explain xkcd - User contributions [en]

3252: Ancestral Genomes

2026-06-02T00:13:29Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ not explanatory

{{comic
| number = 3252
| date = May 29, 2026
| title = Ancestral Genomes
| image = ancestral_genomes_2x.png
| imagesize = 299x416px
| noexpand = true
| titletext = SUGGESTIONS FOR FUTURE RESEARCH: No further research is needed as it is frankly none of our business.
}}

==Explanation==
{{incomplete|This page was DELETED TO RESPECT THE COMIC’S PRIVACY. Don't remove this notice too soon.}}

A {{w|genotype}} is the complete genetic makeup of an individual, i.e. all of its genes. In humans, genotypes are almost always inherited from an individual’s parents; the two parents’ genotypes combine during sexual reproduction to form the genotype of the child. {{w|mutation|Mutations}} do occur, where parts of the DNA change randomly in a way that gives rise to a new genotype, and [https://www.cbc.ca/radio/quirks/october-21-2017-1.4363723/how-many-mutant-genes-does-a-person-have-1.4363741 each human has about 60 such mutations, on average,] out of about 20,000 genes. However, most mutations are "silent", i.e. not causing any visible changes. Depending on the behavior of the mutation, and if it even occurs to any gamete cells or those that produce them, it may spread throughout a population, or disappear again, or end up only being present in a certain fraction of the population. Either way, when studying a genotype, it is ''exceedingly rare'' to not arise through sexual intercourse, and impossible to spread throughout the population without it. As modern-day genetics researchers, [[Megan]] and [[Cueball]] should definitely know this fact.

Currently in the United States, topics around sex are at least partially considered taboo. This taboo most strictly covers depictions of sex and nudity in media, which are usually the domain of pornography and less mainstream art forms (e.g. nude photography). Megan defending themselves as not being “weirdos” suggests that she in fact does not want to break the taboo. In academic science however, such topics are generally part of regular scientific discussion, including depictions and descriptions that would be considered offensive in other circumstances. For example, Wikimedia Commons contains many depictions of sexual intercourse for scientific and educational purposes. While some researchers, like the ones depicted in the comic, might be offended by such “lewd” contents, most would regard them well as long as they further the research on the topic at hand. Real-world biologists or geneticists would most likely not be offended by these issues, as sexual reproduction is a common or even predominant topic in both fields. Furthermore, the obscenity of the topic (genetic distributions affected by sexual reproduction) is very low in comparison to fields that deal with intercourse directly. This view seems to be shared by the off-screen commenter in the comic.

What is more problematic, and also addressed by the researcher’s comments, is the privacy of the individuals in the population under examination. Namely, using such data, it might be possible to figure out who had intercourse with whom, possibly reducing the timeframe to within less than a year based on the offspring’s age. However, since the analysis depicted likely takes place over many generations within a population, and is done on historical data, it is likely that the vast majority of the people whose genomes were analyzed are no longer alive. This is supported by the description of the population as “ancestral”. Beyond a certain point, even private data pertaining to deceased people is no longer considered sensitive, as it becomes the subject of history. The only problematic part is the ancestral information for living individuals, which is indeed worthy of protection—but not for the reasons given.

The title text is a reference to [[2268: Further Research is Needed]]. This one is based on the fact that most scientific papers contain a section suggesting future research avenues. This is done in the hope that other researchers will pick up where the authors have left off, or to announce the author’s own intentions for follow-up work. However, in this case, Megan and Cueball are both averse to the idea of future research, since as established they don’t think it’s appropriate to do so, which is ironic given the reason for the section.

Genetics and sex have also appeared in [[830: Genetic Analysis]]. Presenting outlandish or plain bad/incorrect research has been a common topic, such as in [[3129: Archaeology Research]] and [[3000: Experimental Astrophysics]].

==Transcript==
:[Cueball and Megan are shown, with Megan using a pointer stick to point at a diagram on a poster. The diagram features tree/root structure with a single node at the top end, branching solid lines leading to more nodes across several levels in most cases, but with at least one node that does not propogate this way and some dotted lines linking down from some branches into other ones. The increasingly branching lower tracks becoming so dense that it almost looks like dark triangles at the bottom of the diagram's last obvious bifurcations. Small and unreadable labels/symbols feature next to most linking lines, and more extensive (but still totally unreadable) information is placed below each of the lowermost 'triangular' terminating clumps.]
:Megan: Our admixture analysis showed that these genotypes arose in the ancestral population almost entirely through sexual intercourse.
:Megan: Upon realizing this, we of course promptly deleted all our data.
:Off-screen voice: What? Why??
:Megan: We're not '''''weirdos!'''''
:Megan: Jeez, give these people some privacy!

