https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=172.68.58.125&feedformat=atomexplain xkcd - User contributions [en]2024-03-28T21:19:02ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=Talk:2064:_I%27m_a_Car&diff=165406Talk:2064: I'm a Car2018-11-03T16:14:05Z<p>172.68.58.125: </p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
Is that a Chevy Volt? --[[Special:Contributions/172.69.62.196|172.69.62.196]] 04:30, 26 October 2018 (UTC)<br />
:Using google image search I could find various different taillight configurations on Chevrolet Volt's, but non where the lights extend to the trunk, and also downward on the site of the trunk. They are either above each other, or extending to the trunk. The one in the comic has both.--[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:51, 26 October 2018 (UTC)<br />
:Having owned a first-generation Volt, it sure looks like it to me. No, the details aren't perfect, but the taper of the lights seems to strongly suggest a first-gen Volt. ~ [[User:BestComicEver|BestComicEver]] ([[User talk:BestComicEver|talk]]) 14:04, 31 October 2018 (UTC)<br />
:I currently own a first-gen Volt, and I instantly thought, "Hey, Randall drew my car!" I am not that into cars, but I still think it's pretty recognizable as a Volt. [[Special:Contributions/172.68.58.125|172.68.58.125]] 16:14, 3 November 2018 (UTC)<br />
<br />
Cars are getting more intelligent and the voters seem to get dumber. This comic states that some cars are more intelligent than the average voters. [[Special:Contributions/141.101.104.209|141.101.104.209]] 06:48, 26 October 2018 (UTC)<br />
<br />
No matter how smart the car is it would need to meet eligibility requirements to vote. Cars are typically registered in a jurisdiction but are generally not recognized as citizens or residents for voting purposes. Only some cars meet the age requirements, e.g. in the United States the median age of an automobile was [https://news.ihsmarkit.com/press-release/automotive/average-age-vehicles-road-remains-steady-114-years-according-ihs-automotive 11.4 years] in 2014 while a voter must be at least 18 years of age to vote in US Federal elections. As for the title text, cars are generally incapable of reproduction [citation needed], ineligible for adoption [citation needed], and generally do not attend school [citation needed], making this scenario multiply implausible [[User:ChronoCronut|ChronoCronut]] ([[User talk:ChronoCronut|talk]]) 09:00, 26 October 2018 (UTC)<br />
: "Only some cars meet the age requirements" Right, but they are very mature for their age. xD [[Special:Contributions/162.158.90.114|162.158.90.114]] 11:35, 26 October 2018 (UTC)<br />
: It's time to start the car suffrage movement! [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 13:13, 26 October 2018 (UTC)<br />
<br />
"The entire comic seems to be related to self-driving cars, which has been a recurring subject on xkcd. As they first begins to drive by themselves, the next step is voting and later getting car babies that can grow up and become honor students." Actually, I think that this comic is about bumper stickers on cars. Of course people put bumper stickers on their cars to make a statement about themselves, but what if the bumper stickers were actually a statement by the car, not the person driving it. That's another common theme. [[User:Andyd273|Andyd273]] ([[User talk:Andyd273|talk]]) 12:26, 26 October 2018 (UTC)<br />
: I agree the comic is about bumper stickers which use "first person" wording taken literally as being the cars themselves talking. However as we hear and see more about self driving cars, and get closer to mythical artificial intelligence, the day may come when this joke about literality could cease to be a joke. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 14:25, 26 October 2018 (UTC)<br />
<br />
If this car made one of the questionable votes against network neutrality? {{unsigned|Gunterkoenigsmann}}<br />
<br />
The first thing that jumped to my mind was that it also mixed in the security issues arising due to the "Internet of Things" problems. Admittedly, most IoT devices are used in DoS attacks and are generally not used as general purpose hacking jump boxes, but I see no reason that cellular network equipped cars could not be hacked and used as a source for voting in digital elections. Adrian Colyer has a great synopsis of two vehicle papers on his blog: https://blog.acolyer.org/2015/12/02/carshark/ and https://blog.acolyer.org/2015/12/03/fast-and-vulnerable/ . [[User:Tovodeverett|Tovodeverett]] ([[User talk:Tovodeverett|talk]]) 13:35, 26 October 2018 (UTC)<br />
: But that would still be someone (a human) voting, albeit using the car as a vehicle [sic] for that vote. So the bumper sticker isn't being literal in this case, the car itself didn't vote, and so the joke doesn't work. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 18:22, 26 October 2018 (UTC)<br />
<br />
I put a citation needed tag in as a joke, and someone actually found a source for it. {{unsigned ip|162.158.74.57}}<br />
: I guessed that was what happened. I wonder how many other obvious statements have citations that someone could find? [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 00:10, 27 October 2018 (UTC)<br />
<br />
I wonder if it's less common to see these pointing out a party affiliation as in "I'm a Democrat" or "I'm a Republican" and more common to instead see them as showing membership in a special interest group like in "I'm a Mom" or "I'm a union worker" or likewise. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 02:40, 27 October 2018 (UTC)<br />
<br />
'''Now deleted thing about the bomber's vehicle'''<br />
<br />
