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July 28[edit]

Is electrical brain stimulation used (like drugs) to produce pleasures in humans in other settings than scientific experiments?[edit]

Thanks. Apokrif (talk) 16:27, 28 July 2021 (UTC)

There is a large review[1] cited in our article in which I couldn't find the work "pleasure" or other words with similar meaning. There are probably easier ways to have fun....! Mike Turnbull (talk) 17:12, 28 July 2021 (UTC)
Our Wirehead (science fiction) article describes some fictional uses. CodeTalker (talk) 02:56, 29 July 2021 (UTC)

July 30[edit]

What's the maximal level of absolute humidity possible practically?[edit]

What's the maximal level of absolute humidity possible practically & naturally on earth (troposphere)? --ThePupil (talk) 03:25, 30 July 2021 (UTC)

This is dependent upon a few factors, mainly temperature (which is not at all uniform in the troposphere). At 25 °C, water has a vapor pressure of 3.169 kPa. Above this pressure, water vapor will condense to the liquid state, so this pressure can be taken as a maximal pressure. At this temperature and pressure, water can be approximated as an ideal gas, which means we can use the ideal gas law (pV=nRT) to approximate the concentration of water the air (n/V=p/RT), which gives us a concentration of 0.00128 moles of water per liter of atmosphere. Using the molar mass of water, that gives us ~0.0231 grams of water per liter of atmosphere, or 23.1 mg of water per liter of atmosphere. Again, that's at roughly room temperature. Since the vapor pressure of water is temperature dependent, and temperature is also a variable in the ideal gas law, we can expect a fair amount of temperature dependent variation in this number. For example, at 55 °C, among the hottest ever recorded surface temperatures, this concentration would be 104 mg of water per liter of atmosphere, while at at the coldest recorded temperature (roughly -90 °C), the concentration would be essentially 0 mg per liter of atmosphere, as the vapor pressure of water is practically zero once you go below the freezing point. Again, these are approximations, but should be fairly good. Note that clouds will contain a much higher concentration of water than that given here, but that is because clouds contain most of their water in the liquid state. Humidity is explicitly the measure of water vapor content in the air, and not water liquid content. --OuroborosCobra (talk) 04:50, 30 July 2021 (UTC)
Dew points of a little over 30°C have been recorded in places like India, the Amazon and around the Persian Gulf. This gives a vapour pressure of around 5 kPa, so that would be around 30 mg per litre, using the answer above. In higher temperatures, the dew point could be higher, but in reality this doesn't happen as much higher temperatures don't occur in places where water is available for evaporation. Evaporation takes enough energy to prevent such temperatures from occurring. PiusImpavidus (talk) 09:06, 30 July 2021 (UTC)
35°C if you narrow it down to single place, single time. Almost 40mg/liter or 0.04 in the kg/m3 units below.Sagittarian Milky Way (talk) 19:41, 30 July 2021 (UTC)
What's the density of steam at 100°C and standard atmospheric pressure? Roger (Dodger67) (talk) 09:33, 30 July 2021 (UTC)
According to Water (data_page)#Water/steam equilibrium properties, about 0.6 Kg/m3. Mike Turnbull (talk) 11:27, 30 July 2021 (UTC)
Well, that doesn't occur naturally as a meteorological phenomenon in the troposphere, but one can argue it occurs naturally in fumaroles. PiusImpavidus (talk) 15:52, 30 July 2021 (UTC)
PiusImpavidus, it is however a regular occurrence in billions of kettles and cooking pots every day. Roger (Dodger67) (talk) 21:39, 30 July 2021 (UTC)

What is the efficacy of a previous COVID infection against another infection?[edit]

The Pfizer vaccine, for example, is over 80% effective after six months but less than 40% against the Delta variant, according to Israeli studies. Are there similar studies for COVID patients who have recovered? (talk) 21:07, 30 July 2021 (UTC)

