explain xkcd - User contributions [en]

2982: Water Filtration

2024-09-09T15:59:36Z

172.70.58.4: /* Explanation */ Clearly some degree of euphamistic terminology.

{{comic
| number = 2982
| date = September 6, 2024
| title = Water Filtration
| image = water_filtration_2x.png
| imagesize = 593x467px
| noexpand = true
| titletext = You'd think the most expensive part would be the quark-gluon plasma chamber, but it's actually usually the tube to the top of the atmosphere to carry the cosmic rays down.
}}

==Explanation==
{{incomplete|Created by WATER. JUST PLAIN WATER. NOTHING DONE TO IT, JUST PLAIN WATER. POSSIBLY DRINKABLE. - Do NOT <s>drink the water</s> delete this tag too soon.}}
This comic seems to be a diagram of how well water is purified, a common procedure done to make said water safe to drink. However, this well water is "purified" through a series of increasingly unnecessary, expensive, and possibly hazardous steps, ending with producing "pure" water synthesized from hydrogen and oxygen (which have each been synthesized from subatomic particles) - before promptly undoing most of the work by re-adding raw well water, and its original minerals and probiotics (which is one way of describing contaminants and biological pathogens) "for taste and to support immune health".

{| class="wikitable"
|-
!Step
!Real Device?
!Used for water purification?
!Explanation
|-
|Water softener
|{{Yes|Real}}
|{{Yes}}
|{{w|Water softening}} is the removal of calcium, magnesium, and certain other metal cations in hard water. The resulting soft water requires less soap for the same cleaning effort, as soap is not wasted bonding with calcium ions. Soft water also extends the lifetime of plumbing by reducing or eliminating scale build-up in pipes and fittings. The comic shows the water either being passed through some granulated material (presumably, {{w|ion-exchange resins}}) or into a precipitation chamber for lime (or soda ash) softening.
|-
|Reverse osmosis
|{{Yes|Real}}
|{{Yes}}
|{{w|Reverse osmosis}} is a common step used in modern water-purification systems. It relies on using osmotic membranes and high pressures to separate water molecules from dissolved solutes and biological substances. Interestingly, it would also act as a softening step, rendering the previous step potentially redundant, depending on the goals for each step. It's also overkill for most wells, as groundwater often needs treatment targeted to only a few contaminants, if any treatment at all.
|-
|Ultraviolet Sterilization
|{{Yes|Real}}
|{{Yes}}
|{{w|Ultraviolet germicidal irradiation|Ultraviolet sterilization}} uses UV lamps at short wavelengths to damage the DNA and thereby kill micro-organisms in the water. In the USA, this is an unlikely method of well water sterilization, as the pathogens most likely to be found in well water (as opposed to surface water) are generally much more responsive to chemical disinfection. Many wells don't even need a disinfection step; whether this well needs disinfection or not, this is hardly the most impractical step in this treatment train.
|-
|Autoclave
|{{Yes|Real}}
|{{Yes}}
|{{w|Autoclaves}} are essentially large pressure cookers that sterilize items and liquids through exposing them to a high temperature (~120°C or ~248°F) over tens of minutes in presence of water. By maintaining a high pressure, the boiling point of water goes up. This creates a very hot and humid atmosphere, making efficient heat transfer with all contents and inactivating all biological entities through this heat. They are commonly used in hospital and laboratory settings to sterilize plastics, glassware, equipment and solutions (like bottles of growth medium for bacteria) to be used in a sterile environment. The advantage of this method compared to dry heat (aka putting things in a 150°C-180°C oven until they are sterile) is that most lab plastics survive a passage at 120°C without melting. While difficult to streamline (as this technique is used for batches), it has the advantage over light-based methods that heat gets everywhere, and that instead of just damaging DNA, you also denature the proteins and other structures of microorganisms.
|-
|Condenser
|{{Yes|Real}}
|{{Yes}}
|This step condenses the steam generated by the autoclave back into water. This is a normal part of the process used in "traditional" water purification by distillation.
|-
|Regular osmosis
|{{Yes|Real}}
|{{No}}
|Regular osmosis (also known as "osmosis") is the tendency of a solvent (like water) to flow through a semipermeable membrane towards the side that has a higher concentration of dissolved molecules or ions. Since the water is already highly purified at this point, osmosis would only work if the output water is ''less'' pure, adding dissolved substances to it.
|-
|X-Ray Sterilization
|{{Yes|Real}}
|{{No}}
|While {{w|Sterilization_(microbiology)#Ionizing_radiation_sterilization|x-ray sterilization}} is used to sterilize equipment, it is not normally used for water.
|-
|Carbon Filter
|{{No|Fake}}
|{{No}}
|The water is passed through some volume of carbon - a riff on activated carbon filters, which ''are'' used in water filtration as seen later in the process.
|-
|Neutron Source
|{{Yes|Real}}
|{{No}}
|A {{w|neutron source}} generates high-energy neutrons. High-energy neutrons are highly penetrating and will cause ionization events to occur due to collision with atoms in the water. This can potentially make the water more radioactive due to the generation of radioactive isotopes.
|-
|Activated Carbon Filter
|{{Yes|Real}}
|{{Yes}}
|{{w|Activated carbon}} is a form of carbon commonly used to filter contaminants from water and air, as it has a large surface area available to adsorb impurities on its surface. While this isn't a strange step to see in a water purification process, Randall makes a pun here with its proximity to the neutron source - the carbon has been '{{w|Neutron activation|activated}}' by the neutron source, and is currently radioactive. Water filtered through this may pick up radioactive isotopes from the filter.
