Ambigram
An ambigram is a calligraphic composition of glyphs that can yield different meanings depending on the orientation of observation. Most ambigrams are visual palindromes that rely on some kind of symmetry, and they can often be interpreted as visual puns.
Although the concept is older, the term "ambigram" was coined by Douglas Hofstadter in 1983–1984.
Most often, ambigrams appear as visually symmetrical words. When flipped, they remain unchanged, or they mutate to reveal another meaning. "Half-turn" ambigrams undergo a point reflection and can be read upside down, while mirror ambigrams have axial symmetry and can be read through a reflective surface like a mirror. Many other types of ambigrams exist.
Ambigrams can be constructed in various languages and alphabets, and the notion often extends to numbers and other symbols. It is a recent interdisciplinary concept, combining art, literature, mathematics, cognition, and optical illusions. Drawing symmetrical words constitutes also a recreational activity for amateurs. Numerous ambigram logos are famous, and ambigram tattoos have become increasingly popular. There are methods to design an ambigram, a field in which some artists have become specialists.
Etymology
The word ambigram was coined in 1983 by Douglas Hofstadter, an American scholar of cognitive science best known as the Pulitzer Prize-winning author of the 1979 book Gödel, Escher, Bach.It is a neologism composed of the Latin prefix ambi- and the Greek suffix -gram.
Hofstadter describes ambigrams as "calligraphic designs that manage to squeeze in two different readings." "The essence is imbuing a single written form with ambiguity".
Hofstadter attributes the origin of the word ambigram to conversations among a small group of friends in 1983-1984.
Prior to Hofstadter's terminology, other names were used to refer to ambigrams. Among them, the expressions "vertical palindromes" by Dmitri Borgmann and Georges Perec, "designatures", "inversions" by Scott Kim, or simply "upside-down words" by John Langdon and Robert Petrick.
Ambigram was added to the Oxford English Dictionary in March 2011, and to the Merriam-Webster dictionary in September 2020. Scrabble included the word in its database in November 2022.
History
Many ambigrams can be described as graphic palindromes.The first Sator square palindrome was found in the ruins of Pompeii, meaning it was created before the Eruption of Mount Vesuvius in 79 AD.
A sator square using the mirror writing for the representation of the letters S and N was carved in a stone wall in Oppède between the Roman Empire and the Middle Ages, thus producing a work made up of 25 letters and 8 different characters, 3 naturally symmetrical, 3 others decipherable from left to right, and 2 others from right to left. This engraving is therefore readable in four directions.
Although the term is recent, the existence of mirror ambigrams has been attested since at least the first millennium. They are generally palindromes stylized to be visually symmetrical.
In ancient Greek, the phrase Nipson anomemata me monan opsin, is a palindrome found in several locations, including the site of the church Hagia Sophia in Turkey. It is sometimes turned into a mirror ambigram when written in capital letters with the removal of spaces, and the stylization of the letter Ν.
A boustrophedon is a type of bi-directional text, mostly seen in ancient manuscripts and other inscriptions. Every other line of writing is flipped or reversed, with reversed letters. Rather than going left-to-right as in modern European languages, or right-to-left as in Arabic and Hebrew, alternate lines in boustrophedon must be read in opposite directions. Also, the individual characters are reversed, or mirrored. This two-way writing system reveals that modern ambigrams can have quite ancient origins, with an intuitive component in some minds.
Mirror writing in Islamic calligraphy flourished during the early modern period, but its origins may stretch as far back as pre-Islamic mirror-image rock inscriptions in the Hejaz.
The earliest known non-natural rotational ambigram dates to 1893 by artist Peter Newell. Although better known for his children's books and illustrations for Mark Twain and Lewis Carroll, he published two books of reversible illustrations, in which the picture turns into a different image entirely when flipped upside down. The last page in his book Topsys & Turvys contains the phrase The end, which, when inverted, reads Puzzle. In Topsys & Turvys Number 2, Newell ended with a variation on the ambigram in which The end changes into Puzzle 2.
In March 1904 the Dutch-American comic artist Gustave Verbeek used ambigrams in three consecutive strips of The UpsideDowns of old man Muffaroo and little lady Lovekins. His comics were ambiguous images, made in such a way that one could read the six-panel comic, flip the book and keep reading.
