explain xkcd - User contributions [en]

3151: Window Screen

2025-10-08T17:23:04Z

Dykotomee: Add citation needed punchline

{{comic
| number = 3151
| date = October 6, 2025
| title = Window Screen
| image = window_screen.png
| titletext = The Nobel Prize in Physiology or Medicine or Home Improvement or DIY
}}

==Explanation==
{{incomplete|This page was created by user interface. Don't remove this notice too soon.}}
[[Cueball]] believes he should receive a {{w|Nobel Prize}} for creating a custom screen for a particularly troublesome window, due to what he considers to be the immense amount of work and consideration that went into it and the high quality of the result. He is writing to the {{w|Nobel Foundation}} to nominate himself. (The Foundation does not currently accept self-nominations, or nominations from anyone not [https://www.nobelprize.org/nomination/peace/#h-qualified-nominators appropriately qualified].)

A {{w|window screen}} is most often used to block insects, other small animals, and debris from passing through an open window, while allowing it to provide both ventilation and light. One can also make a light, half-printed mesh that attaches to the outside of the glass to display an outward-facing image, without overly spoiling the view from the inside, or a more dense one to neutrally shade the incoming light, still without significantly obscuring it. Most windows are flat and rectangular, and pre-made meshes for these can be measured and cut with basic tools. Some windows have complex shapes. It can be very difficult to design a screen that neatly matches a complex glass surface.

An {{w|Angle#Types_of_angles|oblique angle}} is any angle that is not a multiple of 90 degrees (not a right or straight angle). While right angles allow for intuitive mapping of sides to an X-Y coordinate plane, acute or obtuse angles indicate that at least one side will have endpoints that differ in both coordinates. This requires extra calculations.

Curved edges require extra care to measure and cut. Circular or semi-circular windows follow a constant curve that can be traced with limited effort, but the window in the comic is irregular.

{{w|Coplanarity|Noncoplanarity}} is a state where all elements of a system cannot be represented on the same plane. This implies that the window is not flat, suggesting that the glass is curved, and/or that the wall that surrounds the screen is not flat. The shape in the comic could possibly occur if the room featured in the first and third panels was at least partly conical, with the window narrowing to match the wall sloping inward to a central point above (this would also fit the earlier mention of multiple curved edges). The glass could also be shaped into an outward bubble. Either way, the mesh must be carefully shaped. Thankfully for the project, there's no indication that it is not a {{w|developable surface}}, which would further complicate the work to be done.

Perfectly fitting a custom screen to such a window may be a significant technical accomplishment that the builder may wish to share with acquaintances. However, it is generally not considered near the level of one of the world's most prestigious awards{{citation needed}}, which often recognize years of effort, rather than something that Cueball did between the "this weekend" and the present (at most one week).

Since no Nobel Prize currently exists that would cover recognition of Cueball's achievement, the title text suggests extending the existing prize in "physiology or medicine" to also potentially cover "home improvement or DIY". [[Randall]] likely chose this original prize category because it is already anomalous in containing an 'or' in its title, where the other prizes have only a single-word description of endeavour. The necessity to distinguish {{w|home improvement}} from {{w|DIY}} by specifying both options seems somewhat more redundant than that between {{w|physiology}} (understanding how organisms normally operate) and {{w|medicine}} (understanding how to treat unhealthy ones).

The comic's release coincided with the [https://www.nobelprize.org/prizes/medicine/2025/press-release/ announcement] of the 2025 Nobel Prize in Physiology or Medicine.

==Trivia==
At the time this comic was released, there was a technical error making it too large to fit into the page on normal desktop/laptop screens. Since [[1084: Server Problem#Trivia|1084: Server Problem]], two versions of each comic are usually available: normal (1x) and high-resolution (2x). This makes the comic look sharp even on high-DPI screens, such as phones, tablets, and some more expensive computer displays. In this case, however, the 2x version was accidentally uploaded as ''both'' versions, making the 1x comic twice as large as it should be. It is possible that Randall did this intentionally as an added punchline.

Users with this issue can zoom in with their browsers (Ctrl+mouse scroll up) to see the comic better. If the screen is large enough, you might consider always reading xkcd on 200% zoom to see the higher resolution comics.

This issue was fixed at some point between 14:57 and 15:54, 7 October 2025 (UTC).

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

:[The text for the first panel appears above the panel itself.]
:This weekend,
:I had to make an oversized screen for a porch window.
:[Cueball is looking out through a window with a straight bottom, slanting sides and a curved upper edge.]

