explain xkcd - User contributions [en]

Talk:1924: Solar Panels

2023-06-08T11:23:10Z

198.41.242.149: jsut commenting a comment ...

Sorry, but who, except the odd American, has *empty space* next to anything that belongs to him? ;-) --[[Special:Contributions/162.158.89.199|162.158.89.199]] 20:47, 4 December 2017 (UTC)
:I think there are a lot of farms and villages where the residents have empty space next to them outside of America. And even inside America anyone in urban areas doesn't have much empty space next to them. But urban areas are prime for rooftop installation, which also has the added benefit of not covering up areas of vegetation. Also apartment buildings are more likely to have flat rooftops which are better for placing solar panels. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 14:26, 6 December 2017 (UTC)
::Well I'm not going to give up a fifth of my precious garden to solar cells, when I can mount them safe and flat on the roof of the house, where they are already at a close to ideal angle (provided your gable goes east-west, OK). And for most people in the old world, as for American suburbia, the available area on a south-facing roof is more close to a third or half of the free space around the house. And I neither want solar cells or my terrace on the north side. :-/ --[[Special:Contributions/162.158.93.21|162.158.93.21]] 10:06, 7 December 2017 (UTC)

And really, if it moves, just keep the diesel engine in it, or switch to hybrid if you can. Batteries that are charged from power plants running on fossile fuel are an ecological nightmare. And car batteries are usually charged overnight, when solar panels are dead. --[[Special:Contributions/162.158.89.199|162.158.89.199]] 20:54, 4 December 2017 (UTC)

:You are right that charging batteries from power plants running on fossile fuel doesn't really bring any ecological advantages ... assuming the engine operates close to optimal parameters. Most cars doesn't operate near optimal parameters inside city, but do on highways, hence hybrid. Also, it is much more ecological to have batteries charged by nuclear power plants. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 04:15, 5 December 2017 (UTC)
::Ja, Germany here. Our whole politics from left to right has this obsessive-compulsive nuclear-power-blows-up-and-poisons-everyone problem, so we're switching them off. --[[Special:Contributions/162.158.89.133|162.158.89.133]] 07:49, 6 December 2017 (UTC)
:::Which has happened now ... so we now buy nuclear power from countries with less safe power plants, while energy prices are skyrocketing yay! --[[Special:Contributions/198.41.242.149|198.41.242.149]] 11:23, 8 June 2023 (UTC)
: I always thought of the main advantage of electrical battery powered cars (instead of petrol or Diesel powered ones) was not so much the immediate ecological improvement, but rather that (once they are the norm) you don't need to convince EVERY SINGLE CAR USER to get rid of their old car and get a new one (Like you have to do now, when you invent engines which use less fuel or something). Instead, when you change the overall energy production of a country (hopefully to something more sustainable and envronmentally friendly), the cars will just passively follow. [[Special:Contributions/162.158.89.37|162.158.89.37]] 14:46, 5 December 2017 (UTC)
:: I think the main motivation for moving to electric vehicles is that it largely moves the pollution away from where people are. (From the energy production, anyway - particulate pollution from brakes, tyres, etc. is a whole other matter...)[[Special:Contributions/162.158.34.4|162.158.34.4]] 09:10, 6 December 2017 (UTC)
:::Not another matter, but the exact thing that makes mass-use of electric cars pointless in the moment, especially when motors have catalytic converters, which they have since the mid-90ies. --[[Special:Contributions/162.158.93.21|162.158.93.21]] 10:10, 7 December 2017 (UTC)

I think that the reference to solar panels on roads in the title text could also be talking about the disaster that is solar roadways.
[[Special:Contributions/108.162.221.244|108.162.221.244]] 22:50, 4 December 2017 (UTC)

