The Philosophy of Time: Absolutism, Relativism, and Eternalism

Presentism holds that only the present moment is real, while eternalism (block universe) holds that all moments exist equally. This philosophical debate has lasted 2000 years. Presentists argue we can only be certain of the present, while eternalists argue all moments exist in the four-dimensional structure. The debate is not merely philosophical but has implications for physics. Presentists might argue that time travel to the past is impossible because the past doesn't exist, while eternalists might argue it's possible because the past exists as a dimension.

The video explores two fundamental theories of time. Presentism (現在主義) views time as a single line moving in one direction, where only the present moment exists—past no longer exists and future hasn't arrived yet. Eternalism (永久主義) proposes that past, present, and future all exist simultaneously, like pages in a book or frames in a movie. The video argues that Eternalism is closer to truth, suggesting that time is not flowing but rather that all moments exist at once, and we simply lack the perception to experience them as such. This theory explains why prophecies always come true in Teyvat—the story is already written.

Presentism is the obsolete theory of linear time that posits the present is all that is real, with the present absolute moving constantly toward the future while leaving the static past behind as unreality. Eternalism is the truer telling that now is merely a facet of a great block, where all moments exist equally. Under eternalism, multiple versions of reality can exist simultaneously, and each is theoretically accessible. This philosophical framework shapes how the New War quest explores time and reality.

Presentism is the philosophical view that only the present moment exists, while the past and future do not. Eternalism (or the Block Universe theory) proposes that all moments in time exist equally, including past, present, and future. These are opposing views about the nature of time and reality. The hosts note that physicists generally prefer eternalism, while philosophers have debated these views for centuries.

Presentism holds that only the present moment exists, while eternalism (the block universe view) argues all times—past, present, and future—are equally real. In eternalism, the past has gone but still exists as part of spacetime, the future hasn't happened yet but already exists, and the present is just a dividing line with no real extent. This creates philosophical tension about whether free will exists if the future is already determined.

The arrow of time - the direction in which we experience time flowing - is fundamentally connected to entropy. Systems evolve toward states of higher entropy because there are more ways to be disordered than ordered. This statistical tendency creates the irreversible processes we observe in everyday life, like coffee and milk mixing but never spontaneously separating.

The video explains that physics equations at the fundamental level do not distinguish between past and future - they work equally well in reverse. The apparent 'arrow of time' may be related to entropy - the tendency of systems to move from ordered to disordered states. As the universe becomes more disordered, we perceive time as flowing. This suggests that time's direction is not fundamental but emerges from the statistical behavior of particles.

Entropy is a measure of disorder or randomness in a system, defined as the number of configurations that resemble a given object; systems naturally evolve toward higher entropy states because there are more disordered configurations than ordered ones, which explains why the universe tends toward homogeneity over time and gives us the 'arrow of time'—the direction in which time flows.

We perceive time as having a direction (past fixed, future open) because of entropy—the tendency toward disorder. While physics equations work both forward and backward, we cannot remember the future because it is statistically much more likely for things to become disordered than ordered. There are billions of ways for an egg to be broken but only one way for it to be whole. As things interact, they naturally progress from organized to disordered states. The arrow of time is our brain detecting increasing disorder in the universe. In a universe at maximum entropy, the arrow of time would disappear.

The arrow of time is one of physics' greatest unsolved mysteries. While fundamental laws are time-reversible, we only experience time moving forward. Rudolph Clausius introduced entropy—a measure of disorder—as the key to understanding this asymmetry. In an isolated system, entropy always increases, explaining why shattered glass never reassembles itself. This thermodynamic arrow suggests the universe began in an extraordinarily low-entropy state, raising profound questions about whether time itself might be an illusion rather than a fundamental property of reality.

Temporal logic is a system for representing propositions qualified in terms of time, enabling statements like 'I am always hungry' or 'I will eventually be hungry.' It differs from atemporal logic by allowing truth values to vary over time. Also called tense logic, it emerged as a modal logic-based system introduced by Arthur Prior in the late 1950s, building on earlier anticipations in Aristotle's work on future contingence. Prior's motivation stemmed from philosophical concerns about free will and predestination, leading him to develop formal systems with temporal connectives F (future) and P (past). This foundational work established temporal logic as a rigorous framework for reasoning about time.

