explain xkcd - User contributions [en]

3136: Pull

2025-09-16T12:30:38Z

2600:100F:B1BF:1721:7937:3C5C:ABC4:4A51: Expanded explanation.

{{comic
| number = 3136
| date = September 1, 2025
| title = Pull
| image = pull_2x.png
| imagesize = 650x220px
| noexpand = true
| titletext = Be careful fighting gravity. If you win, it's a long way down.
}}

==Explanation==
[[Megan]] and [[Cueball]] are lying in the grass on an orb – possibly a stylized Earth, though the curvature suggests a ''much'' smaller body. However, instead of the conventional frame orientation where gravity points towards the bottom of the image, the viewpoint is stationary outside the Earth while we see it slowly rotating, reminiscent of the alternate frame of reference apparently in use in [[2800: Down]]. Shown this way, we may have the intuitive feeling that the protagonists should fall off, and this makes a point how weird it is that gravity keeps us stuck to an orb, continuing with the theme of "how reality is odd" last seen in the prior comic, [[3135: Sea Level]].

In the first panel, Cueball expresses that he doesn't like being stuck there, possibly because he wants to explore other worlds or because he finds Earth limiting. The alternative would be "falling off", as in succumbing to the [[123|centrifugal force]] that results from the Earth's rotation – this would appear in the comic's perspective as both characters slowly "falling" away towards the right side of the panel. As this centrifugal effect is quite slight compared to the gravitational acceleration we're used to (0.34% of it at the equator), Megan and Cueball would have roughly three more minutes until they "fell" off-panel, assuming their position is of a mid-northern latitude typical to the US – unless they're able to fly under their own power now that they're no longer constrained by gravity, or unless the rest of Planet Earth also has its gravity turned off and violently explodes as a result.

In the second panel, Megan uses a more metaphorical sense of the word pull, she is attracted to lying on the grass doing nothing and blames her inability to get up and do things on gravity. This could also mean that if the pull (aka gravity) is less, she could get up more easily and get to where she wants to go.

Cueball replies that the pull might weaken over time. In a literal sense, gravity will not decrease significantly even in the long term and is likely not an actual obstacle to Megan getting up (assuming the sphere is Earth, which is the only known planet with humans on it{{cn}} as of the comic's publication). [https://www.cbc.ca/radio/quirks/sept-1-2018-gene-editing-in-dogs-wildfire-prediction-zika-fizzles-and-more-1.4804892/is-earth-getting-heavier-or-lighter-1.4804900 Earth gains mass] from dust and meteorites but also loses mass, mainly due to escaping hydrogen and helium. The net effect of these is for Earth to lose about 50,000 tonnes per year; in the 5‑minute period Megan mentions, equivalent to 500 kg out of the Earth's mass of 5.972 × 1024 kg, changing gravity by a factor of about 10-22 (1 part in 10 sextillion). Locally, gravity can also change due to mass redistribution. The Earth's core is very slowly cooling, leading to decreasing radius and thus increasing gravity at the surface. Towards the end of its life, the Earth's water will be boiled off due to the expanding Sun, leading to a decrease in gravity. Metaphorically, Cueball seems to just be saying that so she will stay a bit longer. Megan agrees.

Fighting the gravity in the title text is reminiscent of the Ancient Greek story of {{w|Icarus}}, who fell down after flying too close to the Sun, where flying might be seen as fighting gravity. It might also just be a rephrasing of the truism "The higher you go, the longer the fall". On the other hand, "it's a long way down" may not refer to falling back to Earth, but rather falling off the Earth, if one were no longer "stuck" to it. In that case, "down" would presumably mean toward the Sun, the center of gravitational pull in the solar system – a very long way away. If one "defeated" ''all'' gravity, "down" would mean "away from the Earth into space" endlessly, unless one happened to collide with some object.

However, you could avoid this if you had a method of self-propulsion, which brings to mind Superman, who is a good example. He can "defeat" gravity and has some method of self-propulsion (which is, obviously, how he flys.) While humans don't have any natural means of self-propulsion while in a gravity free environment{{cn}}, they can use artificial methods (eg: a jetpack.).

==Transcript==
:[Cueball and Megan lying on a surface with grass, and the surface is round. They are orientated sideways, slightly facing up.]
:Cueball: I don't like being stuck to this orb,
:Cueball: but I guess falling off would be worse.

:[Cueball, Megan, and the surface are now rotated a little bit from the first panel.]
:Megan: I wouldn't mind if it pulled a little less hard, though.
:Megan: I have places to be.
:Megan: I shouldn't just lie around in the grass.

:[Cueball, Megan, and the surface are now rotated a little bit more from the second panel, slightly facing down.]
:Cueball: Maybe the pull will weaken if you wait around a little longer.
:Megan: Good idea. I'll give it another five minutes.

