explain xkcd - User contributions [en]

2966: Exam Numbers

2024-07-31T18:47:45Z

141.101.105.132:

{{comic
| number = 2966
| date = July 31, 2024
| title = Exam Numbers
| image = exam_numbers_2x.png
| imagesize = 553x400px
| noexpand = true
| titletext = Calligraphy exam: Write down the number 37, spelled out, nicely.
}}

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

At a kindergarden-level education, it is assumed that an individual might write down a relatively small number{{cn}} like 300, or maybe even 5000. But when people get more education or simply absorb information from pop culture, they get more intuition on how big numbers get, so it is a very complicated problem for a postgraduate student to write a big number. Some example responses to the very last question may include TREE(3), Graham's number, 3^^^3, or Aleph-0.

However, it is another problem to write down the number in notation, because mathematical notation is inherently abstract. For example, what is stopping somebody from just writing down "the biggest number + 1"? Is it valid to write a Python program? Some<ref>https://www.youtube.com/watch?v=Mzgw6zMtipQ : Quest To Find The Largest Number
- CodeParade</ref> may argue that the only valid solution is to write down a [https://en.wikipedia.org/wiki/Lambda_calculus Lambda calculus] computation which results in a very big number.

===Pre-Algebra Final Exam===
x = 3x - 8 -> 3x - x = - 8 -> 2x = -8 -> x= - 4
===Calculus Final Exam===
Integrate[x Sin[x]^2, {x, 0, Pi}]

Answer: Pi^2/4 or approx 2.4674

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
6 Different math test questions. The first one says: Kindergarten math:Write down the biggest number you can think of
{{comic discussion}}

==References==
<references />

2950: Situation

2024-07-29T08:21:28Z

141.101.105.132:

{{comic
| number = 2950
| date = June 24, 2024
| title = Situation
| image = situation_2x.png
| imagesize = 578x306px
| noexpand = true
| titletext = We're right under the flight path for the scheduled orbital launch, but don't worry--it's too cold out for the rockets to operate safely, so I'm sure they'll postpone.
}}

==Explanation==
This comic depicts a situation involving multiple pieces of infrastructure: a ship, sailing towards icebergs, which is tethered to an airship flying next to a power plant towards a bridge. Each of these are labelled with details that clearly reference famous disasters, all of which were caused (at least in part) by design failures. All of these incidents are common case studies for engineers studying how things can go very wrong. The implication is that, by putting them all together, most engineers would be highly concerned with the potential for catastrophe.

;"Unsinkable Ocean Liner" refers to the RMS ''{{w|Titanic}}''.
:The ''Titanic'' was a British ocean liner which famously {{w|Sinking of the Titanic|sank}} on its maiden voyage in 1912. It was the largest ship in operation at the time, and was called "unsinkable" due to its size and much-lauded design features. The ship struck an iceberg on the fourth day of its first voyage, breaching the hull and ultimately causing it to sink, resulting in 1,496 deaths. Multiple design inadequacies (although none without precedent in contemporaneous vessels) were afterwards identified as contributing to the rapid speed of the ship sinking and to the high loss of life. These included too few lifeboats (despite being designed to accommodate enough for her full passenger capacity), the use of steel that became very brittle at low temperatures (although not known at the time) and compartments lacking watertight ceilings (therefore allowing water levels within to top over into previously unaffected sections). However, a significant part of blame should also be attributed to a series of reckless practices commonplace at the time, such as lax signaling discipline and a general disregard for the hazards of collisions (Titanic's captain having previously gone on record stating he believed an iceberg to be incapable of sinking a vessel up to modern day construction standards and consequently ran near full speed through known ice fields). Furthermore, a number of operational mistakes were made, such as slowing the ship in response to the imminent collision and therefore reducing its maneuverability, incorrectly reporting her position as being on the other side of the ice field, and not informing passengers that the ship was sinking when calling them out of their cabins, nor sounding a general alarm.

;"Hydrogen-filled Scout Airship for Iceberg Spotting" refers to the {{w|Hindenburg Disaster}}.
:The {{w|LZ 129 Hindenburg|''Hindenburg''}} was a German airship which used hydrogen as a lifting gas. In 1937, during a landing in New Jersey, the ship caught fire and the highly combustible hydrogen quickly ignited, causing the ship to crash and resulting in 36 deaths. While the origins of the fire are still debated, the apparent dangers of using large amounts of such gas in airships were made dramatically clear (although the accident also showed that at least some sorts of accidents are actually more survivable with an airship; if a heavier-than-air aircraft had caught fire and crashed to earth from a similar altitude as the ''Hindenburg'', there would've been few if any survivors, compared to around two-thirds of the airship's occupants).
:Ironically, the airship in the comic appears to have been commissioned for the purpose of mitigating iceberg risks (unless 'iceberg spotting' is for the purpose of steering the 'Unsinkable Ocean Liner' towards icebergs, perhaps as a tourist attraction).

;"Soviet Era Nuclear Reactor Undergoing a Turbine Test" refers to the {{w|Chernobyl Disaster}}.
:The {{w|Chernobyl Nuclear Power Plant}} is located near the city of Pripyat, in Ukraine (part of the Soviet Union at the time of the disaster). On 26 April 1986, a reactor core partially melted during a turbine test. This led to an explosion, causing a massive release of radiation. This incident remains the worst nuclear accident to date. The disaster was determined to have resulted from a combination of human error and uncommon circumstances for which the reactor wasn't designed.
:The number of fatalities from the disaster are difficult to calculate; two people died from the initial damage, twenty-eight more from acute radiation sickness, and fifteen people who were directly exposed developed terminal thyroid cancer. The radiation, however, spread far beyond the plant itself, and the number of premature deaths ultimately attributable to subsequent exposure can't be calculated directly, though most estimates are in the thousands or tens of thousands. Radiation contamination still affects wildlife in the accident exclusion zone.

;"Bridge Prone to Aeroelastic Flutter in High Winds" refers to the {{w|Tacoma Narrows Bridge (1940)|Tacoma Narrows Bridge}}.
:The Tacoma Narrows Bridge, a suspension bridge in the U.S. state of Washington, was initially built in 1940. From the time of its construction, the bridge was observed to sway and {{w|Aeroelasticity#Flutter|flutter}} in high winds, and was nicknamed "Galloping Gertie". About four months after opening, in 40 mile-per-hour (64 km/h) winds, the bridge fluttered so violently that it collapsed into the strait. There were no human fatalities, but one dog died and several other people were injured. This collapse is frequently used to demonstrate the dangers of harmonic vibration in infrastructure, particularly structures exposed to strong winds. The bridge was eventually rebuilt, with a redesign intended to prevent such fluttering.

;The title text refers to the {{w|Space Shuttle Challenger Disaster}}.
:The {{w|Space Shuttle Challenger|''Challenger''}} was an American space shuttle which broke up shortly after its launch in 1986, killing all seven crew members aboard before reaching orbit (but successfully avoiding harm to anyone underneath its flight path, as this area had fortunately been cleared of occupants for {{w|range safety}} reasons). The disaster was caused by a failure of O-ring seals on one of the shuttle's rocket boosters and the subsequent leak of hot gases. The likely cause of these failures was the seals being unable to maintain their integrity due to being well below their design temperature range in the immediate lead-up to being exposed to launch conditions, due to much colder than normal weather in the launch area. Engineers for the company that had built the boosters raised this concern and recommended postponing the launch, but were overruled.

As illustrated, it appears that the ship is about to sail under the bridge, while the airship will fly over it, causing the tether between the two to snag the bridge unless the airship descends sufficiently before then. It is not clear how or if the reactor will contribute to the resulting incident.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[An airship flying, labeled:]
:Hydrogen-filled scout airship for iceberg spotting
:[The airship is chained to a ship, going along a river, labeled:]
:Unsinkable ocean liner
:[In the background on the coast a nuclear power plant, labeled:]
:Soviet-era nuclear reactor undergoing a turbine test
:[The boat and airship are steering towards a bridge, labeled:]
:Bridge prone to aeroelastic flutter in high winds
:[Two unlabeled icebergs are on the water on either side of the bridge.]

:[Caption below the panel:]
:In retrospect, we should have noticed how nervous the situation was making the engineers.

{{comic discussion}}

[[Category:Engineering]]
[[Category:Aviation]]
[[Category:Space]]

2949: Network Configuration

2024-07-29T08:20:44Z

141.101.105.132:

{{comic
| number = 2949
| date = June 21, 2024
| title = Network Configuration
| image = network_configuration_2x.png
| imagesize = 740x272px
| noexpand = true
| titletext = If you repeatedly rerun the development of technological civilization, it turns out that for some reason the only constant is that there is always a networking utility called 'netcat', though it does a different thing in each one.
}}

==Explanation=
In this comic, [[Cueball]] takes an uncommon networking bug - needing to establish a fresh connection for each {{w|Network_packet|packet}} sent - to the extreme. Instead of merely redoing the appropriate handshakes for data transfer, he is reconstructing the entire {{w|Human_history|history of human civilization}} each time. As this originally took multiple millennia, doing it for every network packet would make communication ''extremely'' slow; in modern networking, we send and receive thousands of packets every second.

Randall may be using a double meaning of the word "rebuild." Instead of just rebuilding his network settings - starting fresh with a clean setup - he is rebuilding civilization itself from scratch, an extreme type of "first principles thinking."

In the last frame of the comic, Cueball looks shaggy and dirty and has a {{w|Hoe_(tool)|grub hoe}} behind him, making it clear he is performing these tasks ''in real life'' just to get his network working again. He says the network packet was stuck in the {{w|Neolithic}} era, the final period of the Stone Age that marked the transition from hunter-gatherer lifestyle to one of settlement. Apparently, Cueball had to go through the effort of inventing farming (one of the developments of the {{w|Neolithic Revolution}}) to keep communicating with [[Ponytail]]. He has also had to build himself a new wooden chair (and possibly desk), and hasn't yet got to the point of developing a notebook computer, so is using an under-desk tower PC connected to a chunky monitor. Presumably his previous equipment and furniture were lost in resetting to the Neolithic, though this seems to have been a localized effect, given that Ponytail appears unaffected.

"Inventing farming takes '''''forever'''''" references the actual rather complex process of inventing farming. First, we needed the last Ice Age to end - around 11,000 years ago - to create suitable climatic environments for agriculture. Then we required advancements in plant cultivation, animal domestication, and tool development - lots of time and experimentation involved there. And the transition from hunter-gatherer societies to sedentary farming communities also needed significant social and cultural adaptations (e.g., new organizational structures).

Randall Munroe is familiar with the popular creative nonfiction topic of what it takes to rebuild civilization, the subject of a book he blurbed on its cover, [https://www.howtoinventeverything.com/ How to Invent Everything], by Ryan North, fellow cartoonist.
* The topic of rebuilding a civilization from scratch was also referenced in comic [[1380: Manual for Civilization]] and in the title text of [[2347: Dependency]].

The title text discusses {{w|netcat}}, a simple utility to make a {{w|Transmission Control Protocol|TCP connection}} which comes in annoyingly incompatible [https://manpages.debian.org/stretch/netcat-traditional/nc.1.en.html nc.traditional] and [https://manpages.debian.org/stretch/netcat-openbsd/nc.1.en.html nc.openbsd] varieties.

