explain xkcd - User contributions [en]

3224: Centimeter Wavelengths

2026-03-26T05:41:06Z

Linus Xu: /* Explanation */ add the IT part of the explanation

{{comic
| number = 3224
| date = March 25, 2026
| title = Centimeter Wavelengths
| image = centimeter_wavelengths_2x.png
| imagesize = 381x335px
| noexpand = true
| titletext = Yes, the cosmic microwave background is great, but what about the earthly microwave foreground?
}}

==Explanation==
{{incomplete|This page was created recently. Don't remove this notice too soon.}}

{{w|Cosmic microwave background radiation}} is {{w|Microwave|microwave radiation}} which permeates throughout the entire observable universe. It originated from light released during proton-electron recombination shortly after the {{w|Big Bang}}, which has since grown less energetic due to {{w|cosmological redshift}}, becoming microwave radiation which we see today. This radiation is not visible to the naked eye, but can be detected using specific radio instruments, including {{w|Super high frequency|centimeter wavelength}} antennas, which are antennas designed to make detection in the 1-10 wavelength range; the Microwave band of radio waves.

In this comic, "Penzias & Wilson" refers to American astronomers and physicists {{w|Arno Allan Penzias}} and {{w|Robert Woodrow Wilson}} who, in 1978, were awarded the Nobel Prize in Physics "for their discovery of {{w|cosmic microwave background radiation}}". The story of their discovery was that during routine experiments with the {{w|Holmdel Horn Antenna}}, a centimeter wavelength antenna, Penzias and Wilson discovered that they were detecting a static background noise that they could not explain. After "debugging" the antenna and removing all potential sources of noise, they found that this background noise was still present, leading to their accidental discovery of the cosmic microwave background radiation.

On the other hand, Wi-Fi networks also transmit the signal using electromagnetic waves at around similar wavelengths. [https://study-ccnp.com/wifi-frequency-phase-wavelength The common frequency bands currently used] are 2.4 GHz and 5 GHz, and 6 GHz is seeing more use recently. The three ranges would roughly correspond to wavelengths of 12.5cm (4.92in), 6cm (2.36in), and 5cm (1.97in) respectively.

This comic is alluding to the fact that Penzias and Wilson are the only people who have won a Nobel prize from trying to debug a centimeter wavelength antenna, due to their accidental discovery of the cosmic microwave background radiation. On the other hand, people working in the IT sector may be spending even more time troubleshooting issues related to Wi-Fi connectivity on their site. Less technically capable workers may need extra support to properly setup up their workflow, while [[:Category:Cueball's computer problems|too capable ones]] could also risk breaking things in [[:2949: Network Configuration|more profound ways]]...

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

:[A scatter plot graph with the Y axis of "time spent debugging centimeter-wavelength antennas" and X axis of "Nobel prizes awarded as a result". The X axis has the numbers 0 and 1 marked, while the Y axis has no numbers marked. Many dots arranged vertically appear at 0 on the X axis (zero Nobel prizes), collectively labeled as "I.T. people troubleshooting WiFi issues". A single dot appears at 1 on the X axis, vertically about 1/3 of the height of the graph up, labeled "Penzias & Wilson".]
:[Caption below the panel:]
:I just think the other people working in the field deserve at least a ''little'' recognition.

{{comic discussion}}<noinclude>

[[Category:Physics]]
[[Category:Scatter plots]]
[[Category:Comics featuring real people]]

Talk:3186: Truly Universal Outlet

2026-03-18T08:01:38Z

Linus Xu:

No comments yet, add the first comment! [[User:CalibansCreations|'''Caliban''']] ([[User talk:CalibansCreations|talk]]) 16:25, 26 December 2025 (UTC)
:You should have mentioned that this is the [[3186:_Truly_Universal_Outlet#Trivia|SECOND YEAR IN A ROW]] without Christmas comics! ;-( --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:17, 28 December 2025 (UTC)

I checked on the info.0.json and there doesn't seem to be a transcript for this one. I don't know whether that's normal, since I understand that most comics have one, but I wrote in a basic transcript. I might have just not looked in the right place. [[User:R128|R128]] ([[User talk:R128|talk]]) 16:58, 26 December 2025 (UTC)
:The info.0.json data has not contained a transcript for a while now. —[[Special:Contributions/73.70.174.157|73.70.174.157]] 05:47, 31 December 2025 (UTC)

