explain xkcd - User contributions [en]

Talk:145: Parody Week: Dinosaur Comics

2022-06-27T21:26:40Z

172.70.115.4: added comment about neopronouns

The word "bicurious" has also been referenced in Dinosaur Comics: [http://www.qwantz.com/index.php?comic=311] [http://www.qwantz.com/index.php?comic=312] [[Special:Contributions/199.27.128.116|199.27.128.116]] 00:27, 26 April 2015 (UTC)
:Great, added for the explanation. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 20:21, 30 July 2016 (UTC)

The paragraph saying Randall is unfamiliar w/ genderqueer pronouns seems mistaken to me. He doesn't delve into a discussion of the different shades of meaning there, sure, but I think that's a stylistic choice consistent with making a readable comic --[[Special:Contributions/172.69.22.104|172.69.22.104]] 02:15, 27 July 2018 (UTC)

I think this page needs to be updated, as you don't need to be genderqueer to use neopronouns. Anyone can use whatever pronouns they want, and I don't agree that the definition of genderqueer on this page is the best one. In fact, the large majority of people who use neopronouns identify as non-binary, and this is seeming to show it's age.

796: Bad Ex

2022-06-18T13:03:37Z

172.70.115.4: /* Explanation */

{{comic
| number = 796
| date = September 22, 2010
| title = Bad Ex
| image = bad ex.png
| titletext = Since the goatee, glasses, and Seltzer & Friedberg DVD collection didn't tip you off, there will be a $20 negligence charge for this service.
}}

==Explanation==
[[Cueball]] has been betrayed by his girlfriend, and later found out that he's not the first one she betrayed. He thinks that the society should provide a service that collects reports about such notorious liars, warning future dates about their true nature.

Cueball's friend, [[White Hat]], is concerned about the matter of personal integrity, comparing this proposed service to {{w|Sex offender registration|sex offender registries}}. Cueball, though, thinks that there are certain governments who would have no problem with personal integrity infringement.

In the last panel, we see such a notification being given to a woman at a date. One interpretation of this comic could be that the bearded man is not, in fact, a douchebag, but Cueball is calling him one because he likes her, and thus wants to separate them.

The "State of California" dialog is a reference to {{w|California_Proposition_65_(1986)|California Proposition 65}} which requires specific products to state: "This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm." California is also known to be one of the states where liberal experimentation would occur.

The title text mentions a few "{{w|douchebag}}" warning signals that the woman should have observed, for instance his interest in the infamous filmmaker duo {{w|Jason Friedberg and Aaron Seltzer}}, known for making shallow parody movies that are notorious for how universally negatively they are recieved, with some of their movies, including {{w|Epic_Movie|Epic Movie}} and {{w|Disaster_Movie|Disaster Movie}}, considered to be among the worst movies ever made.

==Transcript==
:[Cueball and White Hat are walking.]
:Cueball: It just blows my mind. She seemed so genuine. I had no idea she was such a serial liar.
:Cueball: I just wish I had our six months back.

:[The view focuses on Cueball.]
:Cueball: Her exes say the same thing happened to them.
:Cueball: Maybe what we need is a terrible-ex tracking and notification service.

:[Cueball turns, thoughtfully.]
:White Hat: But after all the problems with sex offender registries, who would agree to run it?
:Cueball: Maybe one of the state governments more willing to experiment could try it out...