Here are some primary sources (some more recent than others, be sure to contextualize each with its date--there's a lot more recent work out there, but I tried to curate a reasonable sized shortlist here to address several different aspects of the empirical question of post-infection immunity. This is, needless to say, an area of ongoing inquiry with a lot of open questions): [2],[3],[4], [5],[6],[7],[8],[9],[10], [11],[12].
And here are some secondary sources, some consisting of news/editorial commentary from peer review journals, others from a variety of news media summarizing, as best each can, the current state of research:[13],[14],[15],[16],[17],[18],[19],[20],[21].
Our WP:SYNTH policies prevent me from extrapolating a generalized figure from the primary sources: I recommend looking at them each in turn, again with the caveat that they come from all over the last nine months or so, and this being an area of swiftly advancing research. However, I can summarize some general points from the primary and secondary sources collectively: in short, there is cautious optimism for a substantial (but far from guaranteed) level of immunity for those who have previously been infected, but because long term data is (by definition) constrained by the length of the pandemic to date, the duration of this immunity is a big unknown. Furthermore, recent viral variants significantly complicate the question, and broadly speaking, researchers and public health officials tend to recommend vaccination for even those who have previously been infected, all other factors being even. More nuance in interpretation you will have to derive from your own review of the materials. SnowRise let's rap 01:49, 31 July 2021 (UTC)
I look at r/coronavirus sometimes. A lot of good info is there, along with a fair amount of not-so-good, but at least it's all in one place. Before Delta they were telling people who had not been infected to get two shots (Pfizer/Moderna), and people who had recovered from infection to get one shot. More recently I've heard people over 60 who have already had two shots are being advised to get a third shot. Some people with long term symptoms after recovering from infection (long covid) have experienced some relief from the symptoms after receiving vaccine. Besides vaccinations, it is still important to mask up, stay away from crowds, etc. The US govt made a big error in betting everything on vaccines: it desperately wants the pandemic to be over, but the virus is not so easy to persuade. 2601:648:8202:350:0:0:0:2B99 (talk) 04:18, 31 July 2021 (UTC)
The issue here is defining "efficacy". Efficacy has many meanings in medicine - not just vaccines. Some measures of efficacy that have been and/or could be used to describe vaccines include: risk of infection, risk of severe infection, risk of hospitalization, risk of death, risk of sequelae after infection resolves, (decrease in) viral load, "transmissibility", and many more. This is why it's never sufficient to say "well the Pfizer vaccine has an efficacy of 95% and the J&J has an efficacy of 85%" - because I just gave you the number for all infections for the Pfizer vaccine, and for severe infections for the J&J vaccine. For the purposes of this answer, I'm going to assume you're interested in any efficacy information, and I'll make it clear what the efficacies are describing.
  • doi:10.1016/j.cell.2021.06.02: Convalescent serum (i.e. antibodies in blood from people previously infected) of people who had "regular" COVID, alpha variant, beta variant, and gamma variant, was tested to see its "strength" at neutralizing the delta variant, and this was compared to the serum's strength at neutralizing a very early sample (from early 2020, i.e. not mutated). Neutralization was decreased by anywhere from about 2-fold to about 6-fold depending on the exact delta variant tested. This basically means that antibodies produced from natural infection are somewhere between 16% and 50% effective at neutralizing the delta variant in vitro. This does not necessarily translate to infections in humans though. Of note, beta-variant antibodies were over 10-fold less effective at neutralizing the delta variant as they were at neutralizing the beta-variant. The same is true for the gamma variant. As such, it is in my opinion not too far a leap to say that people who previously were infected with the beta or gamma variants are likely not very protected against re-infection with the delta variant.
  • doi:10.1038/s41586-021-03777-9: Similar results - convalescent serum (i.e. antibodies in blood from people previously infected) was 4- to 6-fold less neutralizing against the delta variant. By 12 months after infection, less than half of people were producing antibody levels that could neutralize the delta variant (compared with almost 90% for the alpha variant).
  • doi:10.1093/jtm/taab104: 4.6x less neutralizing against delta than against "regular" COVID.
I stopped looking once I found 3 decent-quality articles that all basically said the same thing - in the average person who was infected with COVID-19, it requires 4-5x more antibodies to neutralize the delta variant as it did/would to neutralize "regular" COVID - or even some other variants. Thus their risk of infection is likely greater - but how much greater cannot be said with any accuracy as titers and "test tube tests" don't tell the full story. Obviously you will also have people who formed stronger immune responses to COVID to begin with, and as such are producing more antibodies than someone who had a very mild and quick infection. Unfortunately, for us to get actual "real life" data so we could say exactly how much more likely a re-infection with delta is than a re-infection with another variant (or original COVID), we need massive amounts of genetic sequencing. Not just for new cases, but we need to go back and sequence old cases - from fall 2020 onwards - to know which variant those people were infected with prior. Without knowing the original variant someone was infected with, we cannot begin to say how effective prior infection is at preventing delta-variant infection.
Not to mention that "prior infection" could mean infection in March 2020, which would have been the original variant, or it could mean infection with the delta variant three months ago. Re-infection of the delta variant after prior infection with the delta variant is unlikely - as the body will have produced antibodies specific for the delta variant. However, other variants will all have different levels of protection against re-infection with delta instead - so it's really complicated.
TLDR: antibodies in convalescent serum are about 4-fold less neutralizing against delta than against other variants - but we won't know for a few months likely how this actually impacts reinfection risk. -bɜ:ʳkənhɪmez (User/say hi!) 19:38, 31 July 2021 (UTC)