:[In each of the remaining panels, the text appears within the panel but above the illustration.]
:It involved countless tiny problems, each somehow way harder than it should be.
:Oblique angles. Curved edges. Noncoplanarity.
:[Cueball is shown pondering various problems involving geometry and angles.]

:... I solved them all.
:I measured precisely. I did trigonometry. I made custom parts.
:And it fit '''''perfectly.'''''
:No gaps, no ripples.
:[Cueball with slightly more hair, looking at the window covered by a bordered mesh.]

:I know that your foundation normally limits its purview to physics, medicine, peace, chemistry and literature.
:However, if you review the attached photo showing how well the screen fits into the...
:[Cueball is revealed to be sitting at a computer, typing a message.]

{{comic discussion}}<noinclude>

[[Category:Comics featuring Cueball]]

Talk:3085: About 20 Pounds

2025-05-06T10:20:59Z

Dykotomee: Add Star Wars comment

Wow - first here! I can't help thinking 'about 20 pounds' could be exactly 10 kg! 0r even one Newton?! [[User:RIIW - Ponder it|RIIW - Ponder it]] ([[User talk:RIIW - Ponder it|talk]]) 05:50, 6 May 2025 (UTC)
:"One Newton" and "10 kg" are totally different things. "10 kg" would cause 1 Newton of gravitational force if you were in a world with about 1% of Earth's gravity, though. --[[Special:Contributions/172.69.109.86|172.69.109.86]] 09:53, 6 May 2025 (UTC)
:20 pounds are 9.072 kg, so not exactly 10 kg (in fact, it rounds to 9). [[Special:Contributions/172.70.134.55|172.70.134.55]] 10:02, 6 May 2025 (UTC)
Though I don't think it at all merits being described as a reference, I am minded of the {{w|The Usenet Oracle}} (at least when I knew of it). Though, if it ''was'' to be a deleliberate shout-out, I'd expect a few more actual in-jokes. [[Special:Contributions/172.70.86.130|172.70.86.130]] 06:10, 6 May 2025 (UTC)

I bet Randall is in some kind of force-interaction-related, What-if-induced rabbit hole right now (or has been at the time of writing). Wondering what the next comic will be about. [[Special:Contributions/172.71.144.175|172.71.144.175]] 08:39, 6 May 2025 (UTC)

"Nature of ... 20 pounds" is a reference to the koan "A monk asked Tozan, 'What is the nature of Buddha?' He replied, 'Three pounds of flax.'" Someone can add this to the explanation. [[Special:Contributions/172.70.111.115|172.70.111.115]] 08:57, 6 May 2025 (UTC)

"something that doesn't interact with electromagnetism cannot be 'seen', as photons will pass through it completely unaffected": is this supposed to be true ? I thought photons interacted with gravity, and even the phrase before states that gravity is believed to affect everything. [[Special:Contributions/172.68.151.93|172.68.151.93]] 09:17, 6 May 2025 (UTC)

My physics skills are rusty but 20 pounds is much more than the Planck mass. Doesn't this imply that Randall's dark matter particles would be black holes? [[Special:Contributions/172.68.243.107|172.68.243.107]] 10:05, 6 May 2025 (UTC)

Since it's Star Wars day and the 20 lbs. reference would be causing a massively large amount of mass, would it be safe to say that they "sense a great disturbance in the force?"
[[Special:Contributions/67.84.20.42|67.84.20.42]] 10:20, 6 May 2025 (UTC)

3057: Excusing Yourself

2025-03-01T02:57:07Z

Dykotomee: Add citation needed to the theory that sleep is essential

{{comic
| number = 3057
| date = February 28, 2025
| title = Excusing Yourself
| image = excusing_yourself_2x.png
| imagesize = 740x334px
| noexpand = true
| titletext = The most awkward part is when you have to pause to put on your shoes before you continue rolling out the door.
}}

==Explanation==
{{incomplete|Created by AN EXTREMELY POLITE BOT - Please continue to tidy up the explanation. Do NOT delete this tag too soon.}}

This comic revolves around different degrees of 'politeness' to leave a gathering, various scenes replicating the end of a social event, possibly a dinner party, but with different outcomes.

The first panel shows [[Megan]] sitting at a table with [[White Hat]] and [[Ponytail]]. She suddenly realizes how late she's 'kept them up', and how she needs to go somewhere early in the morning. Despite this and the fact that sleep is essential{{Citation needed}}, she stays and offers to help tidy up the house before she leaves, possibly the most polite you can be in this situation, as it does not suggest the reason for leaving is related to the quality of the gathering and suggests she would stay longer if not for other obligations.