|-
|Gamma Ray Sterilization
|{{Yes|Real}}
|{{No}}
|Similar to x-ray sterilization, this step uses {{w|Sterilization (microbiology)#Ionizing radiation sterilization|gamma rays}} to sterilize the water. Gamma rays can potentially irradiate the water through photodisintegration if their energy is higher than the binding energy of oxygen.
|-
|Cosmic Ray Sterilization
|{{No|Fake}}
|{{No}}
|Similar to the previous step, but this time using high energy {{w|cosmic rays}} to do so. This would be incredibly impractical, as cosmic rays are generally blocked by the atmosphere at high altitudes (as stated in the title text). Furthermore, their extremely high energy (shown to be in the exa-electron volt (EeV, or 10<sup>18</sup> eV) range) would cause multiple high-energy particles to be created on impact with the water molecules, irradiating the water significantly.
|-
|Electrolysis
|{{Yes|Real}}
|{{No}}
|The water is broken down into hydrogen and oxygen gas using an electric current. Assuming the gas outputs of this process are pure hydrogen and oxygen gas, this *would* be an extremely effective sterilization tactic, seeing as no known organism or water pollutant is entirely composed out of hydrogen or oxygen gas. Along with the next step, this step may be a misguided attempt to "take the water apart and clean each part individually". The hydrogen is sent to the ionizer, while the oxygen is sent to the oxygen spallation step.
|-
|Oxygen Spallation
|{{No|Fake}}
|{{No}}
|Almost all oxygen in existence was originally created via {{w|stellar nucleosynthesis}}. Now, in this step in the purification, the oxygen is apparently broken down back into hydrogen via a fictional form of {{w|Cosmic_ray_spallation|spallation}}. While spallation can form lighter nuclei from heavier ones, there is no known process to convert oxygen back down to hydrogen. It is unclear what happens to the neutrons present in the oxygen nuclei - whether they are removed, used to create hydrogen isotopes or allowed to decay into protons and electrons (the components of yet more hydrogen, when properly reintroduced). The hydrogen formed here is merged with the rest of the hydrogen before being sent to the ionizer.
|-
|Ionizer
|{{Yes|Real}}
|{{No}}
|The hydrogen output by the previous step is made into a plasma with free electrons and protons (not bound into atoms).
|-
|Quark-Gluon Plasma Chamber
|{{No|Fake}}
|{{No}}
|The plasma output from the previous step is further energized into a {{w|quark–gluon plasma}}, such as the one found just after the Big Bang. This follows the theme of the previous steps, which all serve to break the water down into their elementary components. The incredible energies involved in doing so are unachievable by current technologies (current particle accelerators can form such a plasma for very short periods of time and involve a very small amount of matter), and serve to highlight the impracticality of this setup (as alluded to in the title text). The energies would also result in formation of lepton pairs from energy, which is presumably where the electrons from the previous step ended up.
|-
|Hydrogenation
|style="background:#FFFF9E;vertical-align:middle;text-align:{{{align|center}}};{{{style|}}}" class="table-yes"|Kinda
|{{No}}
|This process converts the quark-gluon plasma output in the previous step into elemental hydrogen, reversing the previous two steps. Presumably, this is done via {{w|hadronization}} and {{w|recombination}}; however, it is unclear how the {{w|baryon asymmetry}} needed to generate matter and not anti-matter is developed. The resulting hydrogen is split into 2 streams leading into the Nucleosynthesis and Reverse Electrolysis steps. In real life, {{w|hydrogenation}} is the process of adding hydrogen to unsaturated hydrocarbons.
|-
|Nucleosynthesis
|{{No|Fake}}
|{{No}}
|Part of the hydrogen produced in the previous step is converted into oxygen via 2 sub-processes. The hydrogen is first converted into helium and carbon through a combination of the {{w|proton-proton chain}} and the {{w|CNO cycle}} as per the labels on the step. The helium and carbon are then converted into oxygen through the {{w|alpha process}}. This step may also involve the {{w|triple-alpha process}}, seeing that the alpha process is typically only applicable to converting carbon into heavier elements owing to the lack of a stable element with eight nucleons. These steps normally occur in the cores of massive stars. It is not known how the oxygen is filtered from the extremely hot plasma of fusion products.
|-
|Reverse Electrolysis
|{{Yes|Real}}
|{{No}}
|This step is essentially a fuel cell, utilizing an electrochemical reaction to convert hydrogen and oxygen back into water and electricity.
|-
|Adding Well Water
|{{Yes|Real}}
|{{Yes}}
|A second pipe is linked to the first that simply feeds untreated well water into the pipes, partially undoing the entire process. Even if the well water is only a small portion of the faucet water, its presence has now made the now incredibly pure water impure. This act of putting well water into the faucet after treating it may be a riff on the cultural interest in "spring water" or "pure glacial water" that is said to have additional minerals or beneficial properties but is oftentimes not meaningfully distinct from properly treated tap water. "Local minerals and probiotics added" may be a reference to Coke's "Dasani" brand drinking water, which is purified by reverse osmosis, and then has a package of minerals added to create the flavor (pure water's actual lack of flavor can be perceived as an unpleasantly 'flat' flavor).

