Editing 3135: Sea Level

{{comic
| number    = 3135
| date      = August 29, 2025
| title     = Sea Level
| image     = sea_level_2x.png
| imagesize = 321x453px
| noexpand  = true
| titletext = They're up there with coral islands, lightning, and caterpillars turning into butterflies.
}}

==Explanation==

The existence of the {{w|Moon}}, and its various impacts (including the movement of the tides, and reflected light it provides) are such stable and constant realities of life on Earth that people tend to take them for granted. This strip points out that, if someone were unaware of the Moon and its impacts, they would seem amazing and even implausible.

[[Cueball]] is wondering aloud what happened to an island, possibly a {{w|sandbar}} that was visible earlier, but is not anymore. [[Megan]] explains to him that the {{w|tide}} has come in and submerged the island. She then explains that the Moon, being quite large, relative to the Earth, and orbiting relatively near, creates gravitational effects that change local sea levels over the course of each day.

The fact that the net gravitational pull at Earth's surface change throughout the day, enough to make the local levels of the ocean visibly rise and fall, would be shocking if we weren't accustomed to it. A visitor to Earth from another planet would have a good chance of being completely blindsided by such an effect. Earth's moon has, by far, the highest mass in relation to its planet in the solar system, and is the only known<!-- shortcut term to encompass the potential 'exomoons' of exoplanets, too --> satellite to have such major impacts on its planet's surface. (Dwarf-planet Pluto is considered too small to be a true planet; and, besides, its primary moon has such a significantly greater mass, by proportion, that both bodies rotate in almost perfect synch with each other and would not currently experience cyclic tides on the surface oceans that they also do not possess.) Someone coming from a planet whose moons have little noticeable effect would likely be surprised at how casual humans are about the situation.

Cueball takes on the position of someone apparently unaware of the Moon's existence, and being shocked by the realities of it. Having a planetary body large enough and close enough to both be clearly visible to the naked eye, and to have obvious (and pragmatically important) impacts on the planet's oceans is really quite amazing. If humanity weren't so used to it, it would seem like an outlandish concept, perhaps imagined for a work of science fiction.

The title text mentions other elements of life on Earth, saying they also seem as outlandish as tides. {{w|Coral islands}} are bodies of land built entirely from the skeletons and secretions of dead animals. {{w|Lightning}} is an electrical discharge in the atmosphere (sometimes striking the Earth) which creates a brief but very intense current, heat, and ionization of the atmosphere.  The {{w|metamorphosis}} of {{w|butterflies}} from caterpillars involves the latter building a chrysalis around themselves, then effectively dissolving into biological soup, which then reforms into a very different form of animal. As with tides, each of these occurrences would seem amazing, possibly unbelievable, to someone who hadn't encountered them before, but are so common in our world that we generally pay them little attention.

This strip is very similar to [[2809: Moon]], as both center around Cueball being shocked by the reality of Earth's Moon. It follows a long-running theme of expressing general amazement about the world in which we live, where things that feel like they should be impossible are so commonplace that we often ignore them. Examples include [[332: Gyroscopes]], [[2115: Plutonium]], [[2540: TTSLTSWBD]], and [[3087: Pascal's Law]].

==Transcript==

:[Single frame, with Megan and Cueball standing at a coastline with grass, with water and waves visible. They are looking at the ocean and are standing together.]

:Cueball: Hey, where's that big island we were looking at this morning?
:Megan: Oh, it's underwater. The ocean's depth here goes up and down by like ten feet every day.
:Cueball: What?
:Megan: It's because the planet has a big moon orbiting near the surface. It causes weird gravity effects.
:Cueball: '''''What???'''''

:[Caption below the frame:]
:People here are used to them, but tides are one of the weirdest and most sci-fi elements of life on Earth.

{{comic discussion}}<noinclude>
[[Category: Comics featuring Cueball]]
[[Category: Comics featuring Megan]]
[[Category: Astronomy]]