]

992: Mnemonics

2018-01-08T05:16:37Z

162.158.75.202: /* Explanation */

{{comic
| number = 992
| date = December 19, 2011
| title = Mnemonics
| image = mnemonics.png
| titletext = 'Sailor Moon's head exploded once' and 'Some men have explosive orgasms' both work for the Great Lakes from west to east (Paddle-to-the-Sea order).
}}

==Explanation==
A {{w|mnemonic}} is any trick that makes memorization easier. For memorizing a sequence of names, a common type of mnemonic takes the initials of the sequence and invents another phrase to them. For example, the order of operations goes '''P'''arentheses, '''E'''xponentiation, '''M'''ultiplication and '''D'''ivision, '''A'''ddition and '''S'''ubtraction, and the traditional mnemonic goes '''P'''lease '''E'''xcuse '''M'''y '''D'''ear '''A'''unt '''S'''ally. To make them more memorable, mnemonics are usually quite silly and often vulgar. In this comic, Randall invents various scientific mnemonics, some of them as suggested replacements for traditional ones.

The category is listed at the top of the box, the members are listed below that. Then there is the traditional mnemonic that children are usually taught in school to help them remember. Below the comic is one or two options for new mnemonics suggested by Randall. The top one is illustrated in the frame.

*{{w|SI}} Prefixes are the prefixes for the systems of units from large to small and since there are so many, the mnemonic needs two lines.
**{{w|Karl Marx}}, as visible in the comic, was a German philosopher and economist who, among other things, popularized the ideas of socialism and communism. Central to his ideas was the {{w|dictatorship of the proletariat}}, or the working class achieved by an uprising of the lower class, which taken literally could be done using zeppelins.
**{{w|Microsoft}}'s {{w|Zune}} was a failed mp3 player that Microsoft brought to market. It never caught on.

*{{w|Taxonomy}} is the science of identifying and naming species. {{w|Katy Perry}}, portrayed in the panel, is an {{w|United States|American}} {{w|pop music}} singer, whose popular songs are ones like "Fireworks" or "I Kissed A Girl".

*In the geologic periods frame, the illustration is of a month's worth of "the pill", a common contraceptive.

*In {{w|Resistor}} Color Codes, {{w|Glenn Beck}} is in the illustration. Beck is a far-right conservative commentator in the US, who used to have a show on the {{w|Fox News}} Network.
**The prevailing mnemonic for resistor color codes is pretty terrible (and memorable), hence Randall's comment "none I care for".
**{{w|WP:BOLD|Be Bold}} is a {{w|Wikipedia}} credo. Respect Others may be a reference to {{w|WP:AGF|Assume Good Faith}}, another Wikipedia philosophy.

*In the Planets frame, the illustration is of Mary and Joseph, who in the story of the Birth of Jesus in the Bible, were mother and father to Jesus. However, Mary's conception of Jesus was from God and Mary was still considered a virgin. This mnemonic shows Joseph not really believing that story. Ironically the upstairs neighbour could have multiple meanings as you can't get more upstairs than heaven and thus God. Given the snarky tone of most xkcd comics take, it is likely a corporeal neighbor that is being suspected, but it is curious that a neighbor of the upstairs variety is specifically referenced especially given the lack of urban density in the time of Christ.
**Most traditional Planets mnemonics include Pluto, which was "officially" considered a planet before 2006.

*The {{w|Great Lakes}} mentioned by the title text are Superior, Michigan, Huron, Erie, and Ontario
**''{{w|Sailor Moon}}'' is a manga series.
**''{{w|Paddle-to-the-Sea}}'' is an illustrated children's book by {{w|Holling C. Holling}} about a toy boat's journey through the Great Lakes.

==Transcript==
:XKCD Presents:
:'''Some New Science Mnemonics'''

:''(Pattern goes:''
:''Subject''
:''Elements''
:''Traditional mnemonic''
:''Contents of frame''
:''New mnemonics)''

:'''Order of Operations'''
:Parentheses, Exponents, Division & Multiplication, Addition & Subtraction
:Traditional: Please Excuse My Dear Aunt Sally
:[Person having a shark delivered to his laptop.]
:Please Email My Dad A Shark
:or
:People Expect More Drugs And Sex

:'''SI Prefixes'''
:Big: Kilo, Mega, Giga, Tera, Peta, Exa, Zetta, (Yotta)
:Milli, Micro, Nano, Pico, Femto, Atto, Zepto, (Yocto)
:Traditional: [I never learned one.]
:[Graph of the declining profits of the Zune.]
:[Karl Marx delivering a number of zeppelins to a bunch of confused proletariats.]
:Big: Karl Marx Gave The Proletariat Eleven Zeppelins(, Yo)
:Small: Microsoft Made No Profit From Anyone's Zunes(, Yo)

:'''Taxonomy'''
:Kingdom, Phylum, Class, Order, Family, Genus, Species
:Traditional: King Philip Came Over For Good Sex
:Katy Perry: I'm not sure who doubts this, really.
:Katy Perry Claims Orgasms Feel Good Sometimes
:or
:Kernel Panics Crash Our Family Game System.

:'''Geologic Periods'''
:(Precambrian), Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Paleogene, Neogene
:Traditional: [I never learned one.]
:[A month's set of birth control pills.]
:PolyCystic Ovarian Syndrome Does Cause Problems That Judicious Contraceptives Partially Negate

:'''Resistor Color Codes'''
:Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White
:Traditional: [none I care for]
:[Glenn Beck holding the traditional "Nanobot Vaccine Chemtrail 9/11" sign.]
:"Big Brother Reptilian Overlords", yelled Glenn, "Brainwashing Via Ground water!!";
:or
:Be Bold, Respect Others; You'll Gradually Become Versatile, Great Wikipedians!

:'''Planets'''
:Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
:Traditional: My Very Excellent Mother Just Served Us Nachos
:[A pregnant Mary attempting to explain things to an incredulous Joseph with black hair and full beard]
:Mary's "Virgin" Explanation Made Joseph Suspect Upstairs Neighbor.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring real people]]
[[Category:Language]]
[[Category:Math]]
[[Category:Physics]]
[[Category:Biology]]
[[Category:Airships]]
[[Category:Sharks]]

Talk:1932: The True Meaning of Christmas

2017-12-23T19:18:04Z

162.158.75.202:

Is that guy with a black "santa cap" Black Hat? [[Special:Contributions/162.158.166.77|162.158.166.77]] 13:38, 22 December 2017 (UTC)
:Since most comics a not in color we safely can assume this Santa Hat as red. And if it should be Black Hat we would be able to identify him. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 14:01, 22 December 2017 (UTC)
::I definitely think it's supposed to be Black Hat Guy (Cueball's comment in the first panel fits). However, as we're uncertain, how about we use "Santa Hat" as in the below comments? -- [[User:Peregrine|Peregrine]] ([[User talk:Peregrine|talk]]) 15:13, 22 December 2017 (UTC)

:: based on speech patterns and topic choice, "Santa Hat" might be Beret Guy. [[Special:Contributions/162.158.75.202|162.158.75.202]] 19:18, 23 December 2017 (UTC)

