The increase in entropy, radioactive decay, and gravitational collapse are all physical phenomena that exhibit a clear directionality, providing evidence for the direction of time.

Temporal asymmetry, time's arrow, and directionality of time are all terms used to describe the concept of time flowing in a single, irreversible direction.

Eternalism is a philosophical theory that posits that all moments of time exist simultaneously and that time is not fundamentally directional.

Temporal subjectivity refers to the psychological phenomenon where the perception of time's passage is influenced by subjective factors such as emotional state and level of engagement.

Ludwig Boltzmann is credited with developing the H-theorem, which provides a statistical explanation for the increase in entropy and the direction of time.

The cosmological arrow of time refers to the idea that the direction of time is determined by the initial conditions of the universe, such as the initial distribution of matter and energy.

The growing block theory posits that time is fundamentally directional and that the universe is constantly expanding into the future, with new moments of time being created as time progresses.

The thermodynamic arrow of time refers to the idea that the direction of time is determined by the increase in entropy, as described by the second law of thermodynamics.

Albert Einstein is credited with developing the theory of relativity, which has implications for our understanding of the direction of time.

The psychological arrow of time refers to the idea that the direction of time is determined by the subjective experiences of conscious beings, such as memory and anticipation.

Eternalism posits that all moments of time exist simultaneously and that time is not fundamentally directional, making it an illusion.

The cosmological arrow of time refers to the idea that the direction of time is determined by the expansion of the universe, as the universe is constantly expanding and cooling.

Stephen Hawking is credited with developing theories in quantum mechanics and cosmology that have implications for our understanding of the direction of time.

The biological arrow of time refers to the idea that the direction of time is determined by the evolution of life and the increase in complexity, as organisms adapt and evolve over time.

Presentism posits that only the present moment is real and that the past and future are fundamentally unreal, making the direction of time a fundamental aspect of reality.