I try not to be nationalistic or jingoistic about anything, but I'm sorry—British plugs are simply the best plugs. Strong, easy to use and safe—fits snugly into the socket, can't expose live or neutral outlets without first connecting to earth, no overly sharp pins. I don't like myself for saying this, but I honestly think the rest of the world would be better off switching to our plugs.[[Special:Contributions/109.149.114.159|109.149.114.159]] 18:00, 26 December 2025 (UTC)
:I'm American, and British plugs and sockets seem huge and clunky to me. I've also heard that (some?) Brits think US plugs are alarmingly flimsy. I'm sure that a big part of the differences of opinion is what we grew up with, and I'd love to hear a physics/engineering/UI/UX-based evaluation of which one is *actually* better. -- [[User:Dtgriscom|Dtgriscom]] ([[User talk:Dtgriscom|talk]]) 19:38, 26 December 2025 (UTC)
:: I am an American (soon to be a Gileadian after we will rename our nation to the Republic of Gilead —— ¡ChrisoFascism sucks!); so now I do not have a dog in this fight, but the [http://wikipedia.org/wiki/europlug | EuroPlug ] looks very space efficient, unlike the bulky American plus & sockets, & the ridiculously enormous UK-plugs.
::I am also an American and I agree with the sentiment that British plugs/sockets seem huge and clunky, but it depends on the plug and socket in the US how flimsy they are. I have found some sockets where plugs will literally fall out of them, and other ones where it is hard to pull them out. But American plugs are dangerous from the lack of protection against contacting power and neutral at the same time while they're live. {{unsigned ip|2601:441:4b7c:7c6a::1009|03:15, 27 December 2025}}
:I've heard this sentiment before, but I have no idea where it comes from. British plugs are ridonkulously huge and not exactly easy to use. From safety perspective, I find it odd only a handful of (European) socket types are recessed. [[Special:Contributions/81.94.52.186|81.94.52.186]] 22:07, 26 December 2025 (UTC)
::British plugs are just the right size for a hand (assuming you don't have ''very'' small hands, when you probably shouldn't be messing about with them) ''and'' the direction the cable emerges is much more convenient (e.g. handy for sockets behind furniture, outlets for worktop equipment in a kitchen or in server racks). At least that's my assesment, having had to use both US and UK systems in all cases. ;) [[Special:Contributions/92.23.2.208|92.23.2.208]] 22:47, 26 December 2025 (UTC)
: British plugs do not even meet their own design specs. This is why there is an internally different, but externally identical (apart from markings) BS 1363-2 plug for EV charging. This exists because if you draw the continuous rated current from a standard socket it is likely to melt.
: British wiring has many problematic aspects. Ring final circuits, undersized wiring for the protective fuse, too many devices on the same circuit, too few outlets so people stack extenders for the one socket in the room and run extensions cords under the rug, excessively tolerant ground fault detectors. Most of the supposed safety features of British plugs are trying to compensate for other design flaws. Not to mention mechanically identical sockets with different continuous current ratings.[[Special:Contributions/76.180.39.133|76.180.39.133]] 23:20, 26 December 2025 (UTC)
: I‘ve also seen this claim before, and ever since, I‘ve wanted to defend Switzerland‘s (type J) plug as I believe it is equivalent in many aspects and superior in some. The current-carrying prongs are plastic sleeved like the British plugs, in addition to the socket being recessed, everything is GFCI-equivalently protected, the plug lies with the prongs parallel to the floor, extension cables have doors in front of the holes, but I think the biggest advantage is the size, as one place in the wall fits three sockets (or one and a light switch). I might not have every argument present at the moment, and I am certainly biased as a Swiss person ofc. [[Special:Contributions/212.186.158.218|212.186.158.218]] 19:44, 28 December 2025 (UTC)

