1515: Basketball Earth

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Basketball Earth
How many points do you get for dunking every basketball in existence at once?
Title text: How many points do you get for dunking every basketball in existence at once?


In this comic Cueball is repeatedly attempting to make a size comparison between the Earth and the Moon. But he only gets to say If the Earth were the size of a basketball, the Moon would be-. Then he is interrupted again and again. (See the title text of 1074: Moon Landing for the same Earth comparison).

A basketball is about 25 cm in diameter and from this it can be inferred that the Moon should then be less than 7 cm in diameter, a typical size for other smaller balls in different sports. Cueball handily illustrates this with two "balls" of the relevant sizes. At first, you think that they just look like the Earth and the Moon. But they are invisibly suspended, and — as seems clear from the first row of panels — they are actually the real Moon and Earth shrunk to the relevant size, hence the title Basketball Earth.

This would place Cueball and his "friends" in God-like positions, outside Earth. Maybe they are even in a different dimension since they can stand and observe the system.

But before Cueball can finish with this common type of comparison, he is interrupted and must begin all over again. We thus never learn what object he would have compared the Moon with. It seems, likely, however, that he would use another ball for the comparison. And the best ball to use would be a tennis ball. See the same sort of comparison of Earth/Moon with basketball/tennis ball in this illustrative video that asks the question: How far away is the Moon?. From this, it is also obvious that the system Cueball shows is not to scale with regard to that distance, which should be 7.37 m! This is not necessarily a mistake of the comic, since Cueball never claims that these two balls are in orbit or that they are even the real ones. He is just (in vain) trying to make a size comparison of the two. (Though perhaps further exposition and demonstration might take place after the size comparison.)

A basketball has an average diameter of 24.6 cm (9.7 inches) vs. a tennis ball, which has an average diameter of 6.7 cm (2.6 inches). The ratio between these two diameters is 0.273, which is the same (to three digits) as the ratio given on the Wikipedia page for the Moon: Mean radius 1737.10 km (0.273 Earths). If he had used a baseball, which is slightly larger, this would still be good enough for demonstrative purposes, as it would have been with an apple.

It is common to describe the relationship between very large (and very small) objects by analogy to common objects on a more human scale. Here is a similar example where someone has made a comparison of the sizes of the Solar system based on a Sun the size of a basketball. And here, coming from smaller scales, is an example that states the following: "Imagine an atom magnified to the size of a football stadium. The nucleus of the atom would be the size of a pea in the centre of the stadium."

It is almost certainly not a coincidence that this comic was released on Earth Day, which is celebrated annually on April 22 to demonstrate support for environmental protection. This seems to be something that Randall cares about a lot, as he has made several comics demonstrating the need for the human race to begin taking better care of our globe. See, for instance, 1321: Cold and 1379: 4.5 Degrees.

This comic clearly demonstrates four examples where the inhabitants of Earth did not take care of the well being of our globe, although here on a somewhat grander scale than what individuals can usually do. The typical case is that people did not do this out of bad intentions, but only because they were careless, curious, playful, or just plain stupid.

This comic may be seen as a spiritual successor to 445: I Am Not Good with Boomerangs and its follow-up, 475: Further Boomerang Difficulties in depicting various failed outcomes to the same opening panel.


The four interruptions are described and explained below. Each of the four attempts has its own row of four panels in the comic. It is clear from panels one and two in each row that the Basketball Earth is rotating quite fast compared to the time frame of the comic since the continents have moved considerably between frames. It is thus not necessarily the interrupters that have moved the Basketball Earth between frames two and three, except of course in the final interruption.

No matter how fast it rotates or whatever happens, we always see the Basketball Earth from the same side, as seen from far above the Atlantic Ocean. We can see the continents of the Americas as well as Africa and sometimes part of Europe, all of which are the borders for this ocean.

It seems most likely that Cueball starts all over every time, with a completely fresh and new Earth-Moon system, since they look the same regardless of the catastrophe befalling the prior Basketball Earth, and the interruptions—the second especially—would be difficult to reverse. We can thus suppose that there is still "normal" life going on for each Basketball Earth before the interruption. Most or all of this life would presumably perish for all of the last three cases.