I don't think it's appropriate to use rooftops as an example of where solar panels should not go when the title text of the comic specifically uses rooftops as an example of a good place for solar panels. How many people have an empty field near their house? I also think it's worth mentioning [https://en.wikipedia.org/wiki/Smart_highway#Photovoltaic_pavement Solar Freakin' Roadways] [[User:YM Industries|YM Industries]] ([[User talk:YM Industries|talk]]) 04:08, 5 December 2017 (UTC)

: I agree, rooftops are kinda the prime example for good places to put solar panels. Especially because even in small cities, there are tons of flat-roofed buildings (which would make the alignment to the sun possible) and it is often (nearly) unused space, whereas an "empty" (as in not-build-upon) space could be used for lots of other things, not least just some wild nature. I went ahead and changed the explanation accordingly, putting hte emphasis mor on inclined vs. flat surfaces (and this free to select optimal direction)[[Special:Contributions/162.158.89.37|162.158.89.37]] 14:46, 5 December 2017 (UTC)

The current transcript is not very useful for people who use screen readers, or for any other purpose (e.g. full text search). Could someone please describe the flowchart in a purely textual, "linear" fashion, as was done for other flowchart comics? Thanks very much in advance! Zetfr 15:01, 5 December 2017 (UTC)
:I tried to improve it, hopefully it's helpful. [[User:Asdf|Asdf]] ([[User talk:Asdf|talk]]) 18:02, 5 December 2017 (UTC)
::Great, thanks a lot! Zetfr 22:06, 5 December 2017 (UTC)

The flowchart doesn't use standard flowchart symbols - they remind me of cars/trucks, each having a (rounded body) plus two wheels (holding yes and no). Anyone think this is deliberate?
:Not particularly as he used similar design in [[1688: Map Age Guide]]. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:01, 6 December 2017 (UTC)

The reason that you don't want to put solar panels on something that is hot is not because hot things use more power. It's because the efficiency of solar panels decreases as a function of temperature: See here for example http://news.energysage.com/solar-panel-temperature-overheating/. This is why solar panels on a road are not a great idea (among other reasons). [[Special:Contributions/108.162.219.76|108.162.219.76]] 01:23, 6 December 2017 (UTC)

Maybe I'm just a bit slow here, but why are jets, cars and deer considered hot to the touch when running? Sure, jets and cars do have hot parts when running - but so have many modern sail boats (at least motorized ones). And what about deer? The only deer being hot is the one in my oven - and there's no sun. [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 14:31, 6 December 2017 (UTC)
:well sailboats have only a small part (the motor) that is becoming really hot, since the body is watercooled. While deer are not getting that hot, a quick google search told me that their regular body temperature is 38.5-39.5°C. Also they do not regulate their temperature by sweating through skinpores as humans, but by sweating in their mouth, and regulating their temperatures through their ears. This means, in my understanding, that when they are running, the body cannot cool down as good as a human one, so i guess the can get up to 40-42°C during that period.
:The second thing to consider is, that hot is always relative. In this context it should mean "hot compared to the cooling water of a solar panel", as solar panels generate power by heating up water in a circuit (on a deer it should be a small cirquit to not put to much ballast on the deer). Heating it up can only generate power, when it is also cooled down. For this it needs a colder reference. When the deer itself is getting ~40°C, thats too hot to have cooling capacity. [[User:Lupo|Lupo]] ([[User talk:Lupo|talk]])
::While I see that PV get less effective if heated up and as such cooling makes sense, this was the first time I heard of that. So thank you for that (really!). In the wiki https://en.wikipedia.org/wiki/Solar_panel cooling isn't even mentioned at all. However, this still does not convince me. https://en.wikipedia.org/wiki/Solar_car https://en.wikipedia.org/wiki/Solar_Impulse Granted, these are all protoptypes/experiments (and the plane is definitely no jet) and will most likely not come to serial production, but nevertheless... {{unsigned|Elektrizikekswerk}}
:::Just revisiting this comments 1.5 years later I notice that I was not entirely correct. Solar panels usually (with exceptions) do not "generate power by heating up water in a circuit". Nevertheless overheating of solar panels can be problematic. The reason why "getting hot" is an argument might just be, because things that get hot while running use (waste) a lot of energy. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:43, 13 August 2019 (UTC)