:Soon...
:[Megan and a person with glasses and a goatee are sitting at a table, on which sit wine glasses and plates. Cueball approaches them carrying a clipboard and a license.]
:Cueball: Excuse me, ma'am.
:Megan: Yes?
:Cueball: This man is known to the state of California to be a ''total douchebag''.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Megan]]
[[Category:Romance]]
[[Category:Multiple Cueballs]]

Talk:2633: Astronomer Hotline

2022-06-15T14:54:52Z

172.70.115.4:

Someone really needs to check on the bot. This is the second day in a row where I have had to begin the article! [[User:SqueakSquawk4|SqueakSquawk4]] ([[User talk:SqueakSquawk4|talk]]) 13:06, 15 June 2022 (UTC)

The fact that this is the Astronomer Helpline seems like commentary on the frequency with which astronomers are asked about mysterious objects, and/or the fact that astronomers (who tend to spend a lot of time looking at the sky) rarely report seeing unidentified objects. It could also be noted that calling fireflies a UFO would technically be accurate, as they are objects which are flying that the observers apparently could not readily identify. [[Special:Contributions/172.71.82.121|172.71.82.121]] 13:36, 15 June 2022 (UTC)

Title text probably referes to [https://en.wikipedia.org/wiki/Periodical_cicadas Periodical cicadas] that appears every 17 years.
[[Special:Contributions/172.71.98.99|172.71.98.99]] 13:58, 15 June 2022 (UTC)

As someone from a country without fireflies, is "Ground Stars" a normal word for fireflies or a joke? (similar to how planets are "wandering stars", so to an astronomer everything is a star, similar to [[2017: Stargazing 2]]) [[User:Sqek|Sqek]] ([[User talk:Sqek|talk]]) 14:17, 15 June 2022 (UTC)
:A joke. [[Special:Contributions/172.70.115.4|172.70.115.4]] 14:54, 15 June 2022 (UTC)

2633: Astronomer Hotline

2022-06-15T14:52:31Z

172.70.115.4: /* Explanation */

{{comic
| number = 2633
| date = June 15, 2022
| title = Astronomer Hotline
| image = Astronomer Hotline.png
| titletext = Employment statistics have to correct for the fact that the Weird Bug Hotline hires a bunch of extra temporary staff every 17 years.
}}

==Explanation==
{{incomplete|Created by 17 YEAR CICADA TRYING TO LOOK LIKE A FIREFLY - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
This comic is a joke about {{w|Helpline|helplines}}, and how people sometimes call helplines for non-significant reason.

The comic starts with someone having called the "Astronomer hotline", hence the title. Judging by the way the helpline employee, [[Cueball]], starts the call, by asking for a description of the weird lights, it is implied that this is the main/only purpose of the helpline.

The caller is in panic, and don't know how to describe the light. But Cueball is used to this and asks the caller to stay calm. And then goes through his check list, asking them if it is day time. Because then he would assume they have just noticed the Sun. This could be seemed very condescending, but it is like when the employee at a tech support hot-line asks if the computer is turned on, or if the caller tried to restart the computer, see [[806: Tech Support]].

The caller is not affronted, but tells that the Sun set, and when Cueball asks if they are stars, and thus stationary, the caller says they are zipping around in the bushes.

At this point Cueball realizes that the the caller just have seen {{w|Fireflies}}. He describes them for the caller as lightning bugs, tree blinkers or ground stars, and tell the caller he is fine, so the caller is now relived. Those descriptions is reminiscent of the fools stars (and planes) mentioned in [[2017: Stargazing 2]].

However, Cueball must admit that astronomers do not know much about fireflies, since they are too fast for the astronomers' telescopes (in general, astronomers don't study terrestrial phenomena). And he thus transfers the caller to the "Weird Bug Hotline."

Before the call ends, at Cueball's end, he hears the first question from the new hotline: Is it currently biting you.
Again going directly to the most important part, is there any immediate danger...

Some people (Often {{w|Unidentified flying object|UFO}} enthusiasts) tend to get a little over-excited about calling every light in the sky they don't expect a UFO. This comic takes this to the extreme, where someone calls a helpline because they saw fireflies, and thought they were UFOs. While UFOs are not mentioned by name, they are heavily implied.