Cant find a definition or recognition of the word autometalogolex. My google-fu is weak. ̶o̶r̶ ̶m̶a̶y̶b̶e̶ ̶h̶e̶ ̶m̶a̶d̶e̶ ̶i̶t̶ ̶u̶p̶ [[User:DPS2004|DPS2004'); DROP TABLE users;--]] ([[User talk:DPS2004|talk]]) 14:11, 22 December 2017 (UTC)
:"autometalogolex" is an invention by Santa Hat and consists of three prefixes "auto-", "meta-", and "logo-" and the word "lex" for law or statute. I'm still thinking about the deeper meaning.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 14:17, 22 December 2017 (UTC)
::Why dont we make it a word? UrbanDictionary is blocked where i am. [[User:DPS2004|DPS2004'); DROP TABLE users;--]] ([[User talk:DPS2004|talk]]) 14:25, 22 December 2017 (UTC)
:I added the meanings of each of the prefixes, as well as a more likely analysis of the root, though "auto-" is still up in the air. It can mean "self" as in the classic meaning, but it can also mean done without interaction (as in "automatic") which sounds closer to the usage present in the comic. I'll leave it to others to refine. We still need to better interpret the fullness of the title text. Respectfully, -- a guy stuck in a government cube all day. {{unsigned ip|108.162.237.184}}
::"auto-" means self. The roots of automatic mean "self-acting" or "self-thinking". [[User:Blaisepascal|Blaisepascal]] ([[User talk:Blaisepascal|talk]]) 15:26, 22 December 2017 (UTC)
:I'd say that Autometalogolex is the word that Santa Hat is making up for the definition that cueball gives "The act of looking up the definition of this word.", so my interpretation is that the definition of Autometalogolex is "The act of looking up the definition of autometalogolex" (so you are all autometalogolexing at this moment) -- [[Special:Contributions/141.101.77.152|141.101.77.152]] 15:06, 22 December 2017 (UTC)volivav
::So what is the word for the act of making up a word for this definition? [[Special:Contributions/172.68.141.82|172.68.141.82]] 00:41, 23 December 2017 (UTC)

:WDYT about my reference to autological words? [https://en.wikipedia.org/wiki/Autological_word] [[User:DarlingGeert|DarlingGeert]]

Doesn't the title text reference Rudolph the Red Nosed Reindeer? [[Special:Contributions/172.69.69.166|172.69.69.166]] 17:25, 22 December 2017 (UTC)
:Thanks, I thought about this too. Please check my additions. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 18:20, 22 December 2017 (UTC)

Tautometalogolex should be "the act of looking up the definition of autometalogolex". [[User:Ralfoide|Ralfoide]] ([[User talk:Ralfoide|talk]]) 18:23, 22 December 2017 (UTC)
:This phrase hits the nail on the head. And that's a recursive never ending action. And this recursion happens to all those "meaning of Christmas stories." --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 00:13, 23 December 2017 (UTC)

Talk:1930: Calendar Facts

2017-12-19T20:48:41Z

162.158.75.202:

Shouldn't it be "libration" not "libation"? Pretty sure drinking has nothing to do with it. Also pretty sure this is a mistake and not a clever alteration. [[Special:Contributions/162.158.62.57|162.158.62.57]] 16:41, 18 December 2017 (UTC)
:No, it's a clever alteration because "libration" is listed right above it. --[[User:Videblu|Videblu]] ([[User talk:Videblu|talk]]) 16:45, 18 December 2017 (UTC)
::That's just a mistake - he meant to write 'vibration'[[Special:Contributions/141.101.76.16|141.101.76.16]] 16:48, 18 December 2017 (UTC)
:::'Vibration' wouldn't make any sense, 'libation' is at least humorous, I vote it was no mistake. [[Special:Contributions/172.68.54.64|172.68.54.64]] 18:00, 18 December 2017 (UTC)
::::You're right - I don't know what I could have been thinking...[[Special:Contributions/141.101.76.16|141.101.76.16]] 08:49, 19 December 2017 (UTC)

I formatted the transcript into a bullet tree since I thought it was the closest equivalent you can get in plain text to the branching flowchart deal in the comic. I'm open to alternative suggestions. The biggest problem I encountered, and one I'd like to see resolved, is what to do in the case where two branching sections butt up against each other, e.g. winter/summer and solstice/Olympics. I used an arrow symbol ("→") on an in-between line just to separate the set of bullets, but if someone wants to change that, I'm up for it. [[User:Kenbellows|Kenbellows]] ([[User talk:Kenbellows|talk]]) 18:04, 18 December 2017 (UTC)
:I find the bullet tree legible for the last few long lines, but it's hard to follow a single path. I was thinking of using (option 1|option 2) syntax, but that would probably look messy too. [[Special:Contributions/162.158.91.29|162.158.91.29]] 18:10, 18 December 2017 (UTC)
:I think indenting when lines diverge and un-indenting when they converge would make it look nice and be easy to follow. I'm willing to do the work if others agree. [[Special:Contributions/162.158.74.9|162.158.74.9]] 23:58, 18 December 2017 (UTC)
::Could you do it? I don't see what it looks like. Is it similar to [http://www.explainxkcd.com/wiki/index.php?title=1930:_Calendar_Facts&oldid=14939 this]? [[Special:Contributions/162.158.88.68|162.158.88.68]] 06:16, 19 December 2017 (UTC)

Random error noticed - the line connecting "International Date" and "Mason-Dixon" to "Line" is drawn in the wrong color. [[Special:Contributions/162.158.75.136|162.158.75.136]] 18:57, 18 December 2017 (UTC)

Isn't the point with this comic that there is at least one valid path for every included element? I don't think Randall intended it to be a factorial combination because as the explanation suggests, most would be wrong/absurd/silly. But why not instead try to find some invalid element when it can be included in any possible path from end to end? Toyota Truck Month or Shark Week might not happen next year, who knows? Can anyone find any element that has no valid path at all? If not, then maybe the main explanation should be updated to fit the model recommended here.[[User:Lunar7|Lunar7]] ([[User talk:Lunar7|talk]]) 20:05, 18 December 2017 (UTC)
:I'm not sure there's any 'fact' that could be constructed that 'scientists are really worried' about. Unless it's something to do with Shark Week. Although having said that, it doesn't actually say that they're worried 'about it', so I guess you could append this to any otherwise true fact and still have something true, albeit non sequitous. [[Special:Contributions/141.101.76.16|141.101.76.16]] 08:53, 19 December 2017 (UTC)

== Generators ==

[https://www.pibweb.com/xkcd_calendar.php PIBWEB online generator of Calendar 'facts'] using this formula.

http://calendarfact.com/ (https://github.com/mstratman/calendarfact)

https://staab.github.io/xkcd-1930/

: Not sure who's responsible for this, but there seem to be a few errors. "Might (not happen/happen twice) this year" is missing "this year", and "the (harvest/super/blood) moon" is similarly missing "moon". Also, I see a part "happens at the same time every year" that I don't see in the comic. Are there any other additions; and is there a way to find them other than keep refreshing? -- [[User:Angel|Angel]] 18:40, 18 December 2017 (UTC)

:: Checked the source; looks like "at the same time" replaces "at the wrong time". Also, some of the options are missing a "." between the main tree and the title text or at the end of the sentence. (And for some reason every time I go to edit this talk page, the wiki logs me out) -- [[Special:Contributions/162.158.91.167|162.158.91.167]] 18:48, 18 December 2017 (UTC)

: The source is on [https://github.com/staab/xkcd-1930 github] - you can add pull requests to fix errors (I'll take care of the aforementioned errors).