July 31[edit]

How can I know my vehicle is power steering or normal steering ?[edit]

How can I know my vehicle is power steering or normal steering ? Rizosome (talk) 15:13, 31 July 2021 (UTC)

RTFM? Mike Turnbull (talk) 15:59, 31 July 2021 (UTC)
(ec)Well, if you have a fairly modern car, you probably do have power-steering - I think it's now fairly ubiquitous, at least in advanced markets. Otherwise, try turning the wheel in the standing car, with the engine on and the engine off. If you have power-steering, it will be a lot easier with the engine on. Another, under-appreciated option: Check the owner's manual ;-). --Stephan Schulz (talk) 16:03, 31 July 2021 (UTC)
  • If it's the common hydraulic kind, power steering may keep working for a little while (at least a few seconds, I don't know) until it loses hydraulic pressure after the engine is turned off. So test it by turning the steering wheel first when the car has been parked a while, then starting the engine and trying again. As for the owner's manual, it may say things like "if you have power steering, then...", which is not helpful for this purpose. -- (talk) 21:22, 31 July 2021 (UTC)
The last car I had without power steering was a 1985 Ford Sierra. Alansplodge (talk) 18:27, 31 July 2021 (UTC)
Nowadays power steering is normal steering. One rare exception: the Alfa Romeo 4C: "To save weight and increase steering feel, the 4C has no power steering." Bumptump (talk) 21:19, 31 July 2021 (UTC)

Turn on the car motor and turn the steering wheel back and forth with the car in neutral (not moving). Then turn off the motor and turn the steering wheel back and forth. If you have to muscle the steering wheel around when the motor is not running, but it moves easily when the motor is running, that is the power steering (which is driven by the car motor) assisting you. 2601:648:8202:350:0:0:0:2B99 (talk) 19:05, 1 August 2021 (UTC)

Via ferratas and lightning rods[edit]

Do the metal cables used in a via ferrata turn, during a thunderstorm, into unwanted lightning rods? What would happen to the climber near the cable or touching it in the case of a lightning strike? --Bumptump (talk) 21:13, 31 July 2021 (UTC)

They would probably be injured or killed. Having said that, anyone on the side or peak of a mountain during a thunderstorm, even in the absence of such attractors, is already at risk from being struck by lighting – two women were killed injured on the summit of Snowdon earlier this week. {The poster formerly known as} (talk) 21:29, 31 July 2021 (UTC)
They're grounded every few meters though... Abductive (reasoning) 23:51, 31 July 2021 (UTC)

August 1[edit]

Why are there not more clusters at indoor PCR test sites?[edit]