Someone will probably address this, but voltage issues aside, I would guess that the USAGE of the various pins across countries is likely different in catastrophic ways. E.g. I imagine that one glob of pins is hot/live in one country but ground/earth in others so that plugging an appliance from different countries into the universal outlet would cause shocks, breaker trips, explosions, etc. I did laugh at the title text - yes, I'm sure building inspectors are constantly encountering this mess. ;) [[Special:Contributions/47.248.235.170|47.248.235.170]] 18:39, 26 December 2025 (UTC)Pat
:Nope. The ground pin is always intentionally made special in all mains plugs existing, and it's basic potty training for electricians to never, ever trust the two others. --[[Special:Contributions/88.65.244.212|88.65.244.212]] 20:24, 26 December 2025 (UTC)
::Case in point, I got myself a three way extension from a supermarket here in France. It was wired up with the live and neutral reversed. I fixed mine, but there may be hundreds of them in use elsewhere. Don't trust that L is L and N is N, just don't. [[Special:Contributions/2A01:CB08:82C3:1A00:B8CA:C260:318B:E48D|2A01:CB08:82C3:1A00:B8CA:C260:318B:E48D]] 11:39, 4 January 2026 (UTC)
[https://www.internationalconfig.com/catalog_pages/universal_adapter_page.jpg Universal/travel plug adaptors] do kind of look like this. Not quite as universal though. [[Special:Contributions/220.244.124.170|220.244.124.170]] 19:50, 26 December 2025 (UTC)
:https://www.youtube.com/watch%3Fv%3DAIOqOxI0K_I --[[Special:Contributions/88.65.244.212|88.65.244.212]] 20:24, 26 December 2025 (UTC)
:Some come surprisingly close: https://tessan.com/products/65w-gan-universal-travel-adapter-wta09 https://canyon.eu/product/cns-ta1005w/ https://aluratek.com/products/universal-20w-travel-adapter (not an endorsement - I expect most if not all of these are dangerous) [[Special:Contributions/2600:4041:351:4800:D040:FA1F:BB70:CDED|2600:4041:351:4800:D040:FA1F:BB70:CDED]] 01:26, 27 December 2025 (UTC)

Just for my own amuesment, I [https://filebin.net/ehv155pyjeib5qkk tried to work out what bits were which], green for the pins, red for 'the aditional bits the pins would rattle around in' (the rest left black). ''Really'' not sure I got all the "D E M O" bits right. E, in particular, looks like it has a reverse pin that goes into the plug, but I'm also not as familiar with the old D+M different ampages/sizes (I'll only ever see them in stage-lighting, and I don't plug 'em in or out) as I am with the type-G I normally use. ...but, if anyone wants it, it'll be downloadable for the next seven days. Tidy it up, ''correct it'' as necessary, change the timings (currently 1 second a frame), recolour it (perhaps use different colours for Live, Neutral and (where there is one) Earth), whatever you want. If it's useful. And if that's done by anyone who can upload to this site (or someone does a better version off their own back). [[Special:Contributions/92.23.2.208|92.23.2.208]] 21:03, 26 December 2025 (UTC)

FWIW, it is notable that this plug is officially not a [[:category:Cursed_Connectors|cursed]] connector. --[[Special:Contributions/2001:A62:572:F601:905B:6D6D:6686:E863|2001:A62:572:F601:905B:6D6D:6686:E863]] 00:14, 27 December 2025 (UTC)

These already exist outside of this comic: https://diyhardware.ph/cdn/shop/files/YAE0838_800x.webp?v=1686379936 [[Special:Contributions/2605:C740:90:F41:842D:1EC2:FEB9:2B80|2605:C740:90:F41:842D:1EC2:FEB9:2B80]] 04:16, 27 December 2025 (UTC)

: You can also [https://images2.minutemediacdn.com/image/upload/c_fill,w_2160,ar_16:9,f_auto,q_auto,g_auto/shape%2Fcover%2Fsport%2Fgrounding640-9ed51722fe5c6fcb6a336b5bbfa005e3.jpg find them on airplanes].
: You can also [https://www.epickatech.com/products/ta-105-universal-travel-adapter buy them for traveling].
: (That travel plug also has "universal" prongs for ''plugging in'' to various different outlets, selected by those sliders on the side.) —[[User:Scs|Scs]] ([[User talk:Scs|talk]]) 06:00, 27 December 2025 (UTC)