Here's mine.

http://www.hearn.to/calendar.html

[[Special:Contributions/172.68.142.65|172.68.142.65]]

Here's one I wrote on jsFiddle. Glad I'm not the only one who read this and immediately thought, "I must code this!" [[Special:Contributions/172.68.34.64|172.68.34.64]] 21:29, 18 December 2017 (UTC)

https://jsfiddle.net/qa290hss/

Here's a GraphML gist that I knocked up:

https://gist.github.com/GeoSpark/0c64cb85ca8927175892f43f23ba1bdb

The only change I made was to "precession", "libration", etc by adding the word "the" in front because it reads better. At least to my British English sensibilities. YLMV.

I tuned it into a twitter bot: http://twitter.com/xkcd_cal_facts. It’s built using Tracery and cheapbotsdonequick.com

https://codepen.io/DouglasMeyer/full/YYqKzX/

== Equinox ==

I don't think this is the correct definition for equinox, the plane comprising the Earth orbit around the Sun is never perpendicular to the Earth's axis. During the equinox the sun rays arrive to the Earth perpendicular to the equator line, this would be better. [[Special:Contributions/172.68.62.238|172.68.62.238]] 22:10, 18 December 2017 (UTC)CBM

I agree with the comment above; the Earth's axis is always tilted 23 degrees from the plane of the orbit. There are times the North pole is tilted toward the Sun and times it is tilted away from the Sun. Twice a year (at the equinoxes) the tilt is perpendicular to the Sun. [[Special:Contributions/108.162.221.239|108.162.221.239]] 22:47, 18 December 2017 (UTC)

I've edited the descriptions - do they look better now? [[Special:Contributions/162.158.126.28|162.158.126.28]] 00:32, 19 December 2017 (UTC)

== Daylight Saving Time ==
Twice the description references locations that don't follow the common DST plan as 'other than the natural latitude would suggest'. The ''longitude'' would suggest a time zone, not the latitude. [[Special:Contributions/108.162.221.239|108.162.221.239]] 22:47, 18 December 2017 (UTC)

== Arbitrary decision by Benjamin Franklin ==
The electric charge on an electron is conventionally described as being negative. I was always taught that this was because of a more or less arbitrary decision made by Franklin. I suspect Mr Munroe is humorously conflating this with Franklin's connection to Daylight Saving Time.

== Favorite combinations ==

My personal favorite: “Did you know that Toyota Truck Month happens at the wrong time every year because of a decree by the pope in the 1500s? Apparently it’s getting worse and no one knows why. While it may seem like trivia, it is now recognized as a major cause of World War 1. [[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 02:06, 19 December 2017 (UTC)

Got this from the link to the fact generator, and I like that too, maybe because it is close to the one above, which I first saw now:
:Calendar Facts by xkcd
:Did you know that Shark Week drifts out of sync with the sun because of a decree by the pope in the 1500s?
:Apparently it's getting worse and no one knows why.
:While it may seem like trivia, it triggered the 2003 Northeast Blackout.
Damn sharks and pope decree. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:08, 19 December 2017 (UTC)

1889: xkcd Phone 6

2017-09-14T15:14:34Z

162.158.75.202: Added more details

{{comic
| number = 1889
| date = September 13, 2017
| title = xkcd Phone 6
| image = xkcd_phone_6.png
| titletext = We understand your privacy concerns; be assured that our phones will never store or transmit images of your face.
}}

==Explanation==
{{incomplete|All features need an explanation, the version number war and title text as well. Do NOT delete this tag too soon.}}

This is the sixth entry in the ongoing [[:Category:xkcd Phones|xkcd Phone series]], released the day after Apple announced their new {{w|iPhone 8}} and the higher-end {{w|iPhone X}} (pronounced iPhone 10) with facial recognition features.

===List of features (clockwise from center/top)===

; Front camera (centered for eye contact during video chat)
: Front camera is a common feature of smartphones. The camera lens is located on the same side of the phone's case as the main screen and therefore it is possible to capture the image of the user's face looking at the screen and display the interlocutor's face on the screen simultaneously, enabling video chat. However, as the camera is usually located above the screen, a user looking at the displayed image of the other person directs his or her eyes at the center of the screen and not at the camera's lens. This is very visible on the other end of the chat as if the person talking was looking down and not in the interlocutor's face which is an uncomfortable situation for most people. For this reason, professionals involved in movie or TV-making, like actors or reporters, are trained to look straight into the camera's lens while talking, which creates impression of looking straight at the viewer's face. During a video chat, however, looking into the lens of an above-screen camera does not allow one to see the interlocutor's face clearly because it is then in the peripheral field of vision.

: To solve this conundrum, Randall proposes locating the camera lens right in the middle of the screen. Therefore the user looking at the screen to see the other person's face would be also looking at the lens, creating an impression of a straight look on the other end of the chat. This is absurd since the lens would then take place of some of the center pixels of the screen, not allowing the display the center part of the captured image of the other person's face (like eyes and/or lips) which is most important for nonverbal communication. Such location of the camera lens would also likely interfere with touch-screen function. It will make other applications on the phone difficult to use, since virtually no user interface is designed to accommodate for a blind spot in the center.

; Full-width rear camera
: Phone cameras tend to have lenses which are quite small and round or square -- same width as height. Full-width makes it sound like the camera lens is really wide, as in a long oval or rectangle shape. This generally would not accomplish anything worthwhile, unless it allowed you to take one-shot panorama photos.

; CDC partnership - phone automatically administers seasonal flu vaccine to cheek every year
: U.S. {{w|Centers for Disease Control and Prevention}} is a government agency tasked with addressing public health concerns such as infectious diseases, including seasonal flu. A common way of limiting spread of an infectious disease is {{w|Vaccine|vaccination}}, which most often involves administering a specially prepared medicine via an {{w|intramuscular injection}}. This features implies that the phone would automatically perform such an injection once a year, by shooting a needle out of a small aperture while the user is holding the phone to his or her cheek during a call.

; 12-function
: Most smartphones can be used for more than 12 different things. However, this may refer to the 12 basic functions of calculus (identity, squaring, cubing, square root, logarithm, exponential, reciprocal, sine, cosine, greatest integer, absolute value, and logistic), or the twelve function keys on a modern keyboard (more than the ten on the original IBM PC keyboard). Alternatively it may be a reference to calculators: basic models are sometimes referred to as four function calculators (addition, subtraction, multiplication and division), and complex scientific calculators may advertise 250 or more functions.