The title text is a reference to bugs that have several years between emerging from their larva state. Most famously are the {{w|Periodical cicadas}}, 13- and 17-year cicadas, that only emerge every 13 or 17 years depending on species. The 17 years in the title text, thus refers to the 17-year cicadas. Every 17 years the bug hotline hires a bunch of temporary staff. Either because there will be more callers due to the unexpected new bug, no one has seen for 17 years, or it could be because they just like to emulate nature and thus do this every 17 years. The largest 17-year cicada appearance in the USA is called {{W|Brood X}} which last occurred in 2021 and before that 1984. There can be smaller broods in other years, but the majority comes out with 17 years interval, and the next it expected in 2038.

The joke in the title text is that the employment statistics for the weird hotline have to correct for this fact.

The reasons that it is 13 and 17 years are a bit {{w|Periodical_cicadas#Predator_satiation_survival_strategy|uncertain}}, but it is quite certain that it is because those numbers are prime numbers, that they have ended up on those numbers of years. Because it is thus unlikely that they will emerge in great numbers the same year as some other cyclic population is at a maximum every time they emerge. Because it they have any other cycle than those prime numbers, it will take a long time before they synchronize again.

Many animals and plants have delayed cycles like these to as to engage the cycles of others in ways that change; for example, oak trees give more acorns every other year, as their reproductive cycle is in symbiosis with how much squirrels bury but do not dig up to eat.

==Transcript==
:[Cueball, with a headset on, is sitting in an office chair at a desk in front of his computer screen, hands on the keyboard. He receives a call, and the callers voice is shown in a jagged frame above Cueball, between his two lines of text.]
:Cueball: Hello, Emergency Astronomer Hotline. How would you describe the lights?
:Caller on phone: ''I don't know! Help!''
:Cueball: Stay calm. Is it day? If so, that's The Sun.

:[Cueball is now seen en face with the headset, but the computer etc. is not shown. The callers voice is now written normally but with zigzag lines going to the text from Cueball's headphone. Cueball's reply have a normal line going up to it.]
:Caller on phone: No, the sun set and then the light appeared!
:Cueball: Hmm, could be stars. Are they stationary?
:Caller on phone: No, they're all zipping around bushes.

:[In a frame-less panel, the setting returns to the one from the first panel. Also with the callers voice in jagged frames again.]
:Cueball: ''Aha!'' Fireflies!
:Caller on phone: "Fireflies"?
:Cueball: Lightning bugs. Tree blinkers. Ground stars.
:Cueball: They're fine.
:Caller on phone: ''Phew!''

:[Same setting as first panel, but broader panel. After Cueball's reply and a short reply from the caller as in the first panel. There is a sound indicating transfer to another hotline. Then to the right there is a square panel with jagged edge, with the voice from the other hotlines employee.]
:Cueball: We don't know much about them as they're too fast for our telescopes, but I can transfer you to the Weird Bug Hotline.
:Caller on phone: Sure, thanks.
:Transfer of call. *''Click''*
:Weird Bug Hotline on phone: ''Hi, Weird Bug Hotline. Is it currently biting you?''

{{comic discussion}}

2631: Exercise Progression

2022-06-11T11:09:59Z

172.70.115.4: /* Explanation */

{{comic
| number = 2631
| date = June 10, 2022
| title = Exercise Progression
| image = exercise progression.png
| titletext = They said after I got into a routine, I'd enjoy getting progressively stronger and stop whining so much about how hard exercise was. Well, they were half right!
}}

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

This graph shows how when most people start exercising, their whining and complaining slowly decreases and they increase the difficulty over time, as their bodies become accustomed to regular exercise. However, Randall is showing that his whining and complaining just increases, at a steady pace as opposed to decreasing in accordance with the "normal" graph.

This is indicative and typical of people who are aggressively uninterested in and not accustomed to exercise. The first time such a person exercises it feels particularly difficult, usually leading to intensely sore muscles the next day. This can make a feedback loop where people avoid the exercise just enough to not increase their fitness so that it becomes easy.