Black Hat[edit]

In the first interruption, Black Hat comes in and is amazed by this cool floating globe. Of course, being Black Hat, he has to prod this nice globe with a digit. But by putting his finger into one of the oceans of this "real" Basketball Earth without a second thought, he apparently generates a megatsunami that rolls in over an unidentified city with skyscrapers, utterly dwarfed by a breaking wave.

This is similar to a scene in "Men in Black II" where K messed with a globe that actually is a small planet, and his finger becomes visible in the sky of its inhabitants. It is also similar to a "Pearls before swine" strip where the character Pig encounters Atlas and the earth in a diner, points to where he lives, and accidentally pokes himself in the eye. It is also reminiscent of Deep Impact in which a meteor strike causes exactly such a tsunami to hit the East Coast of the United States. Since Black Hat puts his finger down in the Atlantic Ocean, the tsunami would hit all bordering coastlines. Since the coast seems to be an eastern coast (assuming a vantage point of South --> North), and because Randall lives there, the city could be New York City or Boston or one of the other large US cities on the East Coast. Of course, the wave would also affect the coastline (far into land) for all the other continents.


The second interruption occurs when Megan arrives and pours liquid (perhaps water) from a sports water bottle onto the Basketball Earth, seemingly flooding its entire surface. This would cause extensive flooding, almost certainly extinguishing all multicellular land-dwelling life. The most familiar analogous situation is from the Bible in the Genesis flood narrative about Noah's Ark. The deluge from Megan's bottle would also change the composition of the ocean and create enormous churn and pressure changes, with widespread or catastrophic effects even on multicellular marine life. And if it were some sort of sports drink inside...


In the third interruption, a cat walks into the shot and then playfully attacks the Basketball Earth, rolling around like it would do with a ball of yarn (see real-life example in this video). This also seems to be an allusion to the logo of the popular web browser Mozilla Firefox, which depicts a fox curled around the earth in a similar manner to that shown in the comic.

The people living upon this Basketball Earth would experience cataclysmic events far greater than Blackhat's digital prodding caused, especially as the Basketball Earth is no longer suspended and was thus taken "out of its orbit" and will eventually hit the floor very hard. One way or another, that will surely cause (undepicted) disasters of tremendous magnitude.


In the fourth and final interruption, Ponytail uses Basketball Earth as an actual basketball. She comes running by Cueball, grabs the Basketball Earth, probably bouncing it off the floor while dribbling towards the basketball hoop where she actually jumps in an attempt to dunk the Basketball Earth. This would not be good for any residents of Basketball Earth[citation needed]; the combined pressure, movement, and impact damage from this simple sequence would surely kill off all complex life on Basketball Earth.

Title text[edit]

This simile-callback is continued in the title text with the idea that "every basketball in existence" (i.e., every basketball upon the Basketball Earth, as well as the Basketball Earth itself) is counted towards the score from a single dunking. Randall may have a good estimate of how many basketballs there are, perhaps through research for some what if? question or other research, but almost certainly assumes that there are no extraterrestrial basketballs not on Basketball Earth. But there might be some question about whether the Basketball Earth's own sub-scale basketballs fall within the regulations.

If we go by the strict rules of league Basketball, the answer would only be two points, as it is illegal to have more than one basketball in play at a time.


[Cueball is standing next to a floating Basketball Earth indicating it with his left hand. The continents are clearly visible as seen from above the Atlantic Ocean. This remains the same all through the comic, except that the Basketball Earth rotates a bit from frame to frame.]
Cueball: If the Earth were the size of a basketball,
[Cueball is now indicating, with his right hand, a small pockmarked moon (also floating), in the correct proportions (regarding size not for their distance) to the Basketball Earth, which is on his other side. Black Hat walks into the panel towards Earth.]
Cueball: The Moon would be—
Black Hat: Hey, cool!
[Black Hat is touching the Basketball Earth with a digit.]
Cueball: Um.
[In the next scene, we see a megatsunami on the verge of crashing down onto a coastal city with skyscrapers. The A's are cut off on each side of the panels frames, i.e. they begin outside and finish outside the frame.]