; Dishwasher safe
: Usually a feature of plastic containers or fancy dishes. Unlikely to appear on a smartphone, though potentially useful if you need to clean your screen.

; GPS transmitter
: Many smartphones have a receiver for the Global Positioning System, which allows a phone to compute its position based on signals from the constellation of GPS satellites. However, a device with a "GPS transmitter" would broadcast signals that would interfere with the GPS receivers of all devices nearby.

; 3-G acceleration
: Usually, a phone is 3g compatible if it uses a certain standard ("third generation") for data transmission. However, 3-G acceleration implies the phone can accelerate at a rate of 3 times the acceleration of gravity, or approximately 30 m/s². An untrained human experiencing 3g for extensive periods of time can suffer injuries at a result.

; Portable, solar-heated
: Portability is pretty much the entire point of using a ''mobile'' phone, so advertising portability is rather pointless. Solar ''power'' charging could be a very useful feature on a phone, but solar ''heating'' usually applies to plumbing, where a water tank is heated by the sun and used to supply hot water to taps. Technically, as the sun heats up everything on Earth, the phone is in fact solar heated.

;Pore-cleaning strip
: Something sticky on that location would be very annoying for people trying to use their beards to make a call. See also [[777: Pore Strips]]

; Maximum strength
:Medicines are often sold a "Maximum strength", as in the highest dose allowed by law or allowed without a prescription. For phones, there are sometimes "hardened" or "ruggedized" versions which are designed to survive harsher environmental conditions such as surviving drops and collisions, excessive water and dust, etc. So Maximum strength could indicate a "ruggedized" phone, though a screen that extended past the edges would likely have the opposite effect.

; Never needs sharpening
: Phones do not need to be sharpened in the first place{{Citation needed}}. This is a feature more likely to be found in a knife advertisement (especially for a knife that cannot be sharpened, like a serrated or ceramic blade), or on a mechanical pencil

; Can survive up to 30 minutes out of water
: This is a play on the common IP-rating of water resistance, which is typically rated for submersion to a rated depth for 30 minutes. A phone which could only be used or carried for 30 minutes and then needed to be immersed in water would be rather inconvenient, especially if it was still susceptible to short-circuiting as most electronic devices do when submerged.

; Exclusive Audubon Society app identifies birds and lets you control their flight
: {{w|National Audubon Society}} is a non-profit organization dedicated to conservation of nature, mainly of birds, also organizing open {{w|birdwatching}} events. An app that identifies bird species, as for example from a photo of a bird made by the smartphone itself, would be cool. An app allowing you to control the bird's flight would be way cooler, but it is not possible at the current state of technology - and it would fly in the face of the Audubon Society core activity. This is a reference to {{w|Unmanned_aerial_vehicle|drones}} (artificial "birds") which are often controlled by a smartphone app. This may also be a reference to [[1425: Tasks]], in which an app that can recognize if a bird is on camera is proposed.

; Extra screen
:Possibly because of the center camera, an additional section of screen was added. Some phones also advertise having extra screen, although this refers to having a larger screen in general, rather than a small rectangle added to the bottom.

; Wireless charging port
:A rather pointless feature; because wireless charging has no wires, it needs no port.

; Safe for ages 6-8 months, 10 months, 18 months-3 years, and 12 years and older
:Usually an item is deemed safe for a particular age or older, or (in the case of toys) is recommended for a particular age range. This is unusual in that it's a hodge-podge of age ranges with no apparent reason why some ages are safe and others are not. It may be a parody of drug commercials that list several age ranges for which the drug had to be separately approved.

; Screen goes past the edge
:A parody of the trend of "edge to edge" displays in recent generations of smartphones, or phones whose screens curve partway around the edge of the phone.

; High thread count CPU
:A CPU thread is a task the CPU performs. Several threads may share memory making them a process. Threads are meant to run in parallel and the operating system distributes the workload on the available hardware execution units. These execution units are sometimes called hardware threads, especially when there is more than one per core. For example, the Intel Core i7 7700 is considered a 4-core, 8-thread CPU. The vague "high thread count" statement could make sense in this context, however, it is most likely a joke about bedding, where it is an actual selling point.

; Shroud of Turin-style facial transfer unlock
:The {{w|Shroud of Turin}} contains an image of a face, ostensibly of {{w|Jesus Christ}}. Presumably, to unlock this phone, the user would have to physically press their face against the phone, the way Jesus Christ's allegedly transferred to the shroud. This is likely a reference to the iPhone X's FaceID unlock, which uses a ''photograph'' of your face to unlock it and which had attracted [https://www.wired.com/story/iphone-x-faceid-security/ significant criticism] immediately before this comic came out.

; Fonts developed by NASA
: Between 1975 and 1992 NASA used the {{w|NASA insignia|"worm" logotype}} in its insignia. It was a special font omitting the horizontal bar in the capitalized letter A. May be a reference to many advertisements that claim their product uses technology developed by NASA. This seems impressive, as NASA technology does tend to be quite strong and advanced, as they claim at their [https://spinoff.nasa.gov/ spin off] website. However, it would not be as impressive due to fonts having very little to do with NASA's core operations.

; Includes applicator
: What tampon packages, cosmetics, paints, and other products often say. An applicator for a phone would be absurd since the phone cannot be applied, spread, inserted, or attached to something else. This may be referring back to the aforementioned yearly vaccine.

; Burns clean coal
: There is a push for clean energy production due to pollution concerns.  Using heat to generate operating electricity for a mobile phone is absurd, as the apparatus to burn any fuel and then extract electricity from that heat would be very large compared to the phone itself, and thus be impractical for a mobile.

; Pre-seasoned
:Pre-seasoned typically refers to cast iron cookware which is ready to use out of the box, as opposed to needing to season it with oil and heat. It can also refer to packaged meats which are ready to cook without needing to be seasoned with herbs and spices, or timber that has been dried and is ready for use.

; Broad-spectrum SPF 30
:The xkcd phone somehow gives an SPF 30 level of skin protection from the sun.

; College-ruled
:College-ruled is a style of notebook paper having narrower lines in order to fit more text per page. That the phone is college-ruled suggests that there are lines permanently displayed on the screen, which would obscure any images on the screen, along with any text that doesn't line up with the lines.

; Sterile packaging
:Useful for medical supplies, less so in a phone.

; Radium backlight
:The discovery of the radioactive element radium sparked a brief fad in which some watch makers painted watch faces or hands with a paint containing radium and a radioluminescent substance such as zinc sulfide which converted the radiation from the radium into visible light. This allowed the time to be read at night without needing an external power source for the light. However, it was eventually realized that regular exposure to radium could result in radiation poisoning, particularly for the workers assembling and painting the watches. A radium-based backlight would therefore be both potentially dangerous (especially for an object carried on one's person much of the time) but also largely useless, as the radioluminescent light is rather dim compared to conventional phone back lights.