In addition, drinking only {{w|Tonicity|extremely hypotonic}} liquid intake can induce the body to expel more water than it took in (taking with it some essential minerals that are not being replaced) to try to maintain equilibrium of concentrations. This effect is not directly dangerous, but could exacerbate other bodily deficiencies in the long term and have the issues of greater than necessary liquid throughput than with 'normal' drinking water. The tendency for {{w|Sports drink#Categories|many 'sports' or 'health' drinks}} to hype the term 'isotonic' is based upon the idea that an ideal concentration of solutes can be added, in-between the opposing problems of having either too many ''or'' too few 'impurities'. The process does not include adding untreated (and probably also untested/unquantified) ground water, which could carry pathogenic organisms and chemicals, and appears to have no mechanism for ensuring what ''might'' be an acceptable level of re-blending for the circumstances.

Alternatively, it may be that the level of purity achieved by this setup is so overkill, and the cost per liter processed so high, that it's simply more efficient to treat just enough of the water to dilute the rest of the water to acceptable levels of contaminants. For example, it's common to use a partial bypass to supply water to the shower, since shower water does not need to be potable. Also, some well water systems are clean enough to not need any treatment at all and can be used straight from the well, and some water systems are only slightly high in a single chemical contaminant that can be addressed by blending the water, either with treated water or another source (treated or untreated). Perhaps the treatment process led to enough radioactivity that blending with the original source was required to address radiological contamination (either gross alpha radiation or specific radionuclides).
|}

The title text briefly covers the cost implications of the components. Various 'real' filter elements will have material or energy costs or both, in operation or to replenish their effectiveness, and the high energy input needed to disassociate hadrons into raw quark–gluon plasma (at bulk levels) would seem to require the most in terms of running the equipment. But it is pointed out that to ''ensure'' enough cosmic rays reach that particular phase of sterilization, there would have to be a pipe (not shown) leading out to the edge of the atmosphere to optimistically carry down such particles (due to also containing ''no'' air, i.e., keeping it out to negate the normal {{w|Air shower (physics)|shielding and dissipating effect}} of the atmosphere on cosmic rays).

Whether a one-off cost or needing regular replacement, the setting up of such a tubular structure (a vertical air-proof pipe perhaps somewhere between 100 and 10000 kilometers high) would be technically challenging and has not ever been actually accomplished. The conditions for a quark–gluon plasma, albeit in limited quantities, at least have been fulfilled at {{w|CERN}}, with its 27 kilometer airless pipe that goes round within a vast circular tunnel.

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

:[Header:]
:How Water Filtration Works

:[A system of various devices between water pipes is shown.]
:[Input:]
:Well water
:[Labels of various devices:]
:Water softener
:Reverse osmosis
:Ultraviolet sterilization
:Autoclave
:Condenser
:Regular osmosis
:X-ray sterilization
:Carbon filter
:Neutron source
:Activated carbon filter
:Gamma ray sterilization
:Cosmic ray sterilization [On the device: "EeV γ"]
:Electrolysis [H<sub>2</sub>O split into O and H]
:Oxygen spallation [O becomes H]
:Ionizer [H split into + and -]
:Quark-gluon plasma chamber [+ and - become QGP]
:Hydrogenation [QGP becomes H]
:Nucleosynthesis [H goes through "P-P CNO" and becomes He and C, then through "Alpha" and becomes O]
:Reverse electrolysis
:[Output after devices:]
:Pure water
:[Second input, mixed with pure water:]
:Well water
:[Label:]
:Local minerals and probiotics added for taste and to support immune health
:[Final output:]
:To faucet

{{comic discussion}}

[[Category:Chemistry]]
[[Category:Physics]]

219: Blanket Fort

2024-08-31T17:44:34Z

172.70.58.4: /* Explanation */ If making that assumption, then it's "Cueball" (more even than "a cueball")

{{comic
| number = 219
| date = February 5, 2007
| title = Blanket Fort
| image = blanket_fort.png
| titletext = Also, we have a fort out in the woods where we stashed that hooker's body.
}}

==Explanation==
In an apparent continuation of comic [[150: Grownups]], [[Megan]] is showing off a {{w|blanket fort}} to her friend [[Ponytail]]. Ponytail answers that Megan's childishness stems from a fear of growing up.

Megan responds that she's fine with growing up. She sees her behavior as a mature realization that some of the things she enjoyed as a child are still enjoyable. When pressed for evidence that she has in any way become an "adult," it is revealed that her boyfriend, presumably Cueball, is inside the blanket fort. He has not spoken because he fears to be found by them when "not exactly dressed," thus implying that "adult" activities had been going on in the fort.

The title text provides another example of this: They built a fort in the woods, another type of fort that a kid would love to have, but then used it to hide a body. This implies that they killed someone, which is not usually something associated with children.{{Citation needed}} A hooker is also more formally known as a {{w|prostitute}}, which is also not usually something associated with children.{{Citation needed}}

==Transcript==
:[Megan and Ponytail are talking with each other. There is a fort made of cushions and blankets on the left.]
:Megan: Like my fort? It uses every blanket and cushion in the apartment.

:Ponytail: Okay, no offense, but this is like that ball pit you made -- Cute, but don't you worry you're clinging to childhood games because you're afraid of change?

