explain xkcd - User contributions [en]

2818: Circuit Symbols

2023-08-22T02:41:52Z

172.70.100.107: Typos woo

{{comic
| number = 2818
| date = August 21, 2023
| title = Circuit Symbols
| image = circuit_symbols_2x.png
| imagesize = 438x362px
| noexpand = true
| titletext = A circle with an A in it means that the circuit has committed a sin and has been marked as punishment.
}}

==Explanation==
{{incomplete|Created by a NAUGHTY CIRCUIT WHICH DESERVES TO BE PUNISHED - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
{| class="wikitable"
! Symbol !! Comic Description !! Comments
|-
| Switch
| Drawbridge
| The symbol represents a physical on/off switch in a circuit, but also resembles a medieval drawbridge.
|-
| Capacitor
| Overpass
| A capacitor is a component that can be used to hold electric charge, but also looks a bit like the map symbol for a highway overpass.
|-
| Ground
| Pogo Stick
| This symbol represents a connection to "ground" (aka earth for folks in the UK). If you squint, it also looks like a pogo stick
|-
| Inductor
| Sheep
| Inductors are essentially the opposite of capacitors and generally consist of a coil of wire. The symbol can also look like fluffy curls of wool.
|-
| Transformer
| Two sheep in love, trapped on opposite side of a fence.
| The input and output coils on a transformer are represented as curly loops, which Randal claims resemble sheep, and the straight line (which represents the core) is a fence.
|-
| Battery
| Battery
| No joke, that's the symbol for a battery
|-
| None
| Baertty
| Randall seems to be mapping the vowels and 't's to the inner lines in the symbol, and asserting that if you sort them long long, short short, you need to put the vowels in the front and the 't's in the back.
|-
| Really None
| Batttttttttttery
| Or, you know, you could just throw in a ton of 't's.
|-
| Photodiode
| Check out this really cool diode
| A photodiode generates current in response to light (the arrows pointing at it.) Randall is instead pretending that the arrows are pointing at it because it's really cool.
|-
| Oscillator
| Wave Pool
| An oscillator generates signals at a given frequencies. A wave pool, it could be argued, is in fact a type of oscillator, just with water instead of electricity
|-
| Transistor
| Trolley Problem
| A transistor will switch on a current flow depending on the input from a input signal. Thus, it switches electricity in the same way that the trolley problem switches the trolley. The symbol also somewhat resembles the usual pictorial depiction of the problem.
|-
| Circle with an A in it (Title text)
| Committed a sin and marked for punishment
| Circles with letters are usually some special component. In this case the "A" stands for ammeter, a device used to measure current. If a circuit misbehaves or "sins", the engineer may use an ammeter to examine the circuit and figure out what is going wrong. This could be considered a form of punishment.
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
picture of drawbridge:drawbridge

{{comic discussion}}
[[Category:Engineering]]
[[Category:Charts]]

2818: Circuit Symbols

2023-08-22T02:40:00Z

172.70.100.107: Added title text description and more detailed inductor description

{{comic
| number = 2818
| date = August 21, 2023
| title = Circuit Symbols
| image = circuit_symbols_2x.png
| imagesize = 438x362px
| noexpand = true
| titletext = A circle with an A in it means that the circuit has committed a sin and has been marked as punishment.
}}

