Anthropic Principle
Argues that observed physical constants must be compatible with the existence of observers, which explains why we find ourselves in a universe fine-tuned for life — without invoking design.
RNA World Hypothesis
Proposes that early life relied on RNA both to store genetic information and catalyze reactions, before DNA and proteins took over those roles separately.
Hydrothermal Vent (Metabolism-First) Origin
Suggests life began not in a surface “soup” but at alkaline hydrothermal vents on the ocean floor, where mineral structures provided ready-made chemical gradients for early metabolism.
Panspermia
Proposes that life, or its chemical precursors, did not originate on Earth but arrived from elsewhere in space via comets, meteorites, or interstellar dust.
The Hard Problem of Consciousness
A framing problem rather than a single theory: why and how physical processes in the brain give rise to subjective experience at all, as opposed to just information processing without any “felt” quality — used as a stress-test against consciousness theories.
Integrated Information Theory (IIT)
Proposes consciousness corresponds to a system’s capacity to integrate information (measured as “phi”), in principle allowing consciousness to be quantified in any physical system, not just brains.