[Back to Cueball standing with the Basketball Earth in the same position as the first panel.]
Cueball: Let's try that again. If the Earth were the size of a basketball,
[Same situation as when Black Hat walked in, except now it is Megan that walks into the frame towards the Basketball Earth holding a sports water bottle.]
Cueball: The Moon would be—
[Megan squirts the Basketball Earth with the liquid in her water bottle while Cueball just stands watching with the Moon behind him].
[Megan just walks away while Cueball stares at his "water" Basketball Earth where the continents have disappeared completely beneath the liquid.]

[Back to Cueball standing with the Basketball Earth in the same position as the first panel.]
Cueball: If the Earth were the size of a basketball,
[Same situation as when Black Hat walked in, except now he spots a cat coming into the frame from the left.]
Cueball: The Moon— would…
[While Cueball watches with the Moon behind him, the cat jumps at the Basketball Earth.]
Cat: Mrowl!
[Cueball continues to watch while the cat rolls around playing with the Basketball Earth as if it was a ball of yarn.]
Cat: Rrrrr

[Back to Cueball standing with the Basketball Earth in the same position as the first panel.]
Cueball: If the Earth were the size of a basketball,
[Same situation as when Black Hat walked in, except this time it is Ponytail who enters the frame at a run coming from the left.]
Cueball: The Moon would, uh…
[While Cueball watches with the Moon behind him, Ponytail has grabbed the Basketball Earth and is dribbling it out of the frame, still running.]
[Zoom out from Cueball who continues to watch while Ponytail reaches a basketball hoop and jumps towards it with the Basketball Earth, obviously in an attempt to make a slam dunk.]

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Apologies to the first editor, who made a snappier version of what I wrote. For the record, whilst fighting a dodgy internet connection I eventually ended up replacing the following...

 Cueball is seen trying to explain the relative sizes of the earth and moon by comparing the earth to a basketball and the moon to what looks like a golf ball. This explanation is constantly thwarted by passerby interacting with the basketball while Cueball is explaining it.
 For the title text, the answer is zero, since it is against basketball rules.

...with what I tried to keep short during my own writing from scratch. I also ommited several other concepts of my own thought: The fact that Blackhat must have used a very light-touch to only generate a megatsunami (albeit already unimaginably large, at Earthball's scale); The possibility of recursion (including something like the Men In Black 'cat collar' allusion); and that in the universe of the comic strip there is only one actual basketball (the Earthball itsself), although I like how we both had the idea that the basketballs upon Earthball would not have counted in a game of basketball with an Earthball-scaled hoop, due to quite obvious interpretations of the sport's regulations. 05:11, 22 April 2015 (UTC)

Oh yeah, and reversion is invited, if deemed preferable. As is amalgamation, and refinement and re-replacement by something even better, of course. As per the standard Wiki creed. Much as I am cringing at having upset the original contributor, I'm quite happy to be gazumped in turn. 05:14, 22 April 2015 (UTC)

If you look at the third frame of the Blackhat sequence and compare it to the frames underneath, you can see that he didn't just touch the Earth or an ocean--he actually rotated it 90 degrees. 09:38, 22 April 2015 (UTC)

Well spotted! Edit that in! (Do it quickly with a pre-prepared edit. I kept getting hit by edit-conflicts, which I set about to resolve amicably without reversing anybody else's input; only to get hit by further edit-conflicts by the next person to come along and improve overlapping pieces, whom I also strived not to disregard.) 09:57, 22 April 2015 (UTC)
No he didn't. the Earth always rotates from the first panel to the next. So that it is in a different position when Black Hat touches it, to where it was the panel before does not imply that he rotated the Earth. If anything he only rotated it a few degrees, as it had already rotated most of those 90 degree from panel 1 to panel 2 before Black Hat reaches the Earth. As far as I can see there has not been any change to include this yet. So that is good. --Kynde (talk) 10:41, 22 April 2015 (UTC)

