explain xkcd - User contributions [en]

619: Supported Features

2018-03-27T12:26:00Z

TheMageKing:

{{comic
| number = 619
| date = August 5, 2009
| title = Supported Features
| image = supported_features.png
| titletext = I hear many of you finally have smooth Flash support, but me and my Intel card are still waiting on a kernel patch somewhere in the pipeline before we can watch Jon Stewart smoothly.
}}

==Explanation==
This comic is a reference to {{w|Linux}} builds adding support and features that will not appeal to the majority of desktop computer and Linux users. Cueball has created a patch that allows support for processors with 4,096 cores, even though most computers have only 8 cores or fewer. He considers this to be more worthwhile an endeavor than full-featured {{w|Adobe Flash|Flash}} support, which is much more commonly used{{Citation needed}}. Flash movies are known for their bad performance and high consumption on CPU power compared with other movie formats. Cueball's friend is uninterested in the 4,096-core-processor fix, and only wants to know if it will help him with Flash video.

However, as of 2013, there are commercial computer systems that can be actually configured up to 2,048 cores (4,096 threads), e.g. [http://www.sgi.com/products/servers/uv/models.html SGI UV 2000]. Linux powers 95% of the world's supercomputers, so while Flash video on desktop Linux would directly affect more people, the high performance computing industry relies on and actually funds Linux development. It should be noted that GNU/Linux now supports flash via {{w|Gnash}}. The first stable release was February 15, 2012; over two and a half years after this comic was written.

The title text mentions the "American political satirist, writer, director, television host, actor, media critic, and stand-up comedian" {{w|Jon Stewart}} which further refers to his famous American late night satirical television program ''{{w|The Daily Show}}''. The show is also available on the internet ([http://www.thedailyshow.com/ www.thedailyshow.com]), presenting the shows on Flash videos.

==Transcript==
:Cueball: It took a lot of work, but this latest linux patch enables support for machines with 4,096 CPUs, up from the old limit of 1,024.
:Friend: Do you have support for smooth full-screen Flash video yet?
:Cueball: No, but who uses that?
:[Friend is holding a laptop.]

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Linux]]

619: Supported Features

2018-03-27T12:17:50Z

TheMageKing:

{{comic
| number = 619
| date = August 5, 2009
| title = Supported Features
| image = supported_features.png
| titletext = I hear many of you finally have smooth Flash support, but me and my Intel card are still waiting on a kernel patch somewhere in the pipeline before we can watch Jon Stewart smoothly.
}}

==Explanation==
This comic is a reference to {{w|Linux}} builds adding support and features that will not appeal to the majority of desktop computer and Linux users. Cueball has created a patch that allows support for processors with 4,096 cores, even though most computers have only 8 cores or fewer. He considers this to be more worthwhile an endeavor than full-featured {{w|Adobe Flash|Flash}} support, which is much more commonly used{{Citation Needed}}. Flash movies are known for their bad performance and high consumption on CPU power compared with other movie formats. Cueball's friend is uninterested in the 4,096-core-processor fix, and only wants to know if it will help him with Flash video.

However, as of 2013, there are commercial computer systems that can be actually configured up to 2,048 cores (4,096 threads), e.g. [http://www.sgi.com/products/servers/uv/models.html SGI UV 2000]. Linux powers 95% of the world's supercomputers, so while Flash video on desktop Linux would directly affect more people, the high performance computing industry relies on and actually funds Linux development. It should be noted that GNU/Linux now supports flash via {{w|Gnash}}. The first stable release was February 15, 2012; over two and a half years after this comic was written.

The title text mentions the "American political satirist, writer, director, television host, actor, media critic, and stand-up comedian" {{w|Jon Stewart}} which further refers to his famous American late night satirical television program ''{{w|The Daily Show}}''. The show is also available on the internet ([http://www.thedailyshow.com/ www.thedailyshow.com]), presenting the shows on Flash videos.

==Transcript==
:Cueball: It took a lot of work, but this latest linux patch enables support for machines with 4,096 CPUs, up from the old limit of 1,024.
:Friend: Do you have support for smooth full-screen Flash video yet?
:Cueball: No, but who uses that?
:[Friend is holding a laptop.]

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Linux]]

886: Craigslist Apartments

2018-03-24T18:24:52Z

TheMageKing:

{{comic
| number = 886
| date = April 15, 2011
| title = Craigslist Apartments
| image = craigslist apartments.png
| titletext = $1600 / 1386153BR 3BATH, MODERN SLIDING DOORS, GUEST ROOMS, GARBAGE DISPOSAL. FREE MANDATORY PARKING (ENFORCED). CONVENIENT TO ALDERAAN.
}}

==Explanation==
This is a comic about the potential pitfalls in finding an apartment on {{w|Craigslist}}. Just as in Craigslist, some of the posts are re-posted several times. Additionally, lots of posts use lots of tildes, exclamation points or asterisks as above to set their posts apart from others.

'''BR''' means bedroom, e.g. 3BR means that apartment has 3 bedrooms (common measurement of apartment size).

*'''$1600 / 2BR <nowiki>~~~</nowiki> Hardwood floors, utilities included. Cats OK, limit one per square foot.'''
:This ad is aimed at "crazy cat ladies/bachelors" who compulsively keep a number of animals much greater than is appropriate to the living space.

*'''$1100 / **** GREAT DEAL SQUARE HOUSE DOOR IN FRONT!!! ****'''
:This is the first repetition of an entry that appears multiple times. It is also extremely generic, telling the reader little useful about the house. The square house might be a garage, or just a regular square house. Beside that, most houses have a door in front{{Citation needed}}, there's nothing special about a door.

*'''$2300 / 3BR !!!!!!!! Elegant apartment permanently lit by strobe light!!!! No floor.'''
:A strobe light is a very bright light that, instead of remaining on, flashes very quickly. It's frequently used in parties. A constant strobe light and the stated lack of a floor would probably make living in the apartment somewhat difficult.{{Citation needed}}

*'''$980 / 1BR New "hammock"-style dwelling. Water and heat free from same dispenser. Viking landlord.'''
: This is a post to live as an oarsman on a {{w|Viking ship}}. The water and heat presumably both come from the sky, in the form of rain and sunlight.

*'''$1550 / 2BR (one inside the other). Has running water, in a sense. Free heat in short, intense bursts. Klein stairs.'''
: This is a completely alien landscape, meant to be unimaginable and maddening. Possibly this represents some "other universe" or an extraterrestrial living space. Clearly this is unlivable, for humans at least. Short, intense bursts of heat disturb if not kill. Stairs that do not have a clear top or bottom and rooms that can be seen as inside of each other would be confusing and impractical if not impossible to navigate. Water that runs 'in a sense' is disturbingly vague. Seems to be on a planet with a quick rotation, also close to a star, hence the "short, intense bursts" of heat.
:(Alternatively, the house could have a {{w|geyser}} inside, which would explain both the 'free heat in short, intense bursts', along with the 'water that runs in a sense'.) A {{w|Klein bottle}} is a surface which has no difference between "inside" and "outside", so essentially if you own a Klein bottle all the universe is inside it (and at the same time it is outside). It is physically impossible to build a Klein bottle in a three-dimensional space. A "Klein stair" is possibly a stair connecting a BR to itself. This is why the 2BR in this ad are "one inside the other".

*'''$3200 / 1BR W/trimmed carpet and pert fixtures. Previous tenants clean. Call now, want you inside. $120/night (no animals)'''
:This is a disguised "adult services" (sex) posting, with references to trimmed pubic hair, an attractive body, and a lack of {{w|Sexually transmitted disease|STD}}s. Craigslist no longer allows posts for this, because prostitution is illegal in most places in the US. This post tries to evade the adult services ban by pretending to be something else. "No animals" would normally be assumed to mean "no pets", but in this context probably refers to STDs (possibly {{w|Pediculosis pubis|crabs}} or {{w|scabies}}) or {{w|bestiality}}.

*'''$2100 / 3BR on scenic Ash Tree Lane. Builder unknown; house has always existed. Walls shift; center of house may contain minotaur.'''
: This {{w|Minotaur}} house is an ad for the house in the novel ''{{w|House of Leaves}}''. It may also refer to the Labyrinth in Ancient Greek mythology.

*'''$600 / 5BR Three floors w/pool, rooftop garden, beautiful glass facade, no catch, 5-min drive to historic Pripyat.'''
:This is an ad for a residence in the {{w|Chernobyl Nuclear Power Plant}}, located near to the town of {{w|Pripyat}}, in northern Ukraine. The NPP is a 3-level structure, and contains a pool for temporary spent nuclear fuel storage. The rooftop now has plants growing on it after years of neglect, and the glass facade references radioactive glassy minerals created by the explosion. Pripyat was founded in 1970 to serve the power plant, so is only 'historic' in the sense that it is associated with the Chernobyl disaster.

*'''$7100 / 60BR Sleek modern w/extreme running water. Previous tenants may resist entry. Contains all new wiring and is a submarine.'''
:This house is a submarine, as indicated by the advertisement, presumably operated by a navy. The "previous tenants", being members of the armed forces, would undoubtedly resist entry of someone attempting to board their submarine. The sixty bedrooms refers to the crew members' bunks on board the ship, which are in extremely tight quarters and can be very uncomfortable. This may also be a reference to [[496: Secretary: Part 3]], which makes reference to [[Black Hat]] stealing a submarine, presumably for [[405: Journal 3]] - apparently this is him trying to get rid of it.

*'''$1616 / 3BR + 2Bath, tub full of blood. Closet full of board games which play themselves. Pets OK but won't survive long.'''
: This is an ad for a house in a generic horror movie.