The second panel shows [[Cueball]] at the same gathering, who says that he must leave due to the fact that he is tired and must sleep. This is considered less polite, as he does not offer to help clean up the way Megan did, and indirectly implies the gathering is no longer entertaining enough to merit staying up; or just that he is ''too'' tired to fully comply with social niceties, in an understandable manner.

Even less polite is the trickster and classhole [[Black Hat]], in the third panel, who excuses himself in typical Black Hat fashion. Instead of him saying that he alone is tired, he says that EVERYONE looks tired ''and'' bored. This is very impolite, especially in a social setting.

The final panel is as wide as three panels, and shows (as three points in time, depicting the unfolding action) [[Danish]] kicking the table, sending the chair tipping backwards and dumping her onto the floor. She then proceeds to roll away from the table, and presumably outside the house. This is rude on multiple levels: she does not give the hosts any chance to wish her goodbye, provides no excuse as to why she is leaving (as if it should be obvious), actively makes more mess by spilling the drinks on the table, and draws significant attention to herself all the while. Moreover, it is a health risk as she may sustain a concussion from such a fall pictured in the comic where the head directly impacts the floor, unless she has {{w|Uke (martial arts)#Ukemi|specifically practiced}} {{w|Stunt#Practical effects|such manouevres}}.

The title text adds to the general awkwardness of having to excuse yourself, when Danish has presumably realized that she has forgot to put on her shoes, and has to stop rolling to put them on before continuing. This interaction is also unusual since in the United States (where Randall resides), hosts are unlikely to request their guests to remove shoes at a house party [https://www.cbsnews.com/news/most-americans-are-shoes-off-at-home/ despite a majority opting to not wear shoes in their own homes]. Therefore, there's a reasonable likelihood that Danish would have had her shoes on already, and would not encounter this issue.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Caption above the panel:]
:Ways to leave a social interaction:
:[An arrow pointing towards the right is shown below the caption. Caption above arrow:]
:Less polite

:[First Panel: From left to right, Ponytail, White Hat, and Megan are sitting at a table with half-full glasses on it. Megan is looking down at her phone.]
:Megan: Oh, gosh, I can't believe how late I've kept you up! I have to wake up early, so I should really go soon.
:Megan: Can I help tidy up?

:[Second Panel: White Hat and Cueball are sitting at a table (only the right half is shown, so Ponytail may be presumed to be in the left chair as in the first panel), on which there are half-full glasses and a plate.]
:Cueball: It's been great, but I'm tired and need to sleep.

:[Third Panel: White Hat and Black Hat are sitting at a table (again, Ponytail may be in the left chair), with two plates and a half-full wine glass at White Hat's spot. Black Hat's arm is resting on his chair.]
:Black Hat: We're about done having fun, right?
:Black Hat: Everyone looks bored.
:Black Hat: And tired.

:[Fourth Panel: Ponytail, White Hat are sitting at the table. Danish (with her hair being only subtly longer than Megan's in the First Panel) is shown in a sequence of actions within the same frame.]
:[Action 1: Danish kicks the table at which she was sat, spilling the drinks on it, while simultaneously pushing her chair backwards, to topple it:]
:''Kick''
:Danish: Bye.
:[Action 2: Danish and her chair crash to the floor, with arm flung back.]
:''Crash''
:[Action 3: Danish tumbles away from the position she fell in, either in a backwards or sideways roll.]

{{comic discussion}}

[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Danish]]
[[Category:Social interactions]]

2804: Marshmallow

2023-07-20T10:46:38Z

Dykotomee: /* Explanation */ Update quotes for enjoy; use "US" instead of "our" when referring to space program in last paragraph; add citation needed at end.

{{comic
| number = 2804
| date = July 19, 2023
| title = Marshmallow
| image = marshmallow_2x.png
| imagesize = 670x334px
| noexpand = true
| titletext = The increasing number of graham crackers and chocolate bars in orbit has created a growing risk of Kessler s'mores.
}}

==Explanation==
{{incomplete|Created by a CELESTIAL S'MORE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
This comic shows the atmospheric re-entry process of a capsule similar to that used in the Apollo moon landing program in the late 1960s and early 1970s. This capsule features a fictional Reentry Marshmallow Toasting Module, with a marshmallow on a deployable stick, which is exposed to airflow during reentry.