:Megan: No. I'm happy to grow up. But I won't pretend fun things aren't still fun out of fear of looking silly.
:Ponytail: But you're 24 and building blanket forts. How have you changed? What's adult about that?

:Megan: Well, there's my boyfriend curled up in the back.
:Ponytail: ...Ah.
:Boyfriend [from inside the fort]: Excuse my shyness. I'm not exactly dressed.

{{comic discussion}}
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Megan]]
[[Category:Sex]]

Talk:2974: Storage Tanks

2024-08-20T16:44:12Z

172.70.58.4:

The symmetry of the truss intrigues me. Struts that are diagonal across the faces of the cuboids is normal, but is it a real thing to also use the body diagonal? Never seen that IRL, not sure if it makes sense from the statics. --[[Special:Contributions/172.70.247.82|172.70.247.82]] 22:16, 19 August 2024 (UTC)

Seems like a pretty menial job for the "head of security". I think he would delegate this to a security guard. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 00:47, 20 August 2024 (UTC)
: They may be head of a department of one.[[Special:Contributions/172.70.85.139|172.70.85.139]] 08:50, 20 August 2024 (UTC)
:: That's part of the joke, that the #1 concern of the Head of Security is calculus teachers wielding power drills for class demonstrations.

The explanation mentions there might be more complex calculus examples where the shape might not be a cylinder. I think some further explanation could be added that this does not change the pressure (hydrostatic paradox) but indeed change the rate of emptying the object. If differing cross sections are relevant at all. [[Special:Contributions/108.162.221.103|108.162.221.103]] 05:40, 20 August 2024 (UTC)
: Non-prismatic geometries are I think the ones being alluded to here, i.e a frustrum with the pointy end down will have a greater reduction in pressure for a given volume of flow towards the end than at the start, which may offset the reduction in absolute pressure. I've also seen examples where the flow rate is considered constant and the problem is to work out the fluid depth as a function of time, e.g. filling a pyramidal pool from a hose. [[Special:Contributions/172.70.58.4|172.70.58.4]] 16:44, 20 August 2024 (UTC)

Its the most difficult job in history, even the best workers couldn't stand 1 day as head of security.[[User:I HAVE NO NAME|I HAVE NO NAME]] ([[User talk:I HAVE NO NAME|talk]]) 05:55, 20 August 2024 (UTC)

I have to admit, I thought I knew calc as I had two semesters of it, but I had to look up what he meant by this. Ouch [[Special:Contributions/172.70.242.55|172.70.242.55]] 13:01, 20 August 2024 (UTC)student

If anyone could suggest something I can do for my class now that I can no longer drill holes in tanks, I'd appreciate the advice, thanks. [[User:Fephisto|Fephisto]] ([[User talk:Fephisto|talk]]) 16:18, 20 August 2024 (UTC)

Talk:2971: Celestial Event

2024-08-16T23:26:38Z

172.70.58.4:

Unfortunately, this calculation doesn't account for the eventual end of total solar eclipses due to the tidal recession of the moon. [[Special:Contributions/172.69.246.142|172.69.246.142]] 05:31, 13 August 2024 (UTC)

:This is a great comment! Very much like something Randall would have written for title text. [[Special:Contributions/172.71.146.49|172.71.146.49]] 05:58, 13 August 2024 (UTC)
:: Agreed! Also, it seems like the article should have a footnote or separate section going full Randall, "Based only on the data given in this cartoon, what is the possible range of Randall Munroe's home location?" --[[User:AnnapolisKen|AnnapolisKen]] ([[User talk:AnnapolisKen|talk]]) 18:21, 13 August 2024 (UTC)
::: Speculating about people's addresses online is generally frowned upon, in court if nowhere else. [[Special:Contributions/172.68.14.183|172.68.14.183]] 00:50, 14 August 2024 (UTC)
:::: As in the original post, the humor in it is that the quest would be effectively useless, right? I mean probably the best data point would be that it's in an area where 17-year cicadas brood. I'm not sure any other data could narrow it down beyond that. --[[User:AnnapolisKen|AnnapolisKen]] ([[User talk:AnnapolisKen|talk]]) 14:05, 15 August 2024 (UTC)

Are all of these events really statistically independent or are e.g. active northern lights and cicada mergence more or less likely to happen at the same time of the year? {{unsigned ip|172.68.194.201|06:15, 13 August 2024}}

: Ooh, great question. It turns out cicadas only emerge in warm weather, particularly in summer, and <s>you can only see the northern lights in winter</s>. That's bad news for us, our superevent might never happen. [[Special:Contributions/172.69.90.3|172.69.90.3]] 01:03, 14 August 2024 (UTC) — edit: oops, I got it wrong. It turns out you can see them all year round. They're actually happening right now in some parts of the US.