I just went to work for a week and would like to get tested, but I don't want to go into a clinic, and then an enclosed room, where other patients, including infectious ones, also take off their masks and sneeze upon having a long swab inserted into their nose. Isn't that a sure way to get a lot of viral particles into the air? Why don't more people get sick from that? Imagine Reason (talk)

People probably would get sick from that, but that's why most people test themselves at home (I do a self test at home twice a week) and all the public testing sites I've seen are in the open air and socially distanced. It probably depends where you live, but in the UK, self-test kits are given away for free at rail stations, pharmacies, etc.--Shantavira|feed me 14:24, 1 August 2021 (UTC)
In the UK, most PCR test sites are drive-through and you are not allowed out of your car. Walk-through sites have one-way systems so that you never come into contact with other members of the public and the testing bays are sanitized after each test. [22] The lateral flow tests that you can do at home are not as reliable, but are a lot less fuss and are the best bet if you don't actually have symptoms. [23] Alansplodge (talk) 22:44, 1 August 2021 (UTC)
That's nice. In the US most test sites are doctor's offices or urgent-care clinics. Completely indoors. Open spaces are harder to come by. I guess I should look for a mobile testing site then. I've gotten the vaccine so I don't know how good antigen tests would be. Also, home test kits have high error rates. Imagine Reason (talk) 23:16, 1 August 2021 (UTC)
Indeed. Over here, the advice is to take a lateral flow test at home - if it's positive - book a PCR test to double-check. Alansplodge (talk) 18:09, 2 August 2021 (UTC)

Conversion of kinetic energy of a superfluid[edit]

Is it possible to convert the indefinite kinetic energy of a superfluid (e.g., after being stirred up) into electricity, similar to hydroelectric power plant? Or would the costs of maintaining the superfluidity be too high? (talk) 14:51, 1 August 2021 (UTC)

Superfluids don't have indefinite kinetic energy. They have no friction so they don't lose any kinetic energy you give them. If you extract that energy, they will slow down like anything else would. --Jayron32 11:59, 2 August 2021 (UTC)

Would a oloid or sphericon planet be able to exist or if magically appeared somewhere be able to continue with its shape?[edit]

Would a oloid or sphericon planet be able to exist or if magically appeared somewhere be able to continue with its shape?

I am asking about those 2 specific things because they are developable surfaces.2804:7F2:691:D026:F49A:3097:3AC3:3524 (talk) 15:43, 1 August 2021 (UTC)

If the planet was small and rigid, I suppose it could hold its shape, just like the random chunks of rock in the asteroid belt hold their own shapes. Mars's moons (which are quite small) are also not very spherical. What we normally call planets are big enough to have substantial surface gravity. So they end up close to spherical or (because of rotation) oblate, to minimize the gravitational potential energy in the mass distribution. Even still, they will have surface features like mountains. The Earth itself is slightly pear-shaped: see geoid. 2601:648:8202:350:0:0:0:2B99 (talk) 19:11, 1 August 2021 (UTC)
A planet is by definition massive enough to be rounded by its own gravity so your objects wouldn't be called planets. PrimeHunter (talk) 23:44, 1 August 2021 (UTC)
The largest nonspherical object in the solar system is Iapetus, with a diameter of approximately 1490 km (since it's nonspherical, it doesn't really have a well defined diameter). The next larger objects, Oberon (diameter 1522 km), Rhea (diameter 1530 km), and Titania (diameter 1576 km), are only slightly larger but are in hydrostatic equilibrium and are therefore close to spherical. So about 1500 km seems to be the limit for a nonspherical body, at least one made from materials common in our solar system. CodeTalker (talk) 05:20, 2 August 2021 (UTC)

August 3[edit]

Plants - berry and juices questions.[edit]

Strawberries, raspberries, and blackberries roughly have the same lifespan, they decay quickly to room temperature. Blueberries spoil/decay 5x slower, so they can last 5x longer. Why is that? I heard the answer has something to do with respiration. All of them must be kept at 33 F - 35 F or 1-2 C. Problem is if it goes to 0 C, ice forms, but the issue isn't when ice forms, but when ice melts, then expansion damages the fruit.