Someone added text suggesting this comic was inspired by the stickers on the bomber's vehicle. Then someone else deleted that text because the comic had been posted before the bomber was arrested so Randall could not have known about the bomber's vehicle.<br />
<br />
Does that mean it was a coincidence?<br />
<br />
Or could the bomber have seen the comic and been inspired by it to put the stickers on the vehicle?<br />
<br />
(The deleted text was "Possibly Randall is ironically referring to the car of the suspect in the pipe bomb case. His whole [https://cdn.cnn.com/cnnnext/dam/assets/181026125735-03-tarp-off-screengrab-1026-closer-exlarge-169.jpg van is covered with pro-Trump, anti-Democrat and anti-liberal stickers]. Or it's just particularly bad timing...")<br />
[[Special:Contributions/172.68.46.173|172.68.46.173]] 05:42, 29 October 2018 (UTC)<br />
<br />
Perhaps it is related to the ongoing push for "motor voter" laws encouraging (or mandating) local DMV offices to register persons to vote at the same time they apply for or renew a driver's license? {{unsigned ip|172.68.141.94}}</div>172.68.58.125https://www.explainxkcd.com/wiki/index.php?title=2064:_I%27m_a_Car&diff=1648412064: I'm a Car2018-10-26T16:00:18Z<p>172.68.58.125: Added a “citation needed” joke</p>
<hr />
<div>{{comic<br />
| number = 2064<br />
| date = October 26, 2018<br />
| title = I'm a Car<br />
| image = im_a_car.png<br />
| titletext = I'm the proud parent of an honor student, and the person driving me is proud, too!<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by A PROUD CAR. Please edit the explanation below and only mention here why it isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
This comic shows a car with a {{w|bumper sticker}}, which is generally a thin rectangle piece of plastic with a message on one side and adhesive on the other side in order to stick to a car. This allows the owner of the car to display a message they want to present to whoever is driving behind them or in their vicinity. Bumper stickers are usually used to express a viewpoint, whether personal or political, held by the owner or driver of the car. This comic makes literal the ones that include or allude to the personal pronoun "I" and its variations, i.e. {{w|Grammatical_person|first person singular}} statements. Of course the intent is that "I" is referring to the person who put the bumper sticker on the car, but as the sticker is attached to the car the more literal interpretation is that "I" is referring to the car. So the humor is derived by the notion that the car itself is making these statements.<br />
<br />
The bumper sticker on the car in the comic is a variation of a sticker used to both encourage people to vote, as well as express their political position: "I'm a ___, and I vote" (where the blank is traditionally filled in with "Democrat" or "Republican" or some other political affiliation). However here it is attributed to an automobile which is not capable of voting.{{Citation needed}}<br />
<br />
The comic could be an indirect reference to the growing "intelligence" of {{w|self-driving cars}}, such that one day they might have the intellect to vote. See ‘{{w|Sally_(short_story)|Sally}}’ by {{w|Isaac Asimov}}.<br />
<br />
The title text seems to be another [https://www.positivepromotions.com/proud-parent-of-an-honor-student-bumper-sticker-personalization-available/p/os-3360/ typical message] on a bumper sticker, saying that the driver is a "Proud Parent Of An Honor Student". However, this sticker is a bit longer, since it continues to state that "the person driving me is proud, too". Thus once again it is the car who is the proud parent. And thus maybe it is a car that is the honor student?<br />
<br />
Of course this comic is also another way to try to get people to register for voting, as the [[Design_of_xkcd.com#Header|header text]] at the top of the xkcd page has recently changed to "Check your registration and find your polling place at [https://www.vote.org/ vote.org]." This is because the {{w|United States midterm election}} will be held on {{w|United States elections, 2018|Tuesday, November 6, 2018}}, 11 days after the release of this comic. Randall has an interest in getting as many as possible to register, see [[1756: I'm With Her]], since he most likely thinks that it is important to use the right to vote.<br />
<br />
==Transcript==<br />
:[The bottom right rear end of a car is shown with a bumper sticker next to the unreadable license plate.]<br />
:I'm a car<br />
:''and I vote''<br />
<br />
==Trivia==<br />
This is the third comic displaying a bumper sticker, after the comics [[80: My Other Car]] and [[1033: Formal Logic]] that came out in 2006 and 2012 respectively.<br />
<br />
Bumper stickers also are mentioned as a future milestone for self-driving cars in [[1925: Self-Driving Car Milestones]].<br />
<br />
Randall also sells bumper stickers with the word "OPINIONS!" on them. [https://store.xkcd.com/products/opinions-bumper-sticker]<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Politics]]</div>172.68.58.125https://www.explainxkcd.com/wiki/index.php?title=2055:_Bluetooth&diff=1637642055: Bluetooth2018-10-06T00:38:18Z<p>172.68.58.125: </p>
<hr />
<div>{{comic<br />
| number = 2055<br />
| date = October 5, 2018<br />
| title = Bluetooth<br />
| image = bluetooth.png<br />
| titletext = Bluetooth is actually named for the tenth-century Viking king Harald "Bluetooth" Gormsson, but the protocol developed by Harald was a wireless charging standard unrelated to the modern Bluetooth except by name.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Please mention a reason here why this isn't complete -- still trying to pair the explanation with the image. Do your jokes at the discussion page! Do NOT delete this tag too soon.}}<br />
<br />