In addition, the tendency for civilizations to independently develop netcat may be an allusion to The Hitchhiker’s Guide to the Galaxy, in which 85% of all planets invariably develop a cocktail whose name is, by pure coincidence, a phonetic homophone to “gin and tonic”, such as the Jynnan tonnyx, while varying wildly in composition. The word "netcat" is a composite of "net" (most likely standing for network each time, although could relate to some form of mesh/trap, a topology or an amount less any deductions), while "cat" may be an abbreviation (for example for catalogue, category, catalyst, catastrophe etc.), or even actually referring to a cat. The various possible combinations could encompass a wide variation in function of similarly named processes.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Ponytail is sitting on an office chair at her computer with a headset on. A zigzag line indicates what is shown on the computer screen]
:Ponytail (typing): Ugh, your connection is so laggy.
:Computer: Yeah, sorry.

:[Cueball is sitting on an office chair at his laptop]
:Cueball (typing): It's because I messed up my network configuration and now I have to rebuild a separate civilization from scratch for each packet.

:[Ponytail at her computer]
:Ponytail (typing): Huh?
:Ponytail (typing): What are you talking about?
:Ponytail (typing): ...Hello?

:[Beat panel, with Ponytail sitting in front of her computer waiting for a response from Cueball]

:[Cueball, with dirt on his head and around him, is at an old computer setup with a hoe leaning on his now non-office chair, blade on the floor]
:Cueball (typing): Sorry, got stuck in the Neolithic that time.
:Cueball (typing): Inventing farming takes '''''forever'''''.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Computers]]
[[Category:Cueball Computer Problems]]

2948: Electric vs Gas

2024-07-29T08:20:02Z

141.101.105.132:

{{comic
| number = 2948
| date = June 19, 2024
| title = Electric vs Gas
| image = electric_vs_gas_2x.png
| imagesize = 284x385px
| noexpand = true
| titletext = An idling gas engine may be annoyingly loud, but that's the price you pay for having WAY less torque available at a standstill.
}}

==Explanation==
{{w|Internal combustion engine|Internal combustion engines}} (ICEs) have long been the most common technology used to propel motor vehicles (usually in the specific form of reciprocating "piston" engines). In US vernacular, the most common vehicle fuel is known as "{{w|gasoline}}", or "gas" for short, leading to these engines being referred to as "gas engines". Gasoline is a product of petroleum refinement, leading to the name "petrol" being used in other dialects.

{{w|Traction motor|Electric motors}} would seem the more well-suited method for propelling a vehicle, and as early as 1885 were an actual form of motor car engine with which the fledgling internal combustion engine had to compete. Despite this early popularity, over most of the 20th century electric motors were sidelined in everyday car design, as supplying the electricity was considered to be impractical for most forms of transportation. Modern forms are rapidly rising in popularity, and [https://www.iea.org/reports/global-ev-outlook-2024/trends-in-electric-cars now constitute 18% of all global vehicle sales]. [[Randall]] is a strong proponent of {{w|electric vehicle}}s (EVs).

In this strip, [[White Hat]] claims to be comparing the pros and cons of electric motors and gas engines. The joke is that every point he makes goes in favor of electric motors. Despite it being posed as a dilemma, it may be very clear which side of the debate White Hat is promoting. On the other hand, it may indicate that one of the things we might consider a pro in electric motors (the instantaneous power now available, exceeding that of many non-electric engines) he would consider a problem — perhaps more accurately, a problem with the ''drivers'' of such vehicles — recklessly using the enhanced capabilities to accelerate to high speeds at all opportunities, whether safe to do so or not.

The strip offers the following points in favor of electric motors:

* "Cleaner and more efficient". ICEs produce and vent harmful combustion products and toxic chemicals, while electric motors produce no emission byproducts at the point of use. The efficiency of both gas and electric motors vary, but the typical ICE vehicle in the US converts around 25% of available energy into motion, while the typical electric vehicle is in the neighborhood of 80%. Even when considering inefficiencies in the source production and transmission and storage and release of energy, battery-driven electric vehicles are generally more efficient than internal combustion propelled vehicles[https://www.factcheck.org/2024/02/electric-vehicles-contribute-fewer-emissions-than-gasoline-powered-cars-over-their-lifetimes/].
** It should be noted that all of this refers to the motors only, and ignores how the fuel and electricity are produced, or the wider environmental impact of the vehicle.

* "More powerful". Electric motors are able to deliver a lot of power from a small motor ''if'' an ample energy supply is available, and can do so 'on demand', often far quicker than a fuel-powered engine that has to put its power through a gearbox in order to service a wide range of road velocities, from standstill to the eventual top speed. Due to battery limitations, short or partial runtime use cases (such as dragsters, hand tools, yard tools, toys and electric scooters) net the most benefit from the small size of a high-powered electric motor.

* "Annoyingly loud". ICEs, by their nature, produce significant noise. Despite noise attenuation measures such as mufflers, they contribute significantly to urban noise. Properly designed electric motors are nearly silent (even if the rest of the vehicle is not). In particular, {{w|blowoff valve|turbocharger blowoff valves}} make particular noises that are completely lacking in an all-electric vehicle being driven at a similar performance level. This might legitimately be considered a problem, though, when everyone is used to a rapidly approaching vehicle providing a very noisy warning of its approach. EV makers have sometimes added [https://www.businessinsider.com/electric-car-ev-fake-engine-sound-hyundai-dodge-toyota-2023-7 fake ICE noises] to appeal to older drivers, and in the U.S. and some other countries, EVs are required to have {{w|Electric vehicle warning sounds|warning sounds}} at low speeds for pedestrian safety.
** At highway speeds, the noise of tires against the road is much louder than a properly muffled ICE, so the intrinsic quietness of an EV's motor is irrelevant in that context.

* "WAY less {{w|torque}} available at standstill". ICEs need to continually operate within a specific range of rotational speeds for best power and fuel efficiency (although the reciprocating engines used in most motor vehicles are still better than some others, such as {{w|gas turbine}} engines, in this regard), which means that a complex system of {{w|transmission|transmission gearing}} is needed to convert this motion into the specific speeds needed at the wheels. When starting from a standstill, this means that torque must be applied to the wheels relatively gradually to avoid stalling the engine. In addition, when a vehicle is standing still, the motor is typically idling at (very) low speed and must be sped up before it produces significant acceleration. Electric motors, in contrast, generally produce their peak torque when at a standstill. This results in electric vehicles having significantly better acceleration and engine responsiveness. Again, this could cause a legitimate problem with drivers changing from ICE to electric motors, because the new cars accelerate more than the driver is used to and provide different feedback. The audible clues of gear changes, whether from automatic or manual systems, are part and parcel of what many people have grown up with and come to rely on in anticipating what might need paying attention to.

It should be noted that White Hat is deliberately confining his arguments to electric vs gas ''motors'' rather than electric or gas-powered ''vehicles''. Doing so ignores the basic reason why internal combustion vehicles have long dominated transportation in certain specific countries: hydrocarbon fuels are a very dense and fairly easy to handle form of energy ''storage''. Providing electrical power to a moving vehicle requires either that the vehicle remain in contact with a power line (as with an electric train or a tram) or else to carry a high-capacity battery (and the ability to recharge that battery in a reasonable amount of time, while stationary). More popular in the USA is a hybrid system, where a combustion engine provides at least some of the power to an electric motor, which was impractical until comparatively recently. Other methods, such as hydrogen fuel cells (a form of "combustion" that can be used more directly to form electricity), have been proposed, but remain experimental or niche, due to various barriers to adoption.

A more comprehensive comparison would include many more factors, both against and in favor of electric cars.

Issues raised with electric vehicles typically include:
* Higher cost of purchase (primarily due to the cost of batteries and, in the USA, now a 100% tariff on Chinese EVs), although partially offset by lower costs of operation
* Long charging times compared to refilling a gas tank (there are some approaches which mitigate this by operating either very high-powered chargers or a battery swap model, rather than charging in-car, but these are not widely adopted)
* Relatively limited range ([https://ev-database.org/compare/electric-vehicle-longest-range 200-500 miles per charge] as of 2024, though this limitation applies to most gas vehicles as well, where 300 mile range is typical)
* Shortened range in hot weather and significantly shortened range in cold weather (while all vehicles have this problem, it's more pronounced in EVs compared to ICEs)
* Limited charging infrastructure compared to the prevalence of fuel stations
* Higher vehicle weight, and resulting higher particulate emissions (from tires, but not brakes, because EVs use of regenerative braking reduces wear on their traditional brakes)
* Reliance on some mineral and metal extraction industries (e.g., lithium) with capacity that lags the recent increased demands for EVs
* Increased demand on electricity production
* [https://archive.is/6xmJV Lower reliability](data possibly skewed by the [https://community.cartalk.com/t/should-i-still-avoid-the-first-model-year-of-a-new-vehicle/118110 newness of EV models]).

Other real pros of electric cars are also not mentioned:
* Lower total cost of ownership (TCO)[https://www.edf.org/sites/default/files/2023-0/WSP%20Total%20Cost%20of%20Ownership%20Analysis%20July%202023.pdf]
* Can "fill" them at home or while parked without having to stay with them (partially negates the "long charging times" con)
* Lower carbon footprint, and reduced dependence on the fossil fuel industry

Rapidly evolving technologies, government policies, and economic realities are changing the relevance and seriousness of these points over time. As of the publication of this strip, the "pros" of EVs do not seem to be universally convincing, as ICEs remain far more popular than EVs in most countries (EVs constitute a majority of new vehicle sales in only four countries: Norway, Iceland, Sweden and Finland). That said, EVs didn't exist as a viable industry 20 years ago, so the current reality reflects rapid and ongoing growth, suggesting that the advantages of EVs are gaining increasing recognition and understanding.

The degree of adoption is also likely to impact the viability of different vehicle types. Infrastructure in most countries has long been built around an assumption of ICEs, so things like fueling stations and ICE-qualified mechanics have traditionally been widely accessible. As EVs becoming increasingly dominant, this could shift, with EV charging infrastructure becoming easier to find than ICE fueling stations, and ICE mechanics potentially becoming more difficult to find. There's typically a certain level of inertia in the adoption of any new technology.

In the EU, [https://www.europarl.europa.eu/topics/en/article/20221019STO44572/eu-ban-on-sale-of-new-petrol-and-diesel-cars-from-2035-explained the sale of new ICE cars is banned from 2035] in an effort to move to EVs, and other jurisdictions are adopting similar policies.

Especially in the United States, this topic is highly contentious for political, economic, engineering, and {{w|Rolling coal|tribal}} reasons (as a quick look at the edit history of this page will confirm).

==Trivia==
The etymology of "gasoline" (commonly abbreviated to "gas") is disputed: it may refer to the gaseous {{w|state of matter}} as, though gasoline itself is generally liquid, it readily emits volatile vapours. Otherwise, it has been suggested to have derived from "Cazelin"/"Cazelline", originally a lamp-oil, sold by a man called {{w|John Cassell}} in the 19th century and much copied (including by the "Gazeline" brand) as the market and supply of such fuels expanded. In non-American english, the octane form of motor-fuel (i.e. non-diesel and excluding aviation fuel) is called "petrol" (derived from "petroleum", or 'oil of the rock'), with similar "electric vs petrol (vs {{w|Hybrid electric vehicle|hybrid}})" comparisons. The registered brand name "Petrol" (sold as a solvent, before being repurposed for use as vehicle fuel) could not be trademarked as it was already the common generic term for equivalent products. The unrefined crude mineral oil from which many different hydrocarbon products can be refined is still more widely known as petroleum. Vehicle fuel may now be partly or wholly composed of non-fossil-fuels to distance them from some of the traditional arguments against petrol/gas consumption, leave other considerations unchanged but possibly introduce {{w|Biofuel#Issues|further issues}}.

While ICE vehicles have, to date, proven more popular than electric equivalents, worldwide, bicycles have been outselling cars [https://www.bikeradar.com/features/bike-vs-car-the-sales-race since at least WWII].

