paradigm shift
noun
a fundamental change in approach or underlying assumptions.
"geophysical evidence supporting Wegener's theory led to a rapid paradigm shift in the earth sciences"
This is not a direct antonym, and I think it is no accident that there is no such word: because positive-catastrophes are impossible in the real, physical world. We don't have a word for it because the course of history has never required one, and probably never will -- on Earth or in any civilization anywhere, anywhen in this universe.
(This is a fascinating realization for me, which is which is why I'm even bothering to post an answer that I suspect will be poorly received here.)
Your criteria are:
- sudden / active / "violent" in nature
- great / extreme
- has far-reaching consequences
- positive in effect
In a world governed by physics, that last item is a deal-breaker. You will never find it coupled with all of the others.
It is easier to destroy than create. That's because of entropy: order inevitably decays into disorder, creating order requires adding energy, and even when you add energy, it will reduce the amount of order unless the energy is added in the form of useful work. Blindly adding energy will always only wreck stuff.
E.g., when tectonic plates shift suddenly, they release a lot of energy, but that energy is released in a chaotic way that reduces order in the surrounding area, tending to undo the beneficial work of living creatures. Without exception, all large-scale physical events in history are similar: volcanic eruptions, meteor impacts, rock slides, etc.
In the physical world, "suddenness" always takes destructive forms, because the laws of thermodynamics do not facilitate massive, sudden and orderly transfers of energy. This is why it's possible to build a single device that can instantly vaporize an entire city, but it's impossible to build a device that could instantly take out everybody's garbage.
The closest thing to an exception I can think of is when a body of water expands outside its current bounds, irrigating a larger area, e.g. the Zanclean flood, or Black Sea deluge. I discount these because they are not sudden -- estimates for both events are around one year of continuous action, and not unambiguously good -- both floods were initially quite destructive, with the benefits of irrigation manifesting months or years later.
This matters because "goodness" for living creatures is almost always coupled with some form of order. Try watching the BBC Earth series with entropy in mind, and you'll recognize countless examples of life forms either benefiting from some pocket of serendipitous order, or working hard to create order (for a benefit that is often obvious), whether it's fish who rearrange shells on the ocean floor, or birds who tidy up a patch in the jungle for a mating dance, or chipmunks and squirrels collecting nuts for the winter, or birds constructing nests. Almost all the things valued by living creatures are, at some level of analysis, pockets of ordered matter among the general disorder.
When energy is added to a system chaotically, it never creates, and always eliminates, pockets of order. Whether we bother to call that event "damage" generally depends only on whether we had any interest in the pockets of order that were eliminated.
So, why "paradigm shift?"
Because all of the above applies to the physical world but not the mental one. It is thanks to the laws of thermodynamics that humanity's physical history can be characterized as a series of sudden, destructive moments separated by long periods of slow, necessarily local (re-)building, with never a single instance of a large pocket of useful order appearing in an instant. But our intellectual history does indeed feature sudden (even "violent") events of far-reaching and positive consequence. For example:
Rather than physical inventions, I deliberately focus on instances where an idea is either formed or proven suddenly, which immediately transforms every society that accepts it. The printing press is the unique exception because mass printing is very pointedly a mechanism that accelerates the accurate spread of knowledge, and building just a single printing press can change the host society, which is not true of, e.g., the steam engine, automobiles, telephones, or even electronics, all of which require not only ideas but also the manufacture of many such devices. That is, it does not really change society if you build just one car, or telephone, or computer. By contrast, it will change society if you tell just one person how to cure scurvy, a disease which killed more seafarers during the Age of Sail than all other causes of death combined. "One weird trick" can keep your sailor alive and sane for an entire voyage.
"Paradigm shift" is a term that is popularly applied to any sudden, rapid, and beneficial change to human understanding.
To be sure, very many developments in humanity's intellectual history have been slow rather than sudden, or harmful rather than positive, or local in effect rather than far-reaching.
All big, sudden, and far-reaching changes in the physical world have been and will always be considered harmful. All big, sudden, and far-reaching positive changes have been and will always be mental.