==Explanation==
{{incomplete|Created by a NAUGHTY CIRCUIT WHICH DESERVES TO BE PUNISHED - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
{| class="wikitable"
! Symbol !! Comic Description !! Comments
|-
| Switch
| Drawbridge
| The symbol represents a physical on/off switch in a circuit, but also resembles a medieval drawbridge.
|-
| Capacitor
| Overpass
| A capacitor is a component that can be used to hold electric charge, but also looks a bit like the map symbol for a highway overpass.
|-
| Ground
| Pogo Stick
| This symbol represents a connection to "ground" (aka earth for folks in the UK). If you squint, it also looks like a pogo stick
|-
| Inductor
| Sheep
| Inductors are essentially the opposite of capacitors and generally consist of a coil of wire. The symbol can also look like fluffy curls of wool.
|-
| Transformer
| Two sheep in love, trapped on opposite side of a fence.
| The input and output looks on a transform are represented as curly loops, which Randal claims resemble sheep, and the straight line (which represents the core) is a fence.
|-
| Battery
| Battery
| No joke, that's the symbol for a battery
|-
| None
| Baertty
| Randall seems to be mapping the vowels and 't's to the inner lines in the symbol, and asserting that if you sort them long long, short short, you need to put the vowels in the front and the 't's in the back.
|-
| Really None
| Batttttttttttery
| Or, you know, you could just throw in a ton of 't's.
|-
| Photodiode
| Check out this really cool diode
| A photodiode generates current in response to light (the arrows pointing at it.) Randall is instead pretending that the arrows are pointing at it because it's really cool.
|-
| Oscillator
| Wave Pool
| An oscillator generates signals at a given frequencies. A wave pool, it could be argued, is in fact a type of oscillator, just with water instead of electricity
|-
| Transistor
| Trolley Problem
| A transistor will switch on a current flow depending on the input from a input signal. Thus, it switches electricity in the same way that the trolley problem switches the trolley. The symbol also somewhat resembles the usual pictorial depiction of the problem.
|-
| Circle with an A in it (Title text)
| Committed a sin and marked for punishment
| Circles with letters are usually some special component. In this case the "A" stands for ammeter, a device used to measure current. If a circuit misbehaves or "sins", the engineer may use an ammeter to examine the circuit and figure out what is going wrong. This could be considered a form of punishment.
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
picture of drawbridge:drawbridge

{{comic discussion}}
[[Category:Engineering]]
[[Category:Charts]]

Talk:2815: Car Wash

2023-08-15T20:04:21Z

172.70.100.107:

You know, I've ''never'' been in a carwash. Not even through a hand-wash (these days set up in just about every other ex-petrol(/'gas') station forecourt not redeveloped otherwise. Driven (or walked) right past them on the ways to places (my walk to the supermarket goes past a hand-car-wash, grocery store and tyre business in an ex-petrol station - then I wander past the autocarwash 'booth' at the supermarket-aligned fuelstop, perhaps through the jetwash lanes if nobody's using them), but never took a car to one. There's buckets and sponges/etc at home. Am I missing something? [[Special:Contributions/172.71.242.11|172.71.242.11]] 20:40, 14 August 2023 (UTC)
:The bucket and sponge method takes time and effort. Automatic car washes are quick and easy. I'm mostly indifferent to car washes, but I like them more than doing it by hand because I'm lazy. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 20:46, 14 August 2023 (UTC)
::I'm indifferent to car washes too. Five years later you just have to do it all over again [[User:Boatster|Boatster]] ([[User talk:Boatster|talk]]) 23:09, 14 August 2023 (UTC)
::Time and money for the carwash: Driving there (risking incidents), possible queuing to get into retail park, queuing to pay (£££s!), possible queuing for car wash, waiting for it to do its thing (risk of damage!), possible queuing to get out drive back (risking incidents, also normal road-grime)...
:::I've never gone out specifically to get my car washed. I'm usually out doing other things, I notice the car wash, and realize that my car is dirty, so I go in. And I can't recall ever having to wait more than 5 minutes on the line, usually there isn't any line at all. It's probably not a coincidence that several of the carwashes in my area are near supermarkets. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 17:03, 15 August 2023 (UTC)
::Time and money for home-wash: Don't need to leave home. Buckets are older than me, sponges/cloths/brushes may in some cases by younger than 50 years old (but all pre-millenium), car-wax/-shampoo bottle (used sparingly) is 5-10yo and nowhere near empty, water (with a water meter, so does cost) is perhaps equivalent to two days of (hand-!)dishwashing [possibly buying a home jet-washer could bring that down, if it "does a lot more with a fastly moving lesser amount", but I might then also be tempted to jetwash the drive/windows/rooftiles as well and I'm not even sure it'd be less water through the nozzle as the tap] and (depending on time of year) may involve various mixes of hot and cold (so heating, though practically individible from other hot-water uses other than the kettle for drinks). Time taken: maybe 15 minutes (±5), at leisure while I appreciate all the distracting luxuries of home, or a highly abbreviated (one-bucket) washover/rinse at significantly less than 5 minutes (I'd still be trying to get into the supermarket, even with no queueueuing; perhaps I'd have been handwashed if ''they'' have no queue, but I wouldn't be back again...) and done. Maybe occasionally get the vacuum out and self-valet the insides, for another <5 minutes and probably entirely covered in electricity by what the solar panels have been feeding in during carwashing-friendly daytime conditions.
::Of course, it'll typically rain shortly afterwards (the rain-gods perhaps even being hopefully invoked by the very act of de-mudding the wheel-arches), but that's not going to differ between either (or neither) efforts to wash. :P [[Special:Contributions/172.70.85.45|172.70.85.45]] 21:40, 14 August 2023 (UTC)
:In Germany, you are discouraged and in many localities it's directly forbidden to wash your car on your premises; it is completely forbidden to wash your car on the street. This because of oil that will enter the sewer system. Automated car washes will recycle water and seperate oil from it. [[Special:Contributions/172.69.150.92|172.69.150.92]] 21:14, 14 August 2023 (UTC)
::Oil? If I notice oil in(/on) the water, I know there's a problem. Maybe a little residue from cleaning inside the fuel-port hatch. The way some people (over)use detergent, I could see ''that'' being an issue, but if you've an oil-leak then that's happening on or off your premises (and mostly off), I'd have thought and you might ''never even know...'' if you don't even wash your own car. [[Special:Contributions/172.70.85.45|172.70.85.45]] 21:40, 14 August 2023 (UTC)