==Transcript==
:[White Hat, with his palm raised, is talking to Cueball.]
:White Hat: Electric motors and gas engines each have their pros and cons.
:White Hat: On one hand, electric motors are cleaner and more efficient. On the other hand, electric motors are more powerful.
:White Hat: So it's hard to say which is better overall.

{{comic discussion}}

[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Engineering]]
[[Category:Climate change]]

2947: Pascal's Wager Triangle

2024-07-29T08:18:59Z

141.101.105.132:

{{comic
| number = 2947
| date = June 17, 2024
| title = Pascal's Wager Triangle
| image = pascals_wager_triangle_2x.png
| imagesize = 740x802px
| noexpand = true
| titletext = In contrast to Pascal's Wager Triangle, Pascal's Triangle Wager argues that maybe God wants you to draw a triangle of numbers where each one is the sum of the two numbers above it, so you probably should, just in case.
}}

==Explanation==
The comic is a conflation of {{w|Pascal's Wager}} and {{w|Pascal's Triangle}}. It's structured as a layout that emulates Pascal's triangle, an infinite triangle of numbers where the top number is 1 and each value below is the sum of the adjacent number(s) above it. The second row has two 1s (each the sum of the single 1 above), and the third row has a 1 (the sum of a single 1 in the second row), a 2 (the sum of both 1s above it), and another 1, and so on. It plays important roles in binomial expansion, probability theory, and other areas of math. While {{w|Blaise Pascal}} did not invent the triangle, it is named after him (an example of {{w|Stigler's law of eponymy}}).

<center>
{|style="text-align: center; vertical-align: bottom; border: none;"
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|colspan=5|
|colspan=2 style="width: 60px; height: 40px;"|…
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|colspan=2 style="width: 60px; height: 40x;"|⋮
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|}
</center>

Pascal's Wager is a philosophical argument proposed by the same Pascal. Essentially it says that if God exists, both the rewards for believing in God and the punishment for nonbelief are infinite; if not, the cost of belief and benefit for nonbelief are negligible. Therefore, if there is a finite possibility that God exists, however small, one should believe in God. One problem with that is that there may be more than one God to believe in, even if only one truly exists. Which one of all the possible Gods should you choose to believe in could be problematic, if the real God insists that you only believe in Him and punishes you for believing in any other gods (even if you somehow also believed in Him). A further problem is that committing to any particular belief in a deity is not a totally zero cost option, and thus affects your life in many needless ways if you subscribe to any particular practice of religion not actually required by any extant god(s), even if any of them exist in the first place.

The comic merges the two Pascalian concepts: each Cueball is wagering his proof of a god or gods to the Cueballs below him, thereby creating Cueballs that believe in the sum of the number of gods of the Cueballs above them. In the second row, the two Cueballs each believe in one god, as intended by the original Cueball. However, in the third row, the Cueball in the middle interprets the two proofs offered to him as proving the existence of two gods. Theoretically, this expansion would continue for all integers as the triangle grows, giving rise to a belief in escalating numbers of gods going down and towards the middle of the triangle. This is clearly not the intent of the first Cueball, who simply offered a proof of his one god, but he has no control over the situation below him.

It is unclear why the Cueballs behave in this fashion, instead of treating all the proofs as proving the existence of the same god. Perhaps each one rewords their arguments for god(s) sufficiently to make them sound different than other gods. This is not without precedent. Scholars of comparative mythology believe that the religion of Proto-Indo-European peoples splintered into many disparate religions of Europe and West Asia; for instance, {{w|%2ADy%C4%93us#%22Sky-Father%22_epithet|Dyeus phter}} (sky father) became Zeus in Greece and Jupiter in Italy.

This comic may be referencing a common counterargument to Pascal's Wager — that it works equally well for ''any'' hypothetical god which offers eternal paradise for one action and eternal damnation otherwise. This can even include hypothetical gods with contradictory criteria for entrance into paradise. In this case, the Cueballs apparently chose to believe in all the deities they've heard of in order to cover their bases.

The title text suggests that everyone should draw a proper Pascal's Triangle, since there is a possibility that God wants you to do so, and if they do then the benefits of pleasing God or the costs of displeasing God could be high, whereas if they have no such desire then there is minimal cost to drawing one anyway. The failing of this logic is that God may have a positive preference for you ''not'' to draw a Pascal's Triangle (though at least according to the Catholic Church this is unlikely, as Pascal himself is on the way to {{w|beatification}}.)

Pascal's Wager was previously mentioned in the title text of [[525: I Know You're Listening]].

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueballs, each holding some document, are shown in a triangular arrangement, with arrows pointing from upper to lower Cueballs:]
:[At the top, row 1 has a Cueball, unnamed but described below as "C1", holding a piece of paper with a crossed-square shape possibly resembling a Punnet Square diagram and with a speech-bubble]
:C1: Hey, you two below me! Here's a proof that you should believe in my god!
:[Two arrows lead diagonally down-left and down-right from C1 to the second row, having two similarly drawn Cueballs (differing only by slight changes in pose) described here as "C2" and "C3"]
:C2 & C3: I'm convinced! Hey, you two below me! Here's a proof that you should believe in my god!
:[Two arrows lead down from each of Row 2's Cueballs to three similar Cueballs on Row 3, "C4", "C5" and "C6", the central Cueball being the target of arrows from both of the predecessors, and the speech-bubbles partly obscuring the predecessor Cueballs and the lines of the arrows]
:C4 & C6: I'm convinced! Hey, you two below me! Here's a proof that you should believe in my god!
:C5: Ok, I believe you both! Hey, you two below me! Here's a proof that you should believe in my '''two''' gods!
:[Two further arrows lead down from each Row 3 Cueball to a total of four Row 4 Cueballs, all but the edge ones having two incoming arrows, "C7" to "C10"]
:C7: I'm convinced! Hey, you two below me! Here's a proof that you should believe in my god!
:C8 & C9: Ok, I believe you both! Hey, you two below me! Here's a proof that you should believe in my '''three''' gods!
:[C10 has no visible bubble, as there is no room for one in-frame, and is itself also slightly obscured by C9's bubble, but would logically be considered to have a "believe in my (singular) god" monologue]
:[Continuing the pattern, Row 5 has "C11" to "C15" Cueballs (with only a small amount of leg visible above the lower edge of the comic frame), each is led to by diagonal arrow(s) originating from the Row4 Cueballs]
:[C11 and C15 have no visible speech bubbles, due to being even more edge-adjacent and C15 even reaching off the edge of the frame with his 'punnet paper', but can be assumed to have a "believe in my god" statement]
:C12 & C14: Ok, I believe you both! Hey, you two below me! Here's a proof that you should believe in my '''four''' gods!
:C13: Ok, I believe you both! Hey, you two below me! Here's a proof that you should believe in my '''six''' gods!
:[No further arrows or Cueballs can be visible, and no further speech-bubbles obscure Row 5, but without any reason to believe they aren't just off frame]

:[Caption below the panel:]
:Pascal's Wager Triangle

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Multiple Cueballs]]
[[Category:Math]]
[[Category:Religion]]

2946: 1.2 Kilofives

2024-07-29T08:18:15Z

141.101.105.132:

{{comic
| number = 2946
| date = June 14, 2024
| title = 1.2 Kilofives
| image = 1 2 kilofives 2x.png
| imagesize = 256x342px
| noexpand = true
| titletext = 'Oh yeah? Give me 50 milliscore reasons why I should stop.'
}}

==Explanation==
Abraham Lincoln's {{w|Gettysburg Address}} features the phrase "four {{wiktionary|score#Noun|score}} and seven"‍ to refer to 87: a "score" is a group of 20, which literally translates as "four-twenties [and] seven". This is because English used to count by twenties (and some modern languages, including French still do, at least partially). However, this practice has died off and most English speakers nowadays would not use "score" in such a manner. Inspired by this, [[Cueball]] (possibly representing [[Randall]]) decides to use unusual prefixes to state the population of a town.

{{w|Metric prefix}}es can be added to a unit to scale up or down its magnitude. For example, "{{w|kilo-}}" means "multiply by 1000", so a {{w|kilometer}} is as long as 1,000 {{w|meter}}s. These prefixes are added to {{w|List of metric units|various metric units}} but, due to their usefulness, have been adopted and added to other, non-metric units, such as "kilocubic feet per second" (for the flow rate of a liquid, much to Randall's chagrin when researching for his book "XKCD What-If"), "megadeath" (how many millions killed in an estimated nuclear blast), or the "{{w|Helen (unit)|millihelen}}" (the amount of feminine beauty needed to launch a ship). Most potentially confusing might be "kilo-/mega-/giga-/terabyte", which has [[394|competing definitions]]. However, they're not ordinarily added before number words to change their magnitude.

Taking "kilofive" to be a unit meaning 5,000, the population of East Hills, 6,000, can therefore be expressed as 1.2 kilofives. But phrasing a number this way requires the listener to make excess calculations to understand it, so [[White Hat]] would probably get confused or annoyed.

It is somewhat common for metric prefixes to go ''after'' numbers in abbreviations. Well-known examples are "{{w|Y2K}}" for "year 2000", and "{{w|4K resolution}}" for "4,000 [pixels]". The number 5,000 may be abbreviated as "{{w|5K}}" in "{{w|5K resolution}}". However, the 'postfix' (suffix) may be intended to modify the implied but unstated unit, where there is an obvious one, or stand for the unit itself in such cases as the word "kilometer" (often abbreviated to /ˈkeɪ/(s), in common use, in phrases such as "{{w|5K run}}") or "{{wiktionary|kilopixel|kilo''pixel''}}" (in this case referencing the horizontal resolution, as in 5120 × 2880 pixels, rather than prior usages such as the 1080 ''horizontal lines'' in the standard known as {{w|1080p}}, or the total ''area'' pixel count in 'megapixel'/'gigapixel' image sensors), thus making it directly stand for a prefixed unit itself, as an adjunct to the standard common shortening of "kilos" for, usually, "kilograms". Saying "1.2 5K" could be even more awkward, liable to be misunderstood as "1.25k" (1,250) instead of the value of 6000.

In the title text, Cueball has apparently annoyed White Hat with his confusing expressions of numbers, but he doubles down, now directly including the word "score". He is riffing on the common expression, "give me one reason why..." but instead of simply asking for one reason, he asks for 50 milliscore reasons, or 50 × 1&frasl;1000 × 20, which is equal to 1.

The comic might refer to the village of {{w|East Hills, New York}}. As of the 2020 census, it had a population of 7,284, or 1.214 kilosixes.

==Trivia==
In Roman numerals, {{w|Roman_numerals#Large_numbers|symbols can be added to numerals}} to denote orders of magnitude. In this system, 1,000 might be written as "CIↃ". This rough pattern of marks, as typically chisled or impressed into wax by a stylus, would later be refined and expressed in the not dissimilar shape of the "M" as most often seen these days to represent the thousands value in dates/etc. Alternately "I" (nominally '1') could be given a bar above it, as would any other such numerals involve in that expression, to indicate the value being denoted being of the higher order.