The title text refers to the common response to such whining by people who '''are''' accustomed to exercise, the reassurance that getting stronger through an exercise routine will encourage him, leading to a reduction in how much he whines. He says they were half right, implying that he indeed enjoys getting stronger, that the exercise simply doesn't become easier. This is not normal for fit nor unfit people. It could be because there are other things about exercise Randall dislikes, or it could be associated with a medical problem.

When people get old or cognitively injured, it can become hard for their mind to learn new things the way a person with a healthier brain would. This can also produce curves like the one drawn.

==Transcript==
:[A graph is shown with labelled axis, and arrows at the tip of each axis. There are two thick arrows plotted, both starting mid-range on the Y-axis, one of them goes upwards at a constant angle of about 40°. The other, which lies over the first mentioned where they overlap close to the Y-axis, first rises a bit before it bends downward and then after having increased its downward bend for a bit it changes to a continuously lower down bending rate and seemingly converges towards a constant y-value close to zero before the end of the graph. Both arrows tip ends at the end of the X-axis. Inside each arrow there is a label.]
:Y-axis: How much you whine and complain about doing exercise"
:X-axis: Workout difficulty
:Upwards arrow: My progression over time
:Downwards arrow: Normal progression over time

{{comic discussion}}

[[Category:Charts]]
[[Category:Comics featuring Randall Munroe]]

2626: d65536

2022-06-05T21:55:05Z

172.70.115.4: /* Transcript */

{{comic
| number = 2626
| date = May 30, 2022
| title = d65536
| image = d65536.png
| titletext = They're robust against quantum attacks because it's hard to make a quantum system that large
}}

==Explanation==
{{incomplete|Created by a HEXAKISMYRIAPENTAKISCHILIAPENTAHECTATRIACONTAKAIHEXAHEDRON - The claim in the trivia that the numbers refer to a comic, should be substantiated with an explanation. If true interesting, if not... Do NOT delete this tag too soon.}}
In binary computing, 16 bit unsigned numbers range from 0 to 65535, for a total of 65536 unique numbers, a number which is hence well-known to software engineers. Generating large numbers in a manner that is truly random is a recurring problem in cryptography, required to send private messages to another party. People today still use dierolls to generate private random numbers.

In role-playing games (and occasionally in other tabletop games), multiple shapes of dice are often used to generate random numbers in specific ranges. By convention, these are referred to as d''n'' according to their number of faces. A traditional six-faced die would be a d6, and many popular pen-and-paper role-playing games use dice ranging between d4 and d20. While there are larger dice used in tabletop games (most commonly d100), these are usually split into multiple smaller ones. For example, a d100 is often two d10s rolled together, with one die providing the first digit and the other die giving the second digit — the total number of possible combinations (100) is the product of the number of faces of the two dice (10 * 10). While "real" {{w|Zocchihedron|d100s}} and other large-numbered dice do exist, most people consider them to be impractical: they need to be either impractically large or have very small faces (resulting in small print for the numbers), they're close enough to being spheres that it's difficult to get them into a stable resting position, and even if they are stationary, determining which face is "on top" is difficult to do by eye. The Zocchihedron (d100) die is also difficult to ensure is ubiased because of geometry requiring different sized faces and therefore a different mixture of 'stopping factors' for each face it could land upon. The largest unbiased die is a [https://en.wikipedia.org/wiki/Disdyakis_triacontahedron d120] (excluding the bipyramids, which can theoretically be made with arbitrarily many sides), so it is very likely that [[Cueball|Cueball's]] d65536 die is also biased.

Here, Cueball has constructed a d65536 for generating random 16 bit numbers. It may have solved the problem of generating large random numbers with fewer die rolls, but it magnifies all of the problems with large-numbered dice to ludicrous extremes. In order for the faces to be readable, the die is ridiculously huge, dwarfing the human standing next to it. Rolling such a die is not only physically challenging, but it would also need a huge space in which to roll if the result is to be random, and that space would need to have an extremely flat and rigid surface in order for the die to come to rest. And even in those problems were solved, simply getting to a vantage point to see the top of the die would be a major challenge, and determining which number was truly on top would be near impossible to do by eye. If one really wished to use dice, it would be much easier to simply use multiple dice rolls. For instance, one could roll eight d4 dice (or use 16 coin flips), and convert the result into binary. This has the same randomness as a single die roll{{fact}}?, but can take much longer, so people do purchase d16s to simplify it and speed it up.

