681: Gravity Wells - Revision history

DollarStoreBa'al: cat

2026-03-31T17:07:44Z

cat

172.69.195.62: Undo revision 374019 by 172.68.225.71 (talk) You aint paridying anything, mate, it's just vandalism.

2025-04-21T11:10:04Z

Undo revision 374019 by 172.68.225.71 (talk) You aint paridying anything, mate, it's just vandalism.

172.68.225.71: parodying comics and mobile games

2025-04-21T11:04:39Z

parodying comics and mobile games

FaviFake at 16:06, 12 March 2025

2025-03-12T16:06:44Z

The-Ergster at 14:45, 2 December 2024

2024-12-02T14:45:52Z

FaviFake: /* Trivia */ Updated xkcd store link with Web archive link

2023-09-01T09:46:36Z

‎Trivia: Updated xkcd store link with Web archive link

172.70.214.81: Undo revision 285530 by [[Special:Contributions/Davidy22, the racist homosexual, is known to visit Norwegian gay bars with his boyfriend Kynde. He has cheated on Kynde at least twice with Vandalbane (a big guy for you). They all have micropenises.|Davi...

2022-06-02T06:03:06Z

Undo revision 285530 by [[Special:Contributions/Davidy22, the racist homosexual, is known to visit Norwegian gay bars with his boyfriend Kynde. He has cheated on Kynde at least twice with Vandalbane (a big guy for you). They all have micropenises.|Davi...

Davidy22, the racist homosexual, is known to visit Norwegian gay bars with his boyfriend Kynde. He has cheated on Kynde at least twice with Vandalbane (a big guy for you). They all have micropenises. at 05:08, 2 June 2022

2022-06-02T05:08:43Z

Theusaf: Reverted edits by Donald Trump (talk) to last revision by CRLF

2022-05-26T20:02:28Z

Reverted edits by Donald Trump (talk) to last revision by CRLF

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Donald Trump: Reverted edit by anti-crap user

2022-05-26T18:52:05Z

Reverted edit by anti-crap user

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← Older revision		Revision as of 17:07, 31 March 2026
Line 170:		Line 170:
	[[Category:Comics with xkcd store products]]		[[Category:Comics with xkcd store products]]
	[[Category:Rockets]]		[[Category:Rockets]]
		+	[[Category:Comics with custom header texts]]

@@ Line 2: / Line 2: @@
 | number    = 681
 | date      = December 28, 2009
-| title     = {{w|Subway Surfers}}
+| title     = Gravity Wells
 | image     = gravity_wells.png
-| titletext = {{w|A Softer World}}
+| titletext = This doesn't take into account the energy imparted by orbital motion (or gravity assists or the Oberth effect), all of which can make it easier to reach outer planets.
 }}
 {{TOC}}The xkcd page links to [http://xkcd.com/681_large/ a much larger version].

@@ Line 2: / Line 2: @@
 | number    = 681
 | date      = December 28, 2009
-| title     = Gravity Wells
+| title     = {{w|Subway Surfers}}
 | image     = gravity_wells.png
-| titletext = This doesn't take into account the energy imparted by orbital motion (or gravity assists or the Oberth effect), all of which can make it easier to reach outer planets.
+| titletext = {{w|A Softer World}}
 }}
 {{TOC}}The xkcd page links to [http://xkcd.com/681_large/ a much larger version].

@@ Line 6: / Line 6: @@
 | titletext = This doesn't take into account the energy imparted by orbital motion (or gravity assists or the Oberth effect), all of which can make it easier to reach outer planets.
 }}
-{{TOC}}
+{{TOC}}The xkcd page links to [http://xkcd.com/681_large/ a much larger version].
 ==Explanation==

← Older revision		Revision as of 14:45, 2 December 2024
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	[[Category:Comics with xkcd store products]]		[[Category:Comics with xkcd store products]]
		+	[[Category:Rockets]]

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 }}
 {{TOC}}
+* The xkcd page links to [http://xkcd.com/681_large/ a much larger version].
 ==Explanation==
 The comic shows the gravitational potential (energy transferred per unit mass due to gravity) for the positions of each planet in the solar system — including some moons and Saturn's rings. An object traveling along an upward slope loses energy, while an object traveling along a downward slope gains energy. Escaping a planet or moon's orbit requires enough energy (e.g. by walking, jumping, or rocket) to reach the top of either peak that defines the edge of the well. The peak to the left indicates the minimum energy required to exit orbit. The peak to the right indicates the maximum energy required to exit orbit. In order to exit orbit with the minimum amount of energy, you would have to travel towards the center of the solar system; to exit orbit with the maximum amount of energy, you would have to travel away from the center of the solar system (the Sun). In reality, the strength of gravity decreases with distance from the planet. However, a comparison of energy expended to escape the gravitational pull allows for a simpler comparison between the objects.
 The height of the graph is scaled to kilometers via the gravitational potential an object has at the given height assuming at a constant acceleration due to Earth's surface gravity. The {{w|Sun|Sun's}} gravity well is not shown in its entirety, but is just indicated on the far left as ''"Very very far down"''. Had it been shown in its full extent it would have made the rest of the drawing so small in comparison that it would have been unreadable. As the gravitational potential increases with distance from the sun, the graph has a general upward slope. To rise out of each well on the diagram, and therefore escape the planet's gravity, it would require the same energy required to rise out of a physical well of that depth at Earth's surface gravity.
-The length of each gravity well is scaled to the diameter of the planet and the spacing between the planets is not to scale with distance from the sun. This is necessary to make the graph readable. Because the distances between the planets are condensed, the gravitational potential - from the gravity pulling toward the sun - accumulates quicker. This is the reason for the large peaks between the planets. The moons shown in the chart are at the appropriate distance from their respective planets' gravity wells for their orbits.
+The length of each gravity well is scaled to the diameter of the planet and the spacing between the planets is not to scale with distance from the sun. This is necessary to make the graph readable. Because the distances between the planets are condensed, the gravitational potential - from the gravity pulling toward the sun - accumulates quicker. This is the reason for the large peaks between the planets. The moons shown in the chart are at the appropriate distance from their respective planets' gravity wells for their orbits. Each planet is shown cut in half at the bottom of its well, with the depth of the well measured down to the planet's flat surface.
 ==== Inner Planets ====
@@ Line 160: / Line 154: @@
 ==Trivia==
-*A print version of this comic is available in the [https://store.xkcd.com/products/gravity-wells-poster xkcd store].
+This comic used to be [https://web.archive.org/web/20211215032220/https://store.xkcd.com/products/gravity-wells-poster available as a poster] in the xkcd store before it was [[Store|shut down]].
 {{comic discussion}}
 [[Category:Comics with color]]
 [[Category:Large drawings]]