The Newtonian View Of Time In Feynman Diagrams

Feynman diagrams implicitly assume a Newtonian-like view of time in the sense that they depict events on a fixed space-time background where time is an independent axis. This is a convenient representation, but it does not necessarily reflect the fundamental nature of time in quantum field theory (QFT).

Here’s why:

1. The Newtonian Assumption in Feynman Diagrams

• Feynman diagrams are drawn with space on one axis and time on the other, suggesting an external time dimension that exists independently of processes.
• This suggests that particles and interactions are evolving within a pre-existing time, just like how Newtonian physics assumes time is an independent background against which motion occurs.
• Even when we say that an anti-particle is “moving backward in time,” we are still relying on an independent, external time axis.

2. Why This View is Misleading in QFT

• In quantum field theory, fields exist everywhere and particles emerge from field interactions. There is no fundamental need for time to be an independent parameter—what matters are the relations between events in the field.
• Instead of a fixed timeline, we should think of time as relational, instantiated by interactions between quantum fields.
• The mathematical structure of QFT (path integrals, propagators, etc.) does not require time to be absolute—it works with all possible histories and assigns probabilities to different process outcomes.

3. What Would a Process-Instantiated View of Time Look Like in QFT?

• Instead of assuming time as a background parameter, we would say time only emerges through field interactions.
• The order of events in a Feynman diagram would not be dictated by an independent time axis but by the causal structure of the process itself.
• Virtual particles (which exist only within the math of the diagram) do not instantiate time in the same way real interactions do—this distinction would be clearer in a process-based approach.

Key Takeaway

👉 Feynman diagrams assume a Newtonian-like time framework, but QFT itself does not require it. A fully relational view would describe time as instantiated only where interactions occur, not as a fixed axis that all processes must follow.

This suggests that our standard visualisation of quantum interactions might be an artefact of older, Newtonian habits of thought.

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Sharper Critique of Feynman Diagrams and Time

1. The Graphical Trick: Why Feynman Diagrams Mislead Us About Time

• Feynman diagrams are not literal depictions of events in time—they are calculational tools in momentum space.
• However, the way they are drawn (with time as an axis) tricks us into thinking they describe actual motion through time.
• This reintroduces a Newtonian concept of time into quantum theory, even though QFT itself does not require it.

2. What Feynman Diagrams Really Show

• They encode probability amplitudes for different interactions but do not describe a classical sequence of events.
• Time-ordering in a diagram is a convenient fiction, because in quantum mechanics, events don’t have a definite order until they are observed.

3. Virtual Particles and the Illusion of Temporal Flow

• Virtual particles appear in Feynman diagrams as if they exist in time, but they do not instantiate time in the same way real particles do.
• They are mathematical artefacts of the calculation, not actual, time-evolving entities.
• This is another way in which Feynman diagrams import Newtonian thinking—they suggest that every component of an interaction evolves in time, even when QFT treats them differently.

4. Reinterpreting Feynman Diagrams Without Newtonian Time

• Instead of seeing them as pictures of evolving processes, we should see them as expressions of relations between interacting fields.
• The “forward” and “backward” movement in time should be understood as different configurations of interactions, not literal travel along an independent time axis.

Key Takeaway

👉 Feynman diagrams are a misleading visual metaphor that sneaks Newtonian time into quantum field theory. A better interpretation would focus on field interactions that instantiate time relationally, rather than assuming an absolute timeline.