Am I the only one who actually tried to find out whether baleen really used to be used in car washes or not?
: I added a quote on its use in the manufacture of brush bristles, although editing is needed. Next might be to figure out what vehicles were used in the 1800s and how they were washed. EDIT: https://academic.oup.com/liverpool-scholarship-online/book/43282/chapter-abstract/363026681?redirectedFrom=fulltext has a paragraph in google's cache that mentions that we can tell there was heavy use of baleen for brushes throughout the 1800s because of the heavy presence in museums. Maybe Randall's comment was inspired by a museum display. This seems possible because there's not much mention of this on the internet. [[Special:Contributions/162.158.154.185|162.158.154.185]] 01:34, 15 August 2023 (UTC)

No mention of the fact that baleen is in whale mouths, so that's where Randall got the idea that the brushes are "licking" the car? [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 17:03, 15 August 2023 (UTC)

Do people actually like car washes? It always seemed like an uncomfortable and at times terrifying experience to me. Maybe some people like it, but I would be very surprised if it's just me, Cueball and now Ponytail who don't like it. [[Special:Contributions/198.41.238.31|198.41.238.31]] 18:30, 15 August 2023 (UTC)
:I always thought they were fun and cozy, like being in a car during a rainstorm. [[Special:Contributions/172.70.100.107|172.70.100.107]] 20:04, 15 August 2023 (UTC)

Apart from queueing, I am not against car washes - happy to stay inside but not always I am allowed to. Kids do not like it. However, most times the only time I wash my car is when I have to take a flight: the parking lot where I usually leave the car provides optional car wash plus interior cleaning during the stop. [[User:Vdm|Vdm]] ([[User talk:Vdm|talk]]) 19:42, 15 August 2023 (UTC)

Talk:2719: Hydrogen Isotopes

2023-01-04T21:30:55Z

172.70.100.107:

This shows as a 404 on xkcd.com but in my RSS feed i can see the comic
: Works for me. [[Special:Contributions/172.69.34.9|172.69.34.9]] 02:25, 3 January 2023 (UTC)
::works for me now too but it didnt before
::: It works on m.xkcd.com and on the homepage of xckd, but the direct link gives me a 404. Various services such as the Wayback Machine show it as loading though. Could be a bad cache on some service. [[Special:Contributions/162.158.63.86|162.158.63.86]] 02:37, 3 January 2023 (UTC)

Could someone add an explanation of Nydnonen? I don't get it and it's google proof [[Special:Contributions/172.71.210.209|172.71.210.209]] 05:04, 3 January 2023 (UTC)Benzodiakanine
: Nothing. Was hopeful about {{w|List of Greek and Latin roots in English/N}} but nope. Tried stemming on all the Wiktionaries too. [[Special:Contributions/172.71.158.91|172.71.158.91]] 05:28, 3 January 2023 (UTC)
::Kudos to whomever figured it out, lol! [[Special:Contributions/172.71.158.231|172.71.158.231]] 08:02, 3 January 2023 (UTC)
:::Seems someone already did. There are four N's in that word replacing three of the consonant in Hydrogen so there are now four Ns one for each of the four neutrons in Nydnonen. ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 08:10, 3 January 2023 (UTC)

