explain xkcd - User contributions [en]

Talk:2984: Asteroid News

2024-09-12T14:58:10Z

162.158.42.82: Added comment

Not sure!! Maybe it is "2016 AJ193" Found this news https://www.news18.com/news/buzz/nasa-detects-the-1000th-near-earth-asteroid-within-colliding-distance-4171781.html , but I can't find a NASA comment or any reputable source.
[[Special:Contributions/172.68.23.189|172.68.23.189]] 00:10, 12 September 2024 (UTC) WaywardMinstrel

The "DEFINATLY" in the explanation header is intentional, a reference to [[2871]] [[User:TheTrainsKid|TheTrainsKid]] ([[User talk:TheTrainsKid|talk]]) 00:52, 12 September 2024 (UTC)

'''Which asteroid is it?''' The explanation currently points towards the 2024 MK asteroid, which might be the most likely contender in that it is recently discovered and had the potential to do something interesting, but the 2063 line makes me hesitant to declare that it is a comic about that asteroid. Feel free to revert my changes if you have evidence pointing specifically to the 2024 asteroid or a theory explaining the 2063 reference (could 2024 MK return to earth in 39 years??). I haven't been able to find much information on this yet. Another possibility is that it is about a fictional asteroid, inspired by this year's discovery. [[User:Alcatraz ii|Alcatraz ii]] ([[User talk:Alcatraz ii|talk]]) 02:55, 12 September 2024 (UTC)
------- Likely to be one of the recently-removed objects on the Sentry list: https://cneos.jpl.nasa.gov/sentry/removed.html Hard to tell though as Sentry doesn't display impact probabilities for removed objects. You'd need some kind of archive of Sentry from a week ago. [[Special:Contributions/172.71.124.147|172.71.124.147]] 05:07, 12 September 2024 (UTC)

Is there a category for comics involving boredom? [[Special:Contributions/172.70.211.100|172.70.211.100]] 03:52, 12 September 2024 (UTC)
* [[13: Canyon]]
* [[24: Godel, Escher, Kurt Halsey]]
* [[52: Secret Worlds]]
* [[402: 1,000 Miles North]]
* [[731: Desert Island]]
* [[877: Beauty]]
* [[895: Teaching Physics]] [[Special:Contributions/172.68.22.9|172.68.22.9]] 04:05, 12 September 2024 (UTC)

Cmon hit the IOF lil asteroid

[[Special:Contributions/172.70.90.64|172.70.90.64]] 07:00, 12 September 2024 (UTC)
:Not even close. [[Special:Contributions/172.70.206.241|172.70.206.241]] 07:08, 12 September 2024 (UTC)
::we just gotta believe :) [[Special:Contributions/172.69.79.183|172.69.79.183]] 07:30, 12 September 2024 (UTC)
:::I tots believe in you <3 [[Special:Contributions/172.68.22.8|172.68.22.8]] 07:33, 12 September 2024 (UTC)
::::thanks ig [[Special:Contributions/172.70.91.253|172.70.91.253]] 07:42, 12 September 2024 (UTC)
:::::Let's make out. [[Special:Contributions/172.71.147.145|172.71.147.145]] 07:50, 12 September 2024 (UTC)
::::::Muah! [[Special:Contributions/172.70.207.96|172.70.207.96]] 08:22, 12 September 2024 (UTC)

I don't think it's right to attribute the opinions of the comic to Blondie. Everything she says is quotes from the astronomers- even "so what's the point" is in quotation marks. --[[User:Mushrooms|Mushrooms]] ([[User talk:Mushrooms|talk]]) 09:35, 12 September 2024 (UTC)

I think the title text is probably referring to [[1291:_Shoot_for_the_Moon]]. [[Special:Contributions/162.158.42.82|162.158.42.82]] 14:58, 12 September 2024 (UTC)

2973: Ferris Wheels

2024-08-19T23:58:03Z

162.158.42.82: /* Explanation */ move reference

{{comic
| number = 2973
| date = August 16, 2024
| title = Ferris Wheels
| image = ferris_wheels_2x.png
| imagesize = 624x280px
| noexpand = true
| titletext = They left the belt drive in place but switched which wheel was powered, so people could choose between a regular ride, a long ride, and a REALLY long ride.
}}