{{w|Bluetooth}} is a technology invented in the mid 1990's and intended for devices to connect wirelessly over a relatively short range for the purpose of transmitting information and/or audio. For example, a headset that connects via Bluetooth could be connected to a computer that's also Bluetooth-enabled, and then whatever would normally come out of the computer's speakers would come out the headset's ear pieces instead, and whatever was spoken into the headset's microphone would be transmitted to the computer's audio input system as if coming in through the computer's microphone. For this to work, the two devices need to be paired, which means they need to know the unique identification number of the other device and have been given permission to communicate with it, as well as knowing what kind of data exchanges are both possible and allowed. This pairing process is not always a smooth process.<br />
<br />
[[Cueball]] is talking to [[White Hat]] about {{w|Bluetooth}} and wireless connectivity. He asks if it has become easier to stream audio via Bluetooth since he last used it. White Hat then replies that it has become an easy-to-use and streamlined service, where connecting devices is easy, and he gives some examples of how easy it is to use. Cueball is excited about this, until White Hat reveals that he was lying and that Bluetooth is still as hard to use as ever. Cueball then invokes the name of "Josiah Bluetooth", a fictitious person implied to have invented the eponymous Bluetooth. Note that while there is no "Josiah Bluetooth" person, there is a "[https://www.impossible.com/josiah/ Josiah Bluetooth]" ceramic speaker.<br />
<br />
This comic also references the common problem of audio playing through the wrong device when Bluetooth is activated.<br />
<br />
The Viking king referenced in the title text, {{w|Harald Bluetooth|Harald “Bluetooth” Gormsson}}, usually called Harald Bluetooth, was a ruler of Denmark and Norway who died in 985 or 986. He of course had nothing to do with wireless Bluetooth connection technology, which wouldn’t be invented for more than a millennium. However Jim Kardach of Intel did name the Bluetooth protocol after him, apparently as he united the various Norse tribes of Denmark into a single kingdom just as Bluetooth unites communication protocols. The {{w|Bluetooth#Logo|Bluetooth logo}} unites the two Norse {{w|runes}} corresponding to "H" and "B" for Harald Bluetooth.<br />
<br />
The title text joke could also be a pun on military “charging”, which would certainly be wireless.<br />
<br />
==Transcript==<br />
:[Cueball and White Hat are talking, Cueball is holding a cell phone and wireless headphones.]<br />
:Cueball: I haven’t used a wireless/bluetooth thingy in like ten years. Is audio stuff still a nightmare?<br />
:White Hat: Nah, it’s great now.<br />
<br />
:[Zoom in on White Hat, Cueball is off-screen.]<br />
:White Hat: You tap devices together twice to link them and they flash in sync. (It pairs using accelerometer timing and sound.) Tap them three times to disconnect.<br />
:White Hat: You can pair multiple inputs and outputs and it handles it smoothly.<br />
:Cueball (off screen): Nice!<br />
:White Hat: It just works. Sound comes from where you expect.<br />
:Cueball (off screen): Wonderful.<br />
<br />
:[Zoom out to White Hat and Cueball facing each other.]<br />
:White Hat: Haha, just kidding, it’s a nightmare.<br />
:Cueball: ''Noooooo!''<br />
:White Hat: When I connect to my car, music starts blasting from my headphones while the car repeatedly plays a “New connection!” chime.<br />
:Cueball: ''This is not what Josiah Bluetooth intended!''<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring White Hat]]<br />
[[Category:Computers]]<br />
[[Category:Smartphones]]</div>172.68.58.125https://www.explainxkcd.com/wiki/index.php?title=2035:_Dark_Matter_Candidates&diff=1636662035: Dark Matter Candidates2018-10-04T19:12:24Z<p>172.68.58.125: /* Maybe those orbit lines on space diagrams are real and very heavy */</p>
<hr />
<div>{{comic<br />
| number = 2035<br />
| date = August 20, 2018<br />
| title = Dark Matter Candidates<br />
| image = dark_matter_candidates.png<br />
| titletext = My theory is that dark matter is actually just a thin patina of grime covering the whole universe, and we don't notice it because we haven't thoroughly cleaned the place in eons.<br />
}}<br />
<br />
==Explanation==<br />
{{w|Dark matter}} is a hypothetical, invisible form of matter used by the vast majority of astronomers to explain the far too high apparent mass of objects at large scales in our universe. In galaxies, stars are orbiting faster than the gravitational force of the sum of the masses of visible matter in the galaxy could cause, and entire galaxies are observed moving much faster around each other than their visible masses could explain. In galactic collisions, the mass can appear to separate from the visible matter, as if the mass doesn't collide but the visible matter does. A small handful of galaxies have been observed to not have this property, suggesting that it is a *thing* that a galaxy can have more or less of and is separable from. At scales of our solar system, those effects are too small and can't be measured. The most plausible explanation for all of these phenomena is that there is some "dark matter" that has gravity, but is otherwise undetectable. In cosmology, dark matter is estimated to account for 85% of the total matter in the universe.<br />
<br />
This comic gives a set of possibilities for what dark matter could possibly be, charted by mass from smallest (given in {{w|Electronvolt#Mass|electronvolts}}) to largest (given in kilograms). Masses in the range 10<sup>-15</sup> kg to 10<sup>-3</sup> kg are given in grams together with appropriate prefixes, while the ton takes the place of 10<sup>3</sup> kg.<br />
<br />
