explain xkcd - User contributions [en]

Talk:2988: Maslow's Pyramid

2024-09-21T19:01:31Z

162.158.41.181: Fix page

Oh wow, first post! {{unsigned|RadiantRainwing|23:11, 20 September 2024}}
: Congratulations on learning how to post![[Special:Contributions/172.68.245.228|172.68.245.228]] 03:40, 21 September 2024 (UTC)
The 20% figure is incorrect. The lower levels of the pyramid have more volume than the upper levels. By my arithmetic, the breakdown is (rounded) 1%, 6%, 15%, 30%, and 49%, so the "safety" level provides 30% of his needs. [[User:Jordan Brown|Jordan Brown]] ([[User talk:Jordan Brown|talk]]) 00:27, 21 September 2024 (UTC)
:Plus the bottom layer ought to get partial credit for supplying basic shelter. [[User:Jordan Brown|Jordan Brown]] ([[User talk:Jordan Brown|talk]]) 00:29, 21 September 2024 (UTC)
:: I question this Cueball's ability to get anything okay enough. {{unsigned|172.70.38.122|03:32, 21 September 2024}}
::Seems like he's judging each layer on a pass-fail basis, no partial credit. So the bottom layer fails because it only provides shelter, but no food or water. Like a crypt, which is what the Egyptian pyramids were for. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 18:19, 21 September 2024 (UTC)

Oh crud. What did I do that I think totally messed up the attributions? 172.68.245.228 [[Special:Contributions/172.68.245.228|172.68.245.228]] 03:53, 21 September 2024 (UTC)
:I think you probably put some ~s in the wrong places? [[Special:Contributions/162.158.41.181|162.158.41.181]] 19:01, 21 September 2024 (UTC)

But *how* did he build it? Was there some sort of internal ramp? Were extraterrestrials involved? [[Special:Contributions/172.70.163.48|172.70.163.48]] 06:58, 21 September 2024 (UTC)
: Couldn't care less. Cueball, I AM impressed. If your friends aren't, you need new friends. [[Special:Contributions/172.71.160.115|172.71.160.115]] 07:37, 21 September 2024 (UTC)

I assumed Cueball was trying to meet the needs, inside the pyramid. :-) Robert Carnegie rja.carnegie@gmail.com [[Special:Contributions/172.70.160.231|172.70.160.231]] 10:49, 21 September 2024 (UTC)

And a pyramid is a very safe building, except for emergency exits. ;-) (Also traps, but no one asked you in.) But it's not going to fall over. Robert Carnegie rja.carnegie@gmail.com [[Special:Contributions/172.69.194.227|172.69.194.227]] 10:53, 21 September 2024 (UTC)
:It's harder to climb over an ''inverted'' pyramid, looking for weak-points. But then it has a weak-point insofar as having to be balanced upon its point, and one of those definitely ''might'' fall over... [[Special:Contributions/162.158.33.237|162.158.33.237]] 17:29, 21 September 2024 (UTC)

2982: Water Filtration

2024-09-14T12:18:24Z

162.158.41.181: Adding some of the nuance I left out

{{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. PLAIN H₂O - 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 set of procedures 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 all of the work by re-adding raw well water and its original minerals and probiotics, (which is one way of describing chemical and biological contaminants) "for taste and to support immune health". In real life, groundwater generally only needs treatment for any contaminants (chemical or biological) known to be a problem based on the results of water testing or an incident, but adding the original water back in could be dangerous if the water has not been sampled recently.
A faucet is "a device that controls the flow of liquid, especially water, from a pipe", commonly known as a ''tap'' in many parts of the world.

