explain xkcd - User contributions [en]

3208: SNEWS

2026-02-18T01:23:00Z

EpicRedhead13: citation needed tag for lolz

{{comic
| number = 3208
| date = February 16, 2026
| title = SNEWS
| image = snews_2x.png
| imagesize = 740x321px
| noexpand = true
| titletext = People say setting of fireworks indoors is dangerous, but I looked at their energy release and it's like 10^-40 foe; totally negligible.
}}

==Explanation==
{{incomplete|This page was created by a Type Ia firework display that Ponytail set off. Don't remove this notice too soon.}}
[[Ponytail]] is showing [[Hairy]] her bedroom. Hairy asks about the large device on the ceiling, and Ponytail explains that it is part of the {{w|SNEWS}} (SuperNova Early Warning System). This provides advance notice of {{w|supernova}}e by detecting {{w|neutrino}}s (tiny particles that travel near the speed of light, rarely interacting with matter). Neutrinos are produced in large quantities during the collapse of the star core, which occurs hours before the main photon production which makes them visible to the eye. She explains this gives {{w|astronomer}}s warning, allowing them to observe the event with telescopes and other instruments.

Hairy reasonably assumes that the device is either a detector, forming part of the SNEWS, or some kind of telescope to be used in the event the SNEWS goes off. However, Ponytail explains that it is a {{w|fireworks}} launcher — presumably linked into the detection network and triggered if it registers an observation — for the purposes of waking her up so she can witness the supernova herself. This is a '''very''' bad idea, for a multitude of reasons.{{Citation needed}} Reckless use of fireworks is known for causing significant property damage and personal injury, even when used outdoors; launching fireworks inside the house means causing an explosion in a confined area, guaranteeing that it will hit the building, maximizing the opportunity to ignite something flammable on the structure, and containing, and therefore amplifying, the sound of the burst (which can already deafen people who are too close). Understandably, Hairy {{tvtropes|ScrewThisImOuttaHere|leaves to sleep at his own house}}.

Some people aren't easily woken up by a simple {{w|alarm clock}}, especially if it is in reach and has a "snooze" function where a button will silence the alarm for several minutes before it beeps again. The similar sounds of "snooze" and SNEWS may be part of the joke.

Ponytail is being {{w|hyperbole|hyperbolic}}, because even if all astronomers were interested in supernovae, not every individual or observatory will be immediately situated to view a particular point in the sky. For example, they may need to wait for the Earth's rotation, causing the phenomenon to "rise" in the east. Others may be located at unfavorable latitudes where the object will never appear above the Earth's horizon. It may also take some time before the supernova reaches an apparent magnitude that is visible during the daytime. Which would be particularly disappointing for ''everyone'' (on Earth) if it all happens to a star currently too close to conjunction with the Sun to see, in spite of the advanced neutrino warning. Neutrinos from a supernova can be distinguished from those generated by the Sun: the latter are relatively steady in their flux (1010–1011 cm-2s-1) with energies < 20 MeV, while the former come in a much higher flux for a few seconds and have energies of 10–50 MeV.

Since historical supernovae have been visible from 6 months to nearly 2 years, it would be unlikely that Ponytail sleeps through a new one in its entirety, although there would still be significant cachet for any astronomer lucky enough to be able to legitimately say that they had seen the 'first light' at the earliest opportunity. It would also be difficult for her to ''not'' sleep through part of the supernova, for the same reason.

The title text is a play on the tremendous amount of energy released by a supernova. The {{w|Foe (unit)|foe}} is an unofficial unit of energy equal to 10^44 Joule (but named directly from initials in the original quantity of "ten to the fifty-one ergs", involving a {{w|Erg|pre-SI}} measurement of energy), which is approximately on the order of the usual amount of energy released by a supernova. In comparison, human-scale amounts of energy — even relatively significant ones such as firework detonations — are negligible. This ignores the fact that energy releases that are "negligible in comparison to a supernova" can still be easily fatal to humans; even the largest man-made nuclear explosion is approximately ''twenty-seven'' orders of magnitude less than the baseline 'foe' value. The described "10-40 foe" is equal to 10 kJ, the energy released by the complete combustion of about 0.6 g of table sugar (sucrose), or the decomposition of about 6 g of nitrocellulose.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[Ponytail is walking into her room. The room has a bed, a set of drawers and a large sci-fi device mounted on the ceiling. Hairy is standing in the room, pointing up at the device.]
:Hairy: What's that device?
:Ponytail: Part of the supernova early warning system.
:Ponytail: There hasn't been a Milky Way supernova in over a century.
:Ponytail: Astronomers don't want to miss the next one.