*'''$1600 / 1386153BR 3bath, modern sliding doors, guest rooms, garbage disposal. Free mandatory parking (enforced). Convenient to Alderaan.'''
:Appearing in the title text, this is a reference to the {{w|Death Star}} in ''Star Wars''. {{w|Alderaan}} is the home planet of {{w|Princess Leia}}, which was obliterated by the Death Star. Mandatory parking references the tractor beams used to drag nearby ships (such as the Millennium Falcon) into the base. The garbage disposal refers to an iconic scene from Star Wars aboard the Death Star involving a garbage disposal. It seems somewhat inconvenient that this "apartment" has over a million bedrooms but only three bathrooms. The guest rooms are probably the detention blocks such as [http://starwars.wikia.com/wiki/Detention_Block_AA-23 Detention Block AA-23].

==Transcript==
:[The comic is a single panel, presented as an apartment search.]
:[Title bar.]
:All apartments
:Search for: [_______] in: All apartments ( ) Title only (*) Entire post Search
:Rent: [Min] [Max] 0+ BR [ ] Cats [ ] Dogs [ ] Has image
:[Date bar.]
:Fri Apr 15
:[Begin the apartment listings.]
:$1600 / 2BR <nowiki>~~~</nowiki> Hardwood floors, utilities included. Cats ok, limit one per square foot.
:$1100 / **** GREAT DEAL SQUARE HOUSE DOOR IN FRONT!!! ****
:$2300 / 3BR !!!!!!!! Elegant apartment permanently lit by strobe light!!!! No floor.
:$1100 / **** GREAT DEAL SQUARE HOUSE DOOR IN FRONT!!! ****
:$980 / 1BR New "hammock"-style dwelling. Water and heat free from same dispenser. Viking landlord.
:$1550 / 2BR (one inside the other). Has running water, in a sense. Free heat in short, intense bursts. Klein stairs.
:$1100 / **** GREAT DEAL SQUARE HOUSE DOOR IN FRONT!!! ****
:$1100 / **** GREAT DEAL SQUARE HOUSE DOOR IN FRONT!!! ****
:$3200 / 1BR W/trimmed carpet and pert fixtures. Previous tenants clean. Call now, want you inside. $120/night (no animals)
:$2100 / 3BR on scenic Ash Tree Lane. Builder unknown; house has always existed. Walls shift; center of house may contain minotaur.
:$1100 / **** GREAT DEAL SQUARE HOUSE DOOR IN FRONT!!! ****
:$600 / 5BR Three floors w/pool, rooftop garden, beautiful glass facade, no catch, 5-min drive to historic Pripyat.
:$7100 / 60BR Sleek modern w/extreme running water. Previous tenants may resist entry. Contains all new wiring and is a submarine.
:$1616 / 3BR + 2Bath, tub full of blood. Closet full of board games which play themselves. Pets ok but won't survive long.

{{comic discussion}}
[[Category:Comics with color]]

804: Pumpkin Carving

2018-03-22T14:15:28Z

TheMageKing: Added a citation needed tag to controversial statement "pumpkins are vegetables"

{{comic
| number = 804
| date = October 11, 2010
| title = Pumpkin Carving
| image = pumpkin carving.png
| titletext = The Banach-Tarski theorem was actually first developed by King Solomon, but his gruesome attempts to apply it set back set theory for centuries.
}}

==Explanation==
This comic is a reference to the custom of making {{w|Jack-o'-lantern|Jack-O'-Lantern}}s to set out on porches and front steps for the holiday of {{w|Halloween}}, which occurs on October 31. Typically they are made with {{w|pumpkins}} by emptying the inside leaving a hollow shell, carving a face or design on the side, then placing a light or candle inside. The Jack-O'-Lantern in the 3rd frame is the typical and standard design for a carved pumpkin.

The comic is set up as a typical TV program where an off-screen interviewer asks four (very) different people what they have made out of their Halloween pumpkin. In the [http://xkcd.com/804/info.0.json official transcript] the interviewer that talks in three of the panels is called an Interlocutor: "a person who takes part in dialogue or conversation."

In the first frame, [[Beret Guy]], naturally, stays oddly on-topic by physically carving an image of a pumpkin in his pumpkin. This means his answer, "I carved a pumpkin," could apply to either the image or the medium of his artwork.

In the second frame, [[Black Hat]] is shown with a container of {{w|nitroglycerin}} next to his pumpkin. Nitroglycerin is a highly explosive liquid that may explode violently with just a small bump. Black Hat has not carved a hole for his lamp, but it seems he has emptied the inside of the pumpkin as the stem at the top has been removed. This will make it possible to fill up the pumpkin with nitroglycerin. Teenagers are a rather impulsive and rebellious lot; as Halloween is a night with lots of meticulously erected decorations and more lax parental supervision, troublemaker teens see it as an enticing time to engage in rampant vandalism, including but not limited to pumpkin-smashing. Hence, the off-panel character presumes that Black Hat is setting up a trap to get back at these ne'er-do-wells. To top it off, Black Hat plans to put up a sign warning passers-by to not smash the pumpkin. This would only serve to tempt impulsive teenagers to disturb it, which is very likely what the sadistic and chaos-loving [[Classhole]] is hoping for. If he succeeds with his plan, with a completely hollowed out pumpkin of the shown size filled with nitroglycerin, it would seem likely that the resulting explosion would leave a largish crater, flatten wood-framed buildings nearby, shatter windows for blocks in all directions, and be more than sufficient to kill the vandal along with others in the surrounding area. This is clearly overkill for such a petty crime.

Black Hat, rather unconvincingly, insists that his pumpkin is suffering from chest pains, and that the nitroglycerin is merely intended for medical treatment. While it is true that this chemical is used to treat {{w|angina}} (chest pain due to blocked arteries in the heart), nitroglycerin used for this purpose is dispensed in the form of small pills containing only trace amounts, and controlled by prescription. Also, pumpkins are a vegetable{{Citation needed}} and do thus not contain nervous or circulatory systems of mammalian complexity; even if they did, the process of pumpkin carving involves hollowing them out, making it a moot point.

In the third frame, [[Megan]] is our typical emotional xkcd comic character. She is the only one out of the four who actually carved a typical jack-o'-lantern; however, she is projecting herself onto it, and has named it Harold. Her dialogue suggests it (or he) is suffering from typical holiday depression, with symptoms such as using a lot of time daydreaming, worrying, and trying to distract herself with holiday traditions, but she already knows that it won't work.

In the fourth frame, [[Cueball]] is shown in front of two un-carved pumpkins exclaming that this is the result of carving one pumpkin. He is referencing the {{w|Banach-Tarski paradox}} (which is made clear in the title text), a theorem which states that it is possible to split a three-dimensional ball, in this case a pumpkin, into a finite number of "pieces," and then reassemble these "pieces" into two distinct balls both identical to the original. This paradox has been proven for theoretical shapes, but requires infinitely complicated pieces which are impossible for anything made of physical {{w|atomic theory|atoms}} rather than mathematical {{w|point (geometry)|points}}.

The off-screen interviewer in that frame references the {{w|Axiom of Choice}}. This axiom is the foundation for many theorems (including the Banach–Tarski paradox) and is extremely influential to modern mathematics; however, it has been historically controversial precisely because it enables this kind of weirdness. It is called an "axiom" because it is a statement that is not meant to be proven or disproven—only accepted or rejected depending on the theoretical framework one wishes to work with. Rejecting the Axiom of Choice results in a perfectly coherent alternate form of set theory. Since the proof for the Banach–Tarski paradox relies on accepting the axiom of choice, the interviewer is suggesting Cueball's unexpected result would not have happened without using the axiom.

The title text references a biblical story involving {{w|Solomon|King Solomon}}. In the story, known as the {{w|Judgment of Solomon}}, two women were brought before him both claiming that a particular child was their own. Solomon tested the women by saying the only solution was to cut the baby in half and give each woman one of the halves, knowing only the real mother would fight to save her child's life even if the price was giving up the whole child to the other woman. The joke is that if Solomon had developed the Banach–Tarski theorem first, then he could have actually believed cutting the baby into pieces was a valid solution. In that scenario, he would have tried to make two whole children from the original and given one to each woman. However, since babies are not infinitely divisible, his attempt would have failed miserably and set back set theory for centuries due to the appearance that he has "proved" the theorem wrong.

The axiom of choice and set theory was later referenced in [[982: Set Theory]] and, much later, the axiom of choice was mentioned again in the title text of [[1724: Proofs]].

This comic was released 20 days before Halloween in 2010, possibly to inspire people with some great ideas for their pumpkins. It has been known (particularly by Randall) that people copy his ideas, for instance this earlier [http://xkcd.com/chesscoaster/ post] on xkcd based on [[249: Chess Photo]]. Soon after he even made a comic, [[254: Comic Fragment]], that was supposed to be impossible to copy, which he mentioned himself later (see the explanation).

==Transcript==
:[Beret Guy, holding his arms out, stands behind a large orange pumpkin with the stem on top. It is sitting on a table. The pumpkin has been carved out as a lamp with large hole, and a lit candle is visible in the hole. The hole is in the shape of another carved out pumpkin. An interviewer speaks from off panel.]
:Interviewer (off-panel): So what did you—
:Beret Guy: I carved a pumpkin!
:Interviewer (off-panel): ...

:[Black Hat stands behind a large orange pumpkin which has not been carved out as a lamp, but the stem at the top has been removed and is placed tilting on the side of the pumpkin. It is sitting on a table. A gray box stands next to and partly in front of the pumpkin. On the end of the box there is a label at the top with unreadable text and below that some kind of drawing with a circle at the top. The interviewer speaks from off panel.]
:Interviewer (off-panel): Taking on teen vandals, I see.
:Black Hat: Heavens, no. My pumpkin simply has chest pains. In fact, I'll leave a note ''warning'' them not to smash it.
:Text on box:
::Nitro-
::glycerin
::Do Not
::Shake

:[Megan stands next to a large orange pumpkin with the stem on top. It is sitting on a table. The pumpkin has been carved out as a typical Halloween lamp. The bottom part of a white candle stick is visible in the mouth shaped hole. The hole is in the shape of a typical jack-o' lantern, with two slanted eyes, double slit nose and a smiling mouth with a tooth sticking out from both upper and lower lip, on either side of the candle stick.]
:Megan: My pumpkin's name is Harold. He just realized that all the time he used to spend daydreaming, he now spends worrying. He'll try to distract himself later with holiday traditions, but it won't work.