==Explanation==
{{incomplete|Created by a BELT POWERED BY A DIFFERENT WIKI PAGE IN ORDER TO KEEP THIS ONE GOING - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic depicts an attempted connection of three {{w|Ferris wheel}}s using a {{w|Belt (mechanical)|mechanical belt drive}}, a system typically used to transfer motion between rotating shafts. By connecting the wheels at different circumferences, the relative motion is geared up or down. If the belt passes around the circumference of one wheel and is connected around the hub of another, the latter will rotate significantly faster. In this case, the second wheel's circumference is in turn connected to a third wheel's hub, resulting in even greater rotational velocity. However, this setup is mechanically unsound and possibly dangerous, as Ferris wheels are not intended to be connected in this way.{{cn}} As shown, the first wheel on the left is running at a normal speed, while the other two are rotating increasingly fast, leading to a potentially hazardous situation where passengers are flung around to various (possibly {{w|G-force#Human tolerance|quite hazardous}}) extents.

Ferris wheels can vary widely in size and speed of rotation, but for illustration, let us assume a diameter of about 200 feet (60 m) and a pretty sedate speed of around 10 minutes per full rotation. The apparent ratio between the connected wheels in the comic is approximately 12.5:1, meaning the motion is significantly sped up as it’s transferred. The second Ferris wheel, driven by the first, could spin at around 1.3 rpm, with passengers moving at 9 mph (14 km/h), giving a more exciting ride, but not inherently dangerous. However, when this motion is further transferred to the third Ferris wheel, it could spin at 16 rpm, with passengers traveling at over 110 mph (180 km/h), subjecting them to 8 Gs of force—conditions that would be hazardous. Randall has previously explored the limits of the human body's tolerance for acceleration in ''What If # 116 "No Rules NASCAR"'' [https://what-if.xkcd.com/116/]. However, since the motor for the first wheel would have been selected merely to drive one wheel, it's unlikely it would be able to power the other two wheels moving at increased speeds.

In the caption [[Randall]] says that he was fired for this ill-advised modification, highlighting the impracticality and dangers of the idea. A cruise line also fired the cartoonist due to an unsound engineering proposal earlier in [[2935: Ocean Loop]].

The title text imagines the consequences of leaving the belt drive system in place but switching which wheel is powered. If the most extreme wheel (the third one on the right) is powered, the gearing would be reversed, making for a possibly pleasant and normal ride on the right-hand wheel, but rendering the experiences of the riders on the other two wheels far too slow for an enjoyable carnival ride. One revolution of the center wheel might take two hours and five minutes, while the left wheel would take around a little more than a day per revolution.    This exaggerates the impracticality and unintended effects of using a belt drive system to link up Ferris wheels, illustrating how such an idea would lead to absurdly varied ride experiences.

==Transcript==
:[Three Ferris wheels are shown side by side, with some people stood on the ground for scale. Each of the first two wheels has a belt connecting its circumference to the axle of the wheel to its right. "Agitrons" indicate that the middle wheel is turning notably faster than the left wheel, with the gondolas seen to be rocking significantly at all points round the wheel. The spokes of the right wheel are completely replaced by "motion lines", indicating that the the right wheel is turning the fastest of all. All its gondolas are hanging outwards against centripetal force, interspersed with their own motion lines.]

:[Caption below the panel:]
:The county fair fired me for adding a belt drive to the Ferris wheels.

==Trivia==
The first (slowest) wheel can be seen to notably lack a 'spoke' at approximately the five o'clock position, supporting the point where its respective passenger seating is hung. Clearly, however, the wheel design is strong enough to withstand much greater forces in the other two versions of the wheel (which appears to be complete in the case of the second, though the thin spokes are only seen as blurs in the third wheel) suggesting that there may not be significant danger from this omission. It does not bode well, however, for general {{w|Occupational Safety and Health Administration|OSHA compliance}} in how they erect/maintain the rides, even before the belt-drive idea added its own issues.