{{comic discussion}}<noinclude>
[[Category:Biology]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Sex]]

3253: Sunbeam

2026-06-02T00:11:38Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ grammar

{{comic
| number = 3253
| date = June 1, 2026
| title = Sunbeam
| image = sunbeam_2x.png
| imagesize = 398x347px
| noexpand = true
| titletext = While weather control is typically thought of as a superpower, the unconscious ability of astronomers and astrophotographers to summon clouds is more properly classified as a curse.
}}

==Explanation==
{{incomplete|This page was created BY A TABLE SOON TO BE LIT BY THE SUN. Don't remove this notice too soon.}}

{{w|Astrophotography}} is the act of taking pictures of very distant objects. Often these are celestial ones, or other star-related phenomena such as nebulae and galaxies, but planets, moons and even spacecraft may photographed either in isolation or in conjunction with other objects along roughly the same line of sight.

In order to take such photos, one needs to know where things are in the sky, especially when the Sun is in the sky and needs to be specifically accounted for to either ensure that it is aimed away from or is a [[2463: Astrophotography|deliberate part of the intended shot]]. The prospective movement of the various objects across the sky (both intended subjects of the photograph and anything that gets in the way) might be intensely studied beforehand, e.g. to ensure that the Moon will rise above a suitable part of the horizon (by working out when and where the photograph should be taken from) or to avoid disappointment in trying to obtain a desired eclipse-orientated image.

Since all natural celestial objects move in predictable ways across the sky (and the movements of satellites can be worked out at least given knowledge of any of their most recent maneuvering) astrophotographers possess an ability that the comic calls an "extremely minor superpower". In this case, it is [[Cueball]] who is pointing out that the passage of the Sun across the sky will move the sunbeams from a certain window across the floor of the room to later illuminate a given table. Though normally it might be considered useful to see by, such direct sunlight would probably be considered problematic, in this case, making the indicated table subject to excessive heat and/or light for comfort, whereas the table currently beyond the beams of sunlight would be a perfectly acceptable place to sit and would remain so.

However, regular people can often easily determine where the sun will fall through a window, making the claim of that being a 'superpower' questionable at best. And it's often useless, e.g., preventing people from being in a bad spot for their meal ostensibly because of sunlight usually has little bearing on how much they enjoy the meal. Hence it's called a very minor superpower. On the other hand, many people need to work in the shade for a plethora of good reasons, and some people occasionally need to work in sunlight. People who need to modulate the sunlight falling into their space, e.g. through large windows, often learn what times to adjust their blinds in a couple or three days at most.

The title text talks about another minor "superpower", that astrophotographers have, which makes clouds always seem to show up in front of the night sky. Because this "ability" is actually just coincidence,{{Citation needed}} that only appears causal to some, as well as that it interferes with their work, by ruining their photos, the title text more accurately classifies it as {{tvtropes|BlessedWithSuck|a curse}}, which is why the rest of the comic describes astrophotographers having only one "actual" superpower.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[Cueball, Megan, and White Hat are in a large dark room, presumably a restaurant, with two tables and a large window, with 4 panels and a topsection. The window is casting a large sunbeam between the two tables.]
:Cueball: Let's take the far table.
:Cueball: The closer one will be in the sun soon.
:[Caption below the panel:]
:Astrophotography gives you exactly one extremely minor superpower.
{{comic discussion}}<noinclude>

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring White Hat]]
[[Category:Photography]]