:[Cueball stands next to a two orange pumpkins with their stems on top, the left pumpkin is slightly larger than the right which is partly in front of the larger pumpkin. They have not been carved out even though a knife lies next to them to the right in front of Cueball on the table where they both stand. The interviewer speaks from off panel.]]
:Cueball: I carved and carved, and the next thing I knew I had ''two'' pumpkins.
:Interviewer (off-panel): I ''told'' you not to take the axiom of choice.

{{comic discussion}}

[[Category:Comics featuring Beret Guy]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics with color]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Math]]
[[Category:Logic]]

730: Circuit Diagram

2018-03-19T13:49:07Z

TheMageKing:

{{comic
| number = 730
| date = April 21, 2010
| title = Circuit Diagram
| image = circuit_diagram.png
| titletext = I just caught myself idly trying to work out what that resistor mass would actually be, and realized I had self-nerd-sniped.
}}

==Explanation==
Another fine example of [[356|nerd sniping]].
There are pieces of circuit diagrams, road maps, chemical diagrams, and other things all mixed in.
Explanations for each below!

{|class="wikitable table-padding left-align"
!Image Fragment
!width="130px" | Image Location
!Description
|-
{{circuit-diagram-part|X=19|Y=25|W=106|H=37|image=circuit_diagram-019-025-106-037-scale.png|text=A map scale. Lists kilometers and miles as equivalent. And makes the diagram many miles wide.}}
{{circuit-diagram-part|X=15|Y=62|W=40|H=85|image=circuit_diagram-015-062-040-085-antenna.png|text=An antenna. Typical of radio receivers or transmitters. Or the Turtle in LOGO programming language}}
{{circuit-diagram-part|X=53|Y=60|W=41|H=87|image=circuit_diagram-053-060-041-087-inductor.png|text=A coil or inductor. Normal, but unlabeled.}}
{{circuit-diagram-part|X=107|Y=86|W=85|H=93|image=circuit_diagram-107-086-085-093-cloverleaf.png|text=A {{w|cloverleaf interchange}} or junction is a feature of road networks that does not belong in a circuit diagram. Of course, other types of {{w|p–n junction|junction}} are important in electronics.
A cloverleaf junction has previously been used in comic: [[253: Highway Engineer Pranks]]}}
{{circuit-diagram-part|X=184|Y=12|W=87|H=63|image=circuit_diagram-184-012-087-063-battery.png|text=A battery. The voltage of square root of two is strange, but getting about 1.41412... volts is not unheard of. This could also indicate an [[wikipedia:Root_mean_square|RMS]] voltage, although this is unlikely given that this is a DC power supply and not an AC generator. The marked polarity is also the reverse of what is implied by the symbol (where the larger terminal is positive). A possible reference to [[567: Urgent Mission]].}}
{{circuit-diagram-part|X=187|Y=110|W=94|H=71|image=circuit_diagram-187-110-094-071-resister.png|text=A 120 ohm resistor is normal enough. "Or to taste" is odd for a circuit diagram and more like instructions from a recipe, e.g., "1 tbsp tomato purée, or to taste".}}
{{circuit-diagram-part|X=283|Y=50|W=90|H=63|image=circuit_diagram-283-050-090-063-switch.png|text=A normal switch, with a notation to glue it open. Reminiscent of the [http://catb.org/esr/jargon/html/magic-story.html MAGIC/MORE MAGIC] switch.}}
{{circuit-diagram-part|X=337|Y=101|W=69|H=64|image=circuit_diagram-337-101-069-064-transisitor.png|text=A bipolar PNP transistor, except that it has two emitters and no collector. It also resembles one of the schematic symbols for a {{w|DIAC}}, except the arrows are backwards.}}
{{circuit-diagram-part|X=52|Y=141|W=79|H=107|image=circuit_diagram-052-141-079-107-compass-points.png|text=Compass points. A map feature, not a circuit feature.}}
{{circuit-diagram-part|X=415|Y=18|W=63|H=58|image=circuit_diagram-415-018-063-058-resister.png|text=A normal resistor, labeled with color code. Brown-Blue-Orange would be 16000 ohms. Resistor color codes are for reading the value on the physical device itself. They would not normally be shown on the circuit diagram, where it's much easier to just write the number, e.g. 16K.}}
{{circuit-diagram-part|X=517|Y=14|W=42|H=32|image=circuit_diagram-517-014-042-032-diode.png|text=A normal diode.}}
{{circuit-diagram-part|X=615|Y=55|W=73|H=74|image=circuit_diagram-615-055-073-074-666timer.png|text=A chip. The normal timer is a "{{w|555_timer_IC|555}}". "666" would be the number of the beast in [http://www.blueletterbible.org/Bible.cfm?b=Rev&c=13&v=18&t=KJV#18 Rev. 13:18]. The pin connected to "?" is the CTRL pin on a normal 555 timer, which would typically be connected to ground (via a decoupling capacitor) if used at all; the implication here seems to be that it would be connected directly to Hell itself.}}
{{circuit-diagram-part|X=632|Y=138|W=69|H=41|image=circuit_diagram-632-138-069-041-bat.png|text=A Batman logo.}}
{{circuit-diagram-part|X=650|Y=211|W=75|H=71|image=circuit_diagram-650-211-075-071-squirrel.png|text=A squirrel, or perhaps a wire bent into the shape of a squirrel. What it does as a circuit element is unclear. If it is a squirrel, it would be an unhelpful addition to the circuit, as squirrels are not conductive{{Citation needed}} and this one would need to be several miles long according to the scale. Squirrels have also appeared in past and future xkcd comics.}}
{{circuit-diagram-part|X=606|Y=165|W=54|H=53|image=circuit_diagram-606-165-054-053-inductor.png|text=A coil or inductor, or a spring symbol in Physics force diagrams, probably the latter as it is labeled with an 11-kilogram mass.}}
{{circuit-diagram-part|X=538|Y=209|W=99|H=59|image=circuit_diagram-538-209-099-059-generator.png|text=A 240-volt AC generator (or other power source).}}
{{circuit-diagram-part|X=483|Y=186|W=111|H=103|image=circuit_diagram-483-186-111-103-shorted-generator.png|text=A shorting wire around a generator. The label reads "Omit this if you're a '''wimp.'''" If this wire is included, it will quickly melt - or worse.}}
{{circuit-diagram-part|X=419|Y=78|W=57|H=75|image=circuit_diagram-419-078-057-075-scarab-beetles.png|text=A jar of {{w|Scarabaeidae|scarab beetles}}.}}
{{circuit-diagram-part|X=482|Y=47|W=28|H=44|image=circuit_diagram-482-047-028-044-variable-resister.png|text=A variable resistor with center tap. Normally, there would be an arrowhead on the center tap.}}
{{circuit-diagram-part|X=507|Y=53|W=22|H=27|image=circuit_diagram-507-053-022-027-capacitor.png|text=A normal capacitor.}}
{{circuit-diagram-part|X=577|Y=318|W=96|H=62|image=circuit_diagram-577-318-096-062-magic.png|text="{{w|Magic Smoke}}" is the legendary stuff that all circuit components require to function. This is why all components cease to function after releasing smoke. }}
{{circuit-diagram-part|X=669|Y=315|W=51|H=66|image=circuit_diagram-669-315-051-066-frayed-wires.png|text=Some frayed or dangling wires.}}
{{circuit-diagram-part|X=567|Y=392|W=58|H=48|image=circuit_diagram-567-392-058-048-buoy.png|text=An object which is either a float used in fishing, a {{w|Tippe top}}, or perhaps a {{w|Naval mine|mine}}.}}
{{circuit-diagram-part|X=458|Y=336|W=111|H=86|image=circuit_diagram-458-336-111-086-moral-rectifier.png|text=A {{w|Diode_bridge|bridge rectifier}}, which would normally turn alternating current at the top and bottom into direct current on the left and right. In this case, it is labeled as a "moral rectifier". This is presumably a play on the idea of moral rectitude – it makes your circuit more moral. Why this matters in a circuit is unclear.}}
{{circuit-diagram-part|X=423|Y=259|W=80|H=85|image=circuit_diagram-423-259-080-085-warm-front.png|text=This resembles both the schematic symbol for part of a transformer and the meteorological symbol for a warm front. A {{w|warm front}} is a feature on a {{w|Surface weather analysis|synoptic weather map}}.}}