Then, what about juices? Why are some juices can last much longer, and in room temperature, than other juices? By looking at expiration dates, cherry juice seems to last a year from shelf life. And apple, grape, and pear juices tends to be mixed together, but not with shorter-lifespan juices like strawberry. So, nobody sells a "blueberry-strawberry" juice mix, certainly not at room temperature, not because of the blueberry, but because of the strawberry. I've never seen a cranberry-strawberry, but I do see cranberry-raspberry, which is puzzling to me, because raspberry juice has the same shelf life as strawberry juice? Does cranberry juice actually have an effect that increases the lifespan of raspberry juice, for example? That it would not otherwise do with strawberry juice? Raspberry and blackberry juice can be mixed together because of their same-lifespan / shelf life.

So what is it in strawberry juice that makes it the shortest shelf life, that has to be refrigerated the most? Thanks. (talk) 03:42, 3 August 2021 (UTC).

  • Juices are covered by a rather unique Juice HACCP program. Typically they are pasteurized, so I'll bet that the shelf life of strawberry juice is not because it is any more likely to be affected by microbial growth, but by physical changes. I'm guessing it turns an ugly color very quickly. Abductive (reasoning) 08:07, 3 August 2021 (UTC)
Another thing that can go wrong is that a solid deposit comes out of the juice and onto the container, which looks ugly. Graeme Bartlett (talk) 22:58, 3 August 2021 (UTC)

Electron flow[edit]

Do electrons flow differently in a wire than in a circuit? Here's what I gathered.

In a wire: both electrons and protons travel from high voltage to low voltage.

In a circuit: electrons will flow from a point of more negative voltage to that of a more positive voltage. Electricity travels from high negative charge (lots of free electrons) to low negative charge or even positive charge (missing electrons). High voltage means more difference in charge, low voltage means less difference in charge.

I presume these aren't contradicting? (talk) 05:45, 3 August 2021 (UTC).