; 4K pixels (50×80)
:This refers to having 4,000 pixels in the screen in total, rather than a screen width of ~4000 pixels. TV's advertised as "4K" are typically up to 4096 × 2160 pixels, or 8.8 million pixels. That would be outstanding for a cell phone whereas 4,000 pixels total would be horrendous. As a comparison, the old Commodore VIC-20 with a resolution of 176 × 184 would have over 8 times the pixels of this phone. It is however quite close to the screen resolution of the sturdy Nokia 3310, boasting a total of 4032 pixels positioned 84 × 48.

In the caption below the phone [[Randall]] presents many different version numbers:
*The number 6 is in correct order of all the xkcd phones
*The {{w|Roman numerals|roman number}} VIII refers to the newly announced {{w|iPhone 8}} and jokes about the roman number X below
*Version number 10 is the current version of Microsoft Windows after omitting the number 9
*The {{w|iPhone X}} was announced together with the iPhone 8 by Apple on September 12, 2017, a day before this comic was released. Apple clarified X must be read as the roman number 10, so for additional absurdity two xkcd phones share the same number, using different numeral
*The number 26 refers to...
*In the year 1876 {{w|Alexander Graham Bell}} received the U.S. Patent No. 174465 for the {{w|invention of the telephone}}, but there is still a {{w|Elisha Gray and Alexander Bell telephone controversy|controversy}} whether {{w|Elisha Gray}} was the first who presented a working telephone.
Below of this numbers Randall states that xkcd isn't responsible for this ''nonconsecutive version number war'', but, as it can be seen here above, he attempts to win. And by counting parallel version numbers xkcd defeated Apple 6:2. The symbols at the end are ™ for trademark, ® for registered trademark, and © for a copyright protection. The degree symbol ° after the letter C could be a play with degree Celsius.

In the title text Randall attributes privacy concerns about the facial recognition feature. A picture of a face will only be used for this new feature but never stored on the device nor transmitted to internet. A ''small'' side effect may be that the famous selfie pictures aren't possible anymore, as well as video calls.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[A smartphone is shown, the screen is slightly wider than the case, in the middle is a photo lens, and at the right bottom a small extra part is added to the screen.]
:[On top a bracket ranges nearly over the entire width of the case. The text reads:]
:Full-width rear camera
:[The label at the photo lens is:]
:Front camera (centered for eye contact during video chat)
:[The label on the extra part says:]
:Extra screen
:[At the bottom below the case a label reads:]
:Wireless charging port

:[The labels left to the phone are:]
:4k pixels (50x80)
:Radium backlight
:Sterile packaging
:College-ruled
:Broad spectrum SPF 30
:Pre-seasoned
:Burns clean coal
:Includes applicator
:Fonts developed by NASA
:Shroud of turn-style facial transfer unlock
:High thread count CPU
:Screen goes past the edge
:Safe for ages 6-8 months, 10 months, 18 months-3 years, and 12 years and older

:[The labels right to the phone are:]
:CDC partnership: Phone automatically administers seasonal flu vaccine to cheek every year
:12-function
:Dishwasher safe
:GPS transmitter
:3-G acceleration
:Portable, solar-heated
:Pore-cleaning strip
:Maximum strength
:Never needs sharpening
:Can survive up to 30 minutes out of water
:Exclusive Audubon Society app identifies birds and lets you control their flight

:[Text below the phone:]
:Introducing
:'''The XKCD PHONE 6, VIII, 10, X, 26, and 1876'''
:''We didn't start this nonconsecutive version number war, but we will not lose it.''™®©°
{{comic discussion}}

[[Category:xkcd Phones]]

Talk:1880: Eclipse Review

2017-08-23T23:27:59Z

162.158.75.202:

The air temperature drop is greater during a total eclipse than during a partial eclipse, while the other two don't affect the air temperature at all. --[[Special:Contributions/162.158.154.97|162.158.154.97]] 10:31, 23 August 2017 (UTC)

A booklet I got on the eclipse said this: "If natural wonders were on a scale of 1 to 10, a partial solar eclipse might be a '''7''', but a total solar eclipse would be a '''1,000,000!!!'''" They were right. I was there. [[User:Jacky720|That's right, Jacky720 just signed this]] ([[User talk:Jacky720|talk]] | [[Special:Contributions/Jacky720|contribs]]) 10:50, 23 August 2017 (UTC)

This is fun. [[Special:Contributions/162.158.134.160|162.158.134.160]] 11:17, 23 August 2017 (UTC)

Is it worth having an "2017 Total Eclipse" tag for the 5 comics? [[Special:Contributions/108.162.212.227|108.162.212.227]] 11:30, 23 August 2017 (UTC)
:Yes. Be sure it includes the other comics that mentioned the eclipse, like [[1868: Eclipse Flights]]. [[User:Dretler|Dretler]] ([[User talk:Dretler|talk]]) 12:37, 23 August 2017 (UTC)
::And it should also be "2017 Total [[Solar]] Eclipse". {{unsigned|Dretler}}
:::Here we go: [[:Category:Total Solar Eclipse 2017]]. Any comic missing? --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 14:41, 23 August 2017 (UTC)

Here's a Whatif topic: What if the earth's orbit around the sun and the moon's orbit around the earth were in the same plane so that a solar eclipse happened every month. How would that affect tides, global temperature, animal behavior, etc? Would the orbits be stable or would the gravitational tugs destabilize the orbits? [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 13:27, 23 August 2017 (UTC)
:Solar eclipse does not affect tides significantly more than the regular movement of the Moon and the Sun, those non-eclipse events where the Moon passes almost in front of the Sun actually make tides somewhat higher on that day, because forces sum up, but a fraction of angular degree misalignment which cases a "miss" does not make much difference for the tides. The effect of blocking the Sun's radiation during eclipse happens over a very small area and for a short time therefore it is too minuscule to affect temperature on Earth, normal Sun activity cycle creates a ''lot'' larger differences in the amount of energy reaching Earth. Animal behavior during eclipse might be a little different if it was a more frequent event, animals (including two-legged naked apes) would just get used to it. -- [[Special:Contributions/162.158.202.10|162.158.202.10]] 14:25, 23 August 2017 (UTC)

SO. TRUE. (I saw it in Salem) [[User:SilverMagpie|SilverMagpie]] ([[User talk:SilverMagpie|talk]]) 13:54, 23 August 2017 (UTC)

;Personal impressions on the 2017 eclipse or before
Maybe we can share some personal impressions from this eclipse or similar events. I personally was in the totality zone of the {{w|Solar eclipse of August 11, 1999|1999 solar eclipse}} in Germany. Weather was bad, dark clouds obscured the sun, and I almost could see nothing of the Sun at all. I was so happy living in that zone and then this. That was really annoying. It got darker, but not that much as expected because of the scattered light from the damn clouds at the horizon. The nature went quiet and automatic lights switched on, but that was it. Nothing cool at all. A much better experience I had recently in {{w|Solar eclipse of March 20, 2015|2015}}, a total eclipse at the Faroe Islands but still 80% at my location. Most of the Sun was blocked, it was getting darker, nature became silent, the temperature decreased and me and all my colleagues were impressed. But of course that also wasn't that cool like a total eclipse can be. So, after a missed total eclipse at home I still have to travel to get the real cool experience.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 15:17, 23 August 2017 (UTC)

;saw Totality from nashville
No question there's a huge different betwen partial and total. Totality is awesome, I recommend anyone to chase one if you can. After the 2 minutes I wished I could rewind it. No video comes close to the IRL experience.