This comic was published the same night that saw both the Perseids meteor shower and an unusually strong northern lights. Strangely, the omission of meteor showers in Randall's account of Celestial Events suggests that this is a coincidence. [[User:Mumiemonstret|Mumiemonstret]] ([[User talk:Mumiemonstret|talk]]) 11:43, 13 August 2024 (UTC)

One eclipse every 350 years is not "1/350" - that would imply the eclipse lasted the whole year. The numerator unit should be a minute or so, vastly changing the result. {{unsigned ip|172.70.39.114|13:16, 13 August 2024}}
: Actually, thanks to unit cancelation, Randall's math checks out. I really really feel that it shouldn't, but it does. It's 1/350 years because what you're calculating is "once every X years". It doesn't actually matter how long an eclipse lasts, so long as it's a sufficiently small amount of time so as to be treated as a single point in time. "When that point in time happens, how frequently will those other things be happening?". You can give that answer in days, years, or whatever other unit of time you prefer. Since we're giving it in years, the number we need is "how often (am eclipse occurs) each year" - [[Special:Contributions/172.68.14.185|172.68.14.185]] 23:32, 13 August 2024 (UTC)
:: Yes, I came back to correct myself on this after more reflection. The implied unit is Event and this is the only such non-dimentionless factor. {{unsigned ip|108.162.245.186|23:40, 13 August 2024}}
: Tru dat, as are the comments regarding changes over time in eclipse parameters and the effects of time approximations. However, if we let "4 minutes" be the mean time of totality for an eclipse, and insert that term (for the record, 7.6E-06) for "1" in "1/350", the equation's solution becomes 4E+14, orders of magnitude greater than the age of the universe and, IIRC, well into its projected "heat death". The joke appears to reside in the proximity of Randall's solution to the commonly-accepted age of the Earth, making the solution "just possible". More "accurate" solutions would not be funny, and we would not have seen this comic.[[Special:Contributions/162.158.41.227|162.158.41.227]] 17:11, 13 August 2024 (UTC)
::In the "1/350years", I took it to mean that the unitless "1" represented a day (within which an eclipse occurs, and across this period would also extend the various other conditions). By treating all other unit-laden values as correctly converted to the number in the term of days (and back-converted to the 'more convenient' billions of years for the result), it probably ...not that I did the mathematics to check this... comes out as Randall suggests.
::If, indeed, the length of an (average, as of Earth's current configuration) eclipse, and all other values were understood as proxies for the "number of eclipse-lengths" (except for the uncloudy sky fraction, which is always a unitless half through cancelling out) then you might end up with a result that's different. But the way to check this is to accept the answer (in billions of years) and all the others with time-lengths (respectively) and work out the rough united-length of the "1" by to identify what unit would best fit that. But I leave that to whoever ''really'' wants to dive that deep into it, as the next logical step beyond mere attempted pedantry. [[Special:Contributions/172.68.205.164|172.68.205.164]] 20:22, 13 August 2024 (UTC)
: Every other 2 billion years, on days when it's cloudy or raining, the neighborhood ''doesn't'' get to see the spectacular show. [[Special:Contributions/162.158.154.98|162.158.154.98]] 19:19, 13 August 2024 (UTC)
::So just like the olympic games: They happen every 4 years, while also every 4 years, but offset by 2, there are the olympic winter games... --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 05:43, 15 August 2024 (UTC)

There are competing factors with regard to the eclipse. Obviously total eclipses don't last for an entire year {{cn}}, but in the distant past when the Moon was significantly closer, they occurred much more frequently than once every 350 years. Far enough back, the moon was significantly larger in the sky and orbited much more rapidly making total solar eclipses a much more common event (even if nobody with eyes was around to see). Using constants for probabilities when things have significant variation is tricky. [[User:Galeindfal|Galeindfal]] ([[User talk:Galeindfal|talk]]) 14:26, 13 August 2024 (UTC)
:I just added (without having seen the above comment) something that deals with that. Actually, that and the way that the 'beat frequency' may ''just'' fail to create an all-effect maximum due to it not being a strictly repeating frequency (if you have an eclipse on one date, with a "1 event in 350 years" calculation for your location/latitude, it doesn't preclude more than one per 350 years or two separated by vastly more than 350 years - though still likely to get "N+1" eclipses over any given 350xN year period for higher Ns).
:If it's a combinatorial experience of fully periodic frquencies (such as with [[1331: Frequency]] then you can be precise over the beat-frequency, but any statistical perturbation can make a 'full hit' into a 'not-fully hit' event quite easily. At its simplest, though the chances of any given day (or useful fraction of a day) of being clear-skied may be 50%, it's not as simple to say "yesterday was cloudy, tomorrow will be clear", or vice-versa. Perhaps slightly more useful to say that than "the year just gone had no clouds, so this year will be full of them" or imagining that every second you could glance up and see "clouds...", "no clouds...", "clouds...", "no clouds...". The meteorological 'calculations' would never be anywhere near as simple as even the (future-trends modified) far-future predictability of the astronomical effects. The biologist might be able to be reasonably sure that the season-locked emergence of a given cicada brood will actually continue to satisfy ''their'' contribution to the calculation for much longer than the weatherman might (though they'd have to admit to the high probability that an ecological upset would flat out end any chances before any of the other forecasts become too hazy to rely upon).
:So the changing of frequencies over the time of the 9calculated) meta-beat's recurrance will make for an compoundedly-chaotic 'actual' meta-beat (assuming it ever completes). This includes the possibility that it actually re-meshes its individual occurances into an actually far more frequent coincidence (two consecutive cicada emergences could end up ''both'' being accompanied by all the other requirements). Depends how much you take at face-value, rather than as a rough and ready 'approximation' for fun-and-non-profit... [[Special:Contributions/172.68.205.164|172.68.205.164]] 20:22, 13 August 2024 (UTC)