The closest regular shape similar to the depicted in the comic could be a {{w|Goldberg polyhedron}}. However, no such polyhedron exists with exactly 65536 hexagonal faces. The closest Goldberg Polyhedron has a mixture of 65520 hexagons and 12 pentagons, totaling 65532 faces. It is possible to construct a fair die without a matching regular shape by limiting the sides which it could land on and designing those sides to be fair (for instance, a prism with rectangular facets that extend its entire length, and rounded ends to ensure it doesn't balance on end).

The title text references how cryptographic systems (especially RSA and other factoring-is-hard based systems) are vulnerable to quantum attacks as quantum computing technology develops. The title text is essentially punning on the idea of a "large" quantum system. "Large" in the quantum computing sense would be on the order of 64 qubits each of which would be an atom or two at most. This would still be microscopic and will never be as large as the giant die the comic is centered on; but for a well-observed environment and human rolling without sufficient entropy (consider somebody obsessed with a certain number dropping the die on something soft), a conventional computer could predict some rolls. See also [[538]] for non-mathematical paths of cryptography.

==Transcript==
:[A large sphere with a several lines, and in some places grids, are shown. Cueball, standing next to it, is dwarfed by its size, as it is at least seven times as tall as he is. The sphere has many lines following various great circles or parallel lesser circles around the curve of the sphere, and some patches of cross hatching to suggest further texturing along these lines hovering just below the degree of most of the illustrative detailing. The lines and grids cover the sphere in three layers of parallel axes, angled sixty degrees from each other, implying a huge mesh of equilateral triangles or hexagons. In the top right part of the ball is a black circle. An arrow points to this circle, and the end of the arrow goes to a larger circle that partly obscures the rightmost part of the sphere. The circle shows a zoom in on the surface in the black circle on the sphere. The zoom shows a small portion of the sphere's surface, showing that the grid comes along because the sphere is divided into elongated hexagonal faces with numbers up to at least five-digits. Seven numbers can be fully seen, but there are nine other faces partly shown, five of these with part of their numbers visible, one of these clearly only have four digits. One of the empty faces must also have a number with only 1-3 digits, as no numbers are visible although a significant part of the face is visible.]

:[Here follows the numbers in the zoomed in part of the sphere, with "..." represents numbers being cut off. The numbers are read in lines left to right, even though the numbers are tilted from down towards the right, which could have suggested a different reading order.]
:30827
:16[bottom part of a cut-off line][small cut-off circle]
:...38
:11875
:25444
:...[top part of a cut-off line]5
:12082
:28525
:3 [left part of a cut-off line]...
:13359
:13874
:[Two cut-off lines, likely the start of the number 2]...

:[Caption below the image:]
:The hardest part of securely generating random 16-bit numbers is rolling the d65536.

==Trivia==
*If a real d65536 were constructed with each number having an equal area and each printed in 12 point font, the resulting die would be about 5 feet (1.5 meters) in diameter, which isn't several times the size of a person as the comic suggests, but is still large enough to be hilariously inconvenient. If it were made out of standard acrylic, and not hollow, it would weigh about 2 tons (1700kg).
*This die would have a 0.00001526 chance of rolling a natural one (or any other number).
*There are seven 16-bit numbers fully visible in the picture: 30827, 25444, 11875, 28525, 12082, 13874 and 13359. [https://dotnetfiddle.net/fjLYZe They conceal a message.] If these numbers are split big-endian into two 8-bit ASCII characters each, the result is <code>xkcd.com/2624/</code>. For example, converting the first number 30,827 to hexadecimal (in which a four digit number covers exactly 65,536 different values) converts to a hex value of 786B. Splitting this into 78 and 6B, these are the hex ASCII codes for "x" and "k" respectively.

