On April 1, 2014, the American Physical Society announced a landmark change in policy: All scientific papers authored by cats would henceforth become freely available to the public.

The announcement was a joke (it was April Fools' Day), but the cat that inspired it was not. His name is Chester — better known to the scientific community as F.D.C. Willard, arguably the most famous cat in physics after Schrödinger's.

In 1975, Chester/Willard's name appeared alongside Michigan State University physics professor Jack Hetherington's on an influential paperabout the low-temperature physics of helium-3 isotopes — versions of an element (helium, in this case) with different numbers of neutrons in their nuclei — published in the journal Physical Review Letters. Hetherington was Chester's owner, and he had initially included the 7-year-old Siamese cat's name on the paper to resolve a grammatical blunder. [The 18 Biggest Unsolved Mysteries in Physics]

As a colleague pointed out while editing the draft, Hetherington listed himself as the study's sole author, yet he had nevertheless written the entire paper using the "we" pronoun. This was against the journal's style rules, the colleague noted. Hetherington's paper would surely be rejected if it wasn't retyped.

Hetherington, however, was eager to submit his work. "Changing the paper to the impersonal seemed too difficult now that it was all written and typed," Hetherington said in the book "More Random Walks in Science" (CRC Press, 1982). "Therefore, after an evening's thought, I simply asked the secretary to change the title page to include the name of the family cat."

Of course, Chester's name was too well known to Hetherington's friends and colleagues, so an alias would be necessary. He settled on F.D.C. Willard — F.D.C. being an acronym for Felis Domesticus Chester, and Willard being the name of Chester's tomcat father.

And so, on Nov. 24, 1975, the paper co-authored by Hetherington and his cat was published in the 35th issue of Physical Review Letters. [Are Cats Smarter Than Dogs?]

Many of Hetherington's colleagues knew about the ruse, it turned out, and few seemed to care. Michigan State's physics department head, for one, embraced the feline deception. "The chairman… was able to inflate some statistic requested by the administration by including Willard among the published authors from the Physics department," Hetherington wrote in a letter. "I'm not sure if it helped or hindered my own grant-getting efforts."

Chester's true identity was ultimately revealed when a student went looking for Hetherington with a question about the paper; when Hetherington couldn't be found, the student asked to speak with Willard instead. "Everyone laughed and soon the cat was out of the bag," Hetherington wrote.

Chester the cat subsequently retired from science, but his alias took on a life of its own. Several years later, a French paper on helium-3 appeared in the journal La Recherche under a single author's name: F.D.C. Willard. (Apparently, Hetherington wrote, the actual research team could not agree on a version of the paper that satisfied them all, so they decided to credit America's best-published cat instead.)

As of today, Chester's paper on helium-3 has been cited more than 50 times, and a menagerie of nonhuman study authors have followed in his formidable paw-steps. In 1978, immunologist and apparent "Lord of The Rings" fan Polly Matzinger co-authored a paper with one Galadriel Mirkwood — the nickname of her trusty Afghan hound. More recently, in 2001, a paper on gyroscopes authored by A.K. Geim and H.A.M.S. ter Tisha appeared in the journal Physica B: Condensed Matter. Geim won a Nobel Prize in 2010 for co-discovering graphene. Tisha was his pet hamster.

Originally published on Live Science.