The comic doesn't actually specify *anything* about the internals of the universal outlet, it just says to cut holes in whatever outlet you have. I find this the funniest part of it. [[User:Rorrison|Rorrison]] ([[User talk:Rorrison|talk]]) 13:07, 27 December 2025 (UTC)
:That was my thought as well. "You can definitely 'plug' your device into this outlet, no promises on whether your device will be able to receive appropriate electrical power from it though."[[Special:Contributions/57.140.28.16|57.140.28.16]] 16:49, 29 December 2025 (UTC)
::Looking through the various usages of the standards, there's not even any guarantee of correct polarity (even for those systems that ''do'' have a correct polarity, rather than don't seemto care, e.g. type C ungrounded and ''both'' subtly different type-L groundeds - and ''very'' interesting to read about the dual-metering situation behind that, BTW).
::For practical examples, type-I in Australasia has Live and Neutral one way round (enforced by the Earth connector ''and'' the pin-angles), but the type-I as used in Argentina respectively has Neutral and Live (for the same enforced orientation). And I think Brazil (type-N) already has its own local issues of the same sockets potentially being L/N (plus Earth pin) ''or'' +~/-~ as antiphases (with third pin acting as baseline Neutral) to effectively give double the (AC) potential.
::Then there's the case of expectations of voltages from 120 to 250, frequencies of at least 50-60Hz (for equipment not smart enough to handle such differences already), and you'd have to have the whole socket rated to at least 16A (even though an ungrounded Europlug/type-C shouldn't ever be drawing more than 2.5A).
::Some of that might be sorted by the socket, a kind of 'smart detection' of what electrical contacts are being made. As per [[Memo Spike Connector]]?) to then feed the right flavour of voltage accordingly. But leaves open how to work out that identical prongs are expecting a particular subset of phase(s) or neutral without 'tickling' the device with various voltages to try to establish what it's happiest with, without actually damaging it or harming its users in the process.
::Also, this isn't ''quite'' so universal... There are plenty of NEMAs (beyond the basic sub-types 1 and 5, that are A and B here), and I'm particularly intrigued by the twist-to-lock (multi-phase) variations that would need a bit more hole-drilling still... [[Special:Contributions/82.132.246.87|82.132.246.87]] 22:17, 29 December 2025 (UTC)

[[927:_Standards|Oh boy there are 15 different plug types, better create a universal outlet that covers everyone's use cases!]] [[Special:Contributions/2A02:3100:8698:AA00:7DEE:9693:120D:56C|2A02:3100:8698:AA00:7DEE:9693:120D:56C]] 14:58, 27 December 2025 (UTC)

I assumed that DEMO was going to be part of the joke, but apparently those are real standards that include the top hole. It's rather shocking that Randall didn't need to make up a single standard to make this look like a cursed connector. [[User:Quantum7|Quantum7]] ([[User talk:Quantum7|talk]]) 12:48, 28 December 2025 (UTC)

Came here expecting at least ''a'' comment saying "Biblically accurate outlet", but I'll gladly be the first to make that joke instead [[Special:Contributions/163.116.181.28|163.116.181.28]] 07:59, 29 December 2025 (UTC)

Surprised that only the voltage differences have been mentioned as issues that would need to be addressed in such a "universal" socket. No one has mentioned the frequency differences (50Hz vs. 60Hz) and the issues that could cause? {{unsigned ip|136.226.98.180|20:01, 5 January 2026}}

I've actually seen outlets that look like this in new building construction (especially hotels) in China. Oh also, if you visit Japan/China, bring a 3-to-2 prong adapter, or only bring two prong (non-grounded) cables. {{unsigned ip|23.234.83.181|20:37, 5 January 2026}}

Ventured adding the table as requested in the incomplete tag. I also found https://en.wikipedia.org/wiki/Mains_electricity_by_country#Identification_guide which has all the plugs’ photos under either public domain or CC BY-SA 3.0, both of which ''should'' be compatible here. I just don’t know how exactly to add them in-line in the table. [[User:Linus Xu|Linus Xu]] ([[User talk:Linus Xu|talk]]) 08:01, 18 March 2026 (UTC)

3186: Truly Universal Outlet

2026-03-18T07:51:42Z

Linus Xu: /* The sockets */ filled in the easy column. Attribution is provided per https://www.dimensions.com/legal .

{{comic
| number = 3186
| date = December 26, 2025
| title = Truly Universal Outlet
| image = truly_universal_outlet_2x.png
| imagesize = 264x358px
| noexpand = true
| titletext = Building Inspectors HATE This One Weird Trick
}}

==Explanation==
{{incomplete|This page was created by a 110 VOLT BRITISH PLUG.
*Need to add pictures of the different outlets and maybe even overlay them onto the comic?.}}

This comic shows a layout for a universal outlet which would theoretically fit any mains power-plug. Throughout the world, countries and regions have [https://www.dimensions.com/collection/electrical-plugs-sockets their own standards for outlets], including their shape, contact amount, and voltage. When traveling, or otherwise using devices from other countries, it is often necessary to have an adapter to connect one type of plug to a different outlet.