{| class="wikitable"
|-
!Step
!Real Device?
!Used for water treatment?
!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. This is one of the few steps in this process that arguably fits the comic title of "Water Filtration."
|-
|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. This is one of the few steps in this process that definitely fits the comic title of "Water Filtration."
|-
|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 uncommon 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. It therefore goes from a purer state to a less pure state, the opposite of filtration.
|-
|X-Ray Sterilization
|{{Yes|Real}}
|{{No}}
|While {{w|Sterilization_(microbiology)#Ionizing_radiation_sterilization|x-ray sterilization}} is used to sterilize equipment, but may also be used as a cold method (in contrast to techniques like pasteurization) of eliminating germs and killing insects in fresh foodstuffs. Has also been used to sterilize postal mail.
|-
|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. The exact {{w|allotropy|allotrope}} of carbon is not mentioned, so this could possibly be a graphite, carbon nanotubes, or even solid diamond "filter". This is one of the few steps in this process that definitely fits the comic title of "Water Filtration."
|-
|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. This is one of the few steps in this process that definitely fits the comic title of "Water Filtration."
|-
|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 1018 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). However, this pipe would not only be a flight hazard, but also to ensure that no air molecules get in, the pipe would have to be similar to a space elevator, which would wreck a lot of havoc on LEO and MEO.
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 [H2O 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]]
[[Category:Engineering]]

2982: Water Filtration

2024-09-14T12:15:02Z

162.158.41.181: Noted which steps are actually filtration and put in some info about irl groundwater treatment (probably still needs more detail /nuance)

{{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. PLAIN H₂O - 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 set of procedures 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 all of the work by re-adding raw well water and its original minerals and probiotics, (which is one way of describing chemical and biological contaminants) "for taste and to support immune health". In real life, groundwater generally only needs treatment for any contaminants (chemical or biological) known to be a problem based on the results of water testing or an incident.
A faucet is "a device that controls the flow of liquid, especially water, from a pipe", commonly known as a ''tap'' in many parts of the world.

{| class="wikitable"
|-
!Step
!Real Device?
!Used for water treatment?
!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. This is one of the few steps in this process that arguably fits the comic title of "Water Filtration."
|-
|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. This is one of the few steps in this process that definitely fits the comic title of "Water Filtration."
|-
|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 uncommon 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. It therefore goes from a purer state to a less pure state, the opposite of filtration.
|-
|X-Ray Sterilization
|{{Yes|Real}}
|{{No}}
|While {{w|Sterilization_(microbiology)#Ionizing_radiation_sterilization|x-ray sterilization}} is used to sterilize equipment, but may also be used as a cold method (in contrast to techniques like pasteurization) of eliminating germs and killing insects in fresh foodstuffs. Has also been used to sterilize postal mail.
|-
|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. The exact {{w|allotropy|allotrope}} of carbon is not mentioned, so this could possibly be a graphite, carbon nanotubes, or even solid diamond "filter". This is one of the few steps in this process that definitely fits the comic title of "Water Filtration."
|-
|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. This is one of the few steps in this process that definitely fits the comic title of "Water Filtration."
|-
|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 1018 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). However, this pipe would not only be a flight hazard, but also to ensure that no air molecules get in, the pipe would have to be similar to a space elevator, which would wreck a lot of havoc on LEO and MEO.
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 [H2O 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]]
[[Category:Engineering]]

Talk:2981: Slingshots

2024-09-05T19:32:08Z

162.158.41.181:

We don't put tables in the transcript, which is supposed to be screen-readable. Tables are not screen-readable. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 04:25, 5 September 2024 (UTC)
:I now see the hidden "Tables are bad?" content in the incomplete transcript notice! Cute! [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 04:33, 5 September 2024 (UTC)
::anybody want to change the transcript? not too confident on how to write it. [[User:42.book.addict|42.book.addict]] ([[User talk:42.book.addict|talk]]) 17:06, 5 September 2024 (UTC)
:::Given it a go. Could add "regular column" and "gravitational column" pre-descriptors to each subsequent pair of row elements, or go the other way and remove the [Row N] bit. Also chose to use the [label]s of [Tick] and [Cross] in place of the 'fancy' characters; could have gone with [Ticked], [Marked with a tick], [Affirmed], etc, but this seemed sensible. Obviously still open for editing.
:::If I'd have started from scratch, I would have used the (previously identical) table-markup version in the Explanation but have put the "Yay/Nay/freetext" explanation in there with it. But that's not to say that it doesn't look fairly ok (if not better?) in the paragraph-by-paragraph treatment as it currently is, with the table there as visual repeat only.
:::YMMV on all aspects of my choice/complicit acceptance, naturally. [[Special:Contributions/172.69.194.143|172.69.194.143]] 18:20, 5 September 2024 (UTC)