{{circuit-diagram-part|X=190|Y=199|W=54|H=52|image=circuit_diagram-190-199-054-052-battery.png|text=A normal 50-volt battery.}}
{{circuit-diagram-part|X=173|Y=200|W=89|H=56|image=circuit_diagram-173-200-089-056-shorted-battery.png|text=A battery is grounded on both sides. Something will melt or burn out quickly, unless these are separate "earth ground"s, in which case the ground might get a bit cooked.}}
{{circuit-diagram-part|X=259|Y=198|W=174|H=25|image=circuit_diagram-259-198-174-025-pull-wire.png|text=Text reads "Pull this wire really tight". This kind of physical-property issue may indicate a high-frequency radio device. Or, given the absurdity of the context, it's a silly reference to a "high tension wire."}}
{{circuit-diagram-part|X=141|Y=211|W=41|H=91|image=circuit_diagram-141-211-041-091-3-8-inch.png|text=A specified 3/8-inch separation. This probably indicates a carefully controlled capacitance issue. Also contradicts the scale of the drawing, by which the distance shown would be about 0.8 miles or 0.8 km.}}
{{circuit-diagram-part|X=173|Y=309|W=92|H=59|image=circuit_diagram-173-309-092-059-eel.png|text=An {{w|electric eel}}. This may be an effective power source in the circuit, capable of producing a shock at up to 600 volts and 1 ampere of current (600 watts), but for less than 2 ms.}}
{{circuit-diagram-part|X=266|Y=307|W=35|H=41|image=circuit_diagram-266-307-035-041-resistor.png|text=A normal resistor.}}
{{circuit-diagram-part|X=222|Y=358|W=34|H=29|image=circuit_diagram-222-358-034-029-capacitor.png|text=A normal capacitor.}}
{{circuit-diagram-part|X=130|Y=335|W=44|H=40|image=circuit_diagram-130-335-044-040-resistor.png|text=A normal resistor, labeled "ë". This may be a play on {{w|e (mathematical constant)|Euler's Number}}, which doesn't normally have a {{w|tréma}} or an {{w|umlaut (linguistics)|umlaut}}. Alternatively instead of being an umlaut or tréma it may indicate the second {{w|derivative}} of e with respect to time in {{w|Newton's notation}}, in which case, as e is a constant, the resistance of this element is zero.}}
{{circuit-diagram-part|X=65|Y=249|W=61|H=92|image=circuit_diagram-065-249-061-092-blender.png|text=Our best guess is that this is a blender. Due to the scale, this would certainly be the worlds largest blender. Reccord setting blenders are not typically part of computer circuts{{Citation needed}}}}
{{circuit-diagram-part|X=20|Y=342|W=115|H=73|image=circuit_diagram-020-342-115-073-arduino.png|text=An {{w|arduino}}, labeled "Arduino, just for blog cred". May refer to the fact that inexpensive, easy-to-integrate single-board computers like the arduino, which have contributed to the rise of {{w|Maker_culture}}, are used and discussed frequently in that culture, and the use of one might impress readers. The comment implies that an arduino is not otherwise needed in this circuit, although it is necessarily hard to tell, given the other components of the circuit.}}
{{circuit-diagram-part|X=39|Y=423|W=118|H=82|image=circuit_diagram-039-423-118-082-meca.png|text=A chip labeled "Most expensive chip available". The small curve at the top is a part of the packaging designed to show its orientation.}}
{{circuit-diagram-part|X=159|Y=428|W=91|H=50|image=circuit_diagram-159-428-091-050-neck-strap.png|text=Labeled "Neck Strap". Perhaps a piece of torture equipment or indicating that the circuit is part of an {{w|electric chair}}? May also be a reference to the grounded wrist straps people working with electronics commonly wear, to prevent accidental static discharges from frying the circuitry.}}
{{circuit-diagram-part|X=147|Y=480|W=110|H=88|image=circuit_diagram-147-480-110-088-switch.png|text=A switch labeled "Hire someone to open and close switch real fast." Possibly meant to perform the function of an oscillator in a more hackish manner and the reason for the neck strap. Could also be a reference to {{w|Maxwell's Demon}}.}}
{{circuit-diagram-part|X=273|Y=498|W=61|H=64|image=circuit_diagram-273-498-061-064-resistor.png|text=A 5 ohm resistor labeled "(decoy)". One end is not attached to anything. Perhaps this indicates wishful thinking that electrons might be tricked into entering this part of the circuit despite the fact that there's nowhere for them to go?}}
{{circuit-diagram-part|X=307|Y=453|W=103|H=56|image=circuit_diagram-307-453-103-056-tongue.png|text=A pair of contacts, labeled "Touch Tongue Here". Could be referring to the practice of daring someone to touch their tongue to the contacts of a 9V battery.}}
{{circuit-diagram-part|X=301|Y=270|W=45|H=45|image=circuit_diagram-301-270-045-045-frown.png|text=A frowny-face. See the float/mine.}}
{{circuit-diagram-part|X=294|Y=311|W=128|H=124|image=circuit_diagram-294-311-128-124-IC.png|text=A small integrated circuit. The lower gate is an inverter, wired as a free-running oscillator. The upper gate is an XOR wired to act as either a free-running oscillator or a latch. Since the XOR will be slower than the inverter, the overall output of the upper gate is probably very chaotic. Two "input" wires are not connected at all. An additional wire is attached to the top with hot glue. This last wire probably acts to control static electricity and leakage.}}
{{circuit-diagram-part|X=302|Y=235|W=91|H=25|image=circuit_diagram-302-235-091-025-curve.png|text=A caution sign at a curve. Another road feature in the circuit. This is a play on the notion that 90-degree corners on printed circuit board traces can disrupt signal integrity.}}
{{circuit-diagram-part|X=401|Y=455|W=67|H=68|image=circuit_diagram-401-455-067-068-CH3.png|text=A {{w|methyl group}} (chemistry) attached to a corner. If the circuit were an organic chemical, it would be reasonable to find a number of these.}}
{{circuit-diagram-part|X=453|Y=167|W=43|H=93|image=circuit_diagram-453-167-043-093-baloon.png|text=A balloon, possibly blowing in a breeze.}}
{{circuit-diagram-part|X=572|Y=68|W=22|H=43|image=circuit_diagram-572-068-022-043-inductor.png|text=A coil or inductor.}}
{{circuit-diagram-part|X=508|Y=96|W=42|H=20|image=circuit_diagram-508-096-042-020-inductor.png|text=A coil or inductor.}}
{{circuit-diagram-part|X=534|Y=61|W=22|H=31|image=circuit_diagram-534-061-022-031-ground.png|text=A ground connection.}}
{{circuit-diagram-part|X=472|Y=49|W=134|H=140|image=circuit_diagram-472-049-134-140-solderr-blob.png|text=A solder blob covering a portion of the circuit. Normally, this would not be part of the circuit diagram, but a mistake in building the circuit.}}
{{circuit-diagram-part|X=493|Y=443|W=207|H=158|image=circuit_diagram-493-443-207-158-res-rats-nest.png|text=A rats nest of 1 ohm resistors. It is labeled "Oh, so you think you're such a whiz at EE201?" The name EE201 (Electrical Engineering 201) follows US course naming conventions for what appears to be a basic level course in electrical engineering (compare the term {{w|101 (term)|101}}), which would include being taught how to [http://www.wikihow.com/Calculate-Series-and-Parallel-Resistance calculate the effective resistance of various resistor networks]. Performing the calculation on a network this complex would probably be extremely difficult. It appears to work out to 0.75800964845 ohms.
A grid of 1 ohm resistors has appeared earlier in [[356: Nerd Sniping]], a comic also referred to in the title text.}}
{{circuit-diagram-part|X=315|Y=533|W=232|H=200|image=circuit_diagram-362-531-151-167-arena.png|text=An arena, with a few bodies in it. Note the direction of movement enforced by the surrounding diodes, {{w|Mad_Max_Beyond_Thunderdome|"two men enter, one man leaves"}}, a film reference.}}
