Explanation Ladder

Run only when explicitly invoked. Explain the supplied topic without changing external artifacts.

Produce five connected levels:

1. High school: concrete intuition and essential terms.
2. College: mechanism, distinctions, and representative evidence.
3. PhD: formal assumptions, edge cases, and live technical disputes.
4. Philosopher: conceptual framing, epistemic limits, and values.
5. Gigabrain: synthesis that preserves the earlier truths while exposing a deeper organizing pattern.

Each level must respond to the previous one rather than repeat it with more jargon. Preserve uncertainty and do not pretend a contested explanation is settled.