{{comic discussion}}

[[Category:Physics]]
[[Category:Engineering]]

2971: Celestial Event

2024-08-15T09:08:47Z

162.158.42.82: /* Explanation */ s/data/computations

{{comic
| number = 2971
| date = August 12, 2024
| title = Celestial Event
| image = celestial_event_2x.png
| imagesize = 471x300px
| noexpand = true
| titletext = If we can get a brood of 13-year cicadas going, we might have a chance at making this happen before the oceans evaporate under the expanding sun.
}}

==Explanation==
{{incomplete|Created by a CURSED SHOP THAT APPEARS EVERY FOUR POINT THREE BILLION YEARS - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic highlights the extreme rarity of witnessing multiple special events—{{w|aurora}}s, {{w|Solar_eclipse#Total_eclipse|total solar eclipses}}, {{w|Great_Comet|great comets}}, and {{w|Periodical cicadas|17-year cicada emergences}}—all occurring simultaneously in the same location. It calculates that such an event would happen only once every 4.3 billion years, a time span comparable to the age of the Earth. The comic was posted shortly after some people reported seeing auroras in conjunction with the {{w|Perseids meteor shower}}.[https://www.msn.com/en-us/weather/topstories/the-2024-perseid-meteor-shower-and-northern-lights-overlapped-in-a-rare-cosmic-display-see-photos-of-the-dazzling-event/ar-AA1oJKKC] [[Randall]] also includes a 50% chance of clear skies, which further reduces the odds of witnessing all events together. The comic exaggerates the difficulty of this happening, emphasizing that these conditions align less often than Earth's lifespan, suggesting such a celestial spectacle might only occur once before Earth becomes uninhabitable.

The calculation assumes that these events occur independently and that their probabilities remain constant over time, leading to the improbable result. However, this is a simplification, as factors like orbital mechanics and atmospheric conditions are not entirely random, whereas others, such as the amount of cloud cover and the existence of cicadas, may change unpredictably over time. Randall estimates that total solar eclipses occur once every 350 years at a given location, a value close to the 320-year interval for his hometown of Boston, Massachusetts, based on [https://eclipse.gsfc.nasa.gov/JSEX/JSEX-index.html NASA's computations.]

The title text humorously suggests using 13-year cicadas instead of 17-year ones to improve the odds, reducing the interval to 3.29 billion years. This idea, along with the possibility of weather manipulation, reflects Randall's satirical take on humanity's desire to control or predict natural phenomena, even when the timescales involved are beyond human comprehension. Earth's oceans may evaporate in about a billion years [https://www.sciencedaily.com/releases/2013/12/131216142310.htm], adding a layer of urgency and humor to the idea of witnessing this "super-event" before life on Earth ceases to exist.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:<u>Approximate frequency in my area</u>

:Active northern lights: 20 days per solar cycle

:A naked-eye "Great Comet": 2 months every 50 years

:Total eclipse: once every 350 years

:Clear skies: 50% of the time

:17-year cicada emergence: 2 months every 17 years

opening bracket

20 days over 11 years multiplied by

2 months over 50 years multiplied by

1 over 350 years multiplied by

one half multiplied by

2 months over 17 years

closing bracket to the power of -1

equals 4.3 billion years

:[Caption below the panel:]
:Every 4 billion years or so, my neighborhood gets to see a ''really'' spectacular show.