{{circuit-diagram-part|X=569|Y=653|W=47|H=51|image=circuit_diagram-569-653-047-051-resistor.png|text=A "{{w|pi}}" ohm resistor.}}
{{circuit-diagram-part|X=610|Y=655|W=75|H=70|image=circuit_diagram-610-655-075-070-generator.png|text=A 500-volt AC generator. The wiring to the right shorts out this generator.}}
{{circuit-diagram-part|X=481|Y=682|W=85|H=64|image=circuit_diagram-481-682-085-064-ground.png|text=A ground connection, labeled "Bury deep, but not too deep". This type of ground connection is called an "earth ground" The "too deep" part might be a reference to {{w|Moria (Middle-earth)|Moria}} in Lord of Rings. The dwarves dug too deeply and disturbed a balrog. See also comic [[760]].}}
{{circuit-diagram-part|X=17|Y=610|W=75|H=73|image=circuit_diagram-017-610-075-073-fishhook.png|text=A ground connection at the end of a curve, looking like a fishhook. Means perhaps "earthed down under", i.e., Australia or the southern hemisphere.}}
{{circuit-diagram-part|X=206|Y=662|W=66|H=45|image=circuit_diagram-206-662-066-045-yarn.png|text=A length of "wire" is labeled "yarn". This probably makes it a terrible conductor.}}
{{circuit-diagram-part|X=102|Y=590|W=93|H=88|image=circuit_diagram-102-590-093-088-fluxcapacitor.png|text=The {{w|DeLorean time machine#Flux capacitor|flux capacitor}} from {{w|Back to the Future}}. This may be difficult to implement, since flux capacitors are not availible to most people{{Citation needed}},}}
{{circuit-diagram-part|X=138|Y=685|W=54|H=24|image=circuit_diagram-138-685-054-024-I95.png|text=A road sign for "I-95". Interstate 95 is the main north-south highway on the east coast of the United States, running from Maine to Florida.}}
{{circuit-diagram-part|X=12|Y=713|W=134|H=36|image=circuit_diagram-012-713-134-036-tothesun.png|text=A connection labeled "To center of Sun". A 93-million-mile or 150-million-km circuit is rather large, but...}}
{{circuit-diagram-part|X=31|Y=753|W=144|H=177|image=circuit_diagram-031-753-144-177-rats-nest.png|text=A rat's nest of wires. Everything winds up being connected. May also be a parody diagram of an [http://i.stack.imgur.com/np2p9.png undirected graph], from graph theory.}}
{{circuit-diagram-part|X=22|Y=513|W=97|H=61|image=circuit_diagram-022-513-097-061-esf.png|text=A label reading "Electrons Single File". If this happens, the resistance in this section of wire would be rather high.}}
{{circuit-diagram-part|X=256|Y=619|W=29|H=39|image=circuit_diagram-256-619-029-039-ground.png|text=A ground connection.}}
{{circuit-diagram-part|X=589|Y=600|W=58|H=46|image=circuit_diagram-589-600-058-046-vibrator.png|text=A vibrator, which would be a motor with an off-center weight attached to it.}}
{{circuit-diagram-part|X=532|Y=779|W=74|H=52|image=circuit_diagram-532-779-074-052-motor.png|text=A motor, labeled "To Scale". This indicates that the physical size and shape of the motor must match the size of the parts around it, or is consistent with the specified scale of the drawing. }}
{{circuit-diagram-part|X=662|Y=822|W=73|H=109|image=circuit_diagram-662-822-073-109-holy-ground.png|text=A ground connection, in a beaker labeled "{{w|Holy Water}}", possibly creating {{w|Holy ground (religion)|holy ground}}.}}
{{circuit-diagram-part|X=197|Y=740|W=48|H=55|image=circuit_diagram-197-740-048-055-speed.png|text=A sign indicating a speed limit of 55 MPH. This is a rather typical road sign, but inappropriate for a circuit diagram.}}
{{circuit-diagram-part|X=238|Y=706|W=100|H=116|image=circuit_diagram-238-706-100-116-flipflop.png|text=A pair of NOR gates wired as a SR (set-reset) {{w|Flip-flop (electronics)|flip-flop}}. The label reads "May use an actual sandal instead", which is a play on the meanings of the term "{{w|Flip-flops|flip-flop}}".}}
{{circuit-diagram-part|X=322|Y=708|W=70|H=54|image=circuit_diagram-322-708-070-054-holdingpen.png|text=Something that could be the side view of a fence, labeled "Holding Pen".}}
{{circuit-diagram-part|X=339|Y=777|W=42|H=49|image=circuit_diagram-339-777-042-049-knot.png|text=A simple overhand knot. Also looks like a pretzel, which would have pretty high resistance.}}
{{circuit-diagram-part|X=191|Y=889|W=149|H=33|image=circuit_diagram-191-889-149-033-ecg.png|text=This appears to be an {{w|Electrocardiography|electrocardiograph}} (ECG) trace, but not the sort that would be seen in a healthy person. If this were a real ECG trace, the absence of large, clear {{w|P wave (electrocardiography)|P waves}} might indicate {{w|Atrial Fibrillation|fine atrial fibrillation}}, but in some recording configurations, P waves are sometimes lost in the noise anyway. Additionally, without a time scale to tell us the ventricular heart rate, it is impossible to make a strong educated diagnosis of any hypothetical disease at all. If we assume it is atrial fibrillation, is not clear if Randall intended this, or if he is just not familiar with how a normal ECG should look. Lastly, it does not appear that this is an actual ECG machine, but simply a bent wire, much like the "Not a resistor" label nearby.}}
{{circuit-diagram-part|X=223|Y=826|W=82|H=68|image=circuit_diagram-223-826-082-068-photodiode.png|text=A photodiode, labeled "Tear Collector". A photodiode is a light-sensing device.}}
{{circuit-diagram-part|X=373|Y=859|W=49|H=68|image=circuit_diagram-373-859-049-068-lamp.png|text=A lamp. This is not [http://electronicsclub.info/circuitsymbols.htm the symbol used in electrical circuits], but a drawing of a lightbulb.}}
{{circuit-diagram-part|X=450|Y=887|W=65|H=32|image=circuit_diagram-450-887-065-032-inductor.png|text=A coil or inductor.}}
{{circuit-diagram-part|X=537|Y=847|W=120|H=72|image=circuit_diagram-537-847-120-072-inductor.png|text=A coil or inductor, labeled "Take off shirt while wiring this part. Ooh, yeah, I like that."}}
{{circuit-diagram-part|X=504|Y=860|W=34|H=41|image=circuit_diagram-504-860-034-041-resistor.png|text=A resistor labeled "?". Presumably this means the resistance is unknown.}}
{{circuit-diagram-part|X=459|Y=828|W=55|H=38|image=circuit_diagram-459-828-055-038-resistor.png|text=A resistor labeled "YES". Likely another improper unit - a reference to boolean values YES (TRUE) and NO (FALSE). Depending on the limits of a circuit, a resistor would still have a YES boolean value. Possibly indicating that this is a real resistor, as opposed to the one above it in the circuit, labeled "not a resistor."}}
{{circuit-diagram-part|X=389|Y=774|W=58|H=53|image=circuit_diagram-389-774-058-053-resistor.png|text=A resistor labeled "8 mm".}}
{{circuit-diagram-part|X=443|Y=747|W=93|H=84|image=circuit_diagram-443-747-093-084-resistor.png|text=A resistor labeled "Not a resistor; wire just does this". Apparently the wire is or must be physically bent into a zig-zag shape, which would not serve much useful purpose in a low frequency or DC circuit, or perhaps it reflects the fact that any wire has a certain (small) amount of resistance just by being a wire. In a {{w|Radio frequency|high frequency circuit}} this can be actually useful, as the shape and length of the {{w|Transmission line|transmission line}} alters the {{w|Electrical impedance|impedance}} of the line. ([https://commons.wikimedia.org/wiki/File:Phaseshifter2.png Example])}}
{{circuit-diagram-part|X=415|Y=863|W=82|H=24|image=circuit_diagram-415-863-082-024-unsure.png|text=A symbol for a feedthrough capacitor, labeled "3 Liters". Probable word-play on "capacity/capacitor." Also similar to the symbol for an orifice or flow restriction used on plumbing or hydraulic diagrams, in which case the "3 Liters" might mean 3 liters per minute or per second.}}
|}

