2.1 The Physics of Modifying Memory

“If there is a moment when you wish everything had never happened, wish time could flow back to the fork in the road, physics usually gives you the answer ‘impossible.’ But in the world of quantum erasure, if you can completely destroy the record of ‘which path,’ then the universe will really pretend you never chose that path. Forgetting is not just psychological self-protection; forgetting is a physical operation that can reset causality.”

The Scully-Drühl Experiment: Proof of the Existence of Regret Medicine

In 1982, physicists Marlan Scully and Kai Drühl proposed an experimental scheme that would make Einstein dizzy.

Scenario Review:

In double-slit interference, if we measure which slit the photon passed through (obtaining path information), the interference fringes disappear, and the photon becomes a particle. This is collapse.

Erasure Operation:

In this experiment, physicists did something cunning.

1. They first marked the photon’s path (e.g., through a polarizer), so that path information already exists in the universe. At this point, interference fringes disappear.

2. Then (before or even after the photon reaches the screen), they introduce a “quantum eraser”. This device will mix the marking information from both paths, making it impossible to determine which path the photon took.

Result:

The moment path information is erased, interference fringes revive.

The photon behaves like a wave again, as if it had never been measured.

Physical Meaning:

This shows that “collapse” is not an irreversible physical destruction but a locking of information.

As long as you unlock (erase information), the wave function can “bounce back” from definite history to an uncertain superposition state.

It’s like you’ve pressed “confirm payment,” but before the bank’s backend settlement completes, you suddenly unplug the network cable, and the transaction is canceled.

Memory as Path Information

Applying this principle to the level of consciousness ($v_{int}$), we obtain a new physical definition of memory.

What is memory?

Memory is path information (Which-Path Information).

• “I was hurt.” — This is a definite path information. It marks that the historical vector evolved along the “victim” trajectory.

• “I failed.” — This is also path information. It collapses your confidence.

As long as these memories (information) exist in your brain’s neuronal connections or in society’s archives, your wave function is in a collapsed state. You cannot see other possibilities; you cannot experience life’s interference patterns (beauty and harmony).

You are locked in the classical reality of “victim” or “loser.”

Active Erasure: Reconstructing the Hamiltonian

But since we are observers, holding the scalpel of “attention,” we can perform quantum erasure.

How to erase a painful memory?

This does not mean developing amnesia (physical deletion); it means eliminating the “distinguishability” of information.

In FS geometry, this means rotating your observation basis so that the originally orthogonal states of “hurt” and “being hurt” undergo aliasing in new dimensions.

• You no longer distinguish “who is right or wrong” (that is path information).

• You begin to focus on “what growth this experience brought me” (this is the interference pattern).

When you successfully shift your focus from “path” to “overall pattern,” physical erasure occurs.

That “knot” that originally pinned you to the past loosens because it loses information support.

Your wave function diffuses again, restoring coherence.

You regain freedom.

Conclusion: The Physical Power of Forgiveness

This explains why “Forgiveness” has such powerful healing power.

Forgiveness is not moral high ground; forgiveness is “information-theoretic data erasure”.

When you forgive, you actively destroy path information about “revenge.” You give up pursuing accountability in the causal chain.

You tell the universe: “I don’t care which path the photon took; I only care whether the pattern it finally draws is beautiful.”

At that moment, past trauma is no longer a heavy anchor; it becomes an interference flower blooming in Hilbert space.

We cannot change facts that happened ($v_{ext}$ events), but we can change the quantum state of facts ($v_{int}$ structure).

By erasing path information, we are actually “rewriting the metadata of history”.

Since we can repair the past through erasure, can we go further? Can we use this mechanism to forcibly inject present will into the past, thus physically “saving” certain tragedies that have already occurred?

Or is our “redemption” essentially a form of reverse time travel?

This leads to the theme of the next section: The Geometry of Redemption. We will see that changing cognition is changing the topological connections of history in the holographic network.