{{comic discussion}}<noinclude>

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Physics]]
[[Category:Astronomy]]

3136: Pull

2025-09-16T12:27:35Z

2600:100F:B1BF:1721:7937:3C5C:ABC4:4A51: Expanded explanation.

{{comic
| number = 3136
| date = September 1, 2025
| title = Pull
| image = pull_2x.png
| imagesize = 650x220px
| noexpand = true
| titletext = Be careful fighting gravity. If you win, it's a long way down.
}}

==Explanation==
[[Megan]] and [[Cueball]] are lying in the grass on an orb – possibly a stylized Earth, though the curvature suggests a ''much'' smaller body. However, instead of the conventional frame orientation where gravity points towards the bottom of the image, the viewpoint is stationary outside the Earth while we see it slowly rotating, reminiscent of the alternate frame of reference apparently in use in [[2800: Down]]. Shown this way, we may have the intuitive feeling that the protagonists should fall off, and this makes a point how weird it is that gravity keeps us stuck to an orb, continuing with the theme of "how reality is odd" last seen in the prior comic, [[3135: Sea Level]].

In the first panel, Cueball expresses that he doesn't like being stuck there, possibly because he wants to explore other worlds or because he finds Earth limiting. The alternative would be "falling off", as in succumbing to the [[123|centrifugal force]] that results from the Earth's rotation – this would appear in the comic's perspective as both characters slowly "falling" away towards the right side of the panel. As this centrifugal effect is quite slight compared to the gravitational acceleration we're used to (0.34% of it at the equator), Megan and Cueball would have roughly three more minutes until they "fell" off-panel, assuming their position is of a mid-northern latitude typical to the US – unless they're able to fly under their own power now that they're no longer constrained by gravity, or unless the rest of Planet Earth also has its gravity turned off and violently explodes as a result.

In the second panel, Megan uses a more metaphorical sense of the word pull, she is attracted to lying on the grass doing nothing and blames her inability to get up and do things on gravity. This could also mean that if the pull (aka gravity) is less, she could get up more easily and get to where she wants to go.

Cueball replies that the pull might weaken over time. In a literal sense, gravity will not decrease significantly even in the long term and is likely not an actual obstacle to Megan getting up (assuming the sphere is Earth, which is the only known planet with humans on it{{cn}} as of the comic's publication). [https://www.cbc.ca/radio/quirks/sept-1-2018-gene-editing-in-dogs-wildfire-prediction-zika-fizzles-and-more-1.4804892/is-earth-getting-heavier-or-lighter-1.4804900 Earth gains mass] from dust and meteorites but also loses mass, mainly due to escaping hydrogen and helium. The net effect of these is for Earth to lose about 50,000 tonnes per year; in the 5‑minute period Megan mentions, equivalent to 500 kg out of the Earth's mass of 5.972 × 1024 kg, changing gravity by a factor of about 10-22 (1 part in 10 sextillion). Locally, gravity can also change due to mass redistribution. The Earth's core is very slowly cooling, leading to decreasing radius and thus increasing gravity at the surface. Towards the end of its life, the Earth's water will be boiled off due to the expanding Sun, leading to a decrease in gravity. Metaphorically, Cueball seems to just be saying that so she will stay a bit longer. Megan agrees.

Fighting the gravity in the title text is reminiscent of the Ancient Greek story of {{w|Icarus}}, who fell down after flying too close to the Sun, where flying might be seen as fighting gravity. It might also just be a rephrasing of the truism "The higher you go, the longer the fall". On the other hand, "it's a long way down" may not refer to falling back to Earth, but rather falling off the Earth, if one were no longer "stuck" to it. In that case, "down" would presumably mean toward the Sun, the center of gravitational pull in the solar system – a very long way away. If one "defeated" ''all'' gravity, "down" would mean "away from the Earth into space" endlessly, unless one happened to collide with some object.

However, you could avoid this if you had a method of self-propulsion, which brings to mind Superman, who is a good example. He can "defeat" gravity and has some method of self-propulsion (which is, obviously, how he flys.) While humans don't have any natural means of self-propulsion while in a gravity free environment, they can use artificial methods (eg: a jetpack.).

==Transcript==
:[Cueball and Megan lying on a surface with grass, and the surface is round. They are orientated sideways, slightly facing up.]
:Cueball: I don't like being stuck to this orb,
:Cueball: but I guess falling off would be worse.

:[Cueball, Megan, and the surface are now rotated a little bit from the first panel.]
:Megan: I wouldn't mind if it pulled a little less hard, though.
:Megan: I have places to be.
:Megan: I shouldn't just lie around in the grass.

:[Cueball, Megan, and the surface are now rotated a little bit more from the second panel, slightly facing down.]
:Cueball: Maybe the pull will weaken if you wait around a little longer.
:Megan: Good idea. I'll give it another five minutes.

{{comic discussion}}<noinclude>

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Physics]]
[[Category:Astronomy]]