{{comic discussion}}

[[Category:Cryptography]]
[[Category:Comics featuring Cueball]]

2628: Motion Blur

2022-06-05T21:13:46Z

172.70.115.4: /* Explanation */

{{comic
| number = 2628
| date = June 3, 2022
| title = Motion Blur
| image = motion_blur.png
| titletext = I can't speak for your other subjects, but MY motion was as smooth and natural as the framerate allowed.
}}

==Explanation==
{{incomplete|Created by a bBboOotTt - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
[[White Hat]] is recording a video while rotating (''panning'') the camera. [[Cueball]] notices that the camera's shutter speed is too fast, which could cause the result to look unnatural or like a sequence of still images instead of like smooth motion when turning the camera. Cueball decides to solve this problem by making himself blurrier than normal, counteracting the problems of the high shutter speed. This is something real people do in the real world, by practicing moving their bodies relative to the motion of the camera.

The title text refers to the fact that only ''one'' object - in this case, Cueball - appearing sharp while everything else in the frame is blurry; it's a celebration and sarcasm regarding the rare experience of valuing having this knowledge and skill.

This is somewhat similar to a trick 'used' by {{w|Flash (DC Comics character)#Jay_Garrick|some fictional characters}} who have the power to make themselves unclear to observers or cameras alike. In real-life it is the difference between "stop motion" and "go motion" tricks.

When light hits a human's retina, it is perceived for a short while even after the light has ceased. This means that objects moving across a human's field of vision at a sufficient speed will naturally appear blurry – in our perception, the light arriving right now from the trailing part of the object will mix with the light that arrived a moment earlier, from the leading part of the object.

A camera's shutter speed is the amount of time that the shutter is open for each frame, allowing the image sensor to capture light. If the shutter speed is too high (relatively to the frame-rate), this blurring will not occur, and the motion will look unnaturally crisp – if something is too small and/or too quick, the illusion of motion may disappear altogether; the object instead will appear as a brief flash of multiple objects standing still, like in the case of a fast-moving mouse cursor on a screen. See for instance this [https://www.youtube.com/watch?v=i9bv00ZA-ao Videography - Slow Shutter Speed vs. Fast Shutter Speed Comparison].

In cinema, the shutter speed is generally set to double the frame-rate, e.g. 1/48 s for footage shot at 24 fps (one of the standard frame-rates, a remnant from the age of mechanical motion picture cameras and film projectors).

An opposing problem is that of a camera not sufficiently matching the relative motion of a moving object, with a shutter speed that is too slow (and may need to be, given the choice of aperture and lighting conditions). Sports photographers must learn how to scan-and-pan their subjects (runners, horses, vehicles, etc) with enough synchronicity to capture them sharply, and possibly seemingly hanging frozen in mid-air against an artistically-blurred background.

It is unclear how Cueball makes the motion blur include both his feet, as the friction with the ground should hinder them from vibrating horizontally in the manner that may cause for motion blur. Additionally, creating the kind of motion blur he does (with evenly distributed horizontal blur) requires extreme acceleration at both ends of the movement.

==Transcript==
:[White Hat is holding a camera up to his face looking to the left away from Cueball and Ponytail standing to his right. Cueball is holding one hand, with a balled up fist, up towards White Hat]
:White Hat: Okay, I'm going to pan around.
:Cueball: No, wait, your shutter speed is too fast, it will look choppy if—

:[White Hat turns clockwise towards Cueball and Ponytail, with the camera held up partly behind his head, so it points in the panel. Cueball clenches both his fists, held down now, and hunches his shoulders. Ponytail stands as before next to him.]
:Cueball: <big>''Hnnnnngh''</big>

:[White Hat has turned around and is now pointing the camera towards Cueball and Ponytail. Cueball now appears blurry while Ponytail looks normal.]

