The ideosphere, much like the noosphere, is the realm of memetic evolution, just like the biosphere is the realm of biological evolution. It is the "place" where thoughts, theories and ideas are thought to be created, evaluated and evolved. The health of an ideosphere can be measured by its memetic diversity.
The ideosphere is not considered to be a physical place by most people. It is instead "inside the minds" of all the humans in the world. It is also, sometimes, believed that the Internet, books and other media could be considered to be part of the ideosphere. Alas, as such media are not aware, it cannot process the thoughts it contains.
According to philosopher Yasuhiko Kimura, the ideosphere is in the form of a "concentric ideosphere" where ideas are generated by a few people with others merely perceiving and accepting these ideas from these "external authorities." He advocates an "omnicentric ideosphere" where all individuals create new ideas and interact as self-authorities.