The comic shows an outlet with fifteen sets of holes merged together, so that any of those plug types might fit. In reality, it's possible that a plug may not be held securely, and it may fall out or lose contact. For example, the hole for types D, M, and O at the top of the outlet has three distinct holes, some of which are entirely contained within others; a prong for a smaller type would not make contact with the walls (without particularly spring-loaded contacts). Different outlets can also mean different voltages, which can risk damage if devices do not account for it. Although universal plug adapters [https://internationalconfig.com/icc6.asp?item=30250 actually exist], none of them are as 'universal' as the one shown in this comic, most likely due to these safety concerns.

The comic also seems to misrepresent type E sockets — it seems like Randall wasn't aware of (or ignored) the fact that type E sockets have a grounding pin that protrudes out from the socket, and represents it as if it were a hole in the socket instead. In reality, it would be difficult to make a socket that safely grounds type E plugs without being simultaneously incompatible with a large number of other plugs that aren't designed to accommodate the grounding pin, probably requiring the prominent socket-pin to be a spring that retracts far into the socket when pressed by a plug's ground pin.

The comic also seems to not notice the lack of grounding for full compatibility with F plugs. This leaves them in the same state as type E, above. This could be fixed by adding the extra pins for grounding. Given that most plugs in E and F regions are compatible with both standards (CEE 7/7) and have the E ground connected to the F ground through a front plate bigger than the hole for the E standard, it would theoretically be possible to make a mostly universal plug (with the exception of pure CEE 7/5 Schuko and some pure French-style CEE 7/6 that don't have the external metallic plate, but both of those are vanishingly rare, phased out by the CEE 7/7).

The title text references the classical clickbait format "<organization/role> hate this one weird trick," implying <organization/role>'s services will be no longer needed if the trick works out as it claims to, and therefore (according to the clickbait) they do not want you to find out about the trick. In this case, however, building inspectors likely hate the design solely because of its grotesque safety problems.

While this comic is not part of the [[:category:Cursed_Connectors|Cursed Connectors series]], it does follow a similar theme of unorthodox or dangerous ways to make electrical connections.

==The sockets==

{| class="wikitable sortable"
!|Socket type
!|Appearance
!|Standardized/Primarily used in... ([https://www.dimensions.com/collection/electrical-plugs-sockets Source])
!|Details
|-
|A
|
|USA, Canada, Mexico, and Japan
|
|-
|B
|
|USA, Canada, Mexico, and Japan
|
|-
|C
|
|Europe, South America and Asia
|
|-
|D
|
|India
|
|-
|E
|
|France, Belgium, Poland, Slovakia and Czechia
|
|-
|F
|
|Europe (excluding UK or Ireland) and Russia
|
|-
|G
|
|UK, Ireland, Malta, Malaysia, and Singapore
|
|-
|H
|
|Israel, the West Bank, and the Gaza Strip
|
|-
|I
|
|{{w|AS/NZS 3112|Australia, New Zealand}}, China, and Argentina
|
|-
|J
|
|Switzerland and Liechtenstein
|
|-
|K
|
|Denmark and Greenland
|
|-
|L
|
|Italy and Chile
|
|-
|M
|
|South Africa
|
|-
|N
|
|Brazil and South Africa
|
|-
|O
|
|Thailand
|
|}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

:[A diagram of an electrical outlet is shown, merging the holes of many international outlets. Dashed lines indicate individual standards' holes, which are labeled by their corresponding letter from A to N. The entire outlet is the combined area of these holes.]
:Wiring tip: To make your building friendly to international visitors, cut holes in your outlet plates to make them compatible with all fifteen IEC plug types.

==Trivia==
*This comic was released on {{w|Boxing Day}} during Christmas of 2025, but makes no reference to Christmas.
**The previous comic, released on Christmas Eve, [[3185: Sauropods]] also made no reference to Christmas.
**This thus marks the second year on a row without any [[:Category:Christmas|Christmas comics]] released during those days, see this [[3029:_Sun_Avoidance#Trivia|trivia]] from the comic [[3029: Sun Avoidance]] released on Christmas Day in 2024 (first time such a day was not given a Christmas comic).