Talk:1240: Quantum Mechanics

2017-07-13T23:32:30Z

162.158.75.202:

To me, it's not about "probably wrong" it's about irrelevant. QM itself says nothing about anything but quantum (particle component) probable vector(s).
Recent success of Bayesian probability in these regards implies more about lack of "common sense" understanding or meaning, than about subjectivity of universe (as if there was a difference?).
QM is not really knowledge in itself, it's just illuminating math (in a very limited realm).
not wrong, just fuzzy [[User:Monteletourneau|Monteletourneau]] ([[User talk:Monteletourneau|talk]]) 05:39, 1 August 2013 (UTC)

Who is CueBall talking to? It is not Meg, unless she dyed her hair. [[Special:Contributions/65.215.93.238|65.215.93.238]]
:[[Ponytail]] --[[Special:Contributions/92.230.59.41|92.230.59.41]] 14:33, 19 July 2013 (UTC)

Are "almost" against common sense? I see you don't know much about quantum mechanics. In quantum mechanics, common sense is about as usefull as in {{w|Alice's Adventures in Wonderland|Alice's Wonderland}}. Possibly less. And that bit about {{w|Quantum tunnelling|going through the wall}} is used in {{w|Flash_memory#NAND_flash|Flash memories}}. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 14:36, 20 July 2013 (UTC)
:Sure. You can see that people do not understand anything about something because you think you know a lot about that something. WRONG! I know exactly what I was talking about and "almost" was a word that I did not chose lightly.[[User:Claudionico|cinico]] ([[User talk:Claudionico|talk]]) 13:48, 22 July 2013 (UTC)

See http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
It applies to us all - the more you think you know the more wrong you are, the more you actually know, the less right you think you are.
[[User:Monteletourneau|Monteletourneau]] ([[User talk:Monteletourneau|talk]]) 05:39, 1 August 2013 (UTC)

"You can safely ignore any sentence that includes the phrase 'according to quantum mechanics'" Including, of course, that one. [[User:Tbrosz|Tbrosz]] ([[User talk:Tbrosz|talk]]) 16:13, 20 July 2013 (UTC)

awe some
[[User:Monteletourneau|Monteletourneau]] ([[User talk:Monteletourneau|talk]]) 05:39, 1 August 2013 (UTC)

"Albert Einstein being famously ''wrong''", isn't that a bit subjective? Although there is little evidence supporting the hidden variable theory, it is not out of the question to consider it, Einstein might've been right you know. --[[Special:Contributions/79.160.93.211|79.160.93.211]] 21:02, 20 July 2013 (UTC)
:Einstein was not ''wrong'', he just was searching to unify relativity mechanics with quantum mechanics. That sentence "God does not play dice" is often misunderstood and in wrong context here. I did remove it.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:27, 20 July 2013 (UTC)
::I don't know about ANY evidence supporting {{w|Hidden variable theory}}, on the other hand I heard that {{w|Bell's_theorem|Bell inequalities}} were experimentally tested and results are against Einstein. Wikipedia itself states that "Most advocates of the hidden variables idea ... are ready to give up locality". Einstein {{w|Principle_of_locality|assumed that the principle of locality was necessary, and that there could be no violations of it}}. Are you seriously saying that someone managed to put their subjective position into that many articles on wikipedia? ; The point of "wrong content" may be more valid, especially considering that Einstein probably was able to understand quantum mechanics, just didn't believe it. It would be very interresting what he would say about the issue if he wouldn't died 9 years before the Bell inequalities were formulated. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 09:21, 22 July 2013 (UTC)
:::Exactly! The EPR paper does not claim that QM is wrong, it just points out the (to Einstein paradoxical) consequences of entanglement. In the same way you can claim that Schroedinger said QM was wrong, because of his famous thought experiment involving an angry cat (he made up the example to criticize the kopenhagen interpretation of "his" wave mechanics).[[Special:Contributions/85.164.251.29|85.164.251.29]] 18:02, 1 September 2013 (UTC)

I recall hearing an argument along these lines... Something about the "fact" that a dog observing a quantum wave form will cause it to collapse, thus the observer is "conscious", and thus has a "soul". How exactly you explain all the misnomers in that set of assumptions, let alone test the hypothesis to begin with, I've no clue. Can we train monkeys to read particle detectors? And what consequence might this have for Schrodinger's poor cat? ;) [[Special:Contributions/99.42.81.32|99.42.81.32]] 06:46, 21 July 2013 (UTC)

:I'm not sure how they managed to actually prove dogs can collapse quantum wave form, but I'm definitely sure that if dog can do that cat can too. Remember that {{w|Schrödinger's cat}} was THOUGH experiment, we don't know if someone really tried it (unless {{w|Cheshire Cat|Lewis Carol did}}). -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 09:21, 22 July 2013 (UTC)

Dog = soul, cat does not, it's proven all right!
Isn't it right there in the equation?
I thought S = soul???
Besides, the bible (NO the devil) tol' me so.
[[User:Monteletourneau|Monteletourneau]] ([[User talk:Monteletourneau|talk]]) 05:39, 1 August 2013 (UTC)

Is this not a reference to the Einstein quote that a mouse wouldn't change the universe by observing it? (In German: "Ich kann mir nicht denken, daß eine Maus das Universum verändert, dadurch, daß sie es betrachtet"){{unsigned ip|91.45.17.43}}

Dogs have souls in Christian philosophical tradition, just not immortal ones. Most Christian philosophers follow a loosely Aristotelian philosophy which says that all living things have some kind of soul: plants have vegetative souls, animals have sensitive souls, and people have rational souls. Thus this sentence ought to be corrected: "the concept of most of the large monotheistic religions [is that] only humans have been created in the image of God and thus only they have souls."

Talk:1240: Quantum Mechanics

2017-07-13T23:31:13Z

162.158.75.202:

1815: Flag

2017-04-24T14:30:17Z

162.158.75.202:

{{comic
| number = 1815
| date = March 24, 2017
| title = Flag
| image = flag.png
| titletext = There's a compromise bill to keep the notification bar but at least charge the battery.
}}

==Explanation==

Presumably [[Randall]] was hired by a committee to propose a new {{w|flag}} for an unspecified country. His process editing the flag involved taking a screenshot of his design to export it, a mistake that went unnoticed by anyone until the flag was officially implemented.

Once the problem was pointed out, the design committee placed the blame on Randall, but could not immediately undo their decision until new suggestions had been submitted and a new committee could agree on another design. Thus the country is now stuck with this design, making it the only country with such a bar in the flag.

The title text mentions a compromise bill that will change the flag. This implies that the flag was approved with the status bar included. Apparently there is some controversy about removing the status bar from the flag as the compromise bill proposes to keeping the status bar and change the displayed percentage of the battery from 39% to 100%. This is wordplay on the term "charge" as used in {{w|vexillology}}, where it refers to a figure appearing on the background of the flag. It may also be a reference to [[1373: Screenshot]].