==Transcript==
:See table.

==Trivia==

*This is one of the [[:Category:Footer comics|five footer comics]] linked at the bottom part of the {{xkcd}} website.

{{comic discussion}}
[[Category:Physics]]
[[Category:Maps]]
[[Category:Footer comics]]
[[Category:Squirrels]]

730: Circuit Diagram

2018-03-19T12:31:48Z

TheMageKing:

{{comic
| number = 730
| date = April 21, 2010
| title = Circuit Diagram
| image = circuit_diagram.png
| titletext = I just caught myself idly trying to work out what that resistor mass would actually be, and realized I had self-nerd-sniped.
}}

==Explanation==
Another fine example of [[356|nerd sniping]].
There are pieces of circuit diagrams, road maps, chemical diagrams, and other things all mixed in.
Explanations for each below!

{|class="wikitable table-padding left-align"
!Image Fragment
!width="130px" | Image Location
!Description
|-
{{circuit-diagram-part|X=19|Y=25|W=106|H=37|image=circuit_diagram-019-025-106-037-scale.png|text=A map scale. Lists kilometers and miles as equivalent. And makes the diagram many miles wide.}}
{{circuit-diagram-part|X=15|Y=62|W=40|H=85|image=circuit_diagram-015-062-040-085-antenna.png|text=An antenna. Typical of radio receivers or transmitters. Or the Turtle in LOGO programming language}}
{{circuit-diagram-part|X=53|Y=60|W=41|H=87|image=circuit_diagram-053-060-041-087-inductor.png|text=A coil or inductor. Normal, but unlabeled.}}
{{circuit-diagram-part|X=107|Y=86|W=85|H=93|image=circuit_diagram-107-086-085-093-cloverleaf.png|text=A {{w|cloverleaf interchange}} or junction is a feature of road networks that does not belong in a circuit diagram. Of course, other types of {{w|p–n junction|junction}} are important in electronics.
A cloverleaf junction has previously been used in comic: [[253: Highway Engineer Pranks]]}}
{{circuit-diagram-part|X=184|Y=12|W=87|H=63|image=circuit_diagram-184-012-087-063-battery.png|text=A battery. The voltage of square root of two is strange, but getting about 1.41412... volts is not unheard of. This could also indicate an [[wikipedia:Root_mean_square|RMS]] voltage, although this is unlikely given that this is a DC power supply and not an AC generator. The marked polarity is also the reverse of what is implied by the symbol (where the larger terminal is positive). A possible reference to [[567: Urgent Mission]].}}
{{circuit-diagram-part|X=187|Y=110|W=94|H=71|image=circuit_diagram-187-110-094-071-resister.png|text=A 120 ohm resistor is normal enough. "Or to taste" is odd for a circuit diagram and more like instructions from a recipe, e.g., "1 tbsp tomato purée, or to taste".}}
{{circuit-diagram-part|X=283|Y=50|W=90|H=63|image=circuit_diagram-283-050-090-063-switch.png|text=A normal switch, with a notation to glue it open. Reminiscent of the [http://catb.org/esr/jargon/html/magic-story.html MAGIC/MORE MAGIC] switch.}}
{{circuit-diagram-part|X=337|Y=101|W=69|H=64|image=circuit_diagram-337-101-069-064-transisitor.png|text=A bipolar PNP transistor, except that it has two emitters and no collector. It also resembles one of the schematic symbols for a {{w|DIAC}}, except the arrows are backwards.}}
{{circuit-diagram-part|X=52|Y=141|W=79|H=107|image=circuit_diagram-052-141-079-107-compass-points.png|text=Compass points. A map feature, not a circuit feature.}}
{{circuit-diagram-part|X=415|Y=18|W=63|H=58|image=circuit_diagram-415-018-063-058-resister.png|text=A normal resistor, labeled with color code. Brown-Blue-Orange would be 16000 ohms. Resistor color codes are for reading the value on the physical device itself. They would not normally be shown on the circuit diagram, where it's much easier to just write the number, e.g. 16K.}}
{{circuit-diagram-part|X=517|Y=14|W=42|H=32|image=circuit_diagram-517-014-042-032-diode.png|text=A normal diode.}}
{{circuit-diagram-part|X=615|Y=55|W=73|H=74|image=circuit_diagram-615-055-073-074-666timer.png|text=A chip. The normal timer is a "{{w|555_timer_IC|555}}". "666" would be the number of the beast in [http://www.blueletterbible.org/Bible.cfm?b=Rev&c=13&v=18&t=KJV#18 Rev. 13:18]. The pin connected to "?" is the CTRL pin on a normal 555 timer, which would typically be connected to ground (via a decoupling capacitor) if used at all; the implication here seems to be that it would be connected directly to Hell itself.}}
{{circuit-diagram-part|X=632|Y=138|W=69|H=41|image=circuit_diagram-632-138-069-041-bat.png|text=A Batman logo.}}
{{circuit-diagram-part|X=650|Y=211|W=75|H=71|image=circuit_diagram-650-211-075-071-squirrel.png|text=A squirrel, or perhaps a wire bent into the shape of a squirrel. What it does as a circuit element is unclear. If it is a squirrel, it would be an unhelpful addition to the circuit, as squirrels are not conductive{{Citation needed}} and this one would need to be several miles long according to the scale. Squirrels have also appeared in past and future xkcd comics.}}
{{circuit-diagram-part|X=606|Y=165|W=54|H=53|image=circuit_diagram-606-165-054-053-inductor.png|text=A coil or inductor, or a spring symbol in Physics force diagrams, probably the latter as it is labeled with an 11-kilogram mass.}}
{{circuit-diagram-part|X=538|Y=209|W=99|H=59|image=circuit_diagram-538-209-099-059-generator.png|text=A 240-volt AC generator (or other power source).}}
{{circuit-diagram-part|X=483|Y=186|W=111|H=103|image=circuit_diagram-483-186-111-103-shorted-generator.png|text=A shorting wire around a generator. The label reads "Omit this if you're a '''wimp.'''" If this wire is included, it will quickly melt - or worse.}}
{{circuit-diagram-part|X=419|Y=78|W=57|H=75|image=circuit_diagram-419-078-057-075-scarab-beetles.png|text=A jar of {{w|Scarabaeidae|scarab beetles}}.}}
{{circuit-diagram-part|X=482|Y=47|W=28|H=44|image=circuit_diagram-482-047-028-044-variable-resister.png|text=A variable resistor with center tap. Normally, there would be an arrowhead on the center tap.}}
{{circuit-diagram-part|X=507|Y=53|W=22|H=27|image=circuit_diagram-507-053-022-027-capacitor.png|text=A normal capacitor.}}
{{circuit-diagram-part|X=577|Y=318|W=96|H=62|image=circuit_diagram-577-318-096-062-magic.png|text="{{w|Magic Smoke}}" is the legendary stuff that all circuit components require to function. This is why all components cease to function after releasing smoke. }}
{{circuit-diagram-part|X=669|Y=315|W=51|H=66|image=circuit_diagram-669-315-051-066-frayed-wires.png|text=Some frayed or dangling wires.}}
{{circuit-diagram-part|X=567|Y=392|W=58|H=48|image=circuit_diagram-567-392-058-048-buoy.png|text=An object which is either a float used in fishing, a {{w|Tippe top}}, or perhaps a {{w|Naval mine|mine}}.}}
{{circuit-diagram-part|X=458|Y=336|W=111|H=86|image=circuit_diagram-458-336-111-086-moral-rectifier.png|text=A {{w|Diode_bridge|bridge rectifier}}, which would normally turn alternating current at the top and bottom into direct current on the left and right. In this case, it is labeled as a "moral rectifier". This is presumably a play on the idea of moral rectitude – it makes your circuit more moral. Why this matters in a circuit is unclear.}}
{{circuit-diagram-part|X=423|Y=259|W=80|H=85|image=circuit_diagram-423-259-080-085-warm-front.png|text=This resembles both the schematic symbol for part of a transformer and the meteorological symbol for a warm front. A {{w|warm front}} is a feature on a {{w|Surface weather analysis|synoptic weather map}}.}}
{{circuit-diagram-part|X=190|Y=199|W=54|H=52|image=circuit_diagram-190-199-054-052-battery.png|text=A normal 50-volt battery.}}
{{circuit-diagram-part|X=173|Y=200|W=89|H=56|image=circuit_diagram-173-200-089-056-shorted-battery.png|text=A battery is grounded on both sides. Something will melt or burn out quickly, unless these are separate "earth ground"s, in which case the ground might get a bit cooked.}}
{{circuit-diagram-part|X=259|Y=198|W=174|H=25|image=circuit_diagram-259-198-174-025-pull-wire.png|text=Text reads "Pull this wire really tight". This kind of physical-property issue may indicate a high-frequency radio device. Or, given the absurdity of the context, it's a silly reference to a "high tension wire."}}
{{circuit-diagram-part|X=141|Y=211|W=41|H=91|image=circuit_diagram-141-211-041-091-3-8-inch.png|text=A specified 3/8-inch separation. This probably indicates a carefully controlled capacitance issue. Also contradicts the scale of the drawing, by which the distance shown would be about 0.8 miles or 0.8 km.}}
{{circuit-diagram-part|X=173|Y=309|W=92|H=59|image=circuit_diagram-173-309-092-059-eel.png|text=An {{w|electric eel}}. This may be an effective power source in the circuit, capable of producing a shock at up to 600 volts and 1 ampere of current (600 watts), but for less than 2 ms.}}
{{circuit-diagram-part|X=266|Y=307|W=35|H=41|image=circuit_diagram-266-307-035-041-resistor.png|text=A normal resistor.}}
{{circuit-diagram-part|X=222|Y=358|W=34|H=29|image=circuit_diagram-222-358-034-029-capacitor.png|text=A normal capacitor.}}
{{circuit-diagram-part|X=130|Y=335|W=44|H=40|image=circuit_diagram-130-335-044-040-resistor.png|text=A normal resistor, labeled "ë". This may be a play on {{w|e (mathematical constant)|Euler's Number}}, which doesn't normally have a {{w|tréma}} or an {{w|umlaut (linguistics)|umlaut}}. Alternatively instead of being an umlaut or tréma it may indicate the second {{w|derivative}} of e with respect to time in {{w|Newton's notation}}, in which case, as e is a constant, the resistance of this element is zero.}}
{{circuit-diagram-part|X=65|Y=249|W=61|H=92|image=circuit_diagram-065-249-061-092-blender.png|text=Our best guess is that this is a blender. Due to the scale, this would certainly be the worlds largest blender. Reccord setting blenders are not typically part of computer circuts{{Citation needed}}}}
{{circuit-diagram-part|X=20|Y=342|W=115|H=73|image=circuit_diagram-020-342-115-073-arduino.png|text=An {{w|arduino}}, labeled "Arduino, just for blog cred". May refer to the fact that inexpensive, easy-to-integrate single-board computers like the arduino, which have contributed to the rise of {{w|Maker_culture}}, are used and discussed frequently in that culture, and the use of one might impress readers. The comment implies that an arduino is not otherwise needed in this circuit, although it is necessarily hard to tell, given the other components of the circuit.}}
{{circuit-diagram-part|X=39|Y=423|W=118|H=82|image=circuit_diagram-039-423-118-082-meca.png|text=A chip labeled "Most expensive chip available". The small curve at the top is a part of the packaging designed to show its orientation.}}
{{circuit-diagram-part|X=159|Y=428|W=91|H=50|image=circuit_diagram-159-428-091-050-neck-strap.png|text=Labeled "Neck Strap". Perhaps a piece of torture equipment or indicating that the circuit is part of an {{w|electric chair}}? May also be a reference to the grounded wrist straps people working with electronics commonly wear, to prevent accidental static discharges from frying the circuitry.}}
{{circuit-diagram-part|X=147|Y=480|W=110|H=88|image=circuit_diagram-147-480-110-088-switch.png|text=A switch labeled "Hire someone to open and close switch real fast." Possibly meant to perform the function of an oscillator in a more hackish manner and the reason for the neck strap. Could also be a reference to {{w|Maxwell's Demon}}.}}