Only massive objects ranging from subatomic particles up to super massive ones are covered in this comic. There are also {{w|Dark matter#Alternative hypotheses|alternative hypotheses}} trying to modify general relativity with no need of additional matter. The problem is that these theories can't explain all different observations at once. Nonetheless dark matter is a mystery because no serious candidate has been found yet.<br />
<br />
The joke in this comic is that the range of the mass of the possible particles and objects stretch over 81 powers of ten, with explanations suggested by astronomers covering only some portions of that range. [[Randall]] fills the gaps with highly absurd suggestions.<br />
<br />
==== Axion ====<br />
An {{w|Axion|axion}} is a hypothetical elementary particle postulated in 1977 to resolve the strong CP problem in {{w|Quantum chromodynamics|quantum chromodynamics}}, a theory of the strong force between {{w|Quark|quarks}} and {{w|Gluon|gluons}} which form {{w|Hadron|hadrons}} like {{w|Proton|protons}} or {{w|Neutron|neutrons}}. If axions exist within a specific range of mass they might be a component of dark matter. The advantage of this particle is that it's based on a theory which could be proved or also disproved by measurements in the future. Other theories, not mentioned in this comic, like the {{w|Weakly interacting massive particles|Weakly interacting massive particles (WIMPs)}} are much more vague.<br />
<br />
==== Sterile neutrino ====<br />
{{w|Sterile neutrino|Sterile neutrinos}} are hypothetical particles interacting only via gravity. It's an actual candidate for dark matter. The well known {{w|Neutrino|neutrinos}} are also charged under the {{w|Weak interaction|weak interaction}} and can be detected by experiments.<br />
<br />
==== Electrons painted with space camouflage ====<br />
{{w|Electron|Electrons}} are fundamental particles which compose the outer layers of atoms. A large number of electrons in the galaxy would be relatively easy to detect, as they not only interact with light (which dark matter does not appear to), but also have a strong electric charge. Presumably, space camouflage is a positively-charged coating which prevents electrons from interacting with light. (Needless to say, this is not an actual candidate for dark matter.) The mass of an electron is about 0.5 MeV which fits well into the graph.<br />
<br />
==== Neutralino ====<br />
A {{w|Neutralino|neutralino}} is a hypothetical particle from {{w|Supersymmetry|supersymmetry}} and is also a current candidate for dark matter. But there is not evidence whether or not supersymmetry is correct and none of the predicted particles have been found yet.<br />
<br />
==== Q-ball ====<br />
In theoretical physics, a {{w|Q-ball}} is a stable group of particles. It's an actual candidate for dark matter.<br />
<br />
(In billiards, a cue ball is the white (or yellow) ball hit with the cue in normal play. In addition, [[Cueball]] is the name explainxkcd uses for the most common xkcd character.)<br />
<br />
==== Pollen ====<br />
{{w|Pollen}} is a joke candidate, though people with seasonal allergies may suspect that the universe is genuinely made up entirely of pollen in the springtime. <br />
<br />
==== No-See-Ums ====<br />
{{w|Ceratopogonidae|No-See-Ums}} are a family (Ceratopogonidae) of small flies, 1–4 mm long, that can pass through most window screens. Another joke candidate, because dark matter is invisible and the name "no-see-ums" implies that the flies are invisible.<br />
<br />
==== Bees ====<br />
Insects of the clade {{w|Bee|Antophila}} are major pollinators of flowering plants. In recent years {{w|Colony collapse disorder|bees have been disappearing}} at an alarming rate; {{w|The Stolen Earth|Doctor Who explained}} that they are in fact aliens leaving Earth prior to a Dalek invasion.<br />
<br />
==== 8-balls ====<br />
In pool, the {{w|Pool (cue sports)|8-ball}} is a black ball numbered 8. It's a pun with Q-ball/cue ball. Unless undetected aliens have discovered billiards and become addicted to it, 8-balls are found only on Earth and are, hence, unlikely dark matter candidates. The 8-ball is also a popular unit of sale for black market pharmaceuticals like cocaine, where it stands for 1/8th of an ounce (3.5g). This doesn't make sense as a dark matter candidate either -- unless dark matter is hard to detect because it's illegal & trying to avoid the cops.<br />
<br />
==== Space Cows ====<br />
Cows are {{w|Bovinae|bovines}} extensively farmed on Earth for milk and meat. Although there is folklore concerning cows {{w|Hey diddle diddle|achieving circum-lunar orbits}}, not to mention their appearance on a {{w|Shindig (Firefly)|beloved space western TV show}}, as Muppet cow [http://muppet.wikia.com/wiki/Natalie Natalie] in the Sesame Street News Flash (and [https://tvtropes.org/pmwiki/pmwiki.php/Main/SpaceWestern others less-remembered]), they have yet to be found elsewhere in the Universe. In the television show "Too Close for Comfort", one of the characters is the cartoonist of a comic strip called "Cosmic Cow". {{w|Spherical cow|Spherical cows}} have also been used (humorously) by physicists needing to simplify some source of mass in a given problem.<br />
<br />
==== Obelisks, Monoliths, Pyramids ====<br />
While those human constructions are huge on a human scale, they're negligible at universe-scale. It would take a large number of such constructions, distributed through space, to replicate the effects of dark matter; while a scenario could be envisioned where enough such constructs existed, with properties and distribution allowing them to match observations, this is obviously not a likely explanation.<br />
They often show up in fiction and pseudo-scientific literature as alien artifacts generating immense unknown power out of nowhere, with the most famous and influential example being the three monoliths from {{w|2001: A Space Odyssey (film)|2001: A Space Odyssey}} (with the largest having a mass of about 500,000 tonnes).<br />