:[Close up of Ponytail, now sitting on the end of the bed]
:Ponytail: 20 years ago, we set up a supernova alert system using neutrino detectors.
:Ponytail: It should give us a few hours' advance notice.

:[In a frame-less panel the view zooms back out, showing Ponytail and Hairy.]
:Ponytail: If it ever goes off, every astronomer on earth will scramble to point their equipment at the sky.
:Hairy: Oh, OK. So is that a detector? Or some kind of telescope?

:[The panel moves to the right, showing Hairy walking away. Ponytail is still on the end of the bed, raising a clenched fist for dramatic effect.]
:Ponytail: Fireworks launcher.
:Ponytail: I '''''refuse''''' to sleep through a supernova.
:Hairy: I think I'll spend the night at my place instead.

==Trivia==
The word "off" is misspelled as "of" in the title text.

This comic was published on the eve of the {{w|Chinese New Year}} or Lunar New Year, which is reckoned by the new moon appearing at this time of year. Celebrations throughout Asia and communities worldwide include setting off firecrackers and launching fireworks.

{{comic discussion}}<noinclude>

[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Astronomy]]

186: Console Lines

2025-12-09T04:06:41Z

EpicRedhead13: Added that the comic was published the day after the Wii was released.

{{comic
| number = 186
| date = November 20, 2006
| title = Console Lines
| image = console_lines.png
| titletext = If I get a Wii, it will be the first game console I've owned.
}}

==Explanation==
This comic relates to {{w|video game consoles}}. At the time this comic was published, there were three major competing products: the {{w|Playstation 3}} by {{w|Sony}}, the {{w|Xbox 360}} by {{w|Microsoft}}, and the {{w|Wii}} by {{w|Nintendo}}. The Wii was released on November 19, 2006, the day before this comic was published. When a game console gets released, fans are often seen queuing outside the stores or camping on the pavement in order to be among the first to get their hands on a console. The comic shows such a console camp and points out the differences between the fan communities. While the fans waiting in line for a Sony or Microsoft product are very rude, the Nintendo fans are apologetic and try to comfort (that is to say, ''console'') those who arrived too late to obtain a package. The cliché that Nintendo fans are nicer and more polite may be attributed to the fact that the Wii is targeted at children and families, while the PS3 and the Xbox are targeted at the more "serious gamer" crowd.

The title text primarily expresses [[Randall]]'s distance from the console wars (he has never owned a game console before), but also indicating an inclination towards the Nintendo Wii.

==Transcript==
:Fans turning away latecomers to all-night game console campouts:
:[Two different lines, presumably leading to video game stores, are shown.]
:[In the line labeled Sony/Microsoft:]
:Cueball: The line is full, asshole! Fuck off!
:[In the line labeled Nintendo:]
:Cueball: I'm so sorry, all the consoles are spoken for.
:Cueball: Do... do you want a hug?

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Video games]]

3024: METAR

2024-12-13T21:57:55Z

EpicRedhead13: Updated the "real" meaning of the time, visibility, and precipitation sections to be a bit more accurate.

{{comic
| number = 3024
| date = December 13, 2024
| title = METAR
| image = metar_2x.png
| imagesize = 640x360px
| noexpand = true
| titletext = In the aviation world, they don't use AM/PM times. Instead, all times are assumed to be AM unless they're labeled NOTAM.
}}

==Explanation==
{{incomplete|Created by an A380 - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

In aviation, the {{w|METAR}} (Meteorological Aerodrome Report) is used to give pilots a brief overview of the current meteorological conditions at the airport.
The METAR follows a specific structure and makes heavy usage of abbreviations, which makes it hard to read for anyone not familiar with it.
The comic makes fun of that by assuming meaning of the words based on what non-aviation people might think the different elements of the METAR report may represent.