{{circuit-diagram-part|X=273|Y=498|W=61|H=64|image=circuit_diagram-273-498-061-064-resistor.png|text=A 5 ohm resistor labeled "(decoy)". One end is not attached to anything. Perhaps this indicates wishful thinking that electrons might be tricked into entering this part of the circuit despite the fact that there's nowhere for them to go?}}
{{circuit-diagram-part|X=307|Y=453|W=103|H=56|image=circuit_diagram-307-453-103-056-tongue.png|text=A pair of contacts, labeled "Touch Tongue Here". Could be referring to the practice of daring someone to touch their tongue to the contacts of a 9V battery.}}
{{circuit-diagram-part|X=301|Y=270|W=45|H=45|image=circuit_diagram-301-270-045-045-frown.png|text=A frowny-face. See the float/mine.}}
{{circuit-diagram-part|X=294|Y=311|W=128|H=124|image=circuit_diagram-294-311-128-124-IC.png|text=A small integrated circuit. The lower gate is an inverter, wired as a free-running oscillator. The upper gate is an XOR wired to act as either a free-running oscillator or a latch. Since the XOR will be slower than the inverter, the overall output of the upper gate is probably very chaotic. Two "input" wires are not connected at all. An additional wire is attached to the top with hot glue. This last wire probably acts to control static electricity and leakage.}}
{{circuit-diagram-part|X=302|Y=235|W=91|H=25|image=circuit_diagram-302-235-091-025-curve.png|text=A caution sign at a curve. Another road feature in the circuit. This is a play on the notion that 90-degree corners on printed circuit board traces can disrupt signal integrity.}}
{{circuit-diagram-part|X=401|Y=455|W=67|H=68|image=circuit_diagram-401-455-067-068-CH3.png|text=A {{w|methyl group}} (chemistry) attached to a corner. If the circuit were an organic chemical, it would be reasonable to find a number of these.}}
{{circuit-diagram-part|X=453|Y=167|W=43|H=93|image=circuit_diagram-453-167-043-093-baloon.png|text=A balloon, possibly blowing in a breeze.}}
{{circuit-diagram-part|X=572|Y=68|W=22|H=43|image=circuit_diagram-572-068-022-043-inductor.png|text=A coil or inductor.}}
{{circuit-diagram-part|X=508|Y=96|W=42|H=20|image=circuit_diagram-508-096-042-020-inductor.png|text=A coil or inductor.}}
{{circuit-diagram-part|X=534|Y=61|W=22|H=31|image=circuit_diagram-534-061-022-031-ground.png|text=A ground connection.}}
{{circuit-diagram-part|X=472|Y=49|W=134|H=140|image=circuit_diagram-472-049-134-140-solderr-blob.png|text=A solder blob covering a portion of the circuit. Normally, this would not be part of the circuit diagram, but a mistake in building the circuit.}}
{{circuit-diagram-part|X=493|Y=443|W=207|H=158|image=circuit_diagram-493-443-207-158-res-rats-nest.png|text=A rats nest of 1 ohm resistors. It is labeled "Oh, so you think you're such a whiz at EE201?" The name EE201 (Electrical Engineering 201) follows US course naming conventions for what appears to be a basic level course in electrical engineering (compare the term {{w|101 (term)|101}}), which would include being taught how to [http://www.wikihow.com/Calculate-Series-and-Parallel-Resistance calculate the effective resistance of various resistor networks]. Performing the calculation on a network this complex would probably be extremely difficult. It appears to work out to 0.75800964845 ohms.
A grid of 1 ohm resistors has appeared earlier in [[356: Nerd Sniping]], a comic also referred to in the title text.}}
{{circuit-diagram-part|X=315|Y=533|W=232|H=200|image=circuit_diagram-362-531-151-167-arena.png|text=An arena, with a few bodies in it. Note the direction of movement enforced by the surrounding diodes, {{w|Mad_Max_Beyond_Thunderdome|"two men enter, one man leaves"}}, a film reference.}}
{{circuit-diagram-part|X=569|Y=653|W=47|H=51|image=circuit_diagram-569-653-047-051-resistor.png|text=A "{{w|pi}}" ohm resistor.}}
{{circuit-diagram-part|X=610|Y=655|W=75|H=70|image=circuit_diagram-610-655-075-070-generator.png|text=A 500-volt AC generator. The wiring to the right shorts out this generator.}}
{{circuit-diagram-part|X=481|Y=682|W=85|H=64|image=circuit_diagram-481-682-085-064-ground.png|text=A ground connection, labeled "Bury deep, but not too deep". This type of ground connection is called an "earth ground" The "too deep" part might be a reference to {{w|Moria (Middle-earth)|Moria}} in Lord of Rings. The dwarves dug too deeply and disturbed a balrog. See also comic [[760]].}}
{{circuit-diagram-part|X=17|Y=610|W=75|H=73|image=circuit_diagram-017-610-075-073-fishhook.png|text=A ground connection at the end of a curve, looking like a fishhook. Means perhaps "earthed down under", i.e., Australia or the southern hemisphere.}}
{{circuit-diagram-part|X=206|Y=662|W=66|H=45|image=circuit_diagram-206-662-066-045-yarn.png|text=A length of "wire" is labeled "yarn". This probably makes it a terrible conductor.}}
{{circuit-diagram-part|X=102|Y=590|W=93|H=88|image=circuit_diagram-102-590-093-088-fluxcapacitor.png|text=The {{w|DeLorean time machine#Flux capacitor|flux capacitor}} from {{w|Back to the Future}}.}}
{{circuit-diagram-part|X=138|Y=685|W=54|H=24|image=circuit_diagram-138-685-054-024-I95.png|text=A road sign for "I-95". Interstate 95 is the main north-south highway on the east coast of the United States, running from Maine to Florida.}}
{{circuit-diagram-part|X=12|Y=713|W=134|H=36|image=circuit_diagram-012-713-134-036-tothesun.png|text=A connection labeled "To center of Sun". A 93-million-mile or 150-million-km circuit is rather large, but...}}
{{circuit-diagram-part|X=31|Y=753|W=144|H=177|image=circuit_diagram-031-753-144-177-rats-nest.png|text=A rat's nest of wires. Everything winds up being connected. May also be a parody diagram of an [http://i.stack.imgur.com/np2p9.png undirected graph], from graph theory.}}
{{circuit-diagram-part|X=22|Y=513|W=97|H=61|image=circuit_diagram-022-513-097-061-esf.png|text=A label reading "Electrons Single File". If this happens, the resistance in this section of wire would be rather high.}}
{{circuit-diagram-part|X=256|Y=619|W=29|H=39|image=circuit_diagram-256-619-029-039-ground.png|text=A ground connection.}}
{{circuit-diagram-part|X=589|Y=600|W=58|H=46|image=circuit_diagram-589-600-058-046-vibrator.png|text=A vibrator, which would be a motor with an off-center weight attached to it.}}
{{circuit-diagram-part|X=532|Y=779|W=74|H=52|image=circuit_diagram-532-779-074-052-motor.png|text=A motor, labeled "To Scale". This indicates that the physical size and shape of the motor must match the size of the parts around it, or is consistent with the specified scale of the drawing. }}
{{circuit-diagram-part|X=662|Y=822|W=73|H=109|image=circuit_diagram-662-822-073-109-holy-ground.png|text=A ground connection, in a beaker labeled "{{w|Holy Water}}", possibly creating {{w|Holy ground (religion)|holy ground}}.}}
{{circuit-diagram-part|X=197|Y=740|W=48|H=55|image=circuit_diagram-197-740-048-055-speed.png|text=A sign indicating a speed limit of 55 MPH. This is a rather typical road sign, but inappropriate for a circuit diagram.}}
{{circuit-diagram-part|X=238|Y=706|W=100|H=116|image=circuit_diagram-238-706-100-116-flipflop.png|text=A pair of NOR gates wired as a SR (set-reset) {{w|Flip-flop (electronics)|flip-flop}}. The label reads "May use an actual sandal instead", which is a play on the meanings of the term "{{w|Flip-flops|flip-flop}}".}}
{{circuit-diagram-part|X=322|Y=708|W=70|H=54|image=circuit_diagram-322-708-070-054-holdingpen.png|text=Something that could be the side view of a fence, labeled "Holding Pen".}}
{{circuit-diagram-part|X=339|Y=777|W=42|H=49|image=circuit_diagram-339-777-042-049-knot.png|text=A simple overhand knot. Also looks like a pretzel, which would have pretty high resistance.}}
{{circuit-diagram-part|X=191|Y=889|W=149|H=33|image=circuit_diagram-191-889-149-033-ecg.png|text=This appears to be an {{w|Electrocardiography|electrocardiograph}} (ECG) trace, but not the sort that would be seen in a healthy person. If this were a real ECG trace, the absence of large, clear {{w|P wave (electrocardiography)|P waves}} might indicate {{w|Atrial Fibrillation|fine atrial fibrillation}}, but in some recording configurations, P waves are sometimes lost in the noise anyway. Additionally, without a time scale to tell us the ventricular heart rate, it is impossible to make a strong educated diagnosis of any hypothetical disease at all. If we assume it is atrial fibrillation, is not clear if Randall intended this, or if he is just not familiar with how a normal ECG should look. Lastly, it does not appear that this is an actual ECG machine, but simply a bent wire, much like the "Not a resistor" label nearby.}}
{{circuit-diagram-part|X=223|Y=826|W=82|H=68|image=circuit_diagram-223-826-082-068-photodiode.png|text=A photodiode, labeled "Tear Collector". A photodiode is a light-sensing device.}}
{{circuit-diagram-part|X=373|Y=859|W=49|H=68|image=circuit_diagram-373-859-049-068-lamp.png|text=A lamp. This is not [http://electronicsclub.info/circuitsymbols.htm the symbol used in electrical circuits], but a drawing of a lightbulb.}}
{{circuit-diagram-part|X=450|Y=887|W=65|H=32|image=circuit_diagram-450-887-065-032-inductor.png|text=A coil or inductor.}}
{{circuit-diagram-part|X=537|Y=847|W=120|H=72|image=circuit_diagram-537-847-120-072-inductor.png|text=A coil or inductor, labeled "Take off shirt while wiring this part. Ooh, yeah, I like that."}}
{{circuit-diagram-part|X=504|Y=860|W=34|H=41|image=circuit_diagram-504-860-034-041-resistor.png|text=A resistor labeled "?". Presumably this means the resistance is unknown.}}
{{circuit-diagram-part|X=459|Y=828|W=55|H=38|image=circuit_diagram-459-828-055-038-resistor.png|text=A resistor labeled "YES". Likely another improper unit - a reference to boolean values YES (TRUE) and NO (FALSE). Depending on the limits of a circuit, a resistor would still have a YES boolean value. Possibly indicating that this is a real resistor, as opposed to the one above it in the circuit, labeled "not a resistor."}}
{{circuit-diagram-part|X=389|Y=774|W=58|H=53|image=circuit_diagram-389-774-058-053-resistor.png|text=A resistor labeled "8 mm".}}
{{circuit-diagram-part|X=443|Y=747|W=93|H=84|image=circuit_diagram-443-747-093-084-resistor.png|text=A resistor labeled "Not a resistor; wire just does this". Apparently the wire is or must be physically bent into a zig-zag shape, which would not serve much useful purpose in a low frequency or DC circuit, or perhaps it reflects the fact that any wire has a certain (small) amount of resistance just by being a wire. In a {{w|Radio frequency|high frequency circuit}} this can be actually useful, as the shape and length of the {{w|Transmission line|transmission line}} alters the {{w|Electrical impedance|impedance}} of the line. ([https://commons.wikimedia.org/wiki/File:Phaseshifter2.png Example])}}
{{circuit-diagram-part|X=415|Y=863|W=82|H=24|image=circuit_diagram-415-863-082-024-unsure.png|text=A symbol for a feedthrough capacitor, labeled "3 Liters". Probable word-play on "capacity/capacitor." Also similar to the symbol for an orifice or flow restriction used on plumbing or hydraulic diagrams, in which case the "3 Liters" might mean 3 liters per minute or per second.}}
|}