For a while, {{w|Long hundred| a hundred actually referred to 120}}.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball, with his palm raised, is talking to White Hat. There is a sign on the ground in the background.]
:Cueball: It's a pretty small town—the population is just 1.2 kilofives.
:[The sign reads:]
:Welcome to
:East Hills
:Pop. 6,000

:[Caption below the panel:]
:I don't know why Abraham Lincoln should be the only one who gets to come up with weird ways to say normal numbers.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring real people]]
[[Category:Math]]
[[Category:Language]]

2938: Local Group

2024-07-29T08:14:41Z

141.101.105.132:

{{comic
| number = 2938
| date = May 27, 2024
| title = Local Group
| image = local_group_2x.png
| imagesize = 547x266px
| noexpand = true
| titletext = Cosmologists estimate the spaghetti strand to be about 200 septillion calories, though it could be higher depending on the nutritional value of dark matter.
}}

==Explanation==
In {{w|Timeline_of_the_far_future|less than 5 billion years}} into the future, the {{w|Andromeda Galaxy}} is expected to {{w|Andromeda–Milky Way collision|collide}} with the {{w|Milky Way}}. This comic suggests this will happen when both galaxies get into a kissing distance after having slurped the same cosmic spaghetti strand. This is a spoof of a famous scene in the movie ''{{w|Lady and the Tramp}}'', where the titular dogs are eating spaghetti at an Italian restaurant. They happen to be eating the same strand from opposite ends, so they end up meeting in the middle and kissing. This scene was mentioned before in [[2612: Lightsabers]], and {{tvtropes|SpaghettiKiss|has been referenced extensively in other media}}.

It's possible that this is also a reference to {{w|Flying_Spaghetti_Monster|Pastafarianism}}, the spoof religion which claims that the universe was created by a "flying spaghetti monster". If both galaxies are eating one of the deity's "noodly appendages," they may be doing what the monster wishes, since one of the religion's holidays is about eating lots of pasta.

The title text figure of 200 septillion (2×1026) calories for the Milky Way-Andromeda noodle equates to approximately 2500 calories per foot of noodle. This value makes sense only if Randall is referring to the physics/chemistry {{w|Calorie|"small" calorie}} (= 4.184 joules) rather than the dietary {{w|Calorie|"large" Calorie}} (= 4184 joules). Dietary Calories, also called kilocalories (kcal), would be the usual meaning in a food-related context like this one, but Randall was trained as a physicist and apparently used the small calorie here. Having 2.5 dietary Calories per foot is roughly correct for a noodle size between thin spaghetti and angel hair. A noodle with similar ingredients and 2,500 dietary calories per foot would be roughly 26 centimeters in diameter, and might more properly be considered a type of pastry.

The nutritional value of dark matter refers to the fact that evidence of 'dark matter' is particularly found in [https://www.nature.com/articles/nature11224 cosmic filaments] and the [https://www.space.com/dark-matter-detected-cosmic-web-filaments-universe-evolution-subaru-telescope cosmic web], implying that such "cosmic spaghetti" would have an appreciable amount of dark matter "sauce" on it. But, because the exact nature of dark matter is unknown, it is likely even more difficult to identify the calorific content that it might provide. Note that these {{w|galactic filament|filaments}} are much larger structures than the {{w|Local Group}} of galaxies that includes the Milky Way and Andromeda.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Two galaxies, positioned on the left and right sides of the panel, are each eating a single noodle of spaghetti, originating from a bowl of spaghetti in between them.]
:[Left galaxy:] ''Sluuurp''
:[Right galaxy:] ''Sluuurp''

:[Caption below the panel:]
:Astronomers have determined that the Milky Way and Andromeda are currently slurping up the same strand of cosmic spaghetti, suggesting that in 5 billion years they will likely kiss.

{{comic discussion}}

[[Category:Astronomy]]
[[Category:Food]]
[[Category:Cosmology]]

2916: Machine

2024-07-29T08:12:45Z

141.101.105.132:

{{comic
| number = 2916
| date = April 5, 2024
| title = Machine
| image = machine_2x.png
| imagesize = 740x740px
| noexpand = true
| titletext = The Credible Machine
}}
* To experience the interactivity, visit the [https://xkcd.com/2916/ original comic].

==Explanation==
This interactive game is the 14th [[:Category:April fools' comics|April fools' comic]] released by [[Randall]]. The previous April fools' comic was [[2765: Escape Speed]] from 2023, which was released on Wednesday, April 19, 2023. "Machine" has been updated multiple times in the weeks following its release, adding the following features:
* the trophy and shot glass props
* the cat, which swats balls in front of it
* the inanimate kitten and bun decorations
* a system of links, which encodes the XY coordinates of the currently viewed cell, and the time (i.e. the entire machine's state after a certain moderation action)
* a button to follow a nearby ball as it traverses through the machine, also preventing it from despawning

As referenced in the title text, this game is a spiritual successor to the 1990s and early 2000s PC puzzle game series {{w|The Incredible Machine}}, a game Randall played as a kid. Both games have several objects in common:
* fan
* cat
* ramps
* balls of varying densities

The comic starts in a main screen where the user can create a {{w|Rube Goldberg machine}} in a "Cell" where the goal is to route a constant stream of colored balls from inputs on the ceiling or walls to outputs of matching colors on the walls or floor. After the comic is first opened a window pops up over the machine where Cueball in a lab coat tells you to route the balls from the inputs to the outputs. A button opens a “tool panel” where there are large and small boards available for use, as well as some gimmicky stuff like prisms (which deflect marbles) and fans (which blow marbles around), plus decorative elements which have no effect on the balls.

Typically, inputs and outputs only accept balls of a single color. However, some outputs accept multiple colors, indicated by a double arrow, and some inputs produce multiple colors. When the player is designing their 'machine', this will involve multiple full streams merged into one (supplied by a double-exit on the adjacent submission). Machines now working in the full grid may, however, find that their sources now contain stray balls of other types that were not handled properly, but there is no way to force a re-edit of the machine to alter its behavior to account for this.

If any balls are left in your cell for more than 30 seconds, they fade away. The first time a ball fades away another popup informs you that the balls are removed for security reasons. An indicator next to each exit increases for each ball of the correct color that passes through an exit, and reduces when no balls pass through, or if balls of the wrong color pass through it. While that exit is not properly supplied it displays a red cross, which changes to a green tick when a sufficient, and sufficiently clean, stream of balls is supplied. The first time you have built a machine which succeeds in routing enough balls of the correct color to ''all'' relevant outputs, a popup will prompt you to submit your cell to be added to the public machine. (Subsequently, the submit button will quietly change from 'inactive' (pale) to clickable (dark). This will change back again if any ball transfers dip back below the required threshold for any reason, such as further editing or an end to a 'fluke' glut of accumulated balls.)

Choosing to submit your cell will give you a textbox to give this cell a name. Proceeding through that, you will now see your cell within the 'grid' and a 'live' feed of balls from any relevant neighboring cells (which may be more sporadic then the feed you designed your cell with, and contain stray balls of different types). If any supplying-neighbors are still marked as "under construction", they ''may'' provide the balls as if perfectly routed from their own (eventual) source, but will eventually dry up. If your newly submitted creation is placed in the lowest row of cells, balls will be dispensed through the exit at the bottom, but there will be no launcher to propel them towards the pit, and they will vanish as they leave the exit.

Upon reopening the link to this comic without coordinate and time parameters, your recently created machine will most likely not be visible in the space you built it in. [https://www.reddit.com/user/xzaphenia/comments/ Reddit user xzaphenia] has claimed on r/xkcd that this is because there is a moderation team (of which they are a member) and that [https://www.reddit.com/r/xkcd/comments/1c1ixmb/comment/kzc3rmg/ the main page only shows public, approved machines]. This team of people, including those credited as co-creators of this comic, select machines according to their preferences (and little to no formal criteria besides [https://www.reddit.com/r/xkcd/comments/1c0sp60/comment/kz6hbgl/ coolness, innovativeness, effectiveness], and [https://www.reddit.com/r/xkcd/comments/1c0bsk2/comment/kyvfean/ privacy concerns]). Given the number of 'bottom-layer' cells that are likely primed ready to be completed (e.g. the grid-width of twelve, perhaps staggered across adjacent rows) and the many possible worldwide contributors at any one time, it may be that the chances of being picked for permanence is low; and certainly would have been lower early on in the comic's existence during the initial frantic rush to participate. [https://www.reddit.com/r/xkcd/comments/1c0sp60/comment/kz6hbgl/ It is also claimed that at some point, moderation will be cut off and the machine will be considered "complete"].

<gallery heights="200" widths="150">
File:2916_popup_intro.png|Introduction popup
File:2916_popup_time.png|Time limit popup
File:2916_popup_submit.png|Submission popup
</gallery>

The button in the bottom right corner allows you to toggle between editing your own machine and a page where you can drag around to view all of the machines that have been submitted and accepted, with a title for each in the upper left corner. In this view you can see that all of the outputs are also inputs for another cell, except for the top row where the inputs come from off screen and the lowest row which output through a launcher of some kind to a set of four colored-coded containers far below. Any empty cells are marked off by yellow tape with the words "UNDER CONSTRUCTION" as well as "DJIA ↑ 31415" once in each cell. "DJIA" stands for the Dow Jones Industrial Average, with "DJIA ↑ 31415" indicating that it rose to 31415 points, 31415 being the first five digits of pi, without the period. This would often be displayed on a yellow 'ticker', which might look superficially similar to the yellow barrier tape.

When viewing the whole machine, a button in the bottom left corner, added later, allows you to follow the path of the nearest ball as it passes from cell to cell. This will also make the ball you are following immortal - not subject to the 30s timeout rule. However, it will stop following at the bottom of the base machine -- it will not follow into the bottom holding containers, nor keep it immortal once down there. Another later addition was a button in the top left corner which copies a URL that will take you directly to the current cell that you are viewing. However, the link that is created will always show you the version of the machine at the time that you were viewing it, without any subsequent additions.

Whenever balls reach the bottom of the grid, they are directed towards four containers, one of each color. Most balls are accurately sent to their appropriate container, though there are some misfires. These containers are above a pit, and dump their contents every 11.5 seconds. Balls in the pit are subject to a 97 (approx) second culling rule (including time spent in the holding containers), unlike the balls in the cells above. If no balls are directed towards the containers, the pit will be empty. If at least one stream of balls is making it, Cueball and Megan sit in a small boat named the USS Buoyancy, and when sufficient balls are being deposited, the boat begins to float and move. Balls that miss or overspill the pit fall out of the bottom of the frame.

Under construction cells will feed balls of the appropriate color into neighboring cells so long as you are not looking at them. Once you scroll to look at them, the supply of balls stops and subsequent cells in the chain will not receive any; scroll away from them again and the supply will resume.

The grid is 12 cells wide, and grows in height. The largest size observed so far is 12x128, for a total of 1536 cells. The machine's height is determined by the lowest cell; this can be either your submitted cell, or a cell created by another user.

Imperfections in the machines (whether accidental or by design) and the impossibility of entirely avoiding collisions when crossing streams inevitably lead to significant levels of losses and pollution with the wrong color balls. Indeed, using the follow ball function appears to demonstrate that it is quite rare for a ball to survive more than several machines without getting stuck somewhere. This should mean that effectively no balls would reach the lower layers. This implies that there is some 'creative accounting' going on to ensure that cells lower in the grid still have balls to process - simulating flow only for a few nearby cells, while assuming that those cells themselves have pure, steady inputs.

There is a hard limit of 100 items (both physically interactive and purely decorative) that can be placed in any given arena. If you have placed 75 items, a count will appear in the component bar of your piece-count ("''##''/100"), which will go away again if you delete items to bring it below this count. The count text turns red at "100/100", at which point no more items can be added, only existing ones moved (or removed, to lower the count again).