{{comic discussion}}

[[Category:Astronomy]]
[[Category:Solar eclipses]]
[[Category:Time]]
[[Category:Animals]]

2962: President Venn Diagram

2024-08-11T20:04:26Z

162.158.42.82: hello people of the past, i am here to give you information

{{comic
| number = 2962
| date = July 22, 2024
| title = President Venn Diagram
| image = president_venn_diagram_2x.png
| imagesize = 445x398px
| noexpand = true
| titletext = Hard to imagine political rhetoric more microtargeted at me than 'I love Venn diagrams. I really do, I love Venn diagrams. It's just something about those three circles.'
}}

==Explanation==
{{notice|This comic contains just one opinion as interpreted by [[Randall|the comic's author]].
Please take care to not add anything to this explanation that might be your own personal political opinion. |image=warning!!.png|**NB. This warning could remain as long as Harris is a candidate in the election. Once this process concludes, we might need a different warning.}}

On the Monday that this comic was published, US Vice President {{w|Kamala Harris}} became the new presumptive {{w|Democratic_Party_(United_States)|Democratic Party}} nominee for the 2024 presidential election, having received verbal endorsements from a majority of Democratic state delegations; the day before, President {{w|Joe Biden}} had {{w|Withdrawal_of_Joe_Biden_from_the_2024_United_States_presidential_election|suspended his re-election bid}} and endorsed Harris. These major events resulted in Harris replacing Biden as one of the top two candidates for {{w|President of the United States|President}} in the 2024 election.

This comic features a three-way {{w|Venn diagram}} (which [[2721: Euler Diagrams|is also an Euler diagram]]). The three circles represent eligibility for US presidency, ability to do a good job as the US president, and love for Venn diagrams:

# '''Good President:''' [[Randall]] believes Harris would be a good president and implies as much, while making the reasonable assumption that he would not be. On the day this comic was published, a top Internet conversation topic was people's opinions of Harris, given the surprise nature of her candidacy, so Randall is adding in his opinion.
# '''Eligibility:''' According to Article II of the {{w|US Constitution}}, someone is {{w|President_of_the_United_States#Eligibility|eligible for the presidency}} if they are a natural-born citizen of the United States, are at least 35 years old, and are a resident in the United States for at least 14 years. Both Randall Munroe and Kamala Harris meet these qualifications. Additionally, the 14th amendment forbids those who have engaged in insurrection against the United States from holding public office without a two-thirds vote of the Congress to allow them to. Harris' opponent is widely considered to have engaged in an act of insurrection on January 6th, 2021, and it will likely fall to the Supreme Court to decide whether or not the presidency counts as a public office.
# '''Vocal Venn diagram affection:''' Harris' affection for Venn diagrams is something of a meme, and has been used by her in her campaign [https://www.independent.co.uk/news/world/americas/us-politics/kamala-harris-campaign-memes-gen-z-b2583802.html]. Randall is also known for his love of Venn diagrams, which feature heavily in xkcd. Randall especially loves Venn diagrams ABOUT Venn diagrams, like this one. While Harris frequently uses Venn diagrams with three intersecting circles as props, she also has [https://www.c-span.org/video/?c5125622/user-clip-circle-venn-diagram discussed them in the abstract, without reference to any physical diagram, even when discussing more than three intersecting categories.]

Part of the humor arises from the contrast of putting on a level playing field three characteristics that range widely from the momentous to the quirky, as well as the implication that Randall and Harris are quite similar in all but one area: their fitness to serve as US President, per Randall's opinion. The diagram does not indicate anyone who Randall would include in the six other areas (categories) of the Venn diagram besides the two in which he listed himself and Harris.

The title text [https://www.youtube.com/watch?v=eWR2uTfrh-k quotes Kamala Harris on her affection for Venn diagrams], and implies that the best way to target Randall with political ads is to mention how amazing Venn diagrams are.

Randall seems to express support for a Democratic Presidential candidate every 8 years, including in a 2016 comic [[I'm With Her]] endorsing {{w|Hillary Clinton}} and in [https://blog.xkcd.com/2008/01/28/obama/ a 2008 blog post] endorsing {{w|Barack Obama}}. In 2032 he will endorse Joe Biden III, followed by himself in 2040, Gabriele Cirulli in 2048, and X Æ A-12 Musk in the 2056 United States of America and Mars (USAM) election.{{Citation Needed}}

==Transcript==
:[A Venn diagram with three circles.]
:[Upper left circle:] Eligible to be President
:[Upper right circle:] Would be a good President
:[Lower circle:] Unusually vocal about love of Venn diagrams
:[Intersection of all three circles:] Kamala Harris
:[Intersection of the upper left and lower circles:] Me