:[Caption below panel:]
:Expert photographers can learn to generate their own motion blur to compensate for other people's bad camera settings.

{{comic discussion}}

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

2628: Motion Blur

2022-06-05T21:11:59Z

172.70.115.4: tried to clarify that this is another self-jab for nerds

{{comic
| number = 2628
| date = June 3, 2022
| title = Motion Blur
| image = motion_blur.png
| titletext = I can't speak for your other subjects, but MY motion was as smooth and natural as the framerate allowed.
}}

==Explanation==
{{incomplete|Created by a bBboOotTt - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
[[White Hat]] is recording a video while rotating (''panning'') the camera. [[Cueball]] notices that the camera's shutter speed is too fast, which could cause the result to look unnatural or like a sequence of still images instead of like smooth motion when turning the camera. Cueball decides to solve this problem by making himself blurrier than normal, counteracting the problems of the high shutter speed. This is something real people do in the real world, by practicing moving their bodies relative to the motion of the camera.

The title text refers to the fact that only ''one'' object - in this case, Cueball - appearing blurred while everything else in the frame is sharp would probably look even more unnatural.

This is somewhat similar to a trick 'used' by {{w|Flash (DC Comics character)#Jay_Garrick|some fictional characters}} who have the power to make themselves unclear to observers or cameras alike. In real-life it is the difference between "stop motion" and "go motion" tricks.

When light hits a human's retina, it is perceived for a short while even after the light has ceased. This means that objects moving across a human's field of vision at a sufficient speed will naturally appear blurry – in our perception, the light arriving right now from the trailing part of the object will mix with the light that arrived a moment earlier, from the leading part of the object.

A camera's shutter speed is the amount of time that the shutter is open for each frame, allowing the image sensor to capture light. If the shutter speed is too high (relatively to the frame-rate), this blurring will not occur, and the motion will look unnaturally crisp – if something is too small and/or too quick, the illusion of motion may disappear altogether; the object instead will appear as a brief flash of multiple objects standing still, like in the case of a fast-moving mouse cursor on a screen. See for instance this [https://www.youtube.com/watch?v=i9bv00ZA-ao Videography - Slow Shutter Speed vs. Fast Shutter Speed Comparison].

In cinema, the shutter speed is generally set to double the frame-rate, e.g. 1/48 s for footage shot at 24 fps (one of the standard frame-rates, a remnant from the age of mechanical motion picture cameras and film projectors).

An opposing problem is that of a camera not sufficiently matching the relative motion of a moving object, with a shutter speed that is too slow (and may need to be, given the choice of aperture and lighting conditions). Sports photographers must learn how to scan-and-pan their subjects (runners, horses, vehicles, etc) with enough synchronicity to capture them sharply, and possibly seemingly hanging frozen in mid-air against an artistically-blurred background.

It is unclear how Cueball makes the motion blur include both his feet, as the friction with the ground should hinder them from vibrating horizontally in the manner that may cause for motion blur. Additionally, creating the kind of motion blur he does (with evenly distributed horizontal blur) requires extreme acceleration at both ends of the movement.

==Transcript==
:[White Hat is holding a camera up to his face looking to the left away from Cueball and Ponytail standing to his right. Cueball is holding one hand, with a balled up fist, up towards White Hat]
:White Hat: Okay, I'm going to pan around.
:Cueball: No, wait, your shutter speed is too fast, it will look choppy if—

:[White Hat turns clockwise towards Cueball and Ponytail, with the camera held up partly behind his head, so it points in the panel. Cueball clenches both his fists, held down now, and hunches his shoulders. Ponytail stands as before next to him.]
:Cueball: <big>''Hnnnnngh''</big>

:[White Hat has turned around and is now pointing the camera towards Cueball and Ponytail. Cueball now appears blurry while Ponytail looks normal.]