<br />
==== Black Holes ruled out by: ====<br />
{{w|Black hole|Black holes}} are known to occur in sizes of a few solar masses (about 10<sup>30</sup>-10<sup>31</sup> kg) as remnants of the core of former big stars, as well as in quite large sizes at the centers of galaxies (millions or even billions of solar masses). But recent gravitational wave detections indicate that black holes at 50 or 100 solar masses also exist, though their origin is still not understood. Randall doesn't mention this but some astronomers hope that these could fill at least a part of the gap. While black holes are widely reported to be ruled out as a candidate for dark matter for various reasons Randall has listed, such constraints are based on "monochromatic" mass distributions -- meaning that all such black holes are assumed to have the same mass -- which is considered physically implausible for populations of merging bodies which are known to have vastly different masses. See: [https://arxiv.org/pdf/1709.07467.pdf Primordial Black Holes as Dark Matter (2017)] and [https://arxiv.org/pdf/1705.05567.pdf Primordial black hole constraints for extended mass functions (2017)] (That this is a common practice in cosmology may be part of the reference to "buzzkill" astronomers.) He rules out all black holes in the range of approximately 10<sup>10</sup> kg to 10<sup>33</sup> kg even when below some gaps at the bars appear.<br />
<br />
Except the last item, all range below the mass of the sun (2x10<sup>30</sup> kg) while the smallest known black hole is about four solar masses.<br />
* Gamma rays: If dark matter were black holes of this size, the black holes could be evaporating by the predicted {{w|Hawking radiation}}, and we'd see a buzz of gamma rays from every direction if many of those objects would exist. Nonetheless this radiation is still hypothetical and not been observed on any known black holes. Furthermore those objects would be very small because the Schwarzschild radius of a 10<sup>12</sup> kg black hole is approximately 148 fm (1.48×10<sup>−13</sup> m), which is between the size of an atom and an atomic nucleus.<br />
* GRB lensing: {{w|Gamma-ray burst|Gamma-ray bursts}} (GRBs) are the brightest events in the universe and have been observed only in distant galaxies. While gravitational microlensing (see below) is an astronomical phenomenon, it doesn't make much sense here. GRBs are short (milliseconds to several hours) and are often detected only by space-borne sensors for gamma-rays -- rarely at any other wavelengths. Measuring lensing effects would be very difficult. This [https://arxiv.org/abs/1406.3102 paper] discusses the probability of detecting lensing effects caused by {{w|Dark matter halo|galactic halo objects}} among the known GRBs given sufficient objects to represent the missing mass. <br />
* Neutron star data: {{w|Neutron star|Neutron stars}} aren't black holes, but they're also very small highly compact objects at about 1.4-2.16 solar masses. While black holes can't be observed directly, neutron stars are detectable in many wavelengths. The number of them gives a clue about the number of black holes close to the mass of the sun, a number which is far too low to make up dark matter.<br />
* Micro lensing: {{w|Gravitational microlensing}} is a gravitational lens effect, (the path of radiation is changed by passing through space bent by nearby mass). This was predicted by Einstein's {{w|General Relativity|Theory of General Relativity}} and was first confirmed in 1919 during a solar eclipse, when a star which was nearly in line with the sun appeared more distant to the sun than usual. Astronomers have found many so called {{w|Einstein ring|Einstein rings}} or Einstein crosses where a massive object in front of other galaxies bends the light toward us. Those massive objects may be black holes, but the number is far too low to explain dark matter.<br />
* Solar system stability: Our {{w|Solar system|solar system}} is 4.5 billion years old and has been very stable since shortly after its formation. If not, we wouldn't exist. If dark objects at 10<sup>24</sup> kg - 10<sup>30</sup> kg (mass of Earth up to mass of Sun) accounted for dark matter and were distributed throughout galaxies, there should be many of them in the vicinity of our solar system and the system wouldn't be stable at all.<br />
* Buzzkill Astronomers: Black holes above a certain size are thought by some astronomers to be impossible to miss, due to the effects they have on nearby matter. At the mass of some 10<sup>30</sup> kg there must be many supernova remnants we still haven't found. Black holes of about 10<sup>35</sup> kg have long been considered dark matter candidates by a minority group of cosmologists, as could be seen here [https://arxiv.org/pdf/1001.2308.pdf Primordial Black Holes as All Dark Matter (2010)] and the Milky Way's first discovered intermediate mass black hole falling in this range shown here [https://www.nao.ac.jp/en/news/science/2016/20160115-nro.html Signs of Second Largest Black Hole in the Milky Way].<br />
Not covered by this comic are {{w|Massive compact halo object|massive astrophysical compact halo objects (MACHOs)}} composed of hard to detect dim objects like black holes, neutron stars, brown dwarfs, and other objects composed of normal {{w|Baryon|baryonic}} matter. Nevertheless observations have shown that the total amount of baryonic matter in our universe on large scales is much smaller than it would be needed to explain all the measured gravitational effects.<br />
<br />
==== Maybe those orbit lines on space diagrams are real and very heavy ====<br />