Randy SO missed the "If you like it..." angle. All the single rooftops! (I'll show myself out) [[Special:Contributions/172.68.244.252|172.68.244.252]] 15:20, 8 December 2017 (UTC)

Why does animals being classified as "moving objects" require a citation? {{unsigned ip|108.162.241.220}}

What about a Tesla with a solar unit with panels that that pop out of the hood storage? [[Special:Contributions/172.68.189.241|172.68.189.241]] 01:24, 4 June 2019 (UTC)

While I get that using solar panels as the sole power source will be a problem on Cars. I think using them to add some charge to the battery of an electric car when it's in a spot where it can not be plugged in, but still in a sunny spot would still be a plus.
Think about it a person drives their car to work, and then leaves it sit in the parking lot for hours, and unless they are in a parking garage or at a graveyard shift, the car is going to be in full or nearly full sun all day, not moving. I know during the summers here this is why the cards are always ovens to get into, because of how much solar heat got trapped in the drivers compartments. I think after sitting out in the sun for 8 hours it will at least have some charge on the battery.
[[Special:Contributions/108.162.212.17|108.162.212.17]] 22:28, 12 August 2019 (UTC)KitRamos
:There are some cars which will go in production soon, using this concept, google for e.g. lightyear cars or sono motors. In the end the car has to be specifically enginered to be able to use solar power efficiently. I also remember to have read somewhere, that for some electical cars (or hybrid) there is a optional solar panel, which can extend range on a sunny day by a few miles. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:21, 13 August 2019 (UTC)

I would just like to point out that this even works for the sun. [[Special:Contributions/172.69.90.23|172.69.90.23]] 17:22, 19 April 2022 (UTC)

Talk:2775: Siphon

2023-05-16T19:23:15Z

198.41.242.149: Add a funny little self-reference

My understanding was that siphoning can essentially be explained by the Bernoulli equation? There is a difference in potential energy between the upper and lower container so it flows. The weight of water in the downhill part of the tube pulls water up the uphill section of the tube (think like a vacuum), and so on until there's either no difference in head or no more water. Siphoning will work with any diameter tube. [[Special:Contributions/172.70.91.151|172.70.91.151]] 15:43, 12 May 2023 (UTC)
:That's right. The only mention of capillary action in the siphon wikipedia article is when talking about phenomenon that *isn't* a siphon. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 16:15, 12 May 2023 (UTC)