===Flag design===
The ''bar'' in ''notification bar'', is a vexillological descriptor, as in the "{{w|Flags_of_the_Confederate_States_of_America#First_flag:_the_.22Stars_and_Bars.22_.281861.E2.80.931863.29|Stars and Bars}}," a term used for the first flag of the {{w|Confederate States of America}}.

Flags are often minimalist and involve geometric shapes and solid colors. A notification bar at the top of the flag would clash with these design elements as well as looking unprofessional.

The elements of the flag's intended design—the colors red, white, and blue; the use of stripes; and the star emblems—are the same that are used in the American flag the {{w|Flag of the United States|Stars and Stripes}}.

The elements of this flag is, however, also present in several other existing flags like those derived from {{w|Union Jack}}, the flag of the {{w|United Kingdom}}, like the flags of {{w|Flag_of_Australia|Australia}} and {{w|Flag_of_New_Zealand|New Zealand}}. They are also in the flags of {{w|Flag of North Korea|North Korea}}, {{w|Flag_of_Liberia|Liberia}} and {{w|Flag_of_Malaysia|Malaysia}}. The flags from USA, Australia, Liberia and Chile have [[commons:Category:Flags_with_white_stars|white stars]], and those of USA and Liberia have [[commons:Category:Flags_with_white_stripes|white bars]] as well.

===Theories===
The low battery status might imply that the country is low on resources. It thus seems like people have taken the reference to modern times smartphones to their hearts and actually wish to have this very modern design.

But if they indeed continue with this, thinking that their country would look better with a full battery charge, they might also consider changing the 3G connection to the {{w|4G|newer 4G}} version and giving the phone a full signal (5/5 instead of only 3/5 dots), and maybe also choose a time that would mean something rather than 5:48 PM. For instance noon/midnight, or 8:00.

The reason such a status bar could be missed in the first place could be that most people today look at pictures on their smartphones all the time, and thus their own phones status bar is indirectly included at the top of all the pictures they see. People thus do not notice these status bars any longer as they are always there and clearly not important for the picture. Randall has mentioned before, in [[1373: Screenshot]], that he cannot take smartphone screenshots seriously if the battery of the device is low, as he cannot focus on the content becoming afraid his own device runs out of power. A problem that only occurs if he sees it on his smartphone, as he then becomes concerned that it is his phone that is about to run out of charge. But in this status bar there are still 39%, high enough not to cause immediate concern. His fear of losing his on-line connection like this was the joke in a the comic [[1802: Phone]] released about a month before this one.

==Transcript==
:[A two colored flag is shown. The left and rightmost parts of the flag are dark blue, and the center is red and each section has a large white star in its center. The colored parts are separated by thinner white vertical stripes. At the top of the flag, there is an off-white status bar like one found at the top of an iOS smart device. On the left it is displaying the strength of the connection (3/5 dots), in the center it is displaying the time and on the right there are three small icons the last is the battery charge:]
:3G
:5:48 PM
:39%

:[Below the panel there are two captions]
:The design committee fired me once they realized that my editing process involved a screenshot, but it was too late.
:Until they change it, our new country has the only national flag to include a phone notification bar.

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Smartphones]]

1820: Security Advice

2017-04-24T14:25:50Z

162.158.75.202:

{{comic
| number = 1820
| date = April 5, 2017
| title = Security Advice
| image = security_advice.png
| titletext = Never give your password or bank account number to anyone who doesn't have a blue check mark next to their name.
}}

==Explanation==
The comic depicts a conversation between [[Cueball]] and [[Ponytail]], discussing the fact that giving people security advice in the past has failed to improve their internet security, and in some cases even made things worse. One such example is telling people to create complicated passwords containing numbers and symbols, which not only made the passwords harder to remember (leading people to create huge security risks by [https://arstechnica.com/security/2015/04/hacked-french-network-exposed-its-own-passwords-during-tv-interview/ leaving post-it notes with their passwords on their computer monitor]), but did not actually make those passwords harder to crack (see [[936: Password Strength]]).

As a result, Cueball suggests using {{w|reverse psychology}} and give out bad advice instead, in hopes of achieving a positive effect. The last panel contains a list with 13 security tips, which are parodies of actual security tips. The title text is just one more tip. See [[#Security tips|table]] below for explanations for all 14 tips.

This comic is yet another [[:Category:Tips|tips comic]].

===Security tips===
{| class="wikitable"
!Security Tip
!Explanation
|- id="tip0"
|Print out this list and keep it in your bank safe deposit box (header)
|This is a standard recommendation for documents that must be kept secure because they are irreplaceable and/or contain sensitive information. However this list itself is easily replaceable and the contents will be well-known, so storing it in a safe place is totally unnecessary. Putting it in a {{w|safe deposit box}} would even be counterproductive since the list can only serve its purpose as a ready reminder if it's easily accessible to everyone. So when people fail to follow this tip, they may end of keeping it in a place where they have easy access to the tips so they may also fail to follow all the others.
|- id="tip1"
|Don't click links to websites
|The usual tip is "Don't click on ''suspicious'' website links" or "Don't click any links in suspicious emails". The comic's variation instead tells users not to click on any links to any websites, which essentially stops them from using the World Wide Web altogether. So this tip is not really helping, as the opposite of this would be to click on all links.
|- id="tip2"
|Use prime numbers in your password
|It is usually recommended that one uses numbers in one's password, to increase its entropy, making it harder to find with a {{w|Brute-force attack|brute force}} attack. In contrast the comic suggests using {{w|prime numbers}} in one's password. Large prime numbers are an essential part of modern cryptography and security systems, when used in algorithms that are computed by machines. They don't have any effect when used by humans in passwords, except for maybe making it harder to remember. In addition, if people were to regularly use prime numbers in their passwords, it would actually make passwords ''easier'' to guess, as it would substantially reduce the number of possible passwords people may choose from.
|- id="tip3"
|Change your password manager monthly
|It is often recommended to change passwords on a regular basis and to use a {{w|password manager}}. Password managers are programs which can help users create, store, and change their passwords easily and securely. Changing password managers monthly would involve copying all stored passwords from one manager to another, which would be quite impractical and has no security benefit.
|- id="tip4"
|Hold your breath while crossing the border
|At some border crossings, government agents may search computers, cell phones, and other electronic devices. The usual advice for such situations ranges from asserting your rights to resetting all devices and deleting all data prior to crossing a border. Holding one's breath can potentially prevent inhaling germs or poisons in some situations, though useless in the context of computer security. These two topics mixed in the same advice won't achieve anything, but if you hold your breath for too long you could pass out when crossing, or look stressed/suspicious and invite even more scrutiny. This could also be a reference to the superstition of holding one's breath when passing a graveyard, or similarly to the movie {{w|Spirited Away}}, where the main character is instructed to hold her breath while crossing the bridge that acts as the border between the human and spirit world. In any case, holding one's breath while browsing the Internet would have no useful effect, supernatural or otherwise.
|- id="tip5"
|Install a secure font
|A real tip might be "Install a secure browser" especially when many people used {{w|Internet Explorer 6}}. Secure fonts do exist and are designed to make checks difficult to alter, but using one on a computer would not help one's internet security. May also refer to Google Chrome [https://www.proofpoint.com/us/threat-insight/post/EITest-Nabbing-Chrome-Users-Chrome-Font-Social-Engineering-Scheme "Install missing font"] malware.
|- id="tip6"
|Use a 2-factor smoke detector
|{{w|Multi-factor authentication|Two factor authentication}} describes the practice of using two different identification factors (such as a password and a code from a secure token) to authenticate the user. A two factor smoke detector presumably uses two or more factors to identify ''smoke'' (such as {{w|Smoke_detector#Ionization|ionization}} and {{w|Smoke_detector#Photoelectric|photoelectric}}). Such devices [https://alarmspecs.com actually exist], but, while improving the user's general safety, they do nothing to improve their internet security.

