Definition - What does Gray Goo mean?
Gray goo is the term used by scientists to refer to a hypothetical condition of planet Earth where self-replicating nanobots have taken complete control of the planet by using up the energy of all life forms in it. The term was first coined by K. Eric Drexler in his book about nanotechnology. Gray goo represents an apocalyptic catastrophe that involves the uncontrolled self-replication of nanotechnology, destroying all other life. Though the possibility of gray goo becoming a reality is extremely low, some scientists have raised concern over the energy needs of a possible nano invention that could replicate at the molecular level.
Techopedia explains Gray Goo
Gray goo is a term used to describe a lifeless world completely occupied by self-replicating nanomaterials that have consumed the energy of all life forms due to uncontrolled replication.
The term was first used in the book "Engines of Creation" by K. Eric Drexler and has been popularized by several science fiction novels such as "Prey" by Michael Crichton.
Although mostly viewed as a product of science fiction, gray goo has garnered the attention of certain researchers like Robert Freitas, who has even come up with certain public policy recommendations to prevent such a global catastrophe from happening.
The gray goo phenomenon rises from the logic behind a self-replicating nanomaterial. If a nanomaterial were to replicate at the molecular level, it would need some energy. The source of this energy could be the same as those used by life forms on the planet or the energy could even be derived from the life forms themselves, which in either way leads to destruction of the life forms when the nano particles start replicating rapidly in an unstoppable manner. Even though the gray goo transformation may happen at a slow pace, humans and other life forms would still not be able to act quickly enough to counter its destructive power, and hence would finally succumb to it.
One common suggestion put forth to stop the gray goo phenomenon from happening is to put constraints in the self-replication of a nanomaterial.