{| class="wikitable"
|-
! Code !! Real Meaning !! According to the comic
|-
| METAR
| Type: Meteorological Aerodrome Report
| The comic assumes that this is just a spelling error and it should be "meter"
|-
| KNYC
| Station ID: 4 character ICAO airport identifier; in this instance the general area code for New York City (not an actual airport, but a weather station for general observations in the New York area)
| Radio station, likely parodying WNYC radio. US radio stations west of the Mississippi River usually start with K and those east of it usually start with W, though there have been exceptions. For example, KDKA in Pittsburgh was one of the first commercially licensed radio stations. Airport, weather, and radio station call signs share a common heritage.
|-
| 251600Z
| Time of observation: 25th day of the month at 4 PM UTC. Z is not part of the time, but simply shorthand for GMT or "Zulu" time.
| Misreading the "Z" as a 2, resulting in a nonsensical time. Hours greater than 24 are sometimes used to indicate a time after midnight, e.g., in Japan 17~25h means from 5 P.M. to 1 A.M. the following day. A normal METAR does not use more than 24 hours, instead incrementing the day, so 25 hours further adds to the nonsensical nature of the interpretation.
|-
| 18035G45KT
| Wind direction and speed: Wind direction: 180° (directly from the south, degrees based on 0°=magnetic north), speed: 35 knots, gusts: 45 knots
| Instead of interpreting the first 5 digits as direction and speed, it is assumed that it is one big number and the G45 stands for the time span in which this was observed with "G" standing for "good". 18,035 knots is an unrealistically high wind speed, faster than orbital velocity; the {{w|jet stream}} typically contains the highest winds on Earth, and may reach about 250 knots.
|-
| 6SM
| In weather reports related to aviation, "6SM" stands for 6 statute miles, meaning that objects can be seen clearly up to 6 miles away.<ref>https://weather.cod.edu/notes/metar.html#:~:text=6SM%2DVisibility,SM)%20up%20to%2010%20SM.</ref> This indicates clear enough weather to fly without instruments; the value has a max range of 10SM.
| The comic interprets "6SM" to humorously mean a "Size '''6 Sm'''all".
|-
| VCFCFZVA
| In the vicinity (VC): funnel cloud (FC) and freezing (FZ) volcanic ash (VA).
| A riff on the repeated letters which give off the impression the string is constructed by typing randomly on the keyboard. All the letters are near each other at the lower left of the keyboard (S, D, and X are somehow avoided).
|-
| +BLUP
| Heavy (+) blowing (BL) unknown precipitation (UP)
| Riffing on the fact that it looks like an onomatopoetic word
|-
| NOSIG
| No significant change is expected to the reported conditions within the next 2 hours
| The comic assumes that the transmitter of the METAR report wants the receivers to know that they do not have a significant other, which the comic finds sad. The observer could be trying to abuse the METAR report as a dating platform.
|-
| LTG OHD
| Lightning overhead
| OHD is interpreted as "overheard" instead of "overhead", indicating that they did not observe it themselves and instead just overheard people talking about it.
|-
| A3808
| Altimeter setting: (calculated) air pressure at {{w|Mean_sea_level|mean sea level}} at the airport is 38.08 <ref>The value of 38.08 inHg is extremely high. The standard atmospheric pressure used in aviation is 29.92 inHg, the highest recorded barometric pressure was 32.00 inHg. Given that the weather station is automated, this value cannot be explained by a typo by the METAR sender.</ref> {{w|Inch_of_mercury|inches of mercury (inHG)}} ("A" for inHG, used primarily in USA, Canada and Japan, "Q" would indicate a value in hPa). This is used to adjust the altimeter in the aircraft to the local air pressure, instead of using the standard setting used in higher air spaces.
| The comic says that the observer saw an {{w|Airbus_A380|Airbus A380-800}}. Note: The {{w|List_of_ICAO_aircraft_type_designators|ICAO aircraft type code}} for the Airbus A380-800 is A388 and not A3808.
|-
| RMK
| Beginning of the section with remarks
| Remarkable. Might be a comment about the A380.
|-
| AO2
| The weather station is automated (A) and has a precipitation discriminator (O2)
| Reference to the {{w|fan fiction|fanfic}} site [https://archiveofourown.org/ Archive of Our Own], often abbreviated as AO3
|-
| SLP130=
| {{w|Sea_level_pressure|Sea-level pressure}} is 1013.0 hPa (approx. 29.91 inHg). The equal sign signifies the end of the METAR.
| "SLP" interpreted as abbreviation for sleepy, the numbers as a time, and the = sign as "around" (maybe confused with ≈)
|-
| NOTAM (title text)
| Not part of a METAR report, but instead another aviation abbreviation. It stands for {{w|NOTAM|Notice to Air Missions}} (previously Notice to Airmen).
| Parsed as "not A.M.", indicating that a given time is to be interpreted as P.M. While AM and PM are indeed not used in aviation, as the comic says, they use a 24-hour clock system, not an "A.M.-by-default" 12-hour clock system.
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