Agree, capillary action does not seem to be referenced or implied in the comic, presenting only the (not "functioning") siphon phenomenon. [[Special:Contributions/172.68.134.142|172.68.134.142]] 16:23, 12 May 2023 (UTC)
:Seconded/thirded. Capillary action isn't even what they were expecting. The small amount of water in the lowe receptical indicates they correctly ''filled'' the tube, but then as the longer length drained it did not then induce further flow up and over through the shorter length. e.g. nature no longer abhored the resulting vacuum (or there was increased negative-pressure vapourisation, beyond that previously expected, or other method of seepage 'airlock'-breaking) and thus the short-end also drained straight back out again instead of becoming a potentially self-sustaining inflow to the whole siphoning setup.
::If the upper end got restricted (say by touching the side of the bucket) the loss of flow would allow air to enter the bottom end and drain out the tube. I've done this. :-( [[User:RIIW - Ponder it|RIIW - Ponder it]] ([[User talk:RIIW - Ponder it|talk]]) 19:07, 12 May 2023 (UTC)
:::Indeed, even having an especially large diameter "tube" (/pipe etc) can allow air from the bottom to flow up to the peak & break the siphon effect. For reliable results, the lower end needs to be kept immersed or the hose needs to be relatively small in diameter. [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 14:11, 13 May 2023 (UTC)
:While the capilliary action element ''could'' induce the start of a rather limited 'empty' siphon setup to start (maybe, I'd have doubts about the 'fluid friction' actually acting against the gravity-feed part, once the surface-tension bit has "climbed the mountain" and started to merely seep out of the other end, almost incidentally, for a sufficiently thin tubing where CA is a significant factor), this suddenly failing for whatever reason (surface-tension effects being nullified) wouldn't then send a token amount of water into the low bucket, nor particularly stop unrelated siphon-flow from continuing properly (in fact, suddenly 'interaction-free' liquid and tubing might siphon ''faster'', with effectively zero fluid boundary effects dragging on the induced flow).
:But perhaps someone with more QFD experience could explain where my assessment is wrong. So not going to personally rewrite the current Explanation intro just now. [[Special:Contributions/172.70.162.161|172.70.162.161]] 16:21, 12 May 2023 (UTC)
:I'd like to contribute as one more data point. I also don't see capillary action as being relevant. In particular, as another commenter said, the water in the lower bucket quite clearly supports the idea that the siphon effect was the subject of the characters' confusion. How else is Randall supposed to depict the siphon effect anyway? I agree that the drawing alone ''could'' also suggest capillary action is what's being investigated, but I don't think it suggests that the caption has ''incorrectly'' referred to it as the siphon effect. [[Special:Contributions/172.71.254.100|172.71.254.100]] 18:44, 12 May 2023 (UTC)

Of course, if some physical law would actually stop working, people wouldn't be confused. They would drop dead. Due to physical laws working on level of elementary particles, every change would have lot of different effects ... and living organism live only thanks to being very carefully balanced in lot of regards. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 20:49, 12 May 2023 (UTC)

Bug report 6EQUJ5: Odd signal emitted from Sagittarius constellation. Status: Closed - could not reproduce. [[Special:Contributions/172.71.26.69|172.71.26.69]] 03:20, 13 May 2023 (UTC)
:(I get that reference... :) However, launching off that to say: ) There's an old (short?) story... H.G. Wells era, possibly, but not him I think... where someone (who happened to be the first decent but amateur astronomer to get a cloudless patch of sky, one night) realises the Moon is in the wrong place, and the news then reaches (and troubles) the professional community who get a chance to observe/notice the change for the first fime and confirm it.. A 'glitch' seems to have passed through space and moved/retimed it, for a limited time, before it later snaps back to where (in the orbit) it now should be.
:The trace of the glitch are seen further afield (implying a 'beam' of 'wrongness'), and ultimately it spawns something like Experimental Theology whereby observations of such clear "hand of the Creator" changes (implying we're essentially in a simulated universe being operated by a 'universal programmer', but in pre-computer terms) merge or muddy the boundaries between scientific rationalism (which clearly falls short) and religious philosophy (where undeniable 'proof' of something godlike is now suddenly an ironically confounding factor).
:Cannot remember much about where I read it, I may be presuming some details about it that aren't actually there (even removing obvious mix-ups with similar brands of tale) and my Google-Fu fails to establish any obvious online reference to it (even just title+synoposis), so instead I'm setting down the 'spoilers' without reservation. [[Special:Contributions/172.70.91.151|172.70.91.151]] 13:04, 15 May 2023 (UTC)

Siphoning is NOT because of capillary action! That should be changed!! [[Special:Contributions/172.70.127.90|172.70.127.90]] 15:35, 13 May 2023 (UTC)

I guess I was wrong that siphons work because of capillary action. [[User:TianHanFei|TianHanFei]] ([[User talk:TianHanFei|talk]]) 1:57, 15 May 2023 (UTC)

::As someone who's been publicly wrong here before, it can be stressful, but if it's any consolation, you're one of today's (probably much fewer than) 10,000: https://xkcd.com/1053/ -- thanks for having a sense of humor about it [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 17:18, 15 May 2023 (UTC)

