The phrase "a perpetually changing" is correct and usable in written English.
It can be used to describe something that is constantly undergoing change or transformation.
Example: "The landscape of technology is a perpetually changing environment that requires constant adaptation."
Alternatives: "an ever-evolving" or "a constantly shifting".
The synaptic architecture of all of the connections between neurons in an individual's brain is a perpetually changing state that results from a combination of early development; nonstop, experience-dependent change; and the unique set of genetically determined protein receptors mediating attention, motivation, and memory in that individual (for an overview, see Eshel [2007]).
Like the majority of large corporations, Enron was a publicly traded joint stock company, whose ownership was thus dispersed over a perpetually changing multitude of shareholders.
Sun employees are each issued a card with a perpetually changing passcode that enables them to log in to the company's internal network from any computer connected to the Internet to retrieve e-mail or other information.
Because the uninsured are a "perpetually changing group," however, a much larger fraction of the population suffers periodic, terrifying spells of being uninsured, and an even larger fraction lives with the fear of losing insurance if anything goes wrong at work or at home.
A 30-page "photo essay" reconstructs in painstaking detail what happened on the seminal wall next to Matisse's sickbed between 1947 and 1948, when it held a perpetually changing, shifting and growing array of coloured shapes and patterns attached to it with pins, curling at the edges, stirring and flapping in drafts from door or window, each generating its own play of light and shadow.
A 30-page "photo essay" reconstructs in painstaking detail what happened on the seminal wall next to Matisse's sickbed between 1947 and 1948, when it held a perpetually changing, shifting and growing array of coloured shapes and patterns attached to it with pins, curling at the edges, stirring and flapping in drafts from door or window, each generating its own play of light and shadow.
Although more than 40 million people lack health insurance, this doesn't matter too much because "the uninsured are a diverse and perpetually changing group".
The port was what drew the Dutch originally, but as "New York at Its Core" argues, "it was human ambition, conflict and ingenuity that transformed this promising location into a great, growing and perpetually changing metropolis". For four centuries, the city's regenerative core fostered expansion and resilience.
Near them stood a rather pretty box with perpetually changing numbers chasing each other across its face, and farther over was something they swore was called a wobulator.
So do a host of visual effects that mirror and mock the people singing or suggest that they (and you) have tumbled into a three-dimensional television set that is perpetually changing channels.
Jonathan Swift's comment that "It is better that a language should not be wholly perfect than that it should be perpetually changing" seems more quaint and extraordinary than ever.