We should clarify that it's the American Dennis and not the British one. There are differences, which I learned the hard way :( [[Special:Contributions/172.69.43.184|172.69.43.184]] 06:48, 5 September 2024 (UTC)
:I expanded (and moved to a Trivia section) the interesting facts of this coincidence. (And I didn't add [https://www.plagiarismtoday.com/2010/10/18/the-odd-case-of-dennis-the-menace/ this link there], but maybe it's of "not even Trivia" interest, so you can have it here instead.) [[Special:Contributions/172.70.86.37|172.70.86.37]] 10:53, 5 September 2024 (UTC)

I'm really surprised that "regular slingshot" is "no" for spacecraft instead of something like "not yet". [[User:SystemParadox|SystemParadox]] ([[User talk:SystemParadox|talk]]) 09:46, 5 September 2024 (UTC)
:There's definitely spring-type "delivery systems" (analogues of the elastic slingshots, arguably) which hasten the detatchment of items on a multi-launch 'racked' delivery system. There's also the (proposed, SFAIK not yet tried in anger) rotating-tether release system, akin to biblical sling(shot)s, that would actually be what the gravitational slingshot is most similar to by pure analogy.
:If we ever get a space-elevator and 'drop' things off from the counterweight station, then that would effectively be a biblical slingshot on a planetary scale. (If we time the drop right, or very wrong, with a heavy enough load or even most of the counterweight itself, such that it ends up eventually impacting Earth or any other inhabited lump of rock, it could well also be a matter of a ''planetary'' slingshot with effects on a ''biblical'' scale!) [[Special:Contributions/172.70.86.37|172.70.86.37]] 10:53, 5 September 2024 (UTC)

Gravitational slingshot & Used for Sport shooting would also be a "not yet".
Imagine a couple of millenia from now, where gravitational slingshoting is a sport, and is called shooting for one of many reasons.
ok, fair. It's a stretch. But I felt I had to mention it.
[[Special:Contributions/162.158.222.142|162.158.222.142]] 12:45, 5 September 2024 (UTC)
: In Futurama they use Gravitational slingshot for [https://futurama.fandom.com/wiki/Leo_Wong%27s_%22Miniature%22_Golf_Course "Miniature" golf]

This comic comes the same week as the release of a movie called Slingshot about the gravitational kind.