I really love this comic. It is great fun. Thanks Randall, happy Earth day. --Kynde (talk) 10:42, 22 April 2015 (UTC)

... a tennis ball an average 7.2 metres away, while the Sun would be 26 metres across and 2.8 km away. 13:25, 22 April 2015 (UTC)

It's 13:23 right now, but the clock of explainxkcd.com says it's 13:37. 13:37, 22 April 2015 (UTC)

If we assume 9,000,000 basketballs sold every year (bbs.ClutchFans.net), one basketball lasts about 10,000 bounces (SoTrueFacts.com), and there's between 2,500 and 3,000 bounces per game (Answers.com) we can extrapolate that on average a basketball doesn't live for more than a year, and the number of basketballs sold replace those which have lifed-out. Let's build in a 10% slush factor and say there 10m basketballs produced in the world last year. Let's further say that there's an extra 1m basketballs sold every year which don't get regular use and are in some kid's room and those have been accumulating for about ten years (different kids get basketballs every year which end up in their bedrooms). Dunking a basketball gives two points, and at 20 million basketballs, that gives 40 million points – and a safe bet you're going to make it to the playoffs that year. Jarod997 (talk) 13:51, 22 April 2015 (UTC)

Is it possible that the megatsunami is actually caused by the gravity of the scale Moon (it being way too close to the scale Earth)? This is a major problem that most children's books (or adult's books or websites) have. They scale the planets/moons/stars but not the distance. As the comment above, to get normal tides, the tennis ball should be 7.2m away at this scale. --Gravitron (talk) 14:06, 22 April 2015 (UTC)

I find it interesting that Randall makes the same mistake a lot of people make reguarding the distance between the earth and moon at that scale. I was watching Veritasium (https://www.youtube.com/watch?v=Bz9D6xba9Og) on Youtube a while back and the guy there was asking people how far away a tennis ball sized moon would be from a basketball sized Earth. Most people made the distance way too small, very similar to how far away they appear in the comic. In reality they would be something like 10 times that distance. Usually Randall is more accurate than this. 14:09, 22 April 2015 (UTC)Agent0013

Unless he was simply trying to compare the relative sizes. It's possible after that he would get in to the relative distance between the two - but good point. Jarod997 (talk) 14:12, 22 April 2015 (UTC)
It seemingly got lost when trying to resolve edits, but I'd calculated and intended to add that (for the size of a baseball, so a tennis ball would slightly different) 110 Moonball diameters separation between the two. Of course no human has (personally) seen that from a proper perspective, i.e. far enough away to get both bodies in the same convenient vision at the same time whilst off to the side. (Even the Apollo astronauts only got to look at one over the top of the other, at various times, or by panning between the two whilst in the midst of their trans-lunar trajectories.) But there's surely been a space probe or two with a suitable imager been tasked towards such a shot whilst off mostly perpendicular to the Earth-Moon and a decent distance away to get both in the same shot without distortion... 17:52, 22 April 2015 (UTC)

I don't agree with the claim (at a couple points in the article) that *all* life would be extinguished by any of these manipulations. 2-4 may kill off most or all macroscopic life, but microbes would survive all of them (unless Megan has bleach in that sports bottle). If 3 or 4 shattered the earth, that might extinguish all microbes, but even that I doubt. The only case I can imagine would be if 3 or 4 caused it to spiral into the sun. Djbrasier (talk) 14:10, 22 April 2015 (UTC)

Title text might be reference to HHGTG: “ Ford Prefect: I read of one planet in the seventh dimension got used as a ball in a game of intergalactic bar billiards. Got potted straight into a black hole, killed ten billion people. Arthur Dent: Madness. Total madness. Ford Prefect: Yeah. Only scored thirty points too. ” 14:23, 22 April 2015 (UTC)