During reentry, the capsule would presumably be going at orbital speeds, which for Earth are in excess of 8 km/s. This high velocity heats up the air around the capsule as the kinetic energy is dissipated.{{Actual citation needed}} This has the effect of heating the marshmallow. Additionally, reentry heating effects typically look like flames covering the bottom of the reentering object. This is very similar to a common practice on the Earth's surface of holding a marshmallow on a stick over a static fire on the ground, like a campfire, which also heats the marshmallow, improving its taste{{citation needed}}.

At the start of the panel, the capsule is approaching atmospheric entry, so any aerodynamic forces would not have begun yet. "All systems nominal" is an aerospace phrase that means all systems (including life support, navigation and stability systems) are performing as expected. However, once the atmospheric effects begin then something goes wrong.

Having a long, thin extension to the airflow will disrupt the aerodynamics, as air starts pushing up against the roasting stick, creating an unbalanced torque that pushes the marshmallow further back into the airflow, rotating the entire capsule. This angular acceleration continues until the aerodynamic design of the rest of the capsule plays a significant factor, rotating the capsule back to its original position, and starting the uncontrollable cycle of oscillations anew. Hence, the astronaut on board reports some oscillations to Houston.

This prompts the unnamed astronaut to tell their colleague, Smith, to put away the marshmallow roaster. This would clean up the aerodynamic profile and stop the oscillation. This is met with resistance that the marshmallow is not cooked yet. This may be expected, as due to the design of the module, it appears as though the marshmallow has been on the outside of the capsule for the entire journey, exposed to the vacuum of space. In this situation, it would have radiated all its heat energy away, reaching temperatures near absolute zero (approximately -273.15 degrees Celsius, the absolute coldest temperature physically achievable). A very brief moment of shock heating from atmospheric effects may not have bought the marshmallow up to a consumable temperature, or even affected the internals of the marshmallow at all. The goal of roasting marshmallows is often to melt the inside of a marshmallow completely, so if this is still frozen, that defeats the entire purpose of the module.

Houston is a city in Texas, United States, where Mission Control for NASA is established. Astronauts in space would communicate with "Houston", as the specific person on the other end would vary with which shift was working. These communications are established via radio. During reentry, the superheated air forms a plasma phase and disrupts radio wave signals. Hence, it is doubtful that Mission Control would have received this communication from the capsule, and it is very unlikely Mission Control would have received further updates from the capsule until the reentry process was largely finished. This would make the Mission Control operators very concerned over the success of the reentry.

The caption for the panel muses that maybe the concept of the module was a mistake, which is a fair assessment given the number of flaws in the design. It would indeed be far better to have ''two'' such units, set upon opposing sides of the module and operated in conjunction, to balance rotational forces. Or even three of them, set 120° apart from each other, perhaps automatically and independently actuated to tune out all ''other'' undesired aerodynamic effects – with the added advantage of simultaneously preparing snacks for all three of the astronauts that typically inhabit an Apollo capsule, not just Smith. However, since there appears to be no way to retrieve the marshmallows without exiting the capsule, they are likely to be somewhat salty and waterlogged by the time the astronauts come to "enjoy" them.

The title text refers to a popular snack of s'mores, made by placing a marshmallow roasted over a fire with some chocolate between two crackers, similar to a sandwich. It also refers to a problem in rocketry known as Kessler syndrome, where vast amounts of space junk in low earth orbit reduce the chance of successful rocket launches, as new launches may crash into existing space junk, causing a rapid unplanned disassembly. These two concepts are combined in a ridiculous way, whereby instead of space junk, it is Graham crackers and chocolate bars that are polluting space. These, combined with the marshmallow from the toasting module, would create celestial s'mores, a novel and frankly whacky concept, as the United States space program does not primarily consist of chocolate and Graham crackers{{citation needed}}.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
[as follows, left to right, top to bottom]
:[Capsule begins reentry.]
:Smith: We're approaching atmospheric entry.
:Smith: All systems nominal.
:Fwip
:[Marshmallow roasting rod deployed]
:Smith: Houston, we're experiencing some oscillations. Vehicle is becoming difficult to control.
:Mission control: Smith, retract that stupid arm.
:Smith: No! It's not ready yet!

:[Caption below the panel:]
:In retrospect, the reentry marshmallow toasting module was a mistake.

{{comic discussion}}
[[Category:Space]]
[[Category:Food]]