Diagrams of our solar system (or any planetary system) often show lines representing the elliptical paths the planet takes around its sun. These lines don't show real objects, though. Astronomers just draw them on pictures of the solar system to show where the planets move. If you draw a line on a map to give someone directions, that line isn't an object in real life; it's just on the map. If these lines were real, they would be ''huge'' (Earth's would be 940 million km long (2π AU) and Neptune's would be 28 ''billion'' kilometers long). [https://www.youtube.com/watch?v=0fKBhvDjuy0 Powers of Ten (1977)] gives a good sense of just how large these orbit lines need to be in order to be visible in space diagrams. If these orbit lines were also very dense, they would have a huge mass and could possibly account for the missing 85% of the mass in the universe. But they would also constantly be impaling the planets, including the Earth, which would probably be a problem{{Citation needed}}. Their mass would also affect planetary motions in ways which we would detect. A related worry about space travel was expressed in previous centuries; it was thought that the planets were embedded within {{w|Celestial spheres|crystal shells}} (spheres or Platonic solids), and a rocket into space could smash the shells and send planets plummeting to Earth. Another joke candidate.<br />
<br />
Due to Gauss' shell theorem the orbit lines wouldn't contribute to gravitational binding energy of the orbiting bodies. Gauss's law for gravity states:<br />
<br />
<blockquote>The gravitational flux through any closed surface is proportional to the enclosed mass.</blockquote><br />
<br />
As a result the systems would be unstable and would "Boil off". Consider the innermost orbiting body, since there is not enough observable mass to bind that body there must be dark matter, but no mass contribution comes from its own orbit line hence it escapes, now the second closest body has even less mass binding it so that body will also escape, by induction no body can be bound by massive orbit lines.<br />
<br />
==== Title text ====<br />
The title text refers to the fact that space is just vast emptiness where a little bit of dirt could be overlooked. Actually the mean density of detectable matter in the universe, according to NASA, is equivalent to roughly [https://map.gsfc.nasa.gov/universe/uni_matter.html 1 proton per 4 cubic meters]. And because this matter is mostly located in galaxies -- and inside there in stars and clouds -- the space between is even more empty. For comparison, one gram hydrogen consists of {{w|Avogadro constant|6.022 x 10<sup>23</sup> atoms}}. Like at home wiping with a cleaning cloth in which we can see the dirt that wasn't clearly visible on the surface we have wiped, Randall believes that some few atoms more per cubic meter could stay undetected in the same way. This isn't true because in the space between galaxies astronomers can detect matter as it spreads over thousands or millions cubic light years. Atoms can't hide; there is always radiation.<br />
<br />
==Transcript==<br />
:Dark matter candidates:<br />
:[A line graph is shown and labeled at left quarter in eV and further to the right in g together with some prefixes.]<br />
:[The labels read:]<br />
:µeV, meV, eV, keV, MeV, GeV, TeV, 10<sup>-18</sup>kg, ng, µg, mg, g, kg, TON, 10<sup>6</sup>kg, 10<sup>12</sup>kg, 10<sup>18</sup>kg, 10<sup>24</sup>kg, 10<sup>30</sup>kg<br />
<br />
:[All items are shown in bars ranging between two approximately values:]<br />
:< 1 µeV - 10 meV: Axion<br />
<br />
:1 eV - 10 keV: Sterile neutrino<br />
<br />
:0.5 MeV (exactly): Electrons painted with space camouflage<br />
<br />
:10 GeV - 10 TeV: Neutralino<br />
<br />
:100 TeV - 10<sup>-17</sup> kg: Q-ball<br />
<br />
:1 ng - 100 ng: Pollen<br />
<br />
:0.1 mg - 1 mg: No-See-Ums<br />
<br />
:10<sup>-1</sup> g (exactly): Bees<br />
<br />
:10 g - 100 g: 8-balls<br />
<br />
:100 kg - TON: Space cows<br />
<br />
:TON - 10<sup>9</sup> kg: Obelisks, monoliths, pyramids<br />
<br />
:10<sup>9</sup> kg - 10<sup>33</sup> kg: Black holes ruled out by:<br />
::10<sup>9</sup> kg - 10<sup>13</sup> kg: Gamma rays<br />
::10<sup>13</sup> kg - 10<sup>17</sup> kg: GRB lensing<br />
::10<sup>15</sup> kg - 10<sup>22</sup> kg: Neutron star data<br />
::10<sup>21</sup> kg - 10<sup>30</sup> kg: Micro lensing<br />
::10<sup>24</sup> kg - 10<sup>30</sup> kg: Solar system stability<br />
::10<sup>30</sup> kg - 10<sup>33</sup> kg: Buzzkill astronomers<br />
<br />
:10<sup>33</sup> kg - >10<sup>36</sup> kg: Maybe those orbit lines on space diagrams are real and very heavy<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Line graphs]]</div>172.68.58.125https://www.explainxkcd.com/wiki/index.php?title=Talk:1895:_Worrying_Scientist_Interviews&diff=146002Talk:1895: Worrying Scientist Interviews2017-09-28T01:02:27Z<p>172.68.58.125: Typo: ; instead of )</p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
Why not use Heliologist? :~) [[User:DarkJMKnight|DarkJMKnight]] ([[User talk:DarkJMKnight|talk]]) 14:49, 27 September 2017 (UTC)<br />
<br />
If the sun is local breaking news, could be an impending dark age (solar activity destroying all technology) or a dark age (solar implosion/explosion/death). [[Special:Contributions/162.158.79.5|162.158.79.5]] 15:42, 27 September 2017 (UTC)<br />
<br />
P<!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
Why not use Heliologist? :~) [[User:DarkJMKnight|DarkJMKnight]] ([[User talk:DarkJMKnight|talk]]) 14:49, 27 September 2017 (UTC)<br />
<br />
If the sun is local breaking news, could be an impending dark age (solar activity destroying all technology) or a dark age (solar implosion/explosion/death). [[Special:Contributions/162.158.79.5|162.158.79.5]] 15:42, 27 September 2017 (UTC)<br />
<br />
