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 serfs, Russia was still very much a post-medieval, traditional peasant society. However, when "Notes From Underground" was written, there was an intellectual ferment on discussions regarding religious philosophy and various 'enlightened' utopian ideas. Dostoevsky, however, along with his notable contemporary, Soren Kierkegaard, rejected such ideas for proto-existentialist themes. Most importantly, the legacy that the work leaves is a challenge to and a method of understanding the larger implications of a utopian society. Utopianism largely pertains to a society's collective dream, but what troubles the Underground Man is this very idea of collectivism. The point the Underground Man makes is that