Are these to scale? I recently read that the Helium is smaller in terms of measured atomic radius than the Hydrogen. Possibly this is true of Deuterium as well? [[Special:Contributions/172.70.85.45|172.70.85.45]] 06:50, 3 January 2023 (UTC)
:They are almost the same size but it depends on temperature: https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.200800063 [[Special:Contributions/162.158.90.153|162.158.90.153]] 08:00, 3 January 2023 (UTC)
::Is the reason Helium is smaller not that there are double the positive charge which the electrons thus orbit in a lower orbit (I know this is not the correct in reality with the orbit). But if true then Deuterium would not have this effect as it is not the weight but the charge that changes the orbit. And Deuterium has the same charge as Hydrogen as does Tritium. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 08:10, 3 January 2023 (UTC)

::[[User:Kynde|Kynde]] is right, it is essentially the charge of the nucleus that determines orbital size, not its mass (which is always thousands of times larger than the mass of the electron). Nuclear mass has only very small effects on the electron orbitals. The most prominent effect probably would be that with a heavier nucleus, the center of mass of the atom would shift a little bit closer to the center of the nucleus (or, in other words, the reduced mass of the electron would increase a little bit), where the "little bit" is on the order of less than 10^-3. Other effects like nuclear size (distribution of the positive charge) or gravitation would be even much smaller. Note that the paper [https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.200800063 cited above] does not deal with the size of atoms. Instead, it describes the effect of temperature on the molecular volume of benzene (C6H6) versus deuterated benzene (C6D6). This makes sense, since the apparent volume of a molecule depends on, among others, the amplitudes of intramolecular vibrations, which in turn depend on bond strength, mean energy (temperature), and atomic mass (hence the isotope effect). However, temperature does not affect the size of an atom. In fact, for a single atom, "temperature" has no meaning at all. --[[Special:Contributions/162.158.86.201|162.158.86.201]] 13:08, 4 January 2023 (UTC)

Is "oops all neutrons" distinct from Neutronium, which is also all neutrons? [[Special:Contributions/172.70.100.131|172.70.100.131]] 07:38, 3 January 2023 (UTC)
:Neutronium is ultra-dense and bound by gravity, with a minimum of about 1.2x1058 neutrons in a 40 kilometer diameter sphere. [[Special:Contributions/162.158.90.153|162.158.90.153]] 08:00, 3 January 2023 (UTC)
::Well actually a {{w|neutron star}} is only 10 km in radius (20 km in diameter) according to Wikipedia. And it is 1057 neutrons acording to this [https://www.astronomy.ohio-state.edu/ryden.1/ast162_5/notes21.html lecture on Neutron Stars]. {{w|Neutronium}} was actually used as a name for neutrons without protons and suggested to be placed as number 0 on the periodical table. But is has also been used as a name for the matter in the center of neutron stars, but usually not in scientific papers! There it is called degenerate matter. The wiki article mentions how a single neutron decays to proton/electron/neutrino in 15 minutes. It also mentions that two neutrons could form for very short periods in nuclear decay. An then mentions that more than two neutrons together is not likely to exist. Specifically mentioning the three from Randall's Oops particle as not being stable for even the shortest of times. Of course a neutron would also not be able to orbit a group of neutrons. But even the three at the center is impossible. More neutrons together would be isotopes of number 0 element... --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 08:22, 3 January 2023 (UTC)
::: My bad memory; thanks. [[Special:Contributions/172.71.154.38|172.71.154.38]] 05:08, 4 January 2023 (UTC)

I think "Maximum Strength" is a reference to medicines marketed as such - in particular brands of Ibuprofen "Maximum Strength Tablets". --[[Special:Contributions/172.69.79.132|172.69.79.132]] 14:59, 3 January 2023 (UTC)
: Yes - typically meaning that it contains far more of whatever its active ingredient is than is necessary to be efficacious.[[Special:Contributions/172.70.91.128|172.70.91.128]] 15:54, 3 January 2023 (UTC)

Considering that Deuterium is derived from Greek and Tritium works in both Greek and Latin, wouldn't the correct name for ⁴H be Tetartium?
:Tetrium maybe? Tetraium? [[Special:Contributions/172.71.154.38|172.71.154.38]] 05:08, 4 January 2023 (UTC)