Free will exists on a temporal gradient rather than being an absolute binary. Choices made further into the future are more constrained by deterministic processes, while choices made closer to implementation become increasingly governed by standard causal processes. There is a transition point where actions shift from what we would describe as choice to ballistic movement that cannot be stopped once initiated.

Events without beginnings don't have ends, creating logical paradoxes where conventional temporal reasoning breaks down. Characters question whether they should follow instructions from mysterious sources or exercise independent judgment. The tension between trusting authority and maintaining autonomy represents fundamental choices affecting outcomes in high-stakes situations. The Architect suggests acting like the '100% Rebel from Gallifrey' and defying destiny, which is what the Doctor is best at. This represents the philosophical stance that individuals can resist predetermined paths and create their own futures. The Doctor's fundamental role involves helping others and guiding them through difficult situations, extending beyond fighting monsters to include offering advice, assistance, and moral support.

Meaningful actions have two temporal dimensions: (1) forward and backward connectedness of components necessary to make sense of them—for example, locking and bolting a door makes sense only in relation to coming out of the house and intending to leave it empty; (2) additional dimension from the past self and envisioned future self from which trips draw their meaning and motivation. Actions are not and could not be caused in the narrow atomic linear sense implied in the term 'cause.' To understand actions properly, we must invoke the notion of explicit purpose which pulls us toward goals we have ourselves envisaged, articulated, and which shapes the succession of action components we undertake. The illusion of free will is ingrained precisely because it prevents us from falling into suicidally fatalistic states of mind. It is one of the brain's most powerful aids to survival. This suggests that our belief in being free, despite being an illusion, can alter what happens in the world—for the better, as it helps us survive. If we truly couldn't deflect predetermined events, the idea that we are free couldn't change anything, making it not truly an illusion.

Free will is logically necessary for consciousness because without it, there would be no genuine choice. If choices were forced, they would not be real choices but merely events that happen. Free will, time (before and after), and consciousness are all logically necessary for each other.

The 1980 film Somewhere in Time demonstrates that time travel can be achieved not through technology but through intense mental focus and emotional connection, illustrating metaphysical concepts like eternalism (where past, present, and future coexist in a four-dimensional block universe) and closed timelike curves (objects or events that return to their starting point without beginning or end), suggesting that love and consciousness may transcend linear time.

This segment explores the philosophical implications of time travel within a narrative framework. The protagonist discovers she has traveled into her own novel, becoming a secondary character with predetermined fate. The narrative explores whether free will exists within predetermined storylines, as the protagonist struggles to understand why she can no longer hear the thoughts of the male lead. The segment raises questions about whether the ability to perceive another's thoughts is a temporary gift or a permanent connection, and whether narrative determinism can be overcome through conscious effort. The protagonist's struggle to change her fate while maintaining her connection to the original narrative creates a paradox of agency within predetermined systems.

Time travel is the movement between different moments in time, analogous to spatial movement. Ancient myths like Hindu stories of King Ravana and Japanese tales of Urashima Taro (720 AD) demonstrate humanity's long fascination with temporal displacement. Early literature evolved from supernatural methods to mechanical devices, with 'The Clock Backwards' (1881) and H.G. Wells' 'The Time Machine' (1895) establishing key templates. General relativity suggests closed timelike curves could enable backward time travel, though Gödel spacetime's physical plausibility is uncertain. The grandfather paradox illustrates causality problems, while Novikov's self-consistency principle offers potential solutions. Philosophers debate whether time is an illusion (Parmenides), absolute (Newton), or a relationship between events (Leibniz). Relativity implies eternalism, where past and future exist as real dimensions, while presentism holds only the present exists. The relativity of simultaneity shows different observers disagree about what exists in the present, challenging classical presentism.

Donnie Darko (2000) is a cult film that combines psychological thriller elements with science fiction concepts, particularly wormhole theory and space-time travel, as the protagonist Donnie Darko, an insomniac teenager, encounters a mysterious rabbit named Frank who warns him about the world's end, with director Richard Kelly later expanding these metaphysical concepts in the 2004 Director's Cut.

Time is not a monolithic concrete track but a mechanism by which limited three-dimensional perception gradually unpacks infinity. Your true self exists outside any temporal frames and can instantly change the order of points in being. When you create memories of the future in imagination, you extract specific scenarios from the infinite ocean of probabilities and stitch them into your personal history as unquestionable facts. From today, 3 months of waiting seem like an endless series of obstacles, but from the future perspective, these months compress into a single moment.