Decoding a METAR Report:

[A METAR report is shown with annotations. The report is:]

<code>
METAR KNYC 251600Z 18035G45KT 6SM VCFCFZVA +BLUP NOSIG LTG OHD A3808 RMK A02 SPL130=
</code>

[The annotations are:]

* <code>METAR</code> "METER" (Usually misspelled)
* <code>KNYC</code> Station ID
* <code>251600Z</code> Time (25:16:002)
* <code>18035G45KT</code> Wind speed has been 18,035 knots for a good 45 minutes now
* <code>6SM</code> Observer is a size 6 small
* <code>VCFCFZVA</code> Sorry, the station cat walked on the keyboard
* <code>+BLUP</code> Weird noise the sky made earlier
* <code>NOSIG</code> Observer has no significant other :(
* <code>LTG OHD</code> We overheard someone saying there was lightning
* <code>A3808</code> Hey look, an Airbus A380-800!
* <code>RMK</code> Remarkable!
* <code>A02</code> Fanfic Archive equipped with a precipitation sensor
* <code>SPL130=</code> Observer got sleepy around 1:30

==References==
{{reflist}}
[https://e6bx.com/metar-decoder/ Metar Decoder]
{{comic discussion}}

2965: Chili Tornado Quake

2024-07-30T03:57:33Z

EpicRedhead13:

{{comic
| number = 2965
| date = July 29, 2024
| title = Chili Tornado Quake
| image = chili_tornado_quake_2x.png
| imagesize = 302x252px
| noexpand = true
| titletext = Buildings constructed from softer materials were damaged by chili pepper impacts to the storm's high Richter-Fujita-Scoville-Mohs hardness rating.
}}

==Explanation==
{{incomplete|Created by a TREMBLING GHOST PEPPER - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

{{comic discussion}}

751: Swimsuit Issue

2024-04-29T16:29:52Z

EpicRedhead13:

{{comic
| number = 751
| date = April 16, 2010
| title = Swimsuit Issue
| image = swimsuit_issue.png
| titletext = Parents: talk to your kids about popup blockers. Also, at some point, sex. But crucial fundamentals first!
}}

==Explanation==
{{w|Sports Illustrated}}, while a sports magazine (from what the title implies), is infamous for its {{w|Sports Illustrated Swimsuit Issue|Swimsuit Issue}}, a yearly issue that heavily features women wearing revealing swimsuits (again, from what the title implies), something generally agreed upon as inappropriate for children.{{Citation needed}}

However, the joke is on the father. Before he could stop the child from reading, the child had already made it clear that he had seen {{w|Hardcore pornography|hard-core pornography}} in the {{w|Pop-up ad|pop-up ads}} he had encountered. He is familiar with the sight of women being "double penetrated" (i.e. engaged in simultaneous vaginal and anal sex) and that said women are completely naked (implied by his surprise to see similar-looking women wearing swimsuits in the magazine). Thus, the swimsuit issue, in which the women are wearing ''some'' clothing and are not engaged in sexual activity, is relatively tame.

The title text has [[Randall]] suggest that {{w|Ad blocking|pop-up blockers}} are far more important than {{w|The birds and the bees}}, a stance that most people do not agree with.{{Citation needed}} There is some sense towards this approach, however. While "the birds and the bees" conversation would have to wait until the child has matured enough to understand, the removal of explicit pop-ups (and other advertisements) is arguably more urgent. Pop-up blockers alone would not prevent '''everything''', but are a valuable asset nonetheless.

==Transcript==
:[A cueball-child, standing and perusing an apparent magazine that they are holding. Cueball himself is approaching in a hurry, already reaching out one arm to intercede in some way.]
:Child: What's this?
:Father: Oh! That's daddy's ''Sports Illustrated'' Swimsuit Issue! It's not appropriate for—
:Child: Wow! They look just like the ladies who get double-penetrated in the popup ads!
:Child But with clothes on!
:Child: Gosh!

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Sex]]
[[Category:Multiple Cueballs]]
[[Category:Kids]]