==Transcript==
:See table.

==Trivia==

*This is one of the [[:Category:Footer comics|five footer comics]] linked at the bottom part of the {{xkcd}} website.

{{comic discussion}}
[[Category:Physics]]
[[Category:Maps]]
[[Category:Footer comics]]
[[Category:Squirrels]]

1484: Apollo Speeches

2018-03-16T14:38:18Z

TheMageKing:

{{comic
| number = 1484
| date = February 9, 2015
| title = Apollo Speeches
| image = apollo_speeches.png
| titletext = While our commitment to recycling initiatives has been unwavering, this is not a cost any of us should be expected to pay.
}}

==Explanation==
As explained in the comic, {{w|Richard Nixon|Nixon}} staffer {{w|William Safire}} wrote [http://www.lettersofnote.com/2010/11/in-event-of-moon-disaster.html two speeches] for the United States President to deliver, depending on whether or not the {{w|Apollo 11}} return launch was successful. When the outcome of an event (moon landing, military actions, etc.) can't be predicted with sufficient certainty, it is a common practice for "[http://www.archives.gov/presidential-libraries/events/centennials/nixon/exhibit/nixon-online-exhibit-disaster.html contingency speeches]" to be prepared.

The rest of the comic runs with this theme, making the false claim that Safire had written several other such contingency speeches for increasingly unlikely possibilities. First listed are a couple pages from the real contingency speech to be delivered in the event that the astronauts were left stranded on the Moon. Lying on top of that is a speech to be delivered in the case that the spacecraft went missing altogether, which was relatively unlikely. The speeches after that deal with the following highly unlikely or impossible contingencies:
*The astronauts had stolen the ship and piloted it towards Mars, which was clearly not feasible: while the crew could have redirected the ship while sending insulting messages to Earth, the spacecraft lacked the power to fly to Mars within any reasonable period of time by several orders of magnitude or the supplies for the astronauts to survive such an extended trip.
**At the time of production for this strip in 2015, several governments and private companies have designs on Martian colonization.
*More astronauts than expected were found in the recovered ship;
**The appearance of three additional astronauts ventures into the realm of possibility normally reserved for science fiction and Twilight Zone episodes.
*The ship had hit the {{w|USS Hornet (CV-12)|USS ''Hornet''}} and crushed Nixon;
**The U.S.S. Hornet was the ship that recovered the Apollo 11 astronauts after they completed their return mission by landing their command module in the Pacific Ocean; President Nixon himself was on board to greet them upon their return. Apollo 11 famously landed in the Pacific Ocean, and the single ship tasked with its recovery would be a very small target to hit for the technology even if that had been the intent, which it was of course not. Spiro Agnew was, in 1969, Vice President of the United States, and thus next in line for the presidency. This joke plays off the extreme improbability of the ship, and indeed President, being hit and triggering a succession, causing "President Agnew" to address the world.
*The re-entry craft had been sold for scrap and crushed along with the astronauts inside.
**Apollo 11 observed a strict quarantine procedure after landing. This possibility requires extraordinary incompetence and unholy zeal for recycling programs. The command module was historically recovered, examined, and is now on permanent display in the {{w|National Air and Space Museum}}. Primary sources state that the astronauts were allowed to leave the craft before it was put on display.{{Citation needed}}

The title text builds upon this last contingency speech, delving into the pathos of the horror of the spacecraft's recycling and its passengers' resulting deaths despite the U.S.'s commitment to recycling initiatives.

Shortly after this comic was released, in that week's ''What if?'', ''those speeches'' are referenced with a link to this comic. (see [http://what-if.xkcd.com/129/ Black Hole Moon]).

This comic was referenced again in another ''What If?'', [https://what-if.xkcd.com/146/ Stop Jupiter].

==Transcript==
:[Commentary above the speeches.]
:In 1969, Nixon staffer William Safire wrote a speech for the president to deliver if the Apollo 11 return launch failed, stranding the doomed astronauts on the Moon.
:Uncovered in 1999, it is often called the greatest speech never given.
:Today, the ''full'' set of Safire's contingency speeches has been found.

:'''In event astronauts stranded on Moon'''
:Fate has ordained that the men who went to the Moon to explore in peace will stay on the Moon to rest in peace.
:[Here, several lines from the original speech are cut.]
:In ancient days, men looked at stars and saw their heroes in the constellations. In modern times, we do much the same, but our heroes are epic men of flesh and blood.
:Others will follow, and surely find their way home. Man’s search will not be denied. But these men were the first, and they will remain the foremost in our hearts. For every human being who looks up at the Moon in the nights to come will know that there is some corner of another world that is forever

:'''In event spacecraft goes missing'''
:Neil Armstrong, Edwin Aldrin, and Michael Collins went to the Moon as ambassadors of peace for all mankind, and all mankind prays that they may yet return safely home.
:We are separated from the Moon by a vast gulf of space, against which their tiny vessel appeared as but a drifting speck. For a few brief seconds, we took our eye off them, and despite days of desperate searching, never again was their vessel sighted from Earth.
:While these men are lost, they are not forgotten, and their sacrifice will not

:'''In even astronauts abscond with spacecraft'''
:We do not know what led Armstrong, Aldrin and Collins to betray the trust we placed in them, abandon their mission, and steer their vessel toward Mars. Nor do we know what compelled them to transmit such hurtful messages back to Earth, heaping contempt on their onetime home.
:But whatever the cause of their dereliction, I call upon the United States to commit itself, before this year is out, to launching a mission to chase down Apollo 11 and return its crew to earth to face justice. We must not rest until

:'''In event spacecraft returns with extra astronauts'''
:While there is much we do not understand, tonight all of earth is united in celebrating the safe return of our brave explorers.
:We of course have many questions, and in the days and weeks to come we will demand answers. How many souls were truly aboard Apollo 11 when it launched? Who are the six men now in quarantine aboard the USS Hornet? What happened

:'''In event spacecraft hits U.S.S. Hornet, crushing Nixon'''
:'''President Agnew''': Tonight, we have experienced a great national triumph and a great national loss. We take joy in the safe return from the Moon of Neil Armstrong, Edwin Aldrin, and Michael Collins, but that joy is tempered with sorrow as we mourn our president’s tragic death beneath their wayward capsule.
:Richard Nixon wholeheartedly supported our courageous astronauts as they carried the hopes and prayers of Earth to the heavens, and in the moment of their homecoming, he himself has departed on that ultimate voyage. As we grieve, we must rededicate ourselves to the cause for which our president

:'''In event spacecraft accidentally sold for scrap and crushed with astronauts inside'''
:My fellow Americans, I am as shocked and appalled as you at this stunning and

{{comic discussion}}
[[Category:Space]]

1440: Geese

2018-03-14T22:12:32Z

TheMageKing: Added Citation Needed

{{comic
| number = 1440
| date = October 29, 2014
| title = Geese
| image = geese.png
| titletext = Anyway, that's a common misconception. Geese live for a long time; all the ones we can see will probably keep flying around for billions of years before they explode.
}}

==Explanation==
[[Megan]] is commenting on a flock of geese passing overhead and says the light from the geese reaching their eyes now could have come from hundreds of years ago. This is a fact for the light from stars, but not for light from geese{{Citation needed}}. [[Cueball]] points out the absurdity of Megan's statement by pointing out that the geese are only a few hundred yards away rather than a few hundred light years. She continues along the same lines when she implies to Cueball that he is observing a past version of her, despite them being only a few feet apart. Technically he ''is'' viewing a past version of her, but not one from "long ago"; if someone is two feet away from you, you are seeing them as they were roughly [http://www.wolframalpha.com/input/?i=2+feet+%C3%B7+air+speed+of+light 2 nanoseconds] ago.

In the title-text Megan continues to treat the geese as if they were stars, which "live" for a few billion years before exploding. Most stars visible with naked eye are within a thousand light-years of Earth, (as discussed in [[1342: Ancient Stars]]), and it's unlikely that any star Megan currently sees actually exploded within the relatively short span of last few thousand years.

Megan's statement "You're hearing how they once sounded." is somewhat more justified - sound from "a few hundred yards away" would take about [http://www.wolframalpha.com/input/?i=400+yards+%C3%B7+air+speed+of+sound one second] to be heard (depending on the exact distance and the prevailing atmospheric conditions). That said, the sound of a goose isn't likely to change enough over the course of a second or two to make this distinction particularly significant.

The strip may also take inspiration from Gamow's "Mr. Tompkins" stories which were designed to help laymen understand some of the consequences of relativity and quantum mechanics. In one of the stories Mr Tompkins visits a town where the speed of light is 30 miles per hour. For the light to have taken hundreds of years to go from the geese to Megan and Cueball, the speed of light in this strip would have to be much slower than in Gamow's story.

Randall has previously mentioned a related misconception in [[1342: Ancient Stars]]. In [[1422: My Phone is Dying]], a phone's "death" is compared to the death of a star.

==Transcript==
:[Geese fly in V-formation. Megan and Cueball are lying on the ground, watching them.]
:Megan: To think... we're seeing light that left those geese centuries ago.
:Megan: By now, they could be long dead.
:Cueball: ...What? They're a few hundred yards away. I hear them honking.
:Megan: Ah, yes. You're hearing how they once sounded.
:Cueball: You're very weird.
:Megan: Or I was, long ago...

{{comic discussion}}
[[Category:Astronomy]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Animals]]