The adjustment due to leap years is far dwarfed by the approximate nature of "20 days" and "2 months" in some of the events. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 15:06, 13 August 2024 (UTC)

Don't know how it could be calculated in, but there's a fundamental conflict between the solar eclipse and aurora borealis. Solar eclipses are only visible during the day {{cn}}, but the aurorae aren't symmetrical around the poles and drag further equator-ward on the night side of the planet. So the occurrences of Northern lights that would reach to Boston latitudes on the *day side* of the planet so as to be visible during a solar eclipse would be much, much rarer (closer to Carrington-event rarity, currently pitched at once every 100 to 1000 years instead of the 11 Randall used, but even then it'd have to be a particularly strong event). [[Special:Contributions/172.70.230.142|172.70.230.142]] 13:34, 14 August 2024 (UTC)

If he had included all these events happening on a Tuesday or a Thursday then we're getting close to 1 every 14 billion years. A time which everyone's neighbourhoods had a really big show. [[User:Kev|Kev]] ([[User talk:Kev|talk]]) 02:36, 15 August 2024 (UTC)

Someone has to say it. The explanation is so long and convoluted that it serves substantially more to confuse than to explain. Someone please edit it mercilessly. [[Special:Contributions/172.69.33.62|172.69.33.62]] 05:14, 15 August 2024 (UTC)
:I bit the bullet. I'm sure I left some important stuff out, but more sure I deleted more unimportant stuff. [[Special:Contributions/172.71.146.211|172.71.146.211]] 06:24, 15 August 2024 (UTC)

But the question is, will the superevent coincide with the release of an [https://xkcd.com/ xkcd comic]? {{unsigned|RadiantRainwing|23:01, 16 August 2024}}

Talk:2971: Celestial Event

2024-08-14T16:48:21Z

172.70.58.4: Datestamped the unsigneds... Might as well do it properly.

Unfortunately, this calculation doesn't account for the eventual end of total solar eclipses due to the tidal recession of the moon. [[Special:Contributions/172.69.246.142|172.69.246.142]] 05:31, 13 August 2024 (UTC)

:This is a great comment! Very much like something Randall would have written for title text. [[Special:Contributions/172.71.146.49|172.71.146.49]] 05:58, 13 August 2024 (UTC)
:: Agreed! Also, it seems like the article should have a footnote or separate section going full Randall, "Based only on the data given in this cartoon, what is the possible range of Randall Munroe's home location?" --[[User:AnnapolisKen|AnnapolisKen]] ([[User talk:AnnapolisKen|talk]]) 18:21, 13 August 2024 (UTC)
::: Speculating about people's addresses online is generally frowned upon, in court if nowhere else. [[Special:Contributions/172.68.14.183|172.68.14.183]] 00:50, 14 August 2024 (UTC)

Are all of these events really statistically independent or are e.g. active northern lights and cicada mergence more or less likely to happen at the same time of the year? {{unsigned ip|172.68.194.201|06:15, 13 August 2024}}

: Ooh, great question. It turns out cicadas only emerge in warm weather, particularly in summer, and <s>you can only see the northern lights in winter</s>. That's bad news for us, our superevent might never happen. [[Special:Contributions/172.69.90.3|172.69.90.3]] 01:03, 14 August 2024 (UTC) — edit: oops, I got it wrong. It turns out you can see them all year round. They're actually happening right now in some parts of the US.

This comic was published the same night that saw both the Perseids meteor shower and an unusually strong northern lights. Strangely, the omission of meteor showers in Randall's account of Celestial Events suggests that this is a coincidence. [[User:Mumiemonstret|Mumiemonstret]] ([[User talk:Mumiemonstret|talk]]) 11:43, 13 August 2024 (UTC)

One eclipse every 350 years is not "1/350" - that would imply the eclipse lasted the whole year. The numerator unit should be a minute or so, vastly changing the result. {{unsigned ip|172.70.39.114|13:16, 13 August 2024}}
: Actually, thanks to unit cancelation, Randall's math checks out. I really really feel that it shouldn't, but it does. It's 1/350 years because what you're calculating is "once every X years". It doesn't actually matter how long an eclipse lasts, so long as it's a sufficiently small amount of time so as to be treated as a single point in time. "When that point in time happens, how frequently will those other things be happening?". You can give that answer in days, years, or whatever other unit of time you prefer. Since we're giving it in years, the number we need is "how often (am eclipse occurs) each year" - [[Special:Contributions/172.68.14.185|172.68.14.185]] 23:32, 13 August 2024 (UTC)
:: Yes, I came back to correct myself on this after more reflection. The implied unit is Event and this is the only such non-dimentionless factor. {{unsigned ip|108.162.245.186|23:40, 13 August 2024}}
: Tru dat, as are the comments regarding changes over time in eclipse parameters and the effects of time approximations. However, if we let "4 minutes" be the mean time of totality for an eclipse, and insert that term (for the record, 7.6E-06) for "1" in "1/350", the equation's solution becomes 4E+14, orders of magnitude greater than the age of the universe and, IIRC, well into its projected "heat death". The joke appears to reside in the proximity of Randall's solution to the commonly-accepted age of the Earth, making the solution "just possible". More "accurate" solutions would not be funny, and we would not have seen this comic.[[Special:Contributions/162.158.41.227|162.158.41.227]] 17:11, 13 August 2024 (UTC)
::In the "1/350years", I took it to mean that the unitless "1" represented a day (within which an eclipse occurs, and across this period would also extend the various other conditions). By treating all other unit-laden values as correctly converted to the number in the term of days (and back-converted to the 'more convenient' billions of years for the result), it probably ...not that I did the mathematics to check this... comes out as Randall suggests.
::If, indeed, the length of an (average, as of Earth's current configuration) eclipse, and all other values were understood as proxies for the "number of eclipse-lengths" (except for the uncloudy sky fraction, which is always a unitless half through cancelling out) then you might end up with a result that's different. But the way to check this is to accept the answer (in billions of years) and all the others with time-lengths (respectively) and work out the rough united-length of the "1" by to identify what unit would best fit that. But I leave that to whoever ''really'' wants to dive that deep into it, as the next logical step beyond mere attempted pedantry. [[Special:Contributions/172.68.205.164|172.68.205.164]] 20:22, 13 August 2024 (UTC)
: Every other 2 billion years, on days when it's cloudy or raining, the neighborhood ''doesn't'' get to see the spectacular show. [[Special:Contributions/162.158.154.98|162.158.154.98]] 19:19, 13 August 2024 (UTC)