Talk:3253: Sunbeam

2026-06-02T00:10:14Z

2601:642:4C00:7984:B516:F866:A46E:3715: reply

did the transcript, but the explanation seems a bit daunting [[User:GreyFox|GreyFox]] ([[User talk:GreyFox|talk]]) 15:32, 1 June 2026 (UTC)
: You beat me to the punch! Very fast editing. And I agree, the explanation seems a little too out of reach for my knowledge base. Most likely explanation is that Astrophotography requires the knowledge of how the sun moves in relative to the Earth to take good photos, but that's just my guess. [[Special:Contributions/66.154.219.128|66.154.219.128]] 15:35, 1 June 2026 (UTC)
:: yeah, i tried to be fast; thanks for fixing the caption for me btw. searching astrophotography on wikipedia didnt really help much; lets wait for another more <s>nerdy</s> experienced user to get that done [[User:GreyFox|GreyFox]] ([[User talk:GreyFox|talk]]) 15:48, 1 June 2026 (UTC)
::: No problem. [[Special:Contributions/66.154.219.128|66.154.219.128]] 16:11, 1 June 2026 (UTC)

Can we deduce that the comic takes place in the northern hemisphere? {{unsigned|184.174.152.128|15:35, 1 June 2026}}
: That was my surface-level interpretation too, that this must be a Southern-facing window in the Northern hemisphere, since the East-West axis (the line that the light will travel along) is roughly parallel to the wall, and the light will pivot to the East (left) as the Sun moves West? [[User:SomeDee|SomeDee]] ([[User talk:SomeDee|talk]]) 15:52, 1 June 2026 (UTC)
:: Either that, or Cueball is wrong: on the southern hemisphere the sun still "moves" from east to west, but north of the observer. If this was the southern hemisphere, the sun beam would thus move towards the far table. [[Special:Contributions/2001:67C:2564:AB0C:1C57:EB42:6C3F:FD47|2001:67C:2564:AB0C:1C57:EB42:6C3F:FD47]] 16:02, 1 June 2026 (UTC)
Yes, when I was in the southern hemisphere all my sense of where the Sun and stars should be moving to was totally off.

The sun could be reflecting off a nearby building, which would mess things up a bit. [[Special:Contributions/64.201.132.210|64.201.132.210]] 16:17, 1 June 2026 (UTC)
:Judging by the style of window, this is most likely near an older part of town or a more suburban area, where there are very few skyscrapers with reflective windows and a lot of wood and brick and mortar buildings, so I think that this is unlikely. [[Special:Contributions/66.154.219.128|66.154.219.128]] 16:31, 1 June 2026 (UTC)
::I was getting that old-downtown-church-vibe, which could easily be near a glass-plated skyscraper. [[Special:Contributions/64.201.132.210|64.201.132.210]] 20:23, 1 June 2026 (UTC)

Hang on, Randall got this wrong. Astrophotography (as defined by the Wikipedia page, the link is https://en.wikipedia.org/wiki/Astrophotography) is the act of taking pictures of the night sky... where there is no sun. An error on his part? [[Special:Contributions/66.154.219.128|66.154.219.128]] 16:21, 1 June 2026 (UTC)

Based on the title text, I'm guessing the joke is that because he said there will be sun, there will instead be clouds. His superpower is presumably summoning clouds. [[Special:Contributions/2607:FB91:17EC:E4FE:AD3:E858:6B10:E3E1|2607:FB91:17EC:E4FE:AD3:E858:6B10:E3E1]] 16:31, 1 June 2026 (UTC)

Wanted to say that you also learn how the sun moves as an astrophotographer, lots of planetary photography can happen during the day (Venus Mercury, strategic sun blocking) and need to take it into account, and there's also taking pictures of the sun with solar filters. So my interpretation of the joke was just genuinely pointing out the mini superpower of intuiting sun movement, rather than a joke about day versus night. [[Special:Contributions/142.114.245.145|142.114.245.145]] 16:36, 1 June 2026 (UTC)
: Hm, good point. Add that to the explanation if you can, I'm running out of the magic smoke that lets me edit pages. (motivation) [[Special:Contributions/66.154.219.128|66.154.219.128]] 16:38, 1 June 2026 (UTC)

I think the point is that someone who does astrophotography is intimately familiar with the motion of objects in the sky due to the rotation of the Earth, the sun is one such object that is visible during the day. Predicting its motion in the sky, due to the earth's rotation allows for the prediction of which table to sit at. The superpower is this predictive ability, which is normally not useful for all that much in modern life.

I don't think Randall messed this up. For example, the zodiac is defined as the Sun's path through the stars, even though the stars and the sun are not visible at the same time. Knowledge of how things move in the night sky is very related to how the Sun moves during the day.