===Toolbox items===
{| class="wikitable" style="margin:auto"
|+ List of objects
|-
! Description !! Effect !! Image
|-
| Plank || Static obstacle || [[File:2916_plank.png|frameless|upright=0.25]]
|-
| Hammer || Static obstacle || [[File:2916_hammer.png|frameless|upright=0.25]]
|-
| Sword || Static obstacle || [[File:2916_sword.png|frameless|upright=0.25]]
|-
| Hinged scoop&dagger; || Rotates around its hinge, tries to stay horizontal with a springy effect || [[File:2916_scoop.png|frameless|upright=0.25]] [[File:2916_scoop_mirrored.png|frameless|upright=0.25]]
|-
| Anvil || Static obstacle || [[File:2916_anvil.png|frameless|upright=0.125]]
|-
| Brick || Static obstacle || [[File:2916_brick.png|frameless|upright=0.125]]
|-
| Fan || Blows away balls in front of it. Different colors are affected by differing amounts (yellow balls are lightest, and can be levitated above an upward-facing fan).|| [[File:2916_fan.png|frameless|upright=0.125]]
|-
| Pillow || Balls will not bounce if they hit it || [[File:2916_pillow.png|frameless|upright=0.125]]
|-
| Bumper || Bounces balls away at significantly higher speed || [[File:2916_round_bumper.png|frameless|upright=0.125]] [[File:2916_bumper_left.png|frameless|upright=0.125]] [[File:2916_bumper_right.png|frameless|upright=0.125]]
|-
| Attractor/Black Hole* || Pulls balls toward center || [[File:2916_attractor.png|frameless|upright=0.125]]
|-
| Repulsor/White hole* || Repels balls away from center || [[File:2916_repulsor.png|frameless|upright=0.125]]
|-
| Prism || "Refracts" and internally-reflects balls as they otherwise pass through the object, the color of the ball ''may'' cause them to react (as much as possible) according to the respective color across the element. || [[File:2916_prism.png|frameless|upright=0.125]]
|-
| Wheel&Dagger; || Spins, deflects balls, can jam with enough resistance (e.g. glut of balls or against other elements). || [[File:2916_wheel.png|frameless|upright=0.125]]
|-
| "Good job" trophy || Static obstacle || [[File:2916_trophy.png|frameless|upright=0.125]]
|-
| Glass cup || Static obstacle. Container, with a nominal capacity of up to four balls (in whole or in part) within it. || [[File:2916_cup.png|frameless|upright=0.125]]
|-
| Cat || Swats away balls in front of itself (was added later) || [[File:2916_cat_new.png|frameless|upright=0.25]]
|-
! colspan="3" style="text-align:center" | Non-physical items
|-
| Right-facing Ponytail, with raised arms || Intangible decoration || [[File:2916_ponytail_arms.png|frameless|upright=0.125]]
|-
| Right-facing Ponytail, standing || Intangible decoration || [[File:2916_ponytail.png|frameless|upright=0.125]]
|-
| Left-facing Cueball, with raised arms || Intangible decoration || [[File:2916_cueball_arms.png|frameless|upright=0.125]]
|-
| Left-facing White Hat, standing || Intangible decoration || [[File:2916_whitehat.png|frameless|upright=0.125]]
|-
| Rightwards-facing Knit Cap, in an 'action' pose || Intangible decoration || [[File:2916_knitcap_resting.png|frameless|upright=0.25]]
|-
| Right-facing Knit Cap, standing || Intangible decoration || [[File:2916_knitcap.png|frameless|upright=0.125]]
|-
| Helmet-wearing figure, standing || Intangible decoration || [[File:2916_helmet.png|frameless|upright=0.125]]
|-
| Squirrel || Intangible decoration || [[File:2916_squirrel.png|frameless|upright=0.125]]
|-
| "Probably Deterministic" sign || Intangible decoration || [[File:2916_deterministic.png|frameless|upright=0.25]]
|-
| [[1682: Bun|Bun]] || Intangible decoration || [[File:2916_rabbit.png|frameless|upright=0.125]]
|-
| Cat || Intangible decoration || [[File:2916_cat.png|frameless|upright=0.125]]
|}

:<nowiki/>* — The Attractor and Repulsor are omnidirectional, but the area of effect can be resized to extend or restrict its influence. You do this by way of its bounding box with corner and mid-edged 'drag nodes' and a circular area that shows the current extent, which are only visible when the element is actively selected. This resize can be no larger than will make the box/circle touch the edges, no smaller than the fixed graphic and will always be identically proportioned in both axes.

:&dagger; — The hinged scoops are strictly horizontal, on building. They will rotate away from and (spring back to) horizontal according to interactions with balls or other non-decorative items that may be placed to disturb their balance, sometimes with further interesting interactions (that may or may not be intentional or useful). There are two selectable versions of this item. (The only ''other'' object class with a clear (and practical) asymmetry, for which a mirrored chirality can be chosen from the sidebar, are the two versions of triangular "Bonk"-bumpers.)

:&Dagger; — The wheel is an actively rotating element that starts off, by default, spinning anticlockwise. Pressing or tapping left/right arrow keys, when a placed wheel is selected, will adjust that wheel's rotation rate to be more/less anticlockwise. Adjusting it beyond zero rotation allows you to make it spin in the opposite direction.
:Rotation can be increased well beyond the point at which the {{w|wagon-wheel effect}} occurs, which may make it difficult to work out the spin direction of an overspeed wheel element (and thus which arrow keys will slow or speed up its rotation, if you have forgotten), though observing its impact upon any balls that strike it ''should'' make its current spin-direction obvious.
:The 'bounding editing box' will usually appear rotated, possibly according to the spinning graphic's current orientation upon selection, but remains at that (often non-orthagonal) angle even as the wheel spins (if it can) during this period of selection for editing.

All other items can be manually re-angled by a 'loop node' arm extending from the bounding box. If you cannot see the 'angle node' for such a selected item, which is normally at the top of any freshly placed item but follows any re-angling that may have already applied, it could be that you have placed the item too close to the edge in which direction the node extends. To rotate it, move the object away from the edge to access the construction node (after which, you can drag the object back if required – but see below).

Rotation may be limited by the {{w|minimum bounding box}} that is the 'selection box', this is not necessarily the more flush {{w|convex hull}} of the collision-map built into the graphic. Should a corner of the bounding box need to move across the edge of the build-area, it will do nothing more than touch the edge until there is sufficient angle-drag to snap it to the angle from which that corner now comes back away from the edge; or, when it has a long straight edge currently flush with the edge boundary, it may snap to exactly 180°, in rotation, whereupon the opposite long straight edge is flush to the construction area edge. All objects that are drag-moved, similarly, cannot be moved any further than their current bounding box touching the construction-area edging. The bounding box for the rotating wheel is a notable exception to this, being not under any direct angle-control by the player. Instead, it seems to use the bounding inscribed circle that defines the wheel edge iteslf.

Apart from some interactions between the hinged scoops and any element (including other hinged scoops), there is no preventative 'collision detection' between objects during user-placement, which may overlap/cover each other (the most recently spawned item graphically overlays any earlier one). The wheel object will only spin if not constrained by other physical elements (including the spokes of an adjacent wheel, not in counter-rotation) but can still be dragged and placed anywhere within the boundary of the construction area.

The continuous stream(s) of balls respect all ''tangible'' objects, which includes any currently being dragged/rotated, though may prematurely vanish if forced between two items moved to touch/overlap each other. It is possible to indirectly nudge balls by carefully moving a tangible object's surface into them (or holding them within it, e.g. the "cup"). This may be useful for rescuing temporarily stray balls (before they time-out anyway), unjamming an area with a construction-induced glut ''or'' for testing a ball-path that is not currently being fed 'naturally'. Doing so ''can'' then conceivably fulfil all the exit-gate requirements (temporarily), as it might also transiently spoil some required routing, but the manual intervention will not be possible once a 'machine' has been submit.

===Non-player items===

Ball containers at the bottom of the machine
{|
|[[File:2916_container_red.png|thumb|center|50px]]
|[[File:2916_container_yellow.png|thumb|center|50px]]
|[[File:2916_container_blue.png|thumb|center|50px]]
|[[File:2916_container_green.png|thumb|center|50px]]
|}

Cueball and Megan in the ''USS Buoyancy''
[[File:4d425c.png|thumb|left|150px]]
 

Pit below the ''USS Buoyancy'' (not to scale)
[[File:2916_pit_bottom.png|thumb|left|300px]]
 

=== Color routing ===
The different ball colors have different physical properties. Red balls are more bouncy than other balls, green balls are heavier, and yellow balls are lighter and slightly bouncy. The following values were extracted from the code:
{| class="wikitable sortable"
! Color
! Mass
! Density
! Restitution (bounciness)
! Linear damping (drag)
|-
! data-sort-key="00F" | Blue
| 0.08
| 1
| 0
| 0
|-
! data-sort-key="F00" | Red
| 0.08
| 1
| 0.8
| 0
|-
! data-sort-key="0F0" | Green
| 0.75
| 9.325
| 0
| 0
|-
! data-sort-key="FF0" | Yellow
| 0.024
| 0.3
| 0.6
| 2
|}

Balls also have spin, but it is subtle and hard to see because the balls have no visible texture.It can be seen, with effort, using green balls (which are heaviest). Rolling down a slope (say, two boards), green balls accumulate spin in the direction they are rolling. Let them drop off the end and then bounce off a brick such that they travel upward, but with very little sideways motion. Then "catch" the balls with a brick just past their apex, when they are moving slowly. If the ball lands on a horizontal brick, it can be seen that the ball will suddenly accelerate left or right based on the spin.

For certain combinations of inlet and outlet 'gates', it is necessary to 'cross the streams'. e.g. to direct righthand-entry balls to a lefthand-exit and vice-versa. It is possible to just construct the field to send two (or more!) sets of balls to fly across a common gap, to land on an appropriate reception area that leads to the chosen exit. But, though this is not {{w|Proton pack#Crossing the streams|completely inadvised}}, the timing of the balls cannot be guaranteed to be in sync (or, rather, anti-sync) with each other and collisions ''will'' occur, especially under the variations of delivery that might significantly alter the ballistic path across the gap. Even if the trial machine works, in isolation with a steady stream of all balls entering the field of play, once submitted it will inevitably be fed by a more chaotically-routed preceeding construction.

In order to maintain sufficient correct arrivals at exits, it may be necessary to add a method of filtering the hues.

This could just mean introducing a 'wrong hue trap' beyond any crossing point(s) that send the occasionally wrong ball back to the cross point (or let them time-out in a dead-end, relying upon few enough failures from the rest of the balls, along with all colliding balls that subsequently missed ''any'' chance of reaching an exit). Alternatively, two (or more) feeds of marbles could be fed through a deliberate 'sorter' that does a sufficiently reasonable job of separating the combined sets out towards their intended target-exits.

The various physical qualities of the balls suggest a number of methods for redirecting separate hues to separate onward journeys. This can be done by isolating a hue from every other hue, then passing on (if necessary) to a setup extracting a different one from the remainder, and perhaps also a third time. It may also be possible to merge 'arrangements' of sorting mechanics to efficiently distribute straight into three ''or even four'' onward tracks towards the desired outputs, but that is left as an exercise to the reader.