Also, the logic behind using two-factor authentication is that '''both''' types of credentials must match to grant access. Smoke detectors work otherwise - usually firing if '''any''' of the sensors detect a fire. If the smoke detector worked according to the authentication logic it will be less likely to detect smoke, effectively lessening fire safety as compared to a single sensor one.

A month before this comic the newest [[:Category:xkcd Phones|xkcd Phone]], [[1809: xkcd Phone 5]], was released with a 28-factor authentication.
|- id="tip7"
|Change your maiden name regularly
|Your maiden name is the family name with which you were born. Literally changing your maiden name, is impossible by the definition of "maiden name". A common tip is to change your passwords regularly. Some password recovery procedures ask for a security question, like "what is your {{w|Maiden and married names|maiden name}}" Maiden names and other trivia typically asked by security questions are not secret, so they are inherently insecure.

A real tip for dealing with security questions is to enter false data.
|- id="tip8"
|Put strange USB drives in a bag of rice overnight
|The usual security tip is "Don't plug strange {{w|USB flash drive|USB drives}} into your computer," because sometimes attackers leave USB devices with malicious programs lying around, hoping that people will plug them into target computers out of curiosity. This tip states that you should "put USB drives in a bag of rice overnight" which is a common technique for drying out water-damaged devices, due to rice's absorbent qualities. This would not clean the drive of viruses, and unless the drive was wet (perhaps because you found it outside due to it being called "strange") it would not do anything. In [[1598: Salvage]], another attempt is made to salvage something unconventional with rice, and here it is shown that Randall considers the rice drying of a wet mobile is a myth, so this is yet another jab at the idea.
|- id="tip9"
|Use special characters like & and %
|You can use special characters to increase the entropy/strength of your password, though as describe in [[936: Password Strength]], that often leads to passwords that are hard to remember but not particularly strong. The password context is missing here, and in everyday situations the characters & and % are not special. These two characters are often disallowed in passwords because of their relevance to {{w|SQL}} (a common database query language). If these characters were used in a password, a badly written security system using SQL could have severe bugs (and security vulnerabilities) similar to the security flaw in [[327: Exploits of a Mom]].
|- id="tip10"
|Only read content published through Tor.com
|{{w|tor (anonymity network)|Tor}} is a software solution to provide anonymity on the web for its users. The website [https://tor.com Tor.com] is the website of fantasy and sci-fi book publisher {{w|Tor Books}}, which has no relation to the Tor-network.
|- id="tip11"
|Use a burner's phone
|A play on using a {{w|Prepay mobile phone|burner phone}} (a cheap/disposable cell phone like those purchased at 7-11, often used for drug deals or other activity one might not want traced), and using the cell phone of a burner, i.e. a person who goes to the {{w|Burning Man|Burning Man festival}}.
|- id="tip12"
|Get an SSL certificate and store it in a safe place
|{{w|Transport Layer Security|SSL/TLS}} is a protocol for securing connections on the internet. To check if someone is who they claim to be, you can check the individual's {{w|Public key certificate|certificate}}. Such a certificate has to be public; storing it in a safe place makes the certificate useless. You have to store the private key that matches the certificate in a safe place, else someone could steal the identity.
|- id="tip13"
|If a border guard asks to examine your laptop, you have a legal right to challenge them to a chess game for your soul.
|This tip is a reference to the common trope [http://tvtropes.org/pmwiki/pmwiki.php/Main/ChessWithDeath Chess with Death], in which a mortal challenges a god to a game or challenge, often for their life. This version of the trope traces back to {{w|Ingmar Bergman|Ingmar Bergman's}} film {{w|The Seventh Seal}}, in which the protagonist {{w|The Seventh Seal#Synopsis|challenges Death}} to a game of chess. But instead of avoiding death, this tip suggests you have the right to do the same to get out of handing your devices over to a border guard. (This trope is also featured in [http://www.explainxkcd.com/wiki/index.php/393 393: Ultimate Game]).

This is the second tip referring to crossing a border.
|- id="tip14"
|'''Title Text''': Never give your password or bank account number to anyone who doesn't have a blue check mark next to their name.
|The usual security tip here is ''"only trust Twitter accounts claiming to be legitimate if they have a blue check mark next to their name"'', which means that the account is verified as legitimate. This tip suggests only giving your ''password'' to verified accounts, although you shouldn't give your password to ''any'' account. It also refers to problems especially visible in the US banking system, where there is very little security for direct account drafts, and because of that it is advised there to keep the account number as secret as possible. In contrast, in Europe giving your account number to someone is one of the most common ways to get paid.

A related tip might be ""Never give your password or bank details to a website that doesn't have a padlock icon next to the URL"". In some browsers, if you access a secure website, there will be a padlock icon in the browser indicating you've connected to a secure website using the secure https protocol. So this tip treats the verified account icon the same way you might treat a secure website icon.
|}

==Transcript==
:[Cueball is listening to Ponytail who holds her hands out in front of her.]
:Ponytail: We've been trying for decades to give people good security advice.
:Ponytail: But in retrospect, lots of the tips actually made things worse.

:[Cueball takes his hand to his chin as Ponytail takes her arms down.]
:Cueball: Maybe we should try to give ''bad'' advice?
:Ponytail: I guess it's worth a shot.

:[Below these two panel is one large and long panel with a long list with 13 tips. The underlined heading and the bracket below it are centered above the bullet list below.]
:<big>Security tips</big>
:(Print out this list and keep it in your bank safe deposit box.)
* Don't click links to websites
* Use prime numbers in your password
* Change your password manager monthly
* Hold your breath while crossing the border
* Install a secure font
* Use a 2-factor smoke detector
* Change your maiden name regularly
* Put strange USB drives in a bag of rice overnight
* Use special characters like & and %
* Only read content published through tor.com
* Use a burner's phone
* Get an SSL certificate and store it in a safe place
* If a border guard asks to examine your laptop, you have a legal right to challenge them to a chess game for your soul.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Chess]]
[[Category:Computers]]
[[Category:Tips]]