From June to September 1908, the British monthly The Strand Magazine published a series of ambigrams by different people in its "Curiosities" column. Of particular interest is the fact that all four of the people submitting ambigrams believed them to be a rare property of particular words. Mitchell T. Lavin, whose "chump" was published in June, wrote, "I think it is in the only word in the English language which has this peculiarity," while Clarence Williams wrote, about his "Bet" ambigram, "Possibly B is the only letter of the alphabet that will produce such an interesting anomaly."
Characteristics
Natural ambigrams
In the Latin alphabet, many letters are symmetrical glyphs. The capital letters B, C, D, E, H, I, K, O, and X have a horizontal symmetry axis. This means that all words that can be written using only these letters are natural lake reflection ambigrams; examples include BOOK, CHOICE, or DECIDE.The lowercase letters o, s, x, and z are rotationally symmetric, while pairs such as b/q, d/p, n/u, and in some typefaces a/e, h/y and m/w, are rotations of each other. Among the lowercase letters "l" is unique since its symmetry is broken if it is close to a reference character which establishes a clear x-height. When rotated around the middle of the x-height l/ȷ or lo/oȷ it doesn't appear the same, but it does when rotated around its center like the uppercase-I. Thus, the words "sos", "pod", "suns", "yeah", "swims", "passed", or "dollop", form natural rotational ambigrams.
More generally, a "natural ambigram" is a word that possesses one or more symmetries when written in its natural state, requiring no typographic styling. The words "bud", "bid", or "mom", form natural mirror ambigrams when reflected over a vertical axis, as does "ليبيا", the name of the country Libya in Arabic. The words "HIM", "TOY, "TOOTH" or "MAXIMUM", in all capitals, form natural mirror ambigrams when their letters are stacked vertically and reflected over a vertical axis. The uppercase word "OHIO" can flip a quarter to produce a 90° rotational ambigram when written in serif style.
Like all strobogrammatic numbers, 69 is a natural rotational ambigram.
Patterns in nature are regularities found in the natural world. Similarly, patterns in ambigrams are regularities found in graphemes.
As a consequence to this "natural" property, some shapes appear more or less appropriate to handle for the designer. Ambigram candidates can become "almost natural", when all the letters except maybe one or two are symmetrically cooperative, for example the word "awesome" possesses 5 compatible letters.
Single word or several words
A symmetrical ambigram can be called "homogram" when it remains unchanged after reflection, and "heterogram" when it transforms. In the most common type of ambigram, the two interpretations arise when the image is rotated 180 degrees with respect to each other.Single
coined the word "homogram" to define an ambigram with identical letters. In this case, the first half of the word turns into the last half.Several
A symmetrical ambigram may be called a "heterogram" when it becomes a different word after rotation. Visually, a hetero-ambigram is symmetrical only when both versions of the pairing are shown together. The aesthetic appearance is more difficult to design when a changing ambigram is intended to be shown in one way only, because symmetry generally enhances the visual appearance of artwork. Technically, there are two times more combinations of letters involved in a hetero-ambigram than in a homo-ambigram. For example, the 180° rotational ambigram "yeah" contains only two pairs of letters: y/h and e/a, whereas the heterogram "yeah / good" contains four: y/d, e/o, a/o, and h/g.There is no limitation to the number of words that can potentially be paired up as hetero-ambigrams, and full ambigram sentences have even been published.
Types
Ambigrams are exercises in graphic design that play with optical illusions, symmetry and visual perception.Some ambigrams feature a relationship between their form and their content. Ambigrams usually fall into one of several categories.
180° rotational
"Half-turn" ambigrams or point reflection ambigrams, commonly called "upside-down words", are 180° rotational symmetrical calligraphies. They can be read right side up or upside down, or both.Reflection
A mirror or reflection ambigram is a design that can be read when reflected in a mirror vertically, horizontally, or at 45 degrees, giving either the same word or another word or phrase.Vertical axis
When the reflecting surface is vertical, the calligraphic design is a vertical axis mirror ambigram.The "museum" ambigram is almost natural with mirror symmetry, because the first two letters are easily exchanged with the last two, and the lowercase letter e can be transformed into s by a fairly obvious typographical acrobatics.
Vertical axis mirror ambigrams find clever applications in mirror writing, that is formed by writing in the direction that is the reverse of the natural way for a given language, such that the result is the mirror image of normal writing: it appears normal when it is reflected in a mirror. For example, the word "ambulance" could be read frontward and backward in a vertical axis reflective ambigram. Following this idea, the French artist Patrice Hamel created a mirror ambigram saying "entrée" one way, and "sortie" the other way, displayed in the giant glass façade of the Gare du Nord in Paris, so that the travelers coming in read entrance, and those leaving read way out.