I admit that I'm super-confused by the structure of the comic. The explanation here describes possible consequences for the actions, but as depicted, only the first has any "real world" effect. I too would expect the water bottle to cause a deluge, but it doesn't seem to. What's going on? Mattdm (talk) 15:40, 22 April 2015 (UTC)

The hoop in panel 16 seems too high, unless both Cueball and Megan are under 5 feet tall. --PsyMar (talk) 17:11, 22 April 2015 (UTC)

It could be perspective...17jiangz1 (talk) 12:58, 23 April 2015 (UTC)

Happy Earth Day everyone. Today is the day we regret everything we do to the earth, and the next is the day we forget all that. The Goyim speaks (talk) 17:59, 22 April 2015 (UTC)

I just noticed that if 1511 (Spice Girl) had had been released on the following Friday, i.e. the slot actually given to comic 1513 (Code Quality), it would have coincided with Victoria "Posh Spice" Beckham's 41st birthday. So, that would probably not have been an intentional direct reference, but soooo close to ending up being an accidental one. While I'm happy to go along with Earth Day as a deliberate reference... it makes you think, eh? (Although I'd be happy if people thought about Earth Day itself more than the synchronicity. It's a good cause, and pause for thought.) 19:55, 22 April 2015 (UTC)

Why the whole paragraph about it being a baseball? We have no indication of what it is, so why not just say "if it's a tennis ball..." 18:35, 22 April 2015 (UTC)

Might be my fault. I assumed it was a basketball/baseball comparison in my original endeavour, and this has persisted through other edits, even after the rather logical "...a tennis ball's proportions". Over-compensated for Randall being Leftpondian, probably, even though I've never played Baseball myself (only Rounders). 19:55, 22 April 2015 (UTC)

The title is almost certainly a reference to the movie "Battlefield Earth" 23:57, 22 April 2015 (UTC)

The points acquired for simultaneously dunking all basketballs in existence, or further out -- EVER made, would be at most 2 points (0 if any of the Referees deemed this an illegal/foreign object or an attempt at cheating). Introducing more basketballs onto the court would not result in more points being scored. Furthermore, the basketball earth, while 'containing' all other basketballs, is still itself a single object. -- Dulock (talk) (please sign your comments with ~~~~)

Does anybody else find it odd that black hat is actually the one causing the LEAST destruction? 03:09, 23 April 2015 (UTC)

Except, in a way, he is causing the most harm. Scenario 2, 3, and 4 do cause everyone to die, but they would be relatively quick, and what black hat does has painful consequences. The megatsunami would cause huge-scale devastation, worst near the sea he poked, but still bad. This would, among other things, require major rebuilding efforts and include crop failures, leading to famines and the like. In addition, it would have scientists trying to explain it, which would lead to confusion, something black hat likes causing. 07:04, 25 March 2016 (UTC)

A useful comparison from the Canadian comedy troupe, "The Frantics": "If we could shrink the sun to the size of a basketball, and the earth to the size of a pea . . . we'd be magic!" (talk) (please sign your comments with ~~~~)

Just re-reading old pages...this discussion reminds me of one of my favourite pieces of public art. In Melbourne Australia, there's a scale model of the solar system along the beach. The sun is a ball around 2m across, mercury is pea sized and around 50m away (dimensions approx, long time since I've visited) and the rest scaled to match. Pluto (old sculpture) is around 5kms away, and a tiny speck on its plinth. And not far away from the sun is Alpha Centauri, apparently to scale if you walk the other way around the earth... 14:41, 19 June 2018 (UTC)

It looks like in the Black Hat part, the Earth is actually skewing in its rotation (it starts out in the first panel with the Americas and Africa, the second panel looks like it's skewed about 45 degrees counter-clockwise, and the third panel definitely looks like Earth has rotated on what would be its side to our standard North Pole-oriented map a whole 90 degrees and therefore, Black Hat's hand (or the tip of his arm as stick figures are often thus undetailed) has landed on Antarctica. Of course, the physical damage to the polar ice cap and its subsequent dispersal into the Southern Ocean would definitely affect sea levels, but a tsunami striking any heavily-populated coastal town is out of the question.