There are competing factors with regard to the eclipse. Obviously total eclipses don't last for an entire year {{cn}}, but in the distant past when the Moon was significantly closer, they occurred much more frequently than once every 350 years. Far enough back, the moon was significantly larger in the sky and orbited much more rapidly making total solar eclipses a much more common event (even if nobody with eyes was around to see). Using constants for probabilities when things have significant variation is tricky. [[User:Galeindfal|Galeindfal]] ([[User talk:Galeindfal|talk]]) 14:26, 13 August 2024 (UTC)
:I just added (without having seen the above comment) something that deals with that. Actually, that and the way that the 'beat frequency' may ''just'' fail to create an all-effect maximum due to it not being a strictly repeating frequency (if you have an eclipse on one date, with a "1 event in 350 years" calculation for your location/latitude, it doesn't preclude more than one per 350 years or two separated by vastly more than 350 years - though still likely to get "N+1" eclipses over any given 350xN year period for higher Ns).
:If it's a combinatorial experience of fully periodic frquencies (such as with [[1331: Frequency]] then you can be precise over the beat-frequency, but any statistical perturbation can make a 'full hit' into a 'not-fully hit' event quite easily. At its simplest, though the chances of any given day (or useful fraction of a day) of being clear-skied may be 50%, it's not as simple to say "yesterday was cloudy, tomorrow will be clear", or vice-versa. Perhaps slightly more useful to say that than "the year just gone had no clouds, so this year will be full of them" or imagining that every second you could glance up and see "clouds...", "no clouds...", "clouds...", "no clouds...". The meteorological 'calculations' would never be anywhere near as simple as even the (future-trends modified) far-future predictability of the astronomical effects. The biologist might be able to be reasonably sure that the season-locked emergence of a given cicada brood will actually continue to satisfy ''their'' contribution to the calculation for much longer than the weatherman might (though they'd have to admit to the high probability that an ecological upset would flat out end any chances before any of the other forecasts become too hazy to rely upon).
:So the changing of frequencies over the time of the 9calculated) meta-beat's recurrance will make for an compoundedly-chaotic 'actual' meta-beat (assuming it ever completes). This includes the possibility that it actually re-meshes its individual occurances into an actually far more frequent coincidence (two consecutive cicada emergences could end up ''both'' being accompanied by all the other requirements). Depends how much you take at face-value, rather than as a rough and ready 'approximation' for fun-and-non-profit... [[Special:Contributions/172.68.205.164|172.68.205.164]] 20:22, 13 August 2024 (UTC)

The adjustment due to leap years is far dwarfed by the approximate nature of "20 days" and "2 months" in some of the events. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 15:06, 13 August 2024 (UTC)

Don't know how it could be calculated in, but there's a fundamental conflict between the solar eclipse and aurora borealis. Solar eclipses are only visible during the day {{cn}}, but the aurorae aren't symmetrical around the poles and drag further equator-ward on the night side of the planet. So the occurrences of Northern lights that would reach to Boston latitudes on the *day side* of the planet so as to be visible during a solar eclipse would be much, much rarer (closer to Carrington-event rarity, currently pitched at once every 100 to 1000 years instead of the 11 Randall used, but even then it'd have to be a particularly strong event). [[Special:Contributions/172.70.230.142|172.70.230.142]] 13:34, 14 August 2024 (UTC)

2960: Organ Meanings

2024-07-19T09:27:48Z

172.70.58.4: Fixed comment on "Appendix"; in biology "vestigial" doesn’t mean that a structure is functionless, only that it no longer performs its original function; e.g., vestigial wings cannot be used for flight but might be used for balance or display.

{{comic
| number = 2960
| date = July 17, 2024
| title = Organ Meanings
| image = organ_meanings_2x.png
| imagesize = 407x346px
| noexpand = true
| titletext = IMO the thymus is one of the coolest organs and we should really use it in metaphors more.
}}

==Explanation==
{{incomplete|Created by a BOT'S PINEAL GLAND - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
This is a graph by [[Randall]] ranking how well he understands the function of certain human organs, compared to how much he understands {{w|metaphor}}s using them. 