{{comic discussion}}<noinclude>
[[Category:Tips]]

3186: Truly Universal Outlet

2026-03-18T07:20:38Z

Linus Xu: Changed subsection title since we are talking about the receiving end

{{comic
| number = 3186
| date = December 26, 2025
| title = Truly Universal Outlet
| image = truly_universal_outlet_2x.png
| imagesize = 264x358px
| noexpand = true
| titletext = Building Inspectors HATE This One Weird Trick
}}

==Explanation==
{{incomplete|This page was created by a 110 VOLT BRITISH PLUG.
*Need to add pictures of the different outlets and maybe even overlay them onto the comic?.}}

This comic shows a layout for a universal outlet which would theoretically fit any mains power-plug. Throughout the world, countries and regions have [https://www.dimensions.com/collection/electrical-plugs-sockets their own standards for outlets], including their shape, contact amount, and voltage. When traveling, or otherwise using devices from other countries, it is often necessary to have an adapter to connect one type of plug to a different outlet.

The comic shows an outlet with fifteen sets of holes merged together, so that any of those plug types might fit. In reality, it's possible that a plug may not be held securely, and it may fall out or lose contact. For example, the hole for types D, M, and O at the top of the outlet has three distinct holes, some of which are entirely contained within others; a prong for a smaller type would not make contact with the walls (without particularly spring-loaded contacts). Different outlets can also mean different voltages, which can risk damage if devices do not account for it. Although universal plug adapters [https://internationalconfig.com/icc6.asp?item=30250 actually exist], none of them are as 'universal' as the one shown in this comic, most likely due to these safety concerns.

The comic also seems to misrepresent type E sockets — it seems like Randall wasn't aware of (or ignored) the fact that type E sockets have a grounding pin that protrudes out from the socket, and represents it as if it were a hole in the socket instead. In reality, it would be difficult to make a socket that safely grounds type E plugs without being simultaneously incompatible with a large number of other plugs that aren't designed to accommodate the grounding pin, probably requiring the prominent socket-pin to be a spring that retracts far into the socket when pressed by a plug's ground pin.

The comic also seems to not notice the lack of grounding for full compatibility with F plugs. This leaves them in the same state as type E, above. This could be fixed by adding the extra pins for grounding. Given that most plugs in E and F regions are compatible with both standards (CEE 7/7) and have the E ground connected to the F ground through a front plate bigger than the hole for the E standard, it would theoretically be possible to make a mostly universal plug (with the exception of pure CEE 7/5 Schuko and some pure French-style CEE 7/6 that don't have the external metallic plate, but both of those are vanishingly rare, phased out by the CEE 7/7).

The title text references the classical clickbait format "<organization/role> hate this one weird trick," implying <organization/role>'s services will be no longer needed if the trick works out as it claims to, and therefore (according to the clickbait) they do not want you to find out about the trick. In this case, however, building inspectors likely hate the design solely because of its grotesque safety problems.

While this comic is not part of the [[:category:Cursed_Connectors|Cursed Connectors series]], it does follow a similar theme of unorthodox or dangerous ways to make electrical connections.

==The sockets==

{| class="wikitable sortable"
!|Socket type
!|Appearance
!|Primarily used in...
!|Details
|-
|A
|
|
|
|-
|B
|
|
|
|-
|C
|
|
|
|-
|D
|
|
|
|-
|E
|
|
|
|-
|F
|
|
|
|-
|G
|
|
|
|-
|H
|
|
|
|-
|I
|
|
|
|-
|J
|
|
|
|-
|K
|
|
|
|-
|L
|
|
|
|-
|M
|
|
|
|-
|N
|
|
|
|-
|O
|
|
|
|}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

:[A diagram of an electrical outlet is shown, merging the holes of many international outlets. Dashed lines indicate individual standards' holes, which are labeled by their corresponding letter from A to N. The entire outlet is the combined area of these holes.]
:Wiring tip: To make your building friendly to international visitors, cut holes in your outlet plates to make them compatible with all fifteen IEC plug types.

==Trivia==
*This comic was released on {{w|Boxing Day}} during Christmas of 2025, but makes no reference to Christmas.
**The previous comic, released on Christmas Eve, [[3185: Sauropods]] also made no reference to Christmas.
**This thus marks the second year on a row without any [[:Category:Christmas|Christmas comics]] released during those days, see this [[3029:_Sun_Avoidance#Trivia|trivia]] from the comic [[3029: Sun Avoidance]] released on Christmas Day in 2024 (first time such a day was not given a Christmas comic).

