3179: Fishing

2025-12-15T14:39:05Z

2A00:FBC:F3A9:497:C1F7:EC5F:4A24:E3B7: /* Explanation */

{{comic
| number = 3179
| date = December 10, 2025
| title = Fishing
| image = fishing_2x.png
| imagesize = 317x500px
| noexpand = true
| titletext = 'That's definitely above the catch-and-release size minimum for planetesimals.' 'I'm going to throw it back anyway.'
}}

==Explanation==
{{incomplete|This page was created BY A FISH WITH THE WEIGHT OF THE SUN. Don't remove this notice too soon.}}
[[Ponytail]] and [[Beret Guy]] are fishing in the middle of a body of water, and Beret Guy has hooked a rock. Similarly to the common meme that sees people catching objects such as boots and shopping carts, he exclaims that it "feels like a big one". Fishers may judge the size of a fish by the amount of resistance they feel on the line, using their judgement of what a given mass and power of fish feels like when submerged and resisting the leverage of their fishing rod, and non-fish objects that are 'hooked' (especially those stuck in the sediment at the bottom) can seem to be reacting like a proper catch. (Also, the boat would be pulled down when reeling, so they could only tell that their downward pull is greater than the boat’s buoyancy.) In this case, though, Beret Guy can apparently feel that it must be "at least 1024 kilograms" — that is, an object with a size in the order of that of the {{w|Earth}} in its entirety, whose mass can be estimated at approximately 6.0 × 1024 kilograms (~1.31 × 1025 pounds). It would be unlikely that this could be confused with a fish.

This kind of "hook it and pull on the line" procedure could be used in space, in a vacuum without water, to estimate the mass of a low-gravity object. That would be based on observing how much mutual inward acceleration was created by the measured force applied. The method would only be effective if the object wasn't too much more massive than the person (and their space suit / ship / etc.) doing the measurement.

Catch-and-release sizes restrict what sizes of catch of various species can be kept, generally to protect stocks. There may be minimum sizes (to protect young fish and ensure that they can reach mature reproductive age) or maximum sizes (to protect existing breeding populations). The title text claims the Earth is large enough to be kept, suggesting that {{w|planetesimals}} ({{w|asteroids}} and {{w|comets}}, for example) might be considered immature, and that they might be expected to eventually grow to 'adult' planet size. Beret Guy is big-hearted enough to want to release the planet back after reeling it in, even though he could keep it, or sportsmanlike, in allowing the catch to be potentially recaught by the next 'lucky' individual.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[Ponytail and Beret Guy are sitting in a boat floating on a body of water, both holding fishing rods. One large fish and four smaller fish are seen swimming in the water, with three of the smaller fish in a group. Ponytail's fishing rod is about halfway down to the bottom, while Beret Guy has hooked his fishing line on a large rock sticking up from the bottom.]
:Beret Guy: It feels like a big one! At least 1024 kilograms!

{{comic discussion}}<noinclude>

[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Beret Guy]]
[[Category:Geology]]
[[Category:Physics]]
[[Category:Sport]]
[[Category:Strange powers of Beret Guy]]

3180: Apples

2025-12-15T14:35:43Z

2A00:FBC:F3A9:497:C1F7:EC5F:4A24:E3B7: /* Explanation */

{{comic
| number = 3180
| date = December 12, 2025
| title = Apples
| image = apples_2x.png
| imagesize = 263x364px
| noexpand = true
| titletext = The experimental math department's budget is under scrutiny for how much they've been spending on trains leaving Chicago at 9:00pm traveling at 45 mph.
}}

==Explanation==
{{incomplete|This page was created BY A CAR HEADING WEST AT 70MPH. Is there not way too much talk about math concepts that has nothing to do with the simple joke in this comic. Like three paragraphs too much (1+2)? Don't remove this notice too soon.}}

Three "experimental mathematicians" have experimentally confirmed the answer to a mathematical query that might normally {{w|word problem (mathematics education)|be described}} to an elementary school class: "If [[Cueball]] has seven apples and [[Hairbun]] has five, how many apples are there in total?" With everyone having literally brought together their stated number of apples, Cueball counts the two groups of apples and states that the total is twelve. [[Blondie]] is very excited that this real world demonstration has perfect agreement with some presupposed theory.