Is it just me or have the recaptchas gotten much more difficult over the past week, to the point of ambiguous or indiscernibly blurred images and frequently rejecting correct responses (i.e. "please try again" in red)? Granted, I'm not saying this behavior makes it any less valid as a captcha, but it's a little surprising to always get several-step challenges lately. [[Special:Contributions/172.71.154.38|172.71.154.38]] 05:08, 4 January 2023 (UTC)
: Captchas are in a continual arms race with bot writers, and wax and wane in difficulty as new attacks and counter-measures are deployed. ReCAPTCHA occasionally becomes more lengthy when they refresh their image library; we may be experiencing that. It sure doesn't seem to be slowing down the creation of new phantom usernames -- does registration even have the captcha? [[Special:Contributions/172.71.154.159|172.71.154.159]] 07:43, 4 January 2023 (UTC)
:: Firstly yes, and that might be the problem, because ReCAPCHA is still quite mild on other sites. Whomever is automating username registration here (which has been going on at least five years) may have fallen prey to a new countermeasure increasing their failure rate and making our site's angry. [[Special:Contributions/172.70.206.150|172.70.206.150]] 12:21, 4 January 2023 (UTC)
::: As a habitual IP of long-standing, I had not had a reCAPTCHA for ''soooo'' long, I realised, when I suddenly had one the other day.
::: It didn't like my first and second answers (traffic lights and crosswalks? ...typical 'on this single image' ones with edge-conditions that I never know what it's fully asking for/used to getting as an answer, inclusive or not of the poles/backdrop surround to the actual lights, tiles with just a sliver of painted road shrface, etc) before passing me on an "of these images" (all with buses/tractors? ...better than the time when it had two tractors, but clearly had been trained by others that its traditional third item counted as a tractor even though I knew it was something like a road-building scraper/planer thing) which worked.
::: But, so far at least, that was the only one (set) I got. And I had noted mysterious 2+hour gaps in silly-name new account creations, at times (notable due to the gap between the new account history and the midnight cutoff/restart in the Recent Changes compilation) - it would be nice to imagine that they were being blocked more. Though I think an immediate account-creation failure probably redoubles their next effort to create an account of some kind. (It's only the failure to ''use'' the account, subsequently, that throttles back the obvious presence of such scripted interventions. Perhaps actually by spending time hammering the server but without any visible results as far as reaches my own limited awareness of server activity via the changelog.)
::: As described, it's an arms race. And while I know I don't hanker back to the days of ''every.'' ''single.'' ''post.'' requiring a reCAPTCHA (sequence) from me, that'd be much nicer than an unusable platform due to scriptspamming. Currently seems to be about right, IMO, especially with theusafBOT's handy high-speed autoreverts on those spams that are (somehow, by using a wetware processor?) momentarily getting through on Unreliable Connection and the others... [[Special:Contributions/172.71.242.156|172.71.242.156]] 15:19, 4 January 2023 (UTC)

Re "ium": Shouldn't we try to keep the explanation short and to the point? This comic is about "isotopes", i.e. about different options of how to construct a single atom (or atom-like entity). IMO, there is no need to include many-body effects in a set of multiple electrons ([https://www.explainxkcd.com/wiki/index.php?title=2719%3A_Hydrogen_Isotopes&type=revision&diff=303973&oldid=303971 "Fermi velocity"] or [https://www.explainxkcd.com/wiki/index.php?title=2719:_Hydrogen_Isotopes&oldid=304060 "electron degeneracy pressure"]); just as there is no need to discuss, say, the kinetic theory of gases made up of these isotopes, or how they would be able to form fluids or solids. It is good to see that people who contribute here know about these effects, but I think that the explanation does not benefit from extending the discussion too far beyond the subject of a given comic. If anything, it might be worthwhile to include a reference to {{w|ion trap|ion traps}} - especially since in a Penning trap electrons actually go in circulating orbits (although not exactly circular). --[[Special:Contributions/172.70.246.210|172.70.246.210]] 11:56, 4 January 2023 (UTC)
: Go for it. We all agree to have our "writing to be edited mercilessly" in the fine print just below the Summary. Editing on whims is good because if someone else liked something earlier they will just merge it back in somehow. [[Special:Contributions/172.70.206.150|172.70.206.150]] 12:21, 4 January 2023 (UTC)

I love the administratium joke, but adding more jokes in the description seems antithetical to the purpose of this website :) [[Special:Contributions/172.70.100.107|172.70.100.107]] 21:30, 4 January 2023 (UTC)