: Destroying *''all''* technology would require something on the scale of a solar expansion (hydrogen exhaustion) Solar flares (even those strong enough to burn all life from the face of the Earth) still would not be sufficient to destroy subterranean shelters like NORAD. Only a total extinction event would be capable of destroying all technology. Even if 99.9% of all humans on Earth were killed off, there are very well secured (& insanely well funded) facilities which will survive any event short of total crust-upheaval, at least for a generation or so. Reverting to primitive lifestyle may possibly happen for a *''majority''* of humans, but modern military systems are such that some humans with tech are almost guaranteed to remain, no matter what terrible events occur. In other words, the wealthiest technocratic elite aren't going to die off any time soon. [[Special:Contributions/172.68.58.125|172.68.58.125]] 00:59, 28 September 2017 (UTC)<br />
<br />
: Which makes me wonder why only a local reporter is covering the story. Sounds like a media beat-up. The joke appears to depend more on someone's imagination than on the actual news story. [[Special:Contributions/198.41.238.34|198.41.238.34]] 23:10, 27 September 2017 (UTC)<br />
<br />
Everyone else is dead except for the reporter who happens to be beret guy<br />
<br />
Marine biologist is probably about oil spills or coral reefs/fish dying etc, rather than invasive species --[[Special:Contributions/141.101.99.209|141.101.99.209]] 16:18, 27 September 2017 (UTC)<br />
<br />
The explanation for "ornithologist" uses "avian dinosaurs" instead of "birds." There's a link to the wikipedia page for birds, but it's still a potentially confusing inside joke. [[Special:Contributions/172.68.54.106|172.68.54.106]] 19:01, 27 September 2017 (UTC)<br />
<br />
So, wait: worried about what the hell is so wrong with interviewers for them to actually want to talk to these kinds of researchers; or about what is happening to the world are we all going to die is it the end times? [[Special:Contributions/162.158.79.71|162.158.79.71]] 19:54, 27 September 2017 (UTC)</div>172.68.58.125https://www.explainxkcd.com/wiki/index.php?title=Talk:1895:_Worrying_Scientist_Interviews&diff=146001Talk:1895: Worrying Scientist Interviews2017-09-28T00:59:24Z<p>172.68.58.125: Solar activity "destroying all technology" would only be likely to occur in a planetary extinction level event.</p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
Why not use Heliologist? :~) [[User:DarkJMKnight|DarkJMKnight]] ([[User talk:DarkJMKnight|talk]]) 14:49, 27 September 2017 (UTC)<br />
<br />
If the sun is local breaking news, could be an impending dark age (solar activity destroying all technology) or a dark age (solar implosion/explosion/death). [[Special:Contributions/162.158.79.5|162.158.79.5]] 15:42, 27 September 2017 (UTC)<br />
<br />
P<!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
Why not use Heliologist? :~) [[User:DarkJMKnight|DarkJMKnight]] ([[User talk:DarkJMKnight|talk]]) 14:49, 27 September 2017 (UTC)<br />
<br />
If the sun is local breaking news, could be an impending dark age (solar activity destroying all technology) or a dark age (solar implosion/explosion/death). [[Special:Contributions/162.158.79.5|162.158.79.5]] 15:42, 27 September 2017 (UTC)<br />
<br />
: Destroying *''all''* technology would require something on the scale of a solar expansion (hydrogen exhaustion; Solar flares (even those strong enough to burn all life from the face of the Earth) still would not be sufficient to destroy subterranean shelters like NORAD. Only a total extinction event would be capable of destroying all technology. Even if 99.9% of all humans on Earth were killed off, there are very well secured (& insanely well funded) facilities which will survive any event short of total crust-upheaval, at least for a generation or so. Reverting to primitive lifestyle may possibly happen for a *''majority''* of humans, but modern military systems are such that some humans with tech are almost guaranteed to remain, no matter what terrible events occur. In other words, the wealthiest technocratic elite aren't going to die off any time soon. [[Special:Contributions/172.68.58.125|172.68.58.125]] 00:59, 28 September 2017 (UTC)<br />
<br />
: Which makes me wonder why only a local reporter is covering the story. Sounds like a media beat-up. The joke appears to depend more on someone's imagination than on the actual news story. [[Special:Contributions/198.41.238.34|198.41.238.34]] 23:10, 27 September 2017 (UTC)<br />
<br />
Everyone else is dead except for the reporter who happens to be beret guy<br />
<br />
Marine biologist is probably about oil spills or coral reefs/fish dying etc, rather than invasive species --[[Special:Contributions/141.101.99.209|141.101.99.209]] 16:18, 27 September 2017 (UTC)<br />
<br />
The explanation for "ornithologist" uses "avian dinosaurs" instead of "birds." There's a link to the wikipedia page for birds, but it's still a potentially confusing inside joke. [[Special:Contributions/172.68.54.106|172.68.54.106]] 19:01, 27 September 2017 (UTC)<br />
<br />
So, wait: worried about what the hell is so wrong with interviewers for them to actually want to talk to these kinds of researchers; or about what is happening to the world are we all going to die is it the end times? [[Special:Contributions/162.158.79.71|162.158.79.71]] 19:54, 27 September 2017 (UTC)</div>172.68.58.125https://www.explainxkcd.com/wiki/index.php?title=Talk:1866:_Russell%27s_Teapot&diff=143152Talk:1866: Russell's Teapot2017-07-24T18:31:51Z<p>172.68.58.125: A catapult in space which further launches a satellite is also a launch vehicle.</p>
<hr />
<div><!--Please sign your posts with ~~~~ and not delete this comment.--><br />
<br />