Isn't David supposed to be using a sling in his fight with Goliath, not a slingshot? That is, a long bit of material that you can use to throw a projectile with higher velocity? There seems to be similar confusion in describing a slingshot as using "mechanical advantage and rotation". A slingshot doesn't really involve rotation, nor does it involve mechanical advantage, really. Mechanical advantage is force amplification, right? And most slingshots don't amplify force, they simply are better than human bodies at delivering that force while moving quickly - that is, they amplify power. Maybe that's splitting hairs. [[Special:Contributions/172.68.71.102|172.68.71.102]] 14:52, 5 September 2024 (UTC)
: I see now that the text has been edited, distinguishing a sling as "an earlier form" of the slingshot. I still don't think that's accurate. They both accelerate a projectile, but they're not at all the same mechanism. Slingshots store deformation energy, and slings store kinetic energy. If we're talking ancient weapons that a slingshot is comparable to, it's far more like a bow than it is a sling. [[Special:Contributions/172.71.22.58|172.71.22.58]] 15:16, 5 September 2024 (UTC)
:: Indeed, the [https://www.etymonline.com/word/slingshot etymologists] tell us that "hand-held implement for throwing stones" is the original meaning of the word "sling", and it dates to 1300. Whereas "slingshot", with "hand catapult" given as a synonym (implying the cleft-stick version), dates only from 1849. The etymologists also tell us that, by the 14th century, "sling" had acquired the additional meaning of "loop for carrying heavy objects", and, by the 18th century, "cloth for suspending an injured arm". These meanings, I argue, gained prominence, while the sling (weapon) fell out of favor, in armies and in language. I daresay that a person with deir arm in a sling would shudder at the prospect of that arm being hurled at an oncoming foe. It appears to me that, at least in the USA where I reside, "slingshot" is now applied to both the "hand catapult" and the "sling (weapon)" to avoid confusion with the sling (object carrier). [[Special:Contributions/172.68.23.190|172.68.23.190]] 15:42, 5 September 2024 (UTC)
::: I'm also in the US, but slingshot to me specifically evokes something where you store and release elastic energy. People often *hear* sling and think it's referring to a slingshot, because they're unfamiliar with an actual sling (weapon). Although slingshot and sling are certainly etymologically related, they are not technologically related. You might argue that a "gravitational slingshot" is a misnomer, in that its arc around a body is more akin to a sling than to a slingshot, I suppose. But a sling is not an earlier form of the "regular slingshot" in this comic. [[Special:Contributions/172.71.31.46|172.71.31.46]] 16:56, 5 September 2024 (UTC)
:::: See the excellent comment below. Instances of this sort of thing abound, porque Inglés es loco. Even in the sciences. A cylindrical, motile structure responsible for motion of, or circulation of water currents around, eukaryotic cells is termed a "flagellum" if it's moving sperm, or a "cilium" if it's moving phlegm on the surface of the trachea. There is no structural or functional difference between the "flagellum" and the "cilium" of these cells, but there are plenty between the "flagellum" of sperm cells and the "flagellum" found on some bacterial cells. However, an attempt to use a common term ({{w|Undulipodium|undulipodium}}) for the common structure was shouted down. The preference was to retain imprecise terms that were understood by some of the people some of the time, rather than trying to adopt a precise term that was understood by nobody. Vox populi, vox Dei. Even if it's illogical. [[Special:Contributions/162.158.41.181|162.158.41.181]] 19:32, 5 September 2024 (UTC)
:: I come from where the Y-Stick-with-rubber-'bowstring' is termed a catapult, and always associated "slingshot" as being the "shot" (projectile) that was slung (either in a David/Golith 'swung sling' or a Dennise The Menace 'pulled elastic' version), where actually deliberately manufactured/harvested beforehand (typically cast lead, as per muskets, or else specific riverbed pebbles) for consistency of mass and convenience of size rather than just relying upon randomly available rocks and stones grabbed from the ground-clutter as and when needed.
:: But when I went looking for references, it seems there's a general merging of terms (apparently also "pea-shooter", among others, although I'd say ''that'' was a short blowpipe/thick straw that a dried pea or pea-sized wad of mashed up paper can be quickly expelled from just by lung-power). And while some 'catapults' might also be the slung type, with the neolithic-era "stout cords and cradle" design, generally the comic-book type (rather than full blown onagers, mangonels or trebuchets) match what both UK and US alternatives of Dennis tend to use, so clearly that's what Randall is talking about. [[Special:Contributions/172.70.91.27|172.70.91.27]] 17:23, 5 September 2024 (UTC)

I vote we use gravitational slingshots to hunt stray probes. Anyone wanna try taking down Voyager I? [[Special:Contributions/172.69.90.237|172.69.90.237]] 14:57, 5 September 2024 (UTC)
:If we fire at Voyager I (or II, especially) and perhaps ''miss'', we then likely set a new record for fastest/furthest object sent out into the universe by man. Win-Win! [[Special:Contributions/172.70.91.27|172.70.91.27]] 17:23, 5 September 2024 (UTC)

