Main Page

Welcome to the explain xkcd wiki! Today, the wiki is in read-only mode to allow for a hosting migration. Please enjoy reading all our xkcd explanations. We have an explanation for all 2 xkcd comics, and only 0 (0%) are incomplete. Help us finish them!

Latest comic

Go to this comic explanation

|< < Prev Comic #2925 (April 26, 2024)

Earth Formation Site

Title text: It's not far from the sign marking the exact latitude and longitude of the Earth's core.

Explanation

This explanation may be incomplete or incorrect: Created by TWO 4,450,002,024-YEAR-OLD PRESIDENTIAL CANDIDATES - Please this edit this comment when editing this page. Do NOT delete this historical tag too soon.

In this comic, Cueball stands in front of a sign that declares itself to be an historical location, the formation of the Earth. The humor of the comic is twofold:

1. the amusing illogic of the assertion
2. the impossibly precise date

#1: The amusing illogic of the assertion

First, the Earth formed at its center, not its surface, so an “Earth formed here” sign on its surface is factually incorrect.

One may argue that technically the sign is above the right spot, just as every location on Earth is above the right spot. However, the sign refers to “this location,” not to a spot underground.

If an omniscient observer wanted to mark the spot in space where the Earth started forming, an historical marker on the surface of the Earth could not be accurate for longer than one split second in time. That’s due to Sun's 225-million year long orbit around the center of the Milky Way galaxy and the movement of the galaxy itself through space relative to other objects. From this perspective, the Earth’s formation did not occur anywhere on Earth.

#2: The impossibly precise date

Secondly, specifying a single year of formation is an amusingly precise choice, absurd in the context of the tens or hundreds of millions of years thought to be required for planet formation. It would require some specific definition of when the gradually-coalescing mass could be considered a planet, as well as the ability to determine when that mass met the definition.

Note: The date shown for the formation of the Earth, 4.45 billion years, also differs from the commonly accepted date, 4.54 (±0.05) billion years. The difference lies in the transposition of two digits, potentially a mistake.

This comic satirizes historical markers by using their standard tone and structure. Typically, these signs are placed at precise locations where historical, religious, and even mythological events happened —- such as where battles have been fought, or where famous people resided or accomplished something, or where something supposedly happened.

The title text refers to the 'exact latitude and longitude of the Earth's core,’ Of course, since the lat-long geographic coordinate system is used for locating places on the surface on the Earth, the center of the Earth does not have latitude and longitude.

The comic and its title text are actually inverse jokes of each other: The historical marker in the comic assigns attributes of the Earth’s center (the site of formation) to a spot on its surface, while the title text assigns attributes of surface locations (latitude and longitude) to the Earth’s center.

This title text language is similar to signs marking specific latitudes, longitudes or other notable locations.

Transcript

This transcript is incomplete. Please help editing it! Thanks.

[Cueball is standing in front of a sign in a field of grass. Rocks and plants are scattered across the ground. The sign reads:]

HISTORICAL MARKER

EARTH

FORMATION SITE

--- 4,450,000,000 BCE ---

At this location in the year 4,450,000,000 BCE, a cloud of dust and gas gravitationally collapsed to form the Earth.

Is this out of date? .

New here?

Last 7 days (Top 10)

Rank Score Pages Changes Username 1 44 32 71 Z1mp0st0rz 2 22 15 27 Charlie Spring 3 21 17 21 TheusafBOT 4 11 5 13 Asdf 5 10 8 9 1234231587678 6 7 4 7 SomeoneIGuess 7 7 5 6 Bryce 8 7 5 6 Maplestrip 9 7 4 6 DKMell 10 6 4 5 Psychoticpotato

Lots of people contribute to make this wiki a success. Many of the recent contributors, listed above, have just joined. You can do it too! Create your account here.

You can read a brief introduction about this wiki at explain xkcd. Feel free to sign up for an account and contribute to the wiki! We need explanations for comics, characters, themes, memes and everything in between. If it is referenced in an xkcd web comic, it should be here.

• If you're new to wikis like this, take a look at these help pages describing how to navigate the wiki, and how to edit pages.

• Discussion about various parts of the wiki is going on at Explain XKCD:Community portal. Share your 2¢!

• List of all comics contains a table of most recent xkcd comics and links to the rest, and the corresponding explanations. There are incomplete explanations listed here. Feel free to help out by expanding them!

• If you see that a new comic hasn't been explained yet, you can create it: Here's how.

• We sell advertising space to pay for our server costs. To learn more, go here.

Rules

Don't be a jerk. There are a lot of comics that don't have set in stone explanations; feel free to put multiple interpretations in the wiki page for each comic.

If you want to talk about a specific comic, use its discussion page.

Please only submit material directly related to —and helping everyone better understand— xkcd... and of course only submit material that can legally be posted (and freely edited). Off-topic or other inappropriate content is subject to removal or modification at admin discretion, and users who repeatedly post such content will be blocked.

If you need assistance from an admin, post a message to the Admin requests board.