{| class="wikitable"
! style="background-color:black; color:white" | To separate !! style="background-color:lightblue" | Blue !! style="background-color:lightgreen" | Green !! style="background-color:yellow" | Yellow !! style="background-color:red" | Red
|-
! style="background-color:red" | Red
| *R/B* | '''Use 'bounce''''
The sole difference is how much balls will rebound from objects. Well managed and constrained ricochets should allow a sorting action.
| *R/G* | '''Use mass or 'bounce''''
Green balls cannot be levitated by a vertical fan. An incline across any such fan(s) will levitate only non-Greens. Green, like Blue, rebounds differently to Red. Green balls are also affected by black holes much less than all other balls.
| *R/Y* | ''See Y/B''
| *R/R* style="text-align: center; background-color:black; color:white" | n/a
|-
! style="background-color:yellow" | Yellow
| *Y/B* | '''All methods'''
Yellow, alone, exhibits high drag against any unforced motion. It is also unique in all other ways; e.g. can be levitated highest, against all other hues (though most profoundly against Green).
| *Y/G* | ''See Y/B''
| *Y/Y* style="text-align: center; background-color:black; color:white" | n/a
| *Y/R* style="text-align: center; background-color:gray" | ''See Y/B'' 
|-
! style="background-color:lightgreen" | Green
| *G/B* | '''Use mass'''
Green balls cannot be levitated by a vertical fan. There is also a not so marginal difference in density that might be exploited, such as by using black holes, which only minimally effects Green (perhaps showing an effective difference between mass of attraction and mass of inertia).
| *G/G* style="text-align: center; background-color:black; color:white" | n/a
| *G/Y* style="text-align: center; background-color:gray" | ''See Y/B'' 
| *G/R* style="text-align: center; background-color:gray" | See R/G
|-
! style="background-color:lightblue" | Blue
| *B/B* style="text-align: center; background-color:black; color:white" | n/a
| *B/G* style="text-align: center; background-color:gray" | See G/B
| *B/Y* style="text-align: center; background-color:gray" | See Y/B
| *B/R* style="text-align: center; background-color:gray" | See R/B
|}

Even when not strictly necessary for one's own submission, once submitted into the full playing grid the player's own contribution may find itself working with less 'pure' delivered ball-streams (from an imperfectly separating feed-in contribution). It is possible that this more interactive disruption can make the new setup behave erratically or even entirely incorrectly.

It might be thought good practice (but not ''necessary'') to deliberately combine any or all inputs and do a full job of splitting them again, just in anticipation of possibly having to deal with such cross-contamination and being able to 'clean up' the onward stream(s) for the benefit of others. This would of course be particularly difficult if the isolated building-phase does not provide all four hues to 'test' against, so any speculatively added filtering would have to be added 'blind' (and only on the offchance that any anticipated incorrect balls will actually enter the arena) and without any legitimate exits to which such rejects could be shunted (therefore could accumulate, up until any 'time out' that might apply to any ball once operational as part of the combined grid).

Single-input/single-output designs might not particularly require ''any'' sorting mechanism, in theory, though the unexpected 'contamination' of the system with balls of different masses/etc could perhaps introduce malfunctioning passage from the added chaos it might succumb to.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[The placeholder image shows four balls, colored red, green, yellow and blue, bouncing on top of three white blocks. Text in the center: "[visit xkcd.com to view]"]

:[In the game, colored balls fall out of rotating half-gears from the wall and/or ceiling while an opposite set of half-gears rotate with a colored triangle pointing to that set of gears. There is a button that says "view machine" button in the bottom right corner. When clicked, it takes you to a larger grid of others' machines that you can view in a larger grid. The button with a wrench is a menu that gives you tools to move the balls to the set of gears with the corresponding triangle.

:[Cueball with lab coat, intro popup]
:Cueball: Balls falling into your cell should be routed to the outputs at a steady rate.

:[Cueball with lab coat, warning popup]
:Cueball: For security reasons, balls that remain in your device for more than 30 seconds will be removed and destroyed.

:[Cueball with lab coat, submit popup]
:Cueball: Congratulations! Your contraption has passed all tests. Press [submit button] to submit it to be added to the machine!

==Trivia==
Once again an April Fool's Day Comic came out late, as Randall did not release this on April 1st, even though April 1st did fall on a Monday, a normal release day. It first came four days later with the Friday release on April 5th. That this is to be considered an April fools' comic, in spite of the later release, was confirmed on the xkcd Facebook page.

*Randall acknowledges the people who helped him create this comic in a [[Header_text#Machine|comic-specific header text]].
**With 11 different involved apart from Randall this is by far the comic with most people involved.
*Some hidden keyboard shortcuts have been found:
** Follow balls: Ctrl + Alt/Option + B (now also accessible by using the button provided)
** Show debug overlay: Ctrl + Shift + Win/Cmd + D
*** This may particularly clash with browser functionality, e.g. Firefox's "New Bookmarks" dialogue which will need closing, though still activating the overlay graphics.
** Delete selected item: Delete (Fn + Delete on Mac)
*When Randall posted a [https://www.facebook.com/TheXKCD/posts/pfbid0Cs97awQZi1ZiaEXouAex9tXrwAS3qJV3RmAiuCq5uvZQwqZVMgDmcqJ7JU9LYodYl link to this comic] on his [https://www.facebook.com/TheXKCD Facebook feed], he directly wrote that it was a late April Fools' Day!
**MACHINE
**Happy Belated April Fool's Day!
**This thus ends any discussion of whether this should be seen as an April Fool's comic or not.
**It just came out 4 days late. This has also happened several times since [[Garden]].
[[File:2916 Machine Facebook April fools' confirmation.png]]
*The [https://github.com/xkcd/incredible source code] for the comic was released on GitHub on May 8, 2024.
**chromakode, one of the developers, also published a [https://chromakode.com/post/xkcd-machine/ blog post discussing the design and development process].

{{comic discussion}}

[[Category:April fools' comics]]
[[Category:Comics with color]]
[[Category:Dynamic comics]]
[[Category:Comics with animation]]
[[Category:Interactive comics]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Knit Cap]]
[[Category:Characters with hats]]
[[Category:Squirrels]]
[[Category:Buns]]
[[Category:Cats]]

2943: Unsolved Chemistry Problems

2024-07-29T07:16:26Z

141.101.105.132:

{{comic
| number = 2943
| date = June 7, 2024
| title = Unsolved Chemistry Problems
| image = unsolved_chemistry_problems_2x.png
| imagesize = 361x386px
| noexpand = true
| titletext = I'm an H⁺ denier, in that I refuse to consider loose protons to be real hydrogen, so I personally believe it stands for 'pretend'.
}}

==Explanation==
Every field of research has [[:Category:Incomplete explanations|unsolved problems]] considered "important" or "significant" that motivate continued research. The scientists at what is apparently the "grand opening" of their new chemistry lab list several real chemistry problems, followed by one also-unsolved-but-less-scientific problem (the p in pH)

'''Arbitrary Enzyme Design:'''

{{w|Enzymes}} are catalytic proteins. Enzyme catalysis is often unique in comparison with other catalysis methods as it is highly specific, or tailored to a specific reaction. As such, enzyme catalysis, besides being the basis of all biochemical processes, is becoming increasingly relevant to industrial synthesis processes. As enzymes can easily be produced synthetically through recombinant gene technology, being able to design an arbitrary enzyme for any reaction would mean that effectively any reaction could be relatively easily catalyzed, revolutionizing the chemical synthesis industry.

'''Protein Folding:'''

{{w|Protein|Proteins}} are large molecules that consist of chains of amino acids. These amino acid chains become {{w|Protein Folding|folded}} in extremely complex ways to form intricate 3D structures, and the way a protein is folded is of critical importance to its function. Because of the huge importance of proteins to biological life, biologists have devoted significant attention over many decades to the problem of {{w|Protein structure prediction|protein structure prediction}}. This refers to the ability to predict the 3D structure of a protein based on the amino acid sequence, and remains one of the most important problems in computational biology. The ability to predict protein structure purely from amino acid sequence — the so-called "de novo" prediction — is known in computational biology as an unusually difficult problem due to the complexity of amino acid chains. Known as "Levinthal's paradox," the number of possible conformations from the backbone conformations alone is estimated to be in the ballpark of 10^300. Despite this, protein folding occurs extremely quickly in reality. Because of this difficulty in sampling conformations, even with optimization, such as secondary structure prediction and Monte Carlo simulation, a "true" accurate simulation is extremely computationally expensive. Because of this, the most accurate solutions, such as AlphaFold, utilize a combination of homology modeling (sampling experimentally determined proteins with similar sequences to infer structural motifs and similarities) and deep learning to accurately guess protein structure. See also [[1430: Proteins]].

'''Depolymerization:'''

Polymers are very large molecules formed out of repeating subunits called monomers. Monomers are molecules, typically organic in nature, that can bond with at least one other molecule, with two or more making long chains or networks called polymers. That process is known as polymerization. Depolymerization is breaking polymers down into the small molecules they were originally made from. This is done through a variety of processes, such as radiation, electrolysis, adding chemicals, and other means. Plastics are the best-known polymers, but cellulose, proteins, and DNA are also technically polymers. The huge number of varieties and mixtures in plastics makes recycling them a huge challenge, and there is increasing concern about plastic waste damaging the environment.

Polymerization is usually exothermic, releasing energy as heat. To reverse this would require adding energy in a targeted way. Simply ''destroying'' a polymer — by means of highly-reactive chemicals, heat, or radiation — doesn't generally release the monomer molecules to a significant degree; most of the reaction products are highly degraded. Most polymers are made by a process of catalysis, with the small monomer molecules interacting via a catalyst structure, often in liquid form, and the eventual product is usually solid. To reverse this would require getting the catalyst to interact in a very precise way with the solid polymer, and it's relatively difficult for the catalyst structure to get into the proper configuration with the solid tangled polymer molecules.

Another highly-desired depolymerization process would be to convert cellulose into its component glucose molecules. That glucose could then be used for a variety of different purposes, including fermentation to alcohol to use as a fuel. Currently, when plants are grown, much of the solar energy and carbon dioxide they absorb ends up in the form of cellulose rather than as starch, sugar, protein, or other substances that we find useful. Our being able to make use of the cellulose would make farming much more energy-efficient. Some organisms are able to depolymerize cellulose by means of enzymes, but our ability to use similar processes on an industrial scale is still limited. (Those organisms use a complex multi-step biochemical process which essentially "invests" energy into splitting off a glucose molecule, then recoups the investment by metabolizing the glucose.) It's also possible to depolymerize cellulose at high temperature and pressure using nothing more than water and acid, but that process is energy-intensive. It ''might'' be possible to do it with a solar-heated reactor.

'''What the “p” in pH stands for:'''

“p” shows up in pH, pOH, pKa, pKb, and other things related to the concentration of H+ ions and OH- ions. The meaning of the "p" in "pH" has been the subject of much dispute. It is sometimes referred to as "power of Hydrogen", perhaps related to the fact that pH is a logarithmic scale, and the logarithm is the inverse of the exponented function and, in all three languages that pH was first published in, the word for "potency" is used for exponents. The term pH was introduced by {{w|Søren Peter Lauritz Sørensen|Søren Peter Lauritz Sørensen}}, who did not publish his results in English, and more accurately translates as "hydric exponent". The letter p could stand for, in the languages in which Sørensen published: the French 'puissance', German Potenz, or Danish potens, all referring to the concept of the "exponent" in exponential functions.

'''Title Text: Hydrogen Denier'''

In the title text, Randall claims to be an H+ denier by refusing to consider loose protons to be hydrogen atoms, and as such, the “p” stands for pretend. Part of the joke is Randall's implication that this is a well-known conspiracy theory that he personally buys into (it isn't). The word "denier" is often used as shorthand for other conspiracy theories, such as a "climate change denier" or a "moon landing denier."

Here's a breakdown of this joke:

* H+ is the chemical symbol for a positively-charged atom of hydrogen, the smallest atom on the Periodic Table. Since hydrogen is normally just one proton and one electron, when you take the electron away, you make it positively charged (the + sign in the superscript) and you effectively end up with just a single loose proton. So the shorthand for "loose proton" is to refer to it as an H+ ion.

