Hot dry rock geothermal energy makes use of hot fluids found naturally in basement rock; but such HWR conditions are rare. By far the bulk of the world’s geothermal resource base (over 98%) is in the form of basement rock that is hot but dry—with no naturally available water. This means that HDR technology is applicable almost everywhere on earth (hence the claim that HDR geothermal energy is ubiquitous). Typically, the temperature in those vast regions of the accessible crystalline basement rock increases with depth. This geothermal gradient, which is the principal HDR resource variable, ranges from less than 20 °C/km to over 60 °C/km,
Notes from Underground individuals. The Underground Man ridicules the type of enlightened self-interest (egoism, selfishness) that Chernyshevsky proposes as the foundation of Utopian society. The concept of cultural and legislative systems relying on this rational egoism is what the protagonist despises. The Underground embraces this ideal in praxis, and he seems to blame it for his current state of unhappiness. This type of rebellion is critical to later works of Dostoevsky as it is used by adolescents to validate their own existence, uniqueness and independence (see Dostoevsky's "The Adolescent"); rebellion in the face of the dysfunction and disorder of adult experience that one