Talk:2966: Exam Numbers

2024-08-01T01:06:51Z

162.158.41.181: /* Number */ new section

pre-algebra: 4, calculus: pi^2 / 4 (about 2.467), physics: cosmological constant: depends on how you measure it [[Special:Contributions/162.158.167.48|162.158.167.48]] 18:11, 31 July 2024 (UTC)

Game theory: -5x10⁶ (maybe helpful, maybe not... just be thankful I didn't include an ''i'' factor in there somewhere...) [[Special:Contributions/172.70.162.185|172.70.162.185]] 18:20, 31 July 2024 (UTC)

Could somebody reformat all the math here in whatever LaTeX plugin this wiki uses? --[[Special:Contributions/162.158.222.102|162.158.222.102]] 18:35, 31 July 2024 (UTC)
:Probably not, because the MathML here is broken. But, also, nothing I see requires anything particularly complicated, it can all stay in fairly straightforward (standardly formatted) text. [[Special:Contributions/141.101.98.224|141.101.98.224]] 18:44, 31 July 2024 (UTC)
I had to look up "TREE(3)." Seriousness aside, I think the largest number would be the astrological sign 1 that has its end_points_ as galaxy clusters. [[Special:Contributions/172.68.245.184|172.68.245.184]] 19:26, 31 July 2024 (UTC)
Which astrological sign? Search engines aren't helping. [[User:Onestay|Onestay]] ([[User talk:Onestay|talk]]) 20:41, 31 July 2024 (UTC)
::The nonexistent one I just made up that looks like a "1." 😃 [[Special:Contributions/172.71.222.6|172.71.222.6]] 21:06, 31 July 2024 (UTC)
Infinity is _not_ a number. [[User:Dúthomhas|Dúthomhas]] ([[User talk:Dúthomhas|talk]]) 19:39, 31 July 2024 (UTC)

If infinity _is_ a number, it might be a possible solution to the game theory question. The average of any set of numbers that includes infinity is infinity, and infinity + 10 is still infinity. I probably wouldn't try that in most classes, but a game theory professor might approve "gaming" the system, as it were.
:If I would prefer no-one (else) to win, I might submit -∞ as my answer. [[Special:Contributions/172.70.90.74|172.70.90.74]] 20:13, 31 July 2024 (UTC)

Infinity is absolutely not a number, and is the one answer I would mark as unambiguously wrong for the last one. Just say TREE(G_64) or something. [[Special:Contributions/162.158.154.31|162.158.154.31]] 20:15, 31 July 2024 (UTC)
:This is correct. No one in post-grad math would write “infinity” and expect that answer to work. Infinity is NOT a number except for seven-year-olds. Yet the explanation above continues to posit it as a possible correct answer. [[User:Dúthomhas|Dúthomhas]] ([[User talk:Dúthomhas|talk]]) 20:49, 31 July 2024 (UTC)
:In IEEE floating point math, Infinity is ''not'' Not A Number. The latter is an indication of error (in a context where errors can't be signalled immediately) and an entirely separate concept to infinity. But both are not Normal Numbers. Or even Denormalized Numbers. Floating point math is a whole lot trickier than it appears to be at first glance, and only extremely tangentially related to mathematical reals. --[[Special:Contributions/172.68.205.54|172.68.205.54]] 00:48, 1 August 2024 (UTC)

I did a bit of a deep dive into wikipedia and the googology wiki and the answer to the last question depends on a few things (along with assuming ZFC). If transfinite ordinals count as numbers, then those at the end of {{w|List of large cardinal properties}} take the cake (if i'm reading it right). Otherwise, something based off [https://googology.fandom.com/wiki/Rayo%27s_number Rayo's number] is the best googologists have come up with so far. [[Special:Contributions/172.69.246.149|172.69.246.149]] 20:18, 31 July 2024 (UTC)Bumpf