{{comic discussion}}

[[Category: Venn diagrams]]
[[Category: Politics]]
[[Category: Elections]]
[[Category: Comics featuring politicians]]

2959: Beam of Light

2024-07-24T07:56:06Z

162.158.42.82: /* Explanation */ redshift

{{comic
| number = 2959
| date = July 15, 2024
| title = Beam of Light
| image = beam_of_light_2x.png
| imagesize = 235x419px
| noexpand = true
| titletext = Einstein's theories solved a longstanding mystery about Mercury: Why it gets so hot. "It's because," he pointed out, "the sun is right there."
}}

==Explanation==
{{incomplete|Created by a BOT FLYING ALONGSIDE A BEAM OF LIGHT NYYOOOOOOOOOOM - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
[[Albert Einstein]] is famous for his theory of {{w|special relativity}} (which deals with the interactions between high speeds and the perceptions of time), and he developed this theory, in part, by imagining himself flying alongside a beam of light. {{w|thought_experiment|Thought experiments}} such as this can reveal what appear to be fundamental principles of the universe that can revolutionize scientific understanding.

In this comic, Albert Einstein is depicted having an early version of this thought experiment. At this stage of theory development, it is less about breaking down the complex nature of relativity and more about how fun it would be to go really fast. So his thought experiment is currently just, so to speak, a flight of fantasy. (Although even Einstein's "NYYOOOM" sound of a car whizzing by is the sound of the {{w|Doppler effect}}, which alludes strongly to the {{w|relativistic doppler effect}} and [[reshift]].) Since this is early in his life, he is most likely sitting in the {{w|Albert_Einstein#1902–1909:_Assistant_at_the_Swiss_Patent_Office|Swiss patent office}} he is so famous for working at, when he got his ground breaking ideas.

In a similar vein, the title text refers to one of the long-standing issues about Mercury: {{w|Tests_of_general_relativity#Perihelion_precession_of_Mercury|its orbit around the Sun}} doesn't ''quite'' match what {{w|Newtonian physics}} would predict. We now know that this is accounted for by {{w|general relativity}}, another of Einstein's notable theories (which relates how gravity, or the space-time curvature that we understand as gravity, influences time and space, including planetary orbits) that was further developed out from the framework of special relativity. Again, we find ourselves overhearing his thoughts before he reaches any insights that will start to explain this. Instead he is stuck at just 'imagining' that Mercury is hot due to its proximity to the Sun, which isn't a particularly novel or useful conclusion, or close to what we would now recognize as Einstein's much-lauded theory.

At around the time of the comic's scenario, being only the first stages of Einstein's thoughts about Relativity, the issue of the Sun's heat was still considered a mystery. The {{w|Kelvin–Helmholtz mechanism}} was proposed as the cause of the Sun's heat but was later superseded by the more modern understanding of nuclear fusion. The {{w|Yarkovsky effect}} had also been previously described as how thermal effects may influence orbital dynamics; this is still useful to know about in the case of asteroids but is not considered a significant factor for Mercury. Neither of these things were ever the focus of Einstein's own studies, though in 1915 he showed that General Relativity could explain Mercury's orbital anomalies, and independent observations during a 1919 solar eclipse helped confirm the principles and make Einstein famous.

An older version of Einstein was previously drawn in [[1206: Einstein]] and [[1233: Relativity]].

==Transcript==
:[Albert Einstein (a relatively young version, drawn with dark curly hair and a dark moustache) sitting on a chair, with a thought bubble above his head. There are papers, books and a cup on the desk in front of him.]
:Einstein (thinking): ''Nyoooooooooom!''
:Einstein (thinking): I'm so fast!
:Einstein (thinking): ''Nyyooooooooom!''

:[Caption below the panel:]
:The first few times Einstein imagined flying alongside a beam of light, he didn't have any particular insights.

{{comic discussion}}

[[Category:Astronomy]]
[[Category:Comics featuring Albert Einstein]]
[[Category:Physics]]