{{comic discussion}}<noinclude>
[[Category:Tips]]

3186: Truly Universal Outlet

2026-03-18T07:17:05Z

Linus Xu: Attempting to lay down the structure for the table

{{comic
| number = 3186
| date = December 26, 2025
| title = Truly Universal Outlet
| image = truly_universal_outlet_2x.png
| imagesize = 264x358px
| noexpand = true
| titletext = Building Inspectors HATE This One Weird Trick
}}

==Explanation==
{{incomplete|This page was created by a 110 VOLT BRITISH PLUG.
*Need to add pictures of the different outlets and maybe even overlay them onto the comic?.}}

This comic shows a layout for a universal outlet which would theoretically fit any mains power-plug. Throughout the world, countries and regions have [https://www.dimensions.com/collection/electrical-plugs-sockets their own standards for outlets], including their shape, contact amount, and voltage. When traveling, or otherwise using devices from other countries, it is often necessary to have an adapter to connect one type of plug to a different outlet.

The comic shows an outlet with fifteen sets of holes merged together, so that any of those plug types might fit. In reality, it's possible that a plug may not be held securely, and it may fall out or lose contact. For example, the hole for types D, M, and O at the top of the outlet has three distinct holes, some of which are entirely contained within others; a prong for a smaller type would not make contact with the walls (without particularly spring-loaded contacts). Different outlets can also mean different voltages, which can risk damage if devices do not account for it. Although universal plug adapters [https://internationalconfig.com/icc6.asp?item=30250 actually exist], none of them are as 'universal' as the one shown in this comic, most likely due to these safety concerns.

The comic also seems to misrepresent type E sockets — it seems like Randall wasn't aware of (or ignored) the fact that type E sockets have a grounding pin that protrudes out from the socket, and represents it as if it were a hole in the socket instead. In reality, it would be difficult to make a socket that safely grounds type E plugs without being simultaneously incompatible with a large number of other plugs that aren't designed to accommodate the grounding pin, probably requiring the prominent socket-pin to be a spring that retracts far into the socket when pressed by a plug's ground pin.

The comic also seems to not notice the lack of grounding for full compatibility with F plugs. This leaves them in the same state as type E, above. This could be fixed by adding the extra pins for grounding. Given that most plugs in E and F regions are compatible with both standards (CEE 7/7) and have the E ground connected to the F ground through a front plate bigger than the hole for the E standard, it would theoretically be possible to make a mostly universal plug (with the exception of pure CEE 7/5 Schuko and some pure French-style CEE 7/6 that don't have the external metallic plate, but both of those are vanishingly rare, phased out by the CEE 7/7).

The title text references the classical clickbait format "<organization/role> hate this one weird trick," implying <organization/role>'s services will be no longer needed if the trick works out as it claims to, and therefore (according to the clickbait) they do not want you to find out about the trick. In this case, however, building inspectors likely hate the design solely because of its grotesque safety problems.

While this comic is not part of the [[:category:Cursed_Connectors|Cursed Connectors series]], it does follow a similar theme of unorthodox or dangerous ways to make electrical connections.

==The plugs==

{| class="wikitable sortable"
!|Socket type
!|Appearance
!|Primarily used in...
!|Details
|-
|A
|
|
|
|-
|B
|
|
|
|-
|C
|
|
|
|-
|D
|
|
|
|-
|E
|
|
|
|-
|F
|
|
|
|-
|G
|
|
|
|-
|H
|
|
|
|-
|I
|
|
|
|-
|J
|
|
|
|-
|K
|
|
|
|-
|L
|
|
|
|-
|M
|
|
|
|-
|N
|
|
|
|-
|O
|
|
|
|}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

:[A diagram of an electrical outlet is shown, merging the holes of many international outlets. Dashed lines indicate individual standards' holes, which are labeled by their corresponding letter from A to N. The entire outlet is the combined area of these holes.]
:Wiring tip: To make your building friendly to international visitors, cut holes in your outlet plates to make them compatible with all fifteen IEC plug types.

==Trivia==
*This comic was released on {{w|Boxing Day}} during Christmas of 2025, but makes no reference to Christmas.
**The previous comic, released on Christmas Eve, [[3185: Sauropods]] also made no reference to Christmas.
**This thus marks the second year on a row without any [[:Category:Christmas|Christmas comics]] released during those days, see this [[3029:_Sun_Avoidance#Trivia|trivia]] from the comic [[3029: Sun Avoidance]] released on Christmas Day in 2024 (first time such a day was not given a Christmas comic).