Isn’t the joke in the pre-algebra that it would require algebra in order ro calculate? [[Special:Contributions/172.68.70.135|172.68.70.135]] 20:36, 31 July 2024 (UTC)
:Yes. I agree that it would be worth adding wording along the lines that “the joke here is that you need algebra to solve the equation”. [[User:Dúthomhas|Dúthomhas]] ([[User talk:Dúthomhas|talk]]) 20:56, 31 July 2024 (UTC)

You know, formatting math on this wiki would be a lot easier if the Math extension were correctly installed, but evidently it's not: <math>\int_0^\pi x \sin^2 x \;dx</math> [[User:Zmatt|Zmatt]] ([[User talk:Zmatt|talk]]) 22:22, 31 July 2024 (UTC)

== Number ==

A number, by definition, is a construct used to classify and/or compare values. How rigorous this needs be for one limits the extent to which they accept things as being a number. Even things like "apple" could be interpreted as (dimensioned) numbers, with a possible value being "1 fruit"; In that regard, one may consider things like apple=orange<grapes.

Just "infinity" is nearly useless in this regard, as it's "no end thing". Usually interpreted (when necessary) as the countable infinite cardinal x=aleph_null, this prevents most useful comparisons, including dimensional analysis since x^n=x for all counting (aka. finite positive integer) n. Spacetime may or may not be boundless, but we can't tell how many edges may or may not loop. Is it infinity? Yes. Is it infinite? God only knows. Can you *count to it*? God can. Does that make it a number? Depends. Is "infinity plus one" a sane concept? No, it can't be finite, ordinal, and/or real in a way addition is defined; It's without end, and if you could add to it, that would indicate an end.

In contrast, classification has its roots in trade, and barter, and tipping. How much of a thing is enough, but not too much. Somebody may accept between 1/2 and 2/3 of a pie you're splitting, because less wouldn't be fair and more may give them a stomach ache; Is 3<=6x<=4 a number? It's similar in uselessness to "infinity", but whether something is less or more can at least still be established within its range. In the limit, Surreal numbers are the principal example of classification, taking the arithmetic mean of the maximum and minimum of their lower and upper bounds, or the predecessor or successor, or zero. For example, y={y|1} is the biggest number less than one, with z<=y<1 for all z<1. It's less than one, but not any "smaller" than one, with an immeasurably infinitesimal difference 0<1-y.

Choice of axioms is very important for all this, since its full extent can render everything except finite non-negative integers "not a number" (by Presburger Arithmetic), or allow everything up to and including unique antichain cardinalities (by Martin's Maximum).

The sixth power of the smallest ordinal with the cardinality of the continuum in the constructed universe (w_1^6 where beth_n=C(w_n)) is the biggest number I can personally conceptualize, although I can consistently work with w_2 in this system as well. Does the fact that this is infinite make it any less useful as a number than 2.5? No. It says I can think accurately about all the standard ways of comparing things in up to 6 infinitely divisible dimensions. Just because one cannot necessarily picture something others can't doesn't mean it doesn't exist. If a one-eyed person can only see a 2 spatial + 1 temporal dimensional image, that doesn't mean depth doesn't exist, it just means it's "hidden" from that perspective. 3+1+2 has two "hidden" dimensions compared to normal 3+1 spacetime, and beth_1 is infinitely divisible unlike the quantum (at most beth_0) nature of our known universe, but I can still work with 3+1+1, and 3+1+2 in the same way people can think about a (possibly looping) universe where everything can be bigger or smaller, and spatial geometry itself may be some degree of spherical, and people have been working with fractions since antiquity, so why should I limit myself to what other people can grasp?

In summary: "number" is too vague for claiming most things "aren't" to be reasonable. Infinite values (that aren't just "infinity", that's vague enough by itself to be almost as unreasonable) are just one one example of a valid answer most people seem to be up in arms about. [[Special:Contributions/162.158.41.181|162.158.41.181]] 01:06, 1 August 2024 (UTC)