To my mind, this comic is more closely related to the inherent calculations from within [[2463: Astrophotography]] (with the name of it being not a coincidence) than merely being good at photographing nebulae/etc. [[Special:Contributions/81.179.199.253|81.179.199.253]] 19:51, 1 June 2026 (UTC)

FWIW you don't need no Astrophotography to predict the sunny table. I see it on my dogs as they lay on the floor after lunch. --[[User:PRR|PRR]] ([[User talk:PRR|talk]]) 20:26, 1 June 2026 (UTC)

Is there something about the illustration that makes it clear which direction the sun is going to move? Or does the speaker in the comic require additional external knowledge about which direction the window is facing? -- [[Special:Contributions/108.18.36.182|108.18.36.182]] 22:21, 1 June 2026 (UTC)

:They only need to know that the sun travels east to west in the sky, and the approximate orientation of the window. (Without regard to the hemisphere or season; in re [https://www.explainxkcd.com/wiki/index.php?title=3253:_Sunbeam&diff=414125&oldid=414124].) [[Special:Contributions/2601:642:4C00:7984:B516:F866:A46E:3715|2601:642:4C00:7984:B516:F866:A46E:3715]] 00:10, 2 June 2026 (UTC)

3253: Sunbeam

2026-06-02T00:05:46Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ I feel this paragraph has much stronger explanatory value

{{comic
| number = 3253
| date = June 1, 2026
| title = Sunbeam
| image = sunbeam_2x.png
| imagesize = 398x347px
| noexpand = true
| titletext = While weather control is typically thought of as a superpower, the unconscious ability of astronomers and astrophotographers to summon clouds is more properly classified as a curse.
}}

==Explanation==
{{incomplete|This page was created BY A TABLE SOON TO BE LIT BY THE SUN. Don't remove this notice too soon.}}

{{w|Astrophotography}} is the act of taking pictures of very distant objects. Often these are celestial ones, or other star-related phenomena such as nebulae and galaxies, but planets, moons and even spacecraft may photographed either in isolation or in conjunction with other objects along roughly the same line of sight.

In order to take such photos, one needs to know where things are in the sky, especially when the Sun is in the sky and needs to be specifically accounted for to either ensure that it is aimed away from or is a [[2463: Astrophotography|deliberate part of the intended shot]]. The prospective movement of the various objects across the sky (both intended subjects of the photograph and anything that gets in the way) might be intensely studied beforehand, e.g. to ensure that the Moon will rise above a suitable part of the horizon (by working out when and where the photograph should be taken from) or to avoid disappointment in trying to obtain a desired eclipse-orientated image.

Since all natural celestial objects move in predictable ways across the sky (and the movements of satellites can be worked out at least given knowledge of any of their most recent maneuvering) astrophotographers possess an ability that the comic calls an "extremely minor superpower". In this case, it is [[Cueball]] who is pointing out that the passage of the Sun across the sky will move the sunbeams from a certain window across the floor of the room to later illuminate a given table. Though normally it might be considered useful to see by, such direct sunlight would probably be considered problematic, in this case, making the indicated table subject to excessive heat and/or light for comfort, whereas the table currently beyond the beams of sunlight would be a perfectly acceptable place to sit and would remain so.

However, regular people can often easily determine where the sun will fall through a window, making the claim of that being a 'superpower' questionable at best. And it's often useless, e.g., preventing people from being in a bad spot for their meal ostensibly because of sunlight usually has little bearing on how much they enjoy the meal. Hence it's called a very minor superpower. On the other hand, many people need to work in the shade for a plethora good reasons, and some people occasionally need to work in sunlight. People who need to modulate the sunlight falling into their space, e.g. through large windows, often learn what times to adjust their blinds in a couple or three days at most.