Most people with a basic level of math would be confident to represent this as 7 + 5 = 12, without needing to count groups of physical objects. However, the title text indicates that there is an entire experimental mathematics department.

This may be reflecting the most basic step of {{w|Number theory|human mathematics}}: realising that having seven of ''any'' discrete item and combining with five more results in twelve items in total. Numbers alone can therefore be freely used without there ''being'' actual items to prove. {{w|History of ancient numeral systems#Clay tokens|Early accounting methods}} initially used proxy representations of the items, in a form of hybrid literal/symbolic manner, which meant that a collection of apples and a collection of animals could be considered almost as conceptually different, even though the same initial numbers would result in identical end-totals.

This Experimental Mathematics department may have been working on this type of problem, as part of a mostly pre-mathematical culture. They are checking that seven apples plus five apples equals twelve apples after some prior work, perhaps having counted that seven sheep plus five sheep equals twelve sheep (if not several other experimentally-proven summations). Prior to checking the apples, they postulated a theory that extends to other items, such as these apples, but only by using actual apples have they confirmed the continuing truth of it.

(There are cases where this might not occur, when combining certain items that aren't uniform and discrete. Measuring volumes of two different substances, combined to make a solution, can result in wildly different volumes of the end solution; both greater and lesser. Combining measured volumes of nearly-freezing and nearly-boiling water, the resulting liquid, eventually at an intermediate temperature, can be {{w|Properties of water#Density of water and ice|measureably different}} from the simple combination of the prior values.)

Branches of science may have a division between the empirical approach (gathering direct evidence or practically demonstrating that something works) and the theoretical (developing abstract models that fit the available information through the use of abstract models). In some cases, advances in theory greatly outpace any direct physical evidence, and may deal with numbers and situations that cannot be readily reproduced or observed. For example, if straying into the territory of irrational or infinitesimal numbers, the usefulness of manifesting with physical objects may be less useful.

The title text states that, more complicated schoolroom mathematical problems are also pursued. Where the question of how many apples there are in total is simple additive arithmetic, a more advanced problem for older students may require a knowledge of {{w|algebra}} and even {{w|System of equations|simultaneous equations}} to calculate the intersection of values that a described using multiple shared variables. A common conceit is to describe journeys by train (in which a position is directly dependant upon a given time). As with the physically performed experimentations with the number of apples, it is alluded to that these more advanced queries are investigated by members of the department becoming repeat passengers upon a particular Chicago-departing rail service. In all likelihood, observers are also being assigned to various Chicago-bound services that match the initial problems' various other stipulations. (In reality, physical trains are probably less reliable incarnations of pure mathematical problems. They are potentially subject to all kinds of delays, even 'non-stop' services may change speed for various reasons and there is no indication that the pure mathematical model being enacted takes account of the train needing to take time to reach even its idealised velocity.) Whatever the test(s) using trains might be, however, the cost of either boarding or outright ''commissioning'' the train journeys is of concern to the department's accountants/auditors, who seem to have number problems of their own (i.e. the depletion of the departmental operating budget).

In reality, {{w|experimental mathematics}} is the branch of mathematics which uses computation, as opposed to "pure" deductive proof methods. This does not involve "verifying" simple arithmetic, but could encompass, for example, calculating long runs of the digits of pi in search of patterns that may not be 'obvious' from known principles but which could be proven once identified as a candidate for proof. Also part of mathematics would be something like [https://nvlpubs.nist.gov/nistpubs/sp958-lide/132-134.pdf experimental statistics], though here usually it means statistically analyzing results of experiments, rather than mathematics itself being experimental.

==Transcript==
:[Hairbun and Cueball stand at the left of the panel. Blondie stands at the right. Between them are two piles of apples, one of seven apples (stacked four on the bottom, two in the middle row, and one on top) and the other of five apples (stacked three on the bottom, and two on top).They are all looking at the apples but Blondie has her arms raised high above her head.]
:Cueball: Okay, with my seven apples added to your five, we have ... let's see ... twelve apples!
:Blondie: Incredible!
:Blondie: Perfect agreement with the theory!

:[Caption below the panel:]
:Experimental mathematicians

{{comic discussion}}<noinclude>
[[Category:Comics featuring Hairbun]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Blondie]]
[[Category:Math]]
[[Category:Food]]

explain xkcd - User contributions [en]

3179: Fishing

3180: Apples