== Potential inspiration ==

One potential source of inspiration for this comic is the Twitter [https://twitter.com/earth_updates account @Earth_Updates], which produces a lot of similar content. [[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 19:54, 12 May 2023 (UTC)

I think if I added it to the article body it would get reverted, but the content seems very similar to how AI media produced delusional worlds for so many factions of people. It is not at all a big stretch to imagine people stepping into a metaverse or matrix where they aren’t sure what is real and physical laws match their intuition more than is actually correct. [[Special:Contributions/162.158.158.171|162.158.158.171]] 08:23, 13 May 2023 (UTC)

== Title text ==

Isn't the title text about stars like our sun rather than about plutonium? [[Special:Contributions/198.41.242.95|198.41.242.95]] 00:55, 13 May 2023 (UTC)h
:Seems to me unlikely that anyone would refer to stars as 'rocks'.[[User:Catherine|Catherine]] ([[User talk:Catherine|talk]]) 02:54, 13 May 2023 (UTC)
::There is Slate that turn into lava spontaneously after lying around for thousands of years. I think the area they are in is called "Smoking Hills". There was recent research why that slate does this while in much the rest of the world slate is just flat, black rocks. I still believe this title text is about plutonium, though, as that slate produces so much heat, that one still hasn't managed to measure how hot it gets - but it produces that heat not for an near-infinite duration.--[[User:Gunterkoenigsmann|Gunterkoenigsmann]] ([[User talk:Gunterkoenigsmann|talk]]) 01:48, 14 May 2023 (UTC)
:::The only {{w|Smoking Hills}} that came to mind was natural shale-fires (chemical burning, and not hot enough for remelting to magma/lava.
:::Possibly there is a {{w|natural nuclear fission reactor|situation}} where it has done as you say (in some natural mass of rock, spotted somewhere in this planet's lithosphere, or elsewhere out there), but given the fine line between nicely sustaining and runaway chain-reactions, I'm not sure how easy it is for nature to 'engineer' a way to land on the {{w|Corium (nuclear reactor)|middle ground}} and not go supercritical.
:::In order for accumulating ores to not just start a low-level fizzle (as above), over millenia, you might need separate ore-patches either side of a fault to come together in a suddenish techtonic slip, rather than a slow buckling of layers to increase effective ore-densities. And then you've got earthquakes, already, so not sure if the very low-grade nuclear explosion that is awfully close to being possible in this chance contrived example (at one end of the probability curve, unless U<sup>238</sup> content is somehow preferentially leached out?) is going to be noticable.
:::But ''just'' hot enough for lava? If not already close to melting, anyway, under local temperatures and pressures? Not sure we've seen anything like it, even if it is technically feasible given enough happenstance setups by geology(/exo-geology), since planets formed. [[Special:Contributions/172.70.91.152|172.70.91.152]] 09:16, 14 May 2023 (UTC)
::::Any sufficiently large rock containing sufficiently high concentrations of radioactive materials (such as the Earth) will partially melt. The energy is released slowly by decay not through fission. The large size ensures that the center is well enough insulate that slow heating accumulates until it reaches lava temperatures. The finite size ensures that enough heat leaks out that the magma does not become gas.[[Special:Contributions/162.158.158.170|162.158.158.170]] 18:29, 16 May 2023 (UTC)

== Title Text-Radiation ==

The title text is referring to the heat created by natural radioactive decay, not humans harnessing it in reactors.

The literal rocks of particularly radioactive elements still in the ground are constantly producing small amounts of heat without our assistance

[[Special:Contributions/172.71.151.48|172.71.151.48]] 06:27, 14 May 2023 (UTC)

Relevant xkcd: https://www.explainxkcd.com/wiki/index.php/1172:_Workflow

Re:Actor: Siphon heat rocks water is the basis for my workflow. Randall please add a option, so siphon heat rocking can be re-enabled on demand.
[[Special:Contributions/198.41.242.149|198.41.242.149]] 19:23, 16 May 2023 (UTC) PicassoCT