Electricity goes from the positive side to the negative side. This is just a definition, made up before electrons were discovered. In wires (and most circuits are made of wires) the electrons move in the opposite direction. The protons don't move. Electrons have a negative charge and a flow of negative charge in one direction gives the same current as a flow of positive charge in the opposite direction. But an electric current isn't always a flow of free electrons. When we send electric current through sea water, we get positively charged sodium ions moving from positive to negative and negatively charged chloride ions moving from negative to positive, both coming from the dissolved salt. PiusImpavidus (talk) 08:15, 3 August 2021 (UTC)
So to give direct answers:
  • "In a wire: both electrons and protons travel from high voltage to low voltage." Incorrect. The electrons travel from negative voltage to positive voltage, the protons don't travel.
  • "In a circuit: electrons will flow from a point of more negative voltage to that of a more positive voltage." Correct, except that the electric current isn't always carried by electrons – but in a wire, or a circuit made of wires, it is.
  • "Electricity travels from high negative charge (lots of free electrons) to low negative charge or even positive charge (missing electrons)." Incorrect, it's the opposite. Electricity goes from positive to negative, although the electrons go from negative to positive. And the current goes from positive potential to negative potential (voltage between two points in a circuit is the difference in potential between those points), not from positive to negative charge, although with non-zero capacitance those are correlated.
  • "High voltage means more difference in charge, low voltage means less difference in charge." Almost. In real circuits, capacitance is never zero and the voltage is proportional to charge divided by capacitance. In ideal circuits (and many real-life electric components are close enough to ideal), capacitance is taken as zero (except where, by design, it's not), so there is no charge, but still voltage. PiusImpavidus (talk) 09:04, 3 August 2021 (UTC)
I'm curious where you listed electricity as the opposite direction of electrons. So can we say electricity travels from high voltage to low voltage? (But not electrons). I should ping @Thinking of England:. (talk) 19:01, 3 August 2021 (UTC).
The direction of current is opposite to the flow of electrons. I think PiusImpavidus explained it correctly. Graeme Bartlett (talk) 22:55, 3 August 2021 (UTC)
Isn't that what current is, the flow of electrons? Okay, so that's 3 questions: the flow of electrons, the flow of electricity, and the flow of current. -_- (talk) 23:18, 3 August 2021 (UTC).
No. The most common form of electric current you may be aware of is the flow of electrons through a conductor, and by arbitrary convention we have defined the direction of that electric current to be opposite that of the direction of the flow of electrons. But there are also examples of flow of positive charge carriers (as has been mentioned by other editors here), and those cases also represent an electric current, and by arbitrary convention we have defined the direction of that electric current to be the same as the direction of the flow of those positive charge carriers. -- ToE 23:57, 3 August 2021 (UTC)
You rang? (I don't know what you expect from me, but perhaps I can rephrase some of the statements already made.)
The net direction of flow of a particular type of charge carrier in a particular system at a particular moment is a well defined physical property. If 6.24×1018 electrons per second are flowing through a conductor from point A to point B, this direction of electron flow is true, independent of any convention. But by convention, we measure the direction of "electrical current" as being in the same direction as the net motion of positive charge carriers and the opposite direction as the net motion of negative charge carriers. And when we say that 1 amp of "electricity flows" from point B to point A (in the example above), we mean that the direction of current, as we define it by convention, is from point B to point A -- even though in that example the direction of net charge carrier motion is opposite. That does not mean there are some separate physical particles of a substance called "electricity" which are flowing opposite those electrons. We simply define the "flow of electricity" by that convention.
Quoting from Electric current§Conventions:
The direction of conventional current is arbitrarily defined as the direction in which positive charges flow. Negatively charged carriers, such as the electrons (the charge carriers in metal wires and many other electronic circuit components), therefore flow in the opposite direction of conventional current flow in an electrical circuit.
Does that help?
As far as flow from high voltage to low voltage, I'd rather not use those terms, as High voltage has a specific meaning. (-10,000 VDC above ground is high voltage, whereas +5 VDC is not.) So speak instead of electricity traveling from more positive voltage to more negative voltage (or to less positive voltage if you wish), and electrons traveling from more negative voltage to more positive voltage. -- ToE 23:49, 3 August 2021 (UTC)
Okay, your last sentence hit the nail, electricity travels from more positive voltage to more negative voltage, electrons travel from more negative to more positive voltage. Which 1 does current go with? (talk) 01:19, 4 August 2021 (UTC).
One note, is that electricity, even in solid conductors, can be the flow of positive charge. See Electron hole and P-type semiconductor. --Jayron32 14:44, 3 August 2021 (UTC)
There are also solid ion conductors, eg for lithium or sodium, but they are special materials and not metals. The main electric flow in a metal like wire is carried by electrons. Electric flow will also be accompanied by a magnetic field. Graeme Bartlett (talk) 22:55, 3 August 2021 (UTC)

CNN report on breakthru covid infections[edit]

[24] Does this story say anything meaningful? It got a fair amount of attention. It says less than 1% of vaccinated people have experienced breakthrough Covid infections, but doesn't give a comparison number for non-vaccinated people. Per [25] the current infection rate in California is 16.4 per 100K, which is far below 1%, and actually suspiciously low (can it possibly be right)? I see all kinds of numbers in the news, that are useless as far as I can tell. They are trying to imply things about without giving enough info to actually compute this important ratio.

