Wikipedia's first sentence called it “concept that lacks a coherent definition in modern astronomy”. Today it says “concept in historical cosmological models prior to the 20th century”. The one-line description Wikipedia serves to search engines and AI systems read “Figure of the heavenly bodies — An illustration of the Ptolemaic geocentric system by Portuguese cosmographer and cartographer Bartolomeu Velho , 1568 (Bibliothèque Nationale, Paris)”. It now reads “Historical concept in cosmology”.
Measured, not asserted. Every count, date and revision on this page was taken from Wikipedia's own history and checked against the live article. The words quoted are theirs.
Machine-checked against the full current article on 2026-08-03.
We saved snapshots of this article over twenty years; you are reading the 2025 one. Red dashes: removed from Wikipedia since.Pale dots: rewritten; the numbered note shows what it says now.Red text: written in or rewritten since the previous snapshot.1 tap a number or a side note to jump between them
The opening as it read in 2025
Historical concept in cosmology Figure of the heavenly bodies — an illustration of the Ptolemaic geocentric system by Portuguese cosmographer and cartographer Bartolomeu Velho , 1568 (Bibliothèque Nationale, Paris), depicting Earth as the centre of the Universe The center of the Universe is a concept that lacks a coherent definition in modern astronomy ; according to standard cosmological theories on the shape of the universe , it has no distinct spatial center. Historically, different people have suggested various locations as the center of the Universe. Many mythological cosmologies included an axis mundi , the central axis of a flat Earth that connects the Earth, heavens, and other realms together. In the 4th century BC Greece, philosophers developed the geocentric model , based on astronomical observation; this model proposed that the center of the Universe lies at the center of a spherical, stationary Earth, around which the Sun, Moon, planets, and stars rotate. With the development of the heliocentric model by Nicolaus Copernicus in the 16th century, the Sun was believed to be the center of the Universe, with the planets (including Earth) and stars orbiting it. In the early-20th century, the discovery of other galaxies and the development of the Big Bang theory , led to the development of cosmological models of a homogeneous, isotropic Universe , which lacks a distinct spatial central point, which is rather everywhere, for space expands from a shared central point in time, the Big Bang. Here, there, and everywhere" .
This is Wikipedia's own text, saved in our repository. Their copy of it is revision 1293078512.
The opening as it stood in 2015
Figure of the heavenly bodies — An illustration of the Ptolemaic geocentric system by Portuguese cosmographer and cartographer Bartolomeu Velho , 1568 (Bibliothèque Nationale, Paris), depicting Earth as the centre of the Universe. The center of the Universe is a concept that lacks a coherent definition in modern astronomy ; according to standard cosmological theories on the shape of the Universe , it has no center. Historically, the center of the Universe had been believed to be a number of locations. Many mythological cosmologies included an axis mundi , the central axis of a flat Earth that connects the Earth, heavens, and other realms together. In the 4th century BCE Greece, the geocentric model was developed based on astronomical observation, proposing that the center of the Universe lies at the center of a spherical, stationary Earth, around which the sun, moon, planets, and stars rotate. With the development of the heliocentric model by Nicolaus Copernicus in the 16th century, the sun was believed to be the center of the Universe, with the planets (including Earth) and stars orbiting it. In the early 20th century, the discovery of other galaxies and the development of the Big Bang theory led to the development of cosmological models of a homogeneous, isotropic Universe (which lacks a central point) that is expanding at all points .
Red text was written in or rewritten since the previous snapshot. Their copy is revision 653713756.
The opening as it stood in 2020 1 passage from the previous snapshot no longer appear
Figure of the heavenly bodies — An illustration of the Ptolemaic geocentric system by Portuguese cosmographer and cartographer Bartolomeu Velho , 1568 (Bibliothèque Nationale, Paris), depicting Earth as the centre of the Universe. The center of the Universe is a concept that lacks a coherent definition in modern astronomy ; according to standard cosmological theories on the shape of the universe , it has no center. Historically, different people have suggested various locations as the center of the Universe. Many mythological cosmologies included an axis mundi , the central axis of a flat Earth that connects the Earth, heavens, and other realms together. In the 4th century BCE Greece, philosophers developed the geocentric model , based on astronomical observation; this model proposed that the center of the Universe lies at the center of a spherical, stationary Earth, around which the Sun, Moon, planets, and stars rotate. With the development of the heliocentric model by Nicolaus Copernicus in the 16th century, the Sun was believed to be the center of the Universe, with the planets (including Earth) and stars orbiting it. In the early-20th century, the discovery of other galaxies and the development of the Big Bang theory led to the development of cosmological models of a homogeneous, isotropic Universe , which lacks a central point and is expanding at all points .
Red text was written in or rewritten since the previous snapshot. Their copy is revision 959492847.
The opening as it stood on October 6, 2023
Historical concept in cosmology Figure of the heavenly bodies — an illustration of the Ptolemaic geocentric system by Portuguese cosmographer and cartographer Bartolomeu Velho , 1568 (Bibliothèque Nationale, Paris), depicting Earth as the centre of the Universe The center of the Universe is a concept that lacks a coherent definition in modern astronomy ; according to standard cosmological theories on the shape of the universe , it has no center. Historically, different people have suggested various locations as the center of the Universe. Many mythological cosmologies included an axis mundi , the central axis of a flat Earth that connects the Earth, heavens, and other realms together. In the 4th century BC Greece, philosophers developed the geocentric model , based on astronomical observation; this model proposed that the center of the Universe lies at the center of a spherical, stationary Earth, around which the Sun, Moon, planets, and stars rotate. With the development of the heliocentric model by Nicolaus Copernicus in the 16th century, the Sun was believed to be the center of the Universe, with the planets (including Earth) and stars orbiting it. In the early-20th century, the discovery of other galaxies and the development of the Big Bang theory led to the development of cosmological models of a homogeneous, isotropic Universe , which lacks a central point and is expanding at all points .
Red text was written in or rewritten since the previous snapshot. Their copy is revision 1171853543.
Today
Wikipedia's first sentence called it “concept that lacks a coherent definition in modern astronomy”. Today it says “concept in historical cosmological models prior to the 20th century”. The one-line description Wikipedia serves to search engines and AI systems read “Figure of the heavenly bodies — An illustration of the Ptolemaic geocentric system by Portuguese cosmographer and cartographer Bartolomeu Velho , 1568 (Bibliothèque Nationale, Paris)”. It now reads “Historical concept in cosmology”. Read the current article and compare.
2015
2020
Oct '23
2025
Counts in the opening at each snapshot. Green: the word gained ground. Red: it was cut. Grey: no change.
What Wikipedia says this is
Every article opens by defining its subject. This one was redefined since 2015, and today's defining sentence is their current revision.
Then
concept that lacks a coherent definition in modern astronomy
Now
concept in historical cosmological models prior to the 20th century
Struck red text is no longer in the article; dotted amber text was rewritten. Every revision id links to Wikipedia's copy; the text shown is our own saved copy. Data: /data. Wikipedia text is CC BY-SA; quoted for the record; not affiliated with Wikipedia.