:[Caption below panel:]
:Expert photographers can learn to generate their own motion blur to compensate for other people's bad camera settings.

{{comic discussion}}

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

136: Science Fair

2022-06-02T19:38:37Z

172.70.115.4: /* Explanation */ whats the cute part i dont get it

{{comic
| number = 136
| date = August 2, 2006
| title = Science Fair
| image = science_fair.png
| titletext = This poster actually inspired a two-hour powerpoint presentation that Al Gore gave around the country.
}}

==Explanation==

A {{w|science fair}} involves schoolchildren doing research on a subject of their choice. The purpose is to give them hands-on experience with scientific techniques. Even so, a project based on {{w|cunnilingus}}, oral stimulation of the female genitalia for sexual enjoyment, would not likely be acceptable in a science fair, a setting that is not only public but also involving children. However, adolescents are often very curious about sex and can often misjudge what is appropriate behaviour.

On the center left are the notations for a {{w|Function (mathematics)|function}} <code>f(t)</code>, its {{w|Fourier transform}} <code>F(ω)</code>, and its {{w|Laplace transform}} <code>ℒ(s)</code>. The section titled "Challenges in frequency domain analysis" show four graphs that may be representative of {{w|Amplitude modulation|amplitude modulation}} (variation in the depth of licking), {{w|Frequency modulation|frequency modulation}} (variation of the rate of licking), a small high frequency signal superimposed on a larger, slower one, and a periodic but non-continuous signal, perhaps a {{w|Trigonometric functions|tangent function}}. These would have more complex Fourier and Laplace transforms than a simple sinusoidal licking function.

The title text is probably a reference to {{w|An Inconvenient Truth}}, a 94-minute documentary film where former US vice president {{w|Al Gore}} teaches the general public about the dangers of global warming. It has been included in science curricula in schools around the world, to the ire of easily bored students everywhere.

This comic was mentioned in [http://blog.xkcd.com/2008/02/25/fruit-opinions/ FRUIT OPINIONS!] on the [http://blog.xkcd.com/ Blag]. Although this comic must have been one of the more controversial, it had nothing on the impact of [[388: Fuck Grapefruit]], which was the cause of the Blag entry, as it became the most controversial comic written to that point (i.e. 2008): ''...beating out comics about cunnilingus, the Obama endorsement, and my making 4chan tiny on the map of the internet''. (See the grapefruit comic for more details).

==Transcript==
:[Text above the drawing:]
:Although it caught me by surprise at the time, looking back I understand why my senior science fair project went over as badly as it did.

:[A science fair project consisting of eight posters on three pink walls is set up for presenting such a project, so it is possible to step in between the walls to read about the project. There are two posters on both the left and the right wall, all four with unreadable text. Three of them clearly have a bolder heading at the top (still unreadable). The last to the right, which has no header, has instead some kind of drawing or formula in the middle, still unreadable.]

:[The central wall has some readable and discernible parts. The top poster is the title of the project, written in very large letters:]
:<big>The <big>Mathematics</big> of <big>Cunnilingus</big> </big>

:[Below the title poster, there are three posters. Two of these are right below, one to the left and one to the right, and the last poster below takes up the rest of the wall. The left of the two posters next to each other has a table with three rows and three columns. The text in each box is unreadable, but some of the text seems to be formulas though. Above the three columns, there are readable legends:]
:f(t);   F(ω);   ℒ(s)

:[The next poster to the right shows a drawing of female genitalia with the clitoris and both sets of Labia shown. It is displayed on a chart with X and Y axes with ticks (but no labels), and there is a box with three lines of unreadable text/legends.]

:[The last poster at the bottom of the central panel shows four line graphs with what looks like modulated signals or other time-domain signals or functions. These are displayed in two rows/columns to the left. To the right of these, there is a readable heading, and below that is more unreadable text:]
:Challenges in frequency-domain analysis

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Sex]]
[[Category:Science]]
[[Category:Charts]]
[[Category:Line graphs]]