* pH is taught in high school science class to essentially measure the concentration of extra loose protons in, say, an aquarium. (Different fish prefer slightly different pH levels/alkalinity.) As mentioned earlier, you can interpret the term "pH" to be referring to the "p" of "H" -- the power/potency of H+ ions.

(Note that in reality, lone H+ ions do not exist in water, and instead they glom onto H2O molecules to form H3O+ and H5O2+/(H2O--H--OH2)+ due to intermolecular hydrogen bonding. If you don't know what these chemical symbols mean, don't worry about it.)

But as an H+ denier, Randall doesn't consider loose protons to be hydrogen atoms. He has a purist's view of hydrogen, that it is just "pretending" to be hydrogen as soon as it loses an electron. As a denier, he interprets the term "pH" as referring to the concentration of "pretend Hydrogen".

==Transcript==
:[Hairbun stands behind a lectern on a podium speaking into a microphone on the lectern. A Cueball like guy stands to the left and another Cueball like guy and Megan stand to the right. There is a large sign hanging in the background along with some ornaments.]
:Sign: Grand Opening
:Hairbun: Our lab will be working on chemistry's top unsolved problems: arbitrary enzyme design, protein folding, depolymerization, and, of course, the biggest one of all:
:Hairbun: ''Figuring out what the "p" in "pH" stands for.''

{{comic discussion}}

[[Category:Comics featuring Hairbun]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics with lowercase text]]
[[Category:Multiple Cueballs]]
[[Category:Chemistry]]

2941: Cell Organelles

2024-07-29T07:15:40Z

141.101.105.132:

{{comic
| number = 2941
| date = June 3, 2024
| title = Cell Organelles
| image = cell_organelles_2x.png
| imagesize = 563x451px
| noexpand = true
| titletext = It's believed that Golgi was originally an independent organism who was eventually absorbed into our cells, where he began work on his Apparatus.
}}

==Explanation==
This comic shows a {{w|Cell (biology)|biological cell}} diagram with a mix of real and fictional {{w|organelle}}s, giving both accurate {{w|Cell biology|cell biology}} terms and humorous ones. Actual cell components include the nucleus, mitochondria, and Golgi apparatus, while unrelated concepts come from geology, engineering, antivirus software, and even Star Wars. Labels like "evil endoplasmic reticulum" and "sticky endoplasmic reticulum" are variations of real cellular organelles. Other labels like "pith," "mantle," and "Vitreous humor," are borrowed from other types of circular cross-sectional diagrams (e.g., of fruit, planets, and eyeballs).

The title text is a fictional backstory to the {{w|Golgi apparatus}}, an essential cell organelle involved in processing and packaging proteins. It suggests that {{w|Camillo Golgi}}, the scientist who discovered the Golgi apparatus, was originally an independent organism that was supposedly absorbed into our cells, where it then started working on what is now known as the Golgi apparatus. The joke is a satirical take on {{w|Symbiogenesis|endosymbiotic theory}}, which posits that certain organelles within {{w|Eukaryote|eukaryotic}} cells, like {{w|mitochondria}} and {{w|chloroplasts}}, originated from independent symbiotic {{w|Prokaryote|prokaryotic organisms}} that were absorbed by a host {{w|germ cell}}. Golgi is drawn in the comic as a cute little alien.

{| class="wikitable sortable"
|-
! Label
! Meaning
! Real?
! Cell organelle?
! Explanation
|-
| {{w|Smooth endoplasmic reticulum}}
| A network of tubular membranes within the cytoplasm of the cell, involved in the transport of materials.
| Yes
| Yes
| An {{w|endoplasmic reticulum}} is considered "smooth" if it is not covered in ribosomes.
|-
| {{w|Lithosphere}}
| The rigid outer part of the earth, consisting of the crust and upper mantle.
| Yes
| No
| Term from geology; part of the Earth's crust. Labeled cross-sectional diagrams of cells and of the layers of the Earth are commonly found in science textbooks.
|-
| {{w|O-ring}}
| A mechanical gasket in the shape of a torus; used to seal connections.
| Yes
| No
| Engineering term. Both the o-ring and pith are drawn connected to the inner cell membrane. Made famous in pop culture for being the root cause of the {{w|Space Shuttle Challenger disaster}}.
|-
| {{w|Pith}}
| The central tissue in plants, used for nutrient transport.
| Yes
| No
| Botanical term. Most people think of pith as the layer of soft tissue between the skin and the flesh of citrus fruit, which explains its position in the diagram. Both the pith and o-ring are drawn connected to the inner cell membrane. A layer of pith was recently seen only 101 comics ago, in [[2840: Earth Layers]].
|-
| {{w|Cell nucleus|Nucleus}}
| The central and most important part of an object, forming the basis for its activity and growth.
| Yes
| Yes
| The cell nucleus is an actual cell organelle which houses {{w|DNA}}.
|-
| {{w|Nucleolus}}
| A small dense spherical structure in the nucleus of a cell during {{w|interphase}}.
| Yes
| Yes
| Actual cell organelle, involved in {{w|ribosome}} production.
|-
| Nucleoloulous
| Not a real term, albeit a portmenau of the aforementioned "Nucleus" and "Nucleolus" words
| No
| No
| A humorous continuation of the terms "nucleus" and "nucleolus"; as the nucleolus does have internal components (such as the fibrillar center). Still, none of the nucleolus's components go by the name "Nucleoloulous"...
|-
| {{w|Nucleon}}s
| Protons and neutrons in the nucleus of an atom.
| Yes
| No
| While cells contain matter which is supposed to contain nucleons,{{Citation needed}} yet the depicted circles are far larger than actual nucleons.
|-
| Drain plug
| A stopper for a drain.
| Yes
| No
| A plumbing term, which could refer to a {{w|porosome}}. Even small, temporary damage to the integrity of the {{w|cell membrane}} puts the cell at immediate and great risk of death.
|-
| Evil endoplasmic reticulum
| Not a real term.
| No
| No
| The rough endoplasmic reticulum is covered in ribosomes; the "evil" endoplasmic reticulum in the comic is covered in small spikes, making it evil.
|-
| {{w|Hypoallergenic}} filling
| Materials that cause relatively fewer allergic reactions.
| Yes
| [[Technically]] not incorrect
| Consumer product term, used e.g. for pillows and mattresses. If the {{w|cytoplasm}} doesn't cause allergic reactions within the cell, it is hypoallergenic.
|-
| Weak spot
| A vulnerable point.
| Yes
| Conceivably
| {{w|Cell membrane}} surfaces do indeed vary in strength, often due to the presence of organelles such as {{w|ion channel pore}}s or {{w|porosome}}s, both of which can be leveraged by viruses to enter cells.
|-
| {{w|Mitochondria}}
| Organelles that generate energy for the cell.
| Yes
| Yes
| Actual cell organelles. Mitochondria are widely known as the "powerhouse of the cell," a phrase originally coined in 1957 by biologist {{w|Philip Siekevitz}}[https://www.scientificamerican.com/article/powerhouse-of-the-cell/] which came to prominence online in the mid-2010s.{{acn}}
|-
| {{w|Midichlorians}}
| Fictional microorganisms in the {{w|Star Wars}} universe, which confer Force sensitivity and thereby associated {{w|Jedi}} (and Sith) powers.
| No
| Fictional
| It's unclear whether {{w|George Lucas}} intended for "midi-chlorians" to be {{w|Symbiogenesis|endosymbiotic organelles}} or internal {{w|Symbiosis|symbionts}}.
|-
| {{w|Chloroplast}}s if you're lucky
| Organelles in plant cells responsible for {{w|photosynthesis}}.
| Yes
| Yes, but in plants and plantlike organisms
| Actual cell organelles, found in plant cells and those of several different lineages of non-plant microorganisms and seaweeds. The phrase "if you're lucky" alludes to the good fortune that an organism, be it plant, animal, or microbe, gains by being able to photosynthesize, getting energy from sunlight, rather than have to run around all the time chasing energy. This benefit makes chloroplasts {{w|Kleptoplasty|worth stealing}}. [https://www.nature.com/articles/s41586-022-05499-y Experiments have been conducted] to transplant components of chloroplasts into mammal cells to slow disease. See also [https://www.gocomics.com/doonesbury/1978/06/26 Zonker Harris].
|-
| Human skin
| The outer covering of the human body.
| Yes
| No
| Skin is a {{w|Tissue_(biology)|tissue}} (multicellular structure). The idea that a complex tissue can be wrapped around a single cell, as if it were a cell wall, or outer {{w|cell membrane}}, or {{w|extracellular matrix}}, is humorously backwards: human skin is made of cells, not the other way around. This may be referencing the common factoid that house dust is mostly human skin, implying that the cell is covered in a layer of dust.
|-
| {{w|Carbonation}}
| {{w|Carbon dioxide}} dissolved in a liquid.
| Yes
| No
| Carbonation causes soda pop and similar liquids to bubble, fizz, foam, and {{w|effervesce}}. The little dots depicted in the comic look like carbonation bubbles.
|-
| Golgi
| {{w|Camillo Golgi}} (1843–1926) was an Italian biologist and {{w|pathologist}} who discovered the Golgi apparatus; known also for his works on the central nervous system.
| Yes
| No
| The real Golgi was not and is not a tiny alien being who merged with our cells,{{Citation needed}} as the comic and title text imply. While the mitochondria and chloroplast may have been evolved in such a manner (through being consumed by a host cell), the golgi apparatus wasn't absorbed in such a manner, and Golgi was most likely not an alien.
|-
| {{w|Golgi apparatus}}
| A complex of {{w|vesicles}} and folded membranes involved in secretion and intracellular transport.
| Yes
| Yes
| Actual cell organelle, which takes {{w|polypeptide}} chains from the rough endoplasmic reticulum via transport vesicles and processes them into their protein structure before sending them (again via vesicles) to their destination such as an organelle or outside of the cell.
|-
| {{w|Norton AntiVirus}}
| A software product designed to protect computers from malware.
| Yes
| No
| Viruses do attempt to insert themselves into cells, and many cell types do have antiviral mechanisms (notably the {{w|CRISPR}} (Clustered Regularly Interspaced Short Palindromic Repeats) DNA sequences in prokaryotes, which resist viral (bacteriophage) infection - however, the cell shown is not prokaryotic, since it contains a nucleus). A system designed to protect against computer viruses is unlikely to be helpful, though, since biological viruses are completely different, and cells have not been architected to support such software.
|-
| Sticky endoplasmic reticulum
| Not a real term, although parts of the reticula have sticky pockets.[https://www.frontiersin.org/articles/10.3389/fcell.2023.1156152/full]
| No
| No
| Another humorous twist on the actual types of endoplasmic reticula.
|-
| {{w|Pleiades}}
| A cluster of stars in the constellation Taurus.
| Yes
| No
| Even a single star is far too big to fit in a cell.{{Citation needed}} The labeled cluster in the comic looks like the actual constellation, as if this were a depiction of the night sky.
|-
| Natural flavor
| Flavoring derived from natural sources.
| Yes
| Conceivably
| A common ingredient on food labels (and sometimes cosmetics, etc.), usually meaning any substance to add flavor, aroma, or both, other than synthetic chemicals which are referred to as artificial flavors.
|-
| {{w|Cellophane}}
| A thin, transparent sheet made of regenerated {{w|cellulose}}.
| Yes
| No
| A type of packaging material. A {{w|cell wall}} is indeed made of cellulose, though not in the form of cellophane. Also, this drawing looks more like an animal cell (albeit a very odd one), which unlike plants and fungi, do not usually have a cell wall.
|-
| {{w|Rough endoplasmic reticulum}}
| Endoplasmic reticulum with {{w|ribosomes}} attached, involved in protein synthesis.
| Yes
| Yes
| Actual cell organelle. "Rough" refers to the presence of ribosomes covering its membrane, which translate {{w|messenger RNA}} into polypeptide chains. Normally the endoplasmic reticulum would wrap around the cell nucleus (as the nuclear envelope is itself a specialized part of the rough endoplasmic reticulum).
|-
| {{w|Ventricle}}
| A chamber of the heart that pumps blood out.
| Yes
| No
| Ventricles are actually part of the body, and they are composed of many cells. Possibly a pun on {{w|vesicle}} (or {{w|vacuole}}), a small membrane-enclosed vessel, such as the transport vesicles that carry polypeptides from the rough endoplasmic reticulum to the Golgi apparatus for processing.
|-
| {{w|Mantle}} 
| The layer of the earth between the crust and the core.
| Yes
| No
| Misplaced geological term with many other meanings. Labeled cross-sectional diagrams of the layers of the Earth are commonly found in science textbooks.
|-
| {{w|Slime}}
| A moist, soft, and slippery substance, or a brand name for a {{w|Slime_(toy)|goopy substance sold as a toy}}.
| Yes
| No
| Could refer to the slimy texture and appearance of {{w|cytoplasm}}, but not specific to cells. Slime was a frequent appearance on the Nickelodeon TV kids channel during [[Randall]]'s youth in the 90s (a signature aspect of the network, it was introduced when Nickelodeon became the American home of the Canadian kids' show {{w|You Can't Do That on Television}}, which had a running gag of dumping green slime on anyone who said "I don't know").
|-
| {{w|Vitreous humour}}
| The clear gel that fills the space between the lens and the retina in the eyeball.
| Yes
| No
| The vitreous humour is in the eye's {{w|extracellular matrix}}, not inside cells. Labeled cross-sectional diagrams of eyes are also commonly found in science textbooks.
|-
| {{w|Seed}}s
| Plant embryos used for reproduction.
| Yes
| No
| Seeds are multicellular, and sometimes contain small proportions of non-cellular tissue. Cells are found in seeds, not the other way around. Seeds would be labeled on a cross-sectional diagram of a fruit, not a cell.
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