A number of organs (and other body parts) are used in common vernacular for metaphorical meaning. The English language is full of sayings like "she had a lot of heart", "go with your gut", and "he hasn't got the stomach for it". One might expect understanding an organ's role and its use in metaphor to be strongly correlated, since the metaphors generally work by drawing a parallel to biological function. However, since our understanding of biological functions has evolved dramatically over time, and metaphorical language does not always keep up, the correspondence is often much looser. To complicate matters, many such anatomical metaphors vary from culture to culture, even though the biological functions remain largely consistent.{{Citation needed}}

The {{w|pineal gland}}, located in the center of the brain, was described as the "Seat of the Soul" by the {{w|Mind–body dualism|mind-body dualist}} {{w|René Descartes}} in the 17th century. If this was true, the metaphors that might be derived from it would be quite clear. It was only in the mid-20th century that its real neuroendocrine (hormone-producing) biological role was grasped. Thus, the real meaning of the metaphor "the pineal gland of something" is uncertain, as is its actual function for the layman. It was also described as a "third eye", as its regulation of the circadian rhythm used to be linked to light perception in the organ, and still is in {{w|Tuatara|Tuataras}}. It is also jokingly stated as still the location of the soul within discordianism.

The {{w|thymus}}, highlighted in the title text, plays an important role in the immune system. It is not commonly used in metaphors,{{Citation needed}} but is perhaps ripe for use in ones describing such things as resilience, indomitability, and adaptability to changing circumstance, were more people to know what it was.

{| class="wikitable" style="margin:auto"
|-
! Organ !! Biological understanding !! Metaphor understanding !! Biological function !! Metaphor meaning(s)!!Comments
|-
| {{w|Appendix_(anatomy)|Appendix}} || 3% || 85% || Maintaining gut flora, introducing pathogens to the immune system || Uselessness || The appendix is vestigial and was long assumed to have no useful function, and thus could be removed with minimal consequences. Modern research has shown that it retains utility as reservoir for useful micro-organisms.
|-
| {{w|Nerves}} || 40% || 90% || Sensing stimuli, and controlling muscles and organs || Courage; lack of courage; unsettledness; arrogance; (emotional) feeling
|-
| {{w|Spine}} || 50% || 80% || Holding other bones up, protecting the spinal cord || Courage; resoluteness; structural integrity; centrality
|-
| {{w|Heart}} || 80% || 90% || Circulation of blood || Emotion; feeling; sympathy; love; courage; resilience; core; essence; the vulnerable self || The function of the heart is (relatively) easy to understand, since it is, in essence, a circulatory pump. But it's long been culturally associated with emotion and resolve.
|-
| {{w|Bones}} || 75% || 80% || Holding the body up, protection of underlying organs || Basic/underlying structure; something hidden; core; essence; an issue of debate
|-
| {{w|Stomach}} || 70% || 65% || Repository for cake and other, less important, foods || Ability to tolerate unpleasant circumstances; motivation || The stomach's primary function is as part of the digestive system, but it's often one of the first organs impacted by illness or disgust, which has made a strong stomach a metaphor for constitution and resolve.
|-
| {{w|Liver}} || 10% || 48% || Processing alcohol and other less important metabolic functions like toxin inactivation, decomposition/production of amino acids and lipids, etc. || Courage or lack thereof (e.g., lily-livered)
|-
| {{w|Lungs}} || 60% || 52% || Oxygenation of blood, exhalation of carbon dioxide || Loudness (e.g., of singing); purification; aerobic stamina
|-
| {{w|Spleen}} || 22% || 34% || Storing extra blood, filtering blood for damaged cells and pathogens || Anger; viciousness
|-
| {{w|Thymus}} || 10% || 13% || Training immune cells (T-Cells) ||
|-
| {{w|Kidneys}} || 47% || 19% || Filtering blood for metabolic wastes and excess minerals ||
|-
| {{w|Pineal gland}} || 2% || 2% || Produces melatonin || Philosophers from Herophilus to Decartes speculated that the pineal gland might be the seat of the soul, or regulate the flow of vital spirits, or otherwise serve an important metaphysical function.
|-
| {{w|Tongue}} || 70% || 5% || Taste, chewing, speaking || Language; unidentified speakers (particularly in relation to gossip/secrets); something long and extended
|}

==Transcript==
:[A graph is shown with X and Y-axis without arrow or ticks. To the left of the Y-axis and below the X-axis there are labels with an arrow pointing up from the top of the Y-axis label and an arrow pointing right above the X-axis label, just beneath the x-axis.]
:Y-axis: How well I understand what it means when used in metaphors
:X-axis: How well I understand its actual biological function

:[On the graph is a scatter plot with 13 labels. Each label is written inside a line that goes just around the words. There are most in the top right corner, but they are spread all over the graph. Here in approximate reading order from top left with indicating of where on the graph the words are located:]
:[Top left:]
:Appendix
:[Top middle:]
:Nerves
:Spine
:[Top right:]
:Heart
:Bones
:Stomach
:[Center left:]
:Liver
:Spleen
:[Center right:]
:Lungs
:[Bottom left:]
:Thymus
:Pineal gland
:[Bottom middle:]
:Kidneys
:[Bottom right:]
:Tongue

{{comic discussion}}

[[Category:Scatter plots]]
[[Category:Rankings]]
[[Category:Biology]]
[[Category:Language]]