{{comic discussion}}<noinclude>
[[Category:Tips]]

Talk:1031: s/keyboard/leopard/

2020-12-18T04:06:20Z

Linus Xu:

My mechanical leopard's been working out for me, just the feeling of my fingers hitting it is amazing. '''[[User:Davidy22|Davidy22]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 08:35, 21 January 2013 (UTC)

Why does it say "s/keyboard/leopard/" in the url of this page, but title of this comic is "s/leopard/leopard/"?[[User:DiEvAl|DiEvAl]] ([[User talk:DiEvAl|talk]]) 17:57, 15 April 2013 (UTC)
:Now I see "s/leopard/leopard/" twice in my previous comment. I forgot that I have an extension installed that was inspired by this comic. :) [[User:DiEvAl|DiEvAl]] ([[User talk:DiEvAl|talk]]) 18:00, 15 April 2013 (UTC)

I swear I read every instance of leopard as keyboard. [[Special:Contributions/173.245.54.89|173.245.54.89]] 23:33, 14 November 2013 (UTC)

Shouldn't the title of the comic end in "g" since it's a global replace, like "s/keyboard/leopard/g"? [[User:Kroq-gar78|Kroq-gar78]] ([[User talk:Kroq-gar78|talk]]) 18:56, 23 November 2013 (UTC)
:I have no idea, but I do know that the current title matches the one on xkcd. We're not changing it, even if there was an error. [[User:NealCruco|NealCruco]] ([[User talk:NealCruco|talk]]) 03:50, 19 February 2014 (UTC)

:I just bought my new leopard today! It's working great, but it's a bit hard to use. Is there such a thing as a leopard-repair shop? [[Special:Contributions/108.162.219.47|108.162.219.47]] 21:03, 3 March 2014 (UTC)
some[http://www.razerzone.com/gaming-leopards-keypads] leopards even have touch screens[[Special:Contributions/108.162.216.45|108.162.216.45]] 05:58, 8 March 2014 (UTC)

You sure it's not a sed command? Regexps just matches! [[Special:Contributions/108.162.215.97|108.162.215.97]] 13:44, 8 September 2014 (UTC)
:actually, it's an ed command.[[User:Taibhse|Taibhse]] ([[User talk:Taibhse|talk]]) 12:10, 12 February 2015 (UTC)

If the first user's leopard now produces language in Chinese, why is the message in English? {{unsigned ip|108.162.250.155}}
:This is more like a joke to me (as a Chinese) because there isn't a real Chinese leopard as far as I'm concerned... Chinese characters are usually typed using an IME and a standard English leopard. We type in the pronunciation romanized and select from a list of characters with the same pronunciation. [[Special:Contributions/162.158.255.164|162.158.255.164]] 03:28, 18 December 2020 (UTC)

The first add-on looks like google translate. {{unsigned ip|108.162.222.159}}

KEYBOARD. [[Special:Contributions/108.162.250.162|108.162.250.162]] 06:58, 12 August 2015 (UTC)

I have an extension that does quite this, so I have no idea who is actually saying "leopard". [[User:Cody Hackins|Cody Hackins]] ([[User talk:Cody Hackins|talk]]) 01:37, 9 March 2016 (UTC)
: Everyone except the person right above you (in allcaps) is just saying leopard. Here. Does this work? K E Y B O A R D?[[Special:Contributions/108.162.245.115|108.162.245.115]] 21:55, 3 June 2016 (UTC)

The first extension is Translate; the third is Wolfram|Alpha. [[User:Papayaman1000|Papayaman1000]] ([[User talk:Papayaman1000|talk]]) 07:15, 5 June 2016 (UTC)

As far as I know, 's/old/new/' only replaces the first instance of 'old' with 'new'. One would gace to use the g flag after the last slash to enable replacement of all instances of 'old'
[[Special:Contributions/141.101.91.223|141.101.91.223]] 23:42, 28 June 2016 (UTC)

My leopard doesn't seems to be working well since I didn't insert my leopard's USB port into my computer.Boeing-787lover 14:03, 22 November 2017 (UTC)

Can anyone think of a regex replacement someone might want to do that would be reasonably typo'd into s/keyboard/leopard/g? It's been bugging me since the comic came out. [[User:Undergroundmonorail|Undergroundmonorail]] ([[User talk:Undergroundmonorail|talk]]) 19:01, 21 July 2019 (UTC)

No speculation on Leopard being a reference to the Apple codename? [[Special:Contributions/108.162.238.161|108.162.238.161]] 15:28, 15 September 2019 (UTC)