In this case, nesting the teapot in a catapult/cannon which is launched by another catapult/cannon might perhaps be sufficient to get past NASA regulations. (Catapults/cannons only launching the payload and not themselves...) <sub>--[[User:Nialpxe|<span style="color: #000; text-decoration: none;">Nialpxe</span>]], 2017. [[User_talk:Nialpxe|<span style="color: #000; text-decoration: none;">(Arguments welcome)</span>]]</sub><br />
:Though there's still the matter of an equal and opposite force pushing the satellite away from its gravitational bonds of the catapult. Even if the 2nd catapult is no longer associated with the Earth or Earth's gravity, the catapult will continue to be a launcher. That's just changing what it is launching *from*. [[Special:Contributions/172.68.58.125|172.68.58.125]] 18:31, 24 July 2017 (UTC)ColinHeico<br />
:But make sure it is a mobile cannon, otherwise it would not qualify as a launch '''vehicle'''. [[Special:Contributions/162.158.89.19|162.158.89.19]] 11:32, 21 July 2017 (UTC)<br />
::I immediately thought "railgun". And the payload can still be a rocket; once it's not touching the ground it's accelerating, not launching. (Also Russell failed to account for female barbers. Honestly, people!) [[Special:Contributions/108.162.241.4|108.162.241.4]] 09:42, 22 July 2017 (UTC)<br />
::: One such company did exist, Quicklaunch had the idea of launching via a space gun. https://en.m.wikipedia.org/wiki/Quicklaunch {{unsigned ip|172.68.141.142}}<br />
<br />
::: He didn't need to account for female barbers (or anybody who isn't a man) because the barber in the paradox shaves precisely those men who don't shave themselves. He ''only'' shaves men, and all men in the town are ''only'' shaved by him or themselves. Everyone else is a completely different story, so they can be shaved by whoever they want (except the barber, who only shaves men). [[Special:Contributions/108.162.241.88|108.162.241.88]] 00:14, 23 July 2017 (UTC)<br />
<br />
:::Only if you assume that females who are barbers don't shave their legs, armpits, or their various lady parts. This only further confuses the paradox. {{unsigned|Mjm87}}<br />
::::For much of Bertrand Russell's life, they didn't. http://mentalfloss.com/article/22511/when-did-women-start-shaving-their-pits [[Special:Contributions/108.162.241.4|108.162.241.4]] 09:42, 22 July 2017 (UTC)<br />
<br />
When I first saw this comic I immediately thought of the Utah Teapot, it's a model used in computer graphics because it's simple and has both convex and concave surfaces. Both teapots, I would assume, (I've only just heard of Russel's Teapot so I could be wrong) are well known to different parts of the nerd community? {{unsigned ip|162.158.255.22}}<br />
<br />
Hopefully it will support HTCPCP-TEA. [[Special:Contributions/108.162.241.34|108.162.241.34]] 17:48, 21 July 2017 (UTC)<br />
<br />
i think people just really like teapot examples {{unsigned ip|108.162.246.23}}<br />
<br />
:The major problem here is that CubeSats are currently only launched into Low Earth Orbit (LEO) and are expected to re-enter the atmosphere within days to weeks. Russell's teapot is (allegedly) in orbit between Earth and Mars and Cueball's device is not likely to have enough delta-v to leave Earth orbit. [[User:SteveBaker|SteveBaker]] ([[User talk:SteveBaker|talk]]) 18:18, 21 July 2017 (UTC)<br />
"A teapot orbits the Sun somewhere in space between the Earth and Mars" This implies that the teapot is physically located between Mars and Earth at all times. Which if true would be a highly irregular orbit requiring constant velocity changes, which is an impossible feat to achieve with current teapot technology. {{unsigned|Mjm87}}<br />
:Nonsense. It would be a ''highly regular orbit'' and many asteroids are already there, despite the most of them are between Mars and Jupiter (Asteroid-Belt):--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:22, 21 July 2017 (UTC)<br />
<br />
I can see both of your points. As mjm87 says, "between the Earth and Mars", taken literally, would mean "on a line between the two planets", which would be a very unusual orbit. And, I agree, it would be impossible without constant velocity changes, so wouldn't be an "orbit" in the usual sense.<br />
On the other hand, I took Russell's words the way Dgbrt seems to have, as meaning "between the orbits of Earth and Mars", as this is the way most astronomers would interpret it. A don't know that there are "many" asteroids that remain between Earth and Mars, but there are quite a few crossing the space, and at least a few with average distances in that range. - N Kalanaga {{unsigned ip|162.158.74.159}}<br />
:There is also quantifier scope ambiguity there. I believe that there is a large constellation of teapot statites, and at any given moment at least one of them is directly between Earth and Mars. --[[Special:Contributions/172.68.54.58|172.68.54.58]] 06:29, 22 July 2017 (UTC)<br />
Since Russell was going for absurdity, I favour the more absurd interpretation namely Mjm87's. [[User:Capncanuck|Capncanuck]] ([[User talk:Capncanuck|talk]]) 08:21, 22 July 2017 (UTC)<br />
:Taking "on a line between the two planets" literally would simply reduce to "inside the orbit of Mars". The Earth moves faster than Mars and right now the Sun is exactly between them on that line. NASA, ESA, and ISRO can not communicate with their orbiters and rovers until the beginning of August (see {{w|Solar conjunction}}). So the meaning "between the orbits of Earth and Mars" is still much more plausible.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 16:11, 22 July 2017 (UTC)<br />
<br />
Don't worry we have been working on it. Launching the project in a few months.<br />
https://www.instagram.com/p/BSmdiMSFBSb/?taken-by=hate_plow<br />
https://www.instagram.com/p/BSwW4MIlE0b/?taken-by=hate_plow<br />
[[User:Zackdougherty|Zackdougherty]] ([[User talk:Zackdougherty|talk]]) 03:10, 22 July 2017 (UTC)</div>172.68.58.125