Cell Organelles

[A cell is shown with the following structures and areas labeled, counter-clockwise from upper left:]

* Smooth endoplasmic reticulum
* Lithosphere
* O-Ring
* Pith
* Nucleus
* Nucleolus
* Nucleoloulous
* Nucleons
* Drain plug
* Evil endoplasmic reticulum
* Hypoallergenic filling
* Weak spot
* Mitochondria
* Midichlorians
* Chloroplasts if you're lucky
* Human skin
* Carbonation
* Golgi
* Golgi apparatus
* Norton AntiVirus
* Sticky endoplasmic reticulum
* Pleiades
* Natural flavor
* Cellophane
* Rough endoplasmic reticulum

[These labels are inside the cell:]

* Ventricle
* Mantle
* Slime
* Vitreous humour
* Seeds

{{comic discussion}}

[[Category:Biology]]

2734: Electron Color

2024-07-29T07:04:36Z

141.101.105.132: /* Explanation */

{{comic
| number = 2734
| date = February 6, 2023
| title = Electron Color
| image = electron_color_2x.png
| imagesize = 568x256px
| noexpand = true
| titletext = There's quark color, but that's not really color--it's just an admission by 20th century physicists that numbers are boring.
}}

==Explanation==
In this comic [[Miss Lenhart]] is teaching a school physics class. One of her students asks what the color of electrons is.

This is a relevant question for a kid to ask since on many scientific diagrams of atoms, the subatomic particles have been assigned colors to identify them for the reader. Neutrons are generally red, green, or gray; protons red or green and electrons might be blue or yellow. But there is no accepted rule for coloring such diagrams, so the kid may be confused. Additionally, some scientific diagrams use color coding rather than actually representative colors, and the kid may be wondering what color particles actually are.

In completely off-character style, Miss Lenhart actually gives a correct fact ''...so "color" isn't even defined for them.'' and states that, unlike the diagrams, which are colored for convenience, the particles are not colored. She however gives a bogus, pseudoscientific explanation: ''They're too small to interact with visible light, ...'' In fact, every optical effect in our world is due to electrons interacting with light. That leads to color because the electrons are usually bound to various atomic nuclei in molecules etc., which leads to differences in how they take up and give out various energies of photon. But the electron itself does not have a particular hue that can be shone upon and absorbed/reflected, it merely governs the possible quanta of energy changes involved in generating the broad spectrum of light that the substance formed of the atom(s) may be seen by. Also protons are far "bigger" than electrons (and would interact strongly!), but their interaction with light (and generally electromagnetic radiation) is rarely observable, because they are shielded by the tiny electrons in ordinary matter. So, whether intended or not, Miss Lenhart is in her usual role of talking <s>bullshit</s> malarkey, also see for instance [[1519: Venus]].

She then continues by saying that electrons are definitely yellow. The reason for this isn't clear. She may be:
* meaning that they should be yellow on diagrams, because she feels this is the correct way to depict them in drawings of atoms,
* referring to the Greek etymology of the word electron ({{w|elektron (resin)|elektron}} is an old name for amber, a yellow gem),
* merely teasing her young pupils, or
* stating how she feels they would be, if they could possess color.

But her off-panel pupils take her word for it. One of the kids says "I knew it", to the "fact" that electrons are yellow, and likewise the other pupils completely ignore what Miss Lenhart just told them. The debate then starts as one pupil claims ''and protons are red?'', and another chimes in, with a ''No, they're gray!'' This only makes sense in a debate of how to draw atoms, not regarding their actual color, as Miss Lenhart just explained.

The opinions over the colors are probably based on what kind of diagrams people were initially exposed to, leading to a predisposition to think that those colors are 'correct'.

Although individual electrons do not have a color, it's possible to produce a solution of {{w|Solvated_electron|so-called 'solvated' electrons}}. In ammonia and amines, in certain concentrations, the solution color is blue, and in higher concentrations metallic gold to bronze.

The title text refers to the {{w|color charge}} property of quarks, a property which is part of {{w|quantum chromodynamics}}. In quantum chromodynamics, a quark's color can take one of three values or charges: red, green, and blue. An antiquark can take one of three anticolors: called antired, antigreen, and antiblue. As mentioned by [[Randall]], these have nothing to do with color as we know it, but is just a way to represent interactions between quarks in a sufficiently analogous fashion that avoids inventing entirely new words to describe a particular threefold quality of the necessary {{w|color confinement|inter-quark groupings}}. And he jokingly says that the 20th century physicists that came up with the three color system did this as as admission that numbers are boring. They could just have called the color charges "1", "2" and "3", though this may imply an unwarranted hierarchy, progression or other standard mathematical relationship that does not actually apply.

==Transcript==
:[Miss Lenhart is teaching a class. A boy with spiky hair sits at his desks with his hand raised asking a question. Jill sits in front of him looking back at him while leaning an arm on the back of her chair.]
:Miss Lenhart: You have a question?
:Boy: Yeah-What color are electrons and protons? Are they yellow? Red? Blue?

:[Zoom in on Miss Lenhart's head.]
:Miss Lenhart: Subatomic particles don't have a color.
:Miss Lenhart: They're too small to interact with visible light, so "color" isn't even defined for them.

:[Zoom back out but only showing Miss Lenhart. Three pupils reply from off-panel with speech lines coming from starburst at the right edge of the panel.]
:Miss Lenhart: That said, electrons are '''''definitely''''' yellow.
:Off-panel voice 1: I knew it!
:Off-panel voice 2: And protons are red, right?
:Off-panel voice 3: ''What?'' No! They're gray!

{{comic discussion}}

[[Category:Comics featuring Miss Lenhart]]
[[Category:Comics featuring Jill]]
[[Category:Kids]] 
[[Category:Physics]]

Talk:2905: Supergroup

2024-03-12T18:28:42Z

141.101.105.132: /* Group (math) connections */ new section

== Title text ==

Isn't the sum in the title text wrong? It should be ''99 Luftballoons'' (or the English cover ''99 Red Balloons'') + ''101 Dalmatians'' + ''I'm Gonna Be (500 Miles)'' = 700 balloons, dalmatians and miles (not 1,200).--[[Special:Contributions/141.101.69.103|141.101.69.103]]
:Maybe it's about Vanessa Carlton's "A Thousand Miles"? [[Special:Contributions/172.69.65.245|172.69.65.245]] 22:13, 11 March 2024 (UTC)
:Note that ''I'm Gonna Be'' is actually about walking 1000 miles, not 500 miles. [[Special:Contributions/172.70.39.41|172.70.39.41]] 08:36, 12 March 2024 (UTC)
::Right! "I-hai would walk five hundred miles, and I-hai would walk five hundred more..." [[User:Transgalactic|Transgalactic]] ([[User talk:Transgalactic|talk]]) 15:29, 12 March 2024 (UTC)

"cover" implies that the combined song already exists and was performed by some other group. I would expect that this supergroup would have created the medley themselves, to fit their particular genre. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 22:23, 11 March 2024 (UTC)

"101 Dalmations" isn't a well known song AFAIK. It was written as the title song of the Disney movie, but wasn't actually used. Wikipedia says it got released on other albums. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 22:38, 11 March 2024 (UTC)

== Comic ==

I don't know all the bands, but it looks like they are: 21 Pilots, 5 Seconds of Summer, 4 Non Blondes, 2 Live Crew, 100 GEC, 3 Doors Down, 9 Inch Nails, 1 Republic, 1 Direction, 30 Seconds to Mars.

== Missed Opportunity ==

I am surprised there were no references to orthosymplectic or superunitary groups.
:That's what I originally thought the joke would be about. This is much more mundane. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 22:34, 11 March 2024 (UTC)
:Well if ''G'' and ''H'' are groups and ''G'' ⊇ ''H'', then ''G'' is a supergroup of ''H'', isn't it? --[[User:Coconut Galaxy|Coconut Galaxy]] ([[User talk:Coconut Galaxy|talk]]) 13:39, 12 March 2024 (UTC)

== extras ==

throw in:

* {{w|23 Skidoo (band)|23 Skidoo}}
* {{w|400 Blows (British band)|400 Blows}}

--[[Special:Contributions/162.158.63.76|162.158.63.76]] 07:10, 12 March 2024 (UTC)

:{{w|Five Finger Death Punch}}
:{{w|Six Feet Under (band)|Six Feet Under}} --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 13:37, 12 March 2024 (UTC)

I remember a great film, ''The Magnificently Dirty Nineteen''. [[Special:Contributions/172.69.195.155|172.69.195.155]]
:Don't forget the sequel ''The Fantastic Ocean's Taking of Pelham Slaughterhouse 143'' [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 14:07, 12 March 2024 (UTC)
::And the supercut "The Fast and the Furious 41" --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 15:01, 12 March 2024 (UTC)

I like the alternate cut: 108 Dalmation Nation Army. [[Special:Contributions/172.69.247.48|172.69.247.48]]

== Group (math) connections ==

I think tat the description misses the connection to math:

* Group is a mathematical concept (**set** of elements with some properties and operations)
* Sub-group is a subset of a group that retains the properties; Super-group can be constructed similarrly;

https://en.wikipedia.org/wiki/Group_(mathematics) ; https://en.wikipedia.org/wiki/Subgroup ; https://en.wikipedia.org/wiki/Supergroup_(physics)

--[[Special:Contributions/141.101.105.132|141.101.105.132]] 18:28, 12 March 2024 (UTC)