ObDisclaimer: I'm not looking for medical advice. I'm vaccinated but know someone who is not, who is hassling about it. Thanks. 2601:648:8202:350:0:0:0:2B99 (talk) 06:53, 3 August 2021 (UTC)

  • So, this 1% is a sort of prevalence figure? Abductive (reasoning) 08:12, 3 August 2021 (UTC)
    • I can't tell. There is no data to show where that number came from. There is some stuff on that might be more informative and that I'll try to look at when I can, but it is late here now. If the 16.1/100k figure is the number of active infections new infections per day right now, and the average one lasts 10 days, then extrapolating over the ~ 500 day pandemic would mean about 8% of the population was infected at one time or another. I guess I can believe that. 2601:648:8202:350:0:0:0:2B99 (talk) 08:32, 3 August 2021 (UTC) (Edited: fix words to fit math).
Somewhat more worrying in terms of breakthrough infections is this recent paper on the CDC website."Outbreak of SARS-CoV-2 Infections...". doi:10.15585/mmwr.mm7031e2. Cite journal requires |journal= (help). It suggests that the Delta variant can cause infection even in those who were fully vaccinated. Mike Turnbull (talk) 11:24, 3 August 2021 (UTC)
When the vaccines first came available, I don't recall anyone claiming their vaccine was 100 percent effective against catching the virus. ←Baseball Bugs What's up, Doc? carrots→ 21:33, 3 August 2021 (UTC)
In terms of a reference for a Wikipedia article, per WP:MEDRS, CNN is not a qualified source to use for adding such information. If the CNN article cites their sources, I would go to those to learn more. --Jayron32 14:42, 3 August 2021 (UTC)
This article from the Seattle Times gives the source of the study as the Kaiser Family Foundation - the KFF press release is here and the data summary is here. Alansplodge (talk) 17:34, 3 August 2021 (UTC)

August 4[edit]

If we take all water in the atmosphere and collect them together it'll be equall to how many percent of the water on the earth?[edit]

If we take all water of the atmosphere (~0.001%) and collect them together, then it'll be equal to how many percent of the water on the earth? Is there any rough information / estimation about it? --ThePupil (talk) 01:09, 4 August 2021 (UTC)

Actually, sources debunking Creationism may already have done this, as they've done calculations about the thermodynamics of condensing that much water vapor to liquid all at once. Spoiler alert: the amount of heat released by that much condensation would be a lot, as in all life gets cooked alive and dies a lot. I think it is talked about here and in this paper --OuroborosCobra (talk) 01:19, 4 August 2021 (UTC)
I've found here that the atmosphere has 37.5 million-billion gallons. I don't know based on what this calculation is made on, but if we compare it to the estimated quantity on the earth, how many percent does it take compared to it? --ThePupil (talk) 01:57, 4 August 2021 (UTC)

According to Wikipedia, the atmosphere of Earth has a mass of 5.15×1018 kg and contains 0.4% water vapor on average. So there's just over 2×1018 kg of water vapor. 1 g of liquid water has a volume of 1 cm³, so 1 kg has a volume of 1 L, and so 2×1018 kg has a volume of 2×1018 L, which is 2,000,000 km³. Again according to Wikipedia, The total volume of water on Earth is estimated at 1,386,000,000 km³. So the water in the atmosphere is 2/1,386 or about 0.14% of all the water. -- (talk) 02:24, 4 August 2021 (UTC)

According to the given data, there are 194040000 km of water in the atmosphare, right? Does it go together with Wisconsin university's statement that the Earth’s atmosphere contains 37.5 million-billion gallons of water?--ThePupil (talk) 02:42, 4 August 2021 (UTC)
No, since km is a unit of length and gallons is a unit of volume. --OuroborosCobra (talk) 03:20, 4 August 2021 (UTC)
I recall reading that if all the water in the atmosphere were to rain out, it would only be 1 inch/ 2cm deep on average. This is consistent with atmospheric pressure being 14.7 psi, and water being about 0.25% of that. Abductive (reasoning) 03:51, 4 August 2021 (UTC)
Ah, I found a USGS website for schoolchildren that says exactly that. Abductive (reasoning) 03:54, 4 August 2021 (UTC)

1 km³ converts to about 264,000,000,000 US gallons. Therefore "37.5 million-billion gallons", i.e. 37,500,000,000,000,000,000 US gallons, converts to only about 142,000 km³. If the figures in Wikipedia are anywhere near correct, whoever wrote that item at the U of Wisc has gotten it wrong by several orders of magnitude. -- (talk) 04:20, 4 August 2021 (UTC)