The title text talks about another minor "superpower", that astrophotographers have, which makes clouds always seem to show up in front of the night sky. Because this "ability" is actually just coincidence,{{Citation needed}} that only appears causal to some, as well as that it interferes with their work, by ruining their photos, the title text more accurately classifies it as {{tvtropes|BlessedWithSuck|a curse}}, which is why the rest of the comic describes astrophotographers having only one "actual" superpower.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[Cueball, Megan, and White Hat are in a large dark room, presumably a restaurant, with two tables and a large window, with 4 panels and a topsection. The window is casting a large sunbeam between the two tables.]
:Cueball: Let's take the far table.
:Cueball: The closer one will be in the sun soon.
:[Caption below the panel:]
:Astrophotography gives you exactly one extremely minor superpower.
{{comic discussion}}<noinclude>

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring White Hat]]
[[Category:Photography]]

3253: Sunbeam

2026-06-02T00:04:03Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ spelling

{{comic
| number = 3253
| date = June 1, 2026
| title = Sunbeam
| image = sunbeam_2x.png
| imagesize = 398x347px
| noexpand = true
| titletext = While weather control is typically thought of as a superpower, the unconscious ability of astronomers and astrophotographers to summon clouds is more properly classified as a curse.
}}

==Explanation==
{{incomplete|This page was created BY A TABLE SOON TO BE LIT BY THE SUN. Don't remove this notice too soon.}}

{{w|Astrophotography}} is the act of taking pictures of very distant objects. Often these are celestial ones, or other star-related phenomena such as nebulae and galaxies, but planets, moons and even spacecraft may photographed either in isolation or in conjunction with other objects along roughly the same line of sight.

In order to take such photos, one needs to know where things are in the sky, especially when the Sun is in the sky and needs to be specifically accounted for to either ensure that it is aimed away from or is a [[2463: Astrophotography|deliberate part of the intended shot]]. The prospective movement of the various objects across the sky (both intended subjects of the photograph and anything that gets in the way) might be intensely studied beforehand, e.g. to ensure that the Moon will rise above a suitable part of the horizon (by working out when and where the photograph should be taken from) or to avoid disappointment in trying to obtain a desired eclipse-orientated image.

Since all natural celestial objects move in predictable ways across the sky (and the movements of satellites can be worked out at least given knowledge of any of their most recent maneuvering) astrophotographers possess an ability that the comic calls an "extremely minor superpower". In this case, it is [[Cueball]] who is pointing out that the passage of the Sun across the sky will move the sunbeams from a certain window across the floor of the room to later illuminate a given table. Though normally it might be considered useful to see by, such direct sunlight would probably be considered problematic, in this case, making the indicated table subject to excessive heat and/or light for comfort, whereas the table currently beyond the beams of sunlight would be a perfectly acceptable place to sit and would remain so.

However, regular people could easily determine where the sun will fall as well, making its claims as a 'superpower' questionable at best, as (assuming that this venue is in the northern hemisphere, with a southerly-facing window) most people will be able to work out the consequences of the changing position of the Sun (w.r.t. the spinning Earth) to a similarly useful degree. Though a layperson might have more doubts about how the changes in the sunbeam's declination might change matters, depending upon the (local) time of day and what season of the year this is happening. Cueball, however, has enough intimate knowlege through his astrophotographic hobby/work to be usefully definite about how things will progress. Hence it's being called a very minor superpower.

The title text talks about another minor "superpower", that astrophotographers have, which makes clouds always seem to show up in front of the night sky. Because this "ability" is actually just coincidence,{{Citation needed}} that only appears causal to some, as well as that it interferes with their work, by ruining their photos, the title text more accurately classifies it as {{tvtropes|BlessedWithSuck|a curse}}, which is why the rest of the comic describes astrophotographers having only one "actual" superpower.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[Cueball, Megan, and White Hat are in a large dark room, presumably a restaurant, with two tables and a large window, with 4 panels and a topsection. The window is casting a large sunbeam between the two tables.]
:Cueball: Let's take the far table.
:Cueball: The closer one will be in the sun soon.
:[Caption below the panel:]
:Astrophotography gives you exactly one extremely minor superpower.
{{comic discussion}}<noinclude>

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring White Hat]]
[[Category:Photography]]

3253: Sunbeam

2026-06-01T23:53:02Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ plural times

3253: Sunbeam

2026-06-01T23:51:47Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ plethora

3253: Sunbeam

2026-06-01T23:49:04Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ open too

3253: Sunbeam

2026-06-01T23:48:15Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ alternative perspective

3253: Sunbeam

2026-06-01T23:44:55Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ grammar

3253: Sunbeam

2026-06-01T23:44:09Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ expound

3253: Sunbeam

2026-06-01T23:41:21Z

2601:642:4C00:7984:B516:F866:A46E:3715: /* Explanation */ revise