Time & Gravity · A track where the open problem is the subject · Step 1 of 9 · 6 min read
Time & Gravity
A common intuition is that experience slides along a worldline and that gravity is a slope in the rate of time. Is any of that physics? Half of it is, and it is among the best-measured facts we have. The other half has no variable in any equation. These nine pages walk from the measured half to the open half without inventing a step.
Begin · Step 2 of 9 · 13 min readEveryone moves at one rate → See the nine steps ↓
About this illustration
This plate is a deterministic drawing, not an AI-generated image and not a photograph. The curve is the kernel's own trajectory; the shading exaggerates a clock-rate difference of about one part in 10^16 per metre so that it can be seen at all.The question, drawn once
A picture of the question, not a result. The horizontal axis is coordinate time, the vertical axis is height, and the shading is how fast a clock runs at each height, darker meaning slower. The marker is 'now' as the intuition imagines it, a point sliding along the worldline; move it with the slider or the arrow keys. General relativity has the worldline and the shading. It has no marker. Which pages carry that difference is what the map below is for.
The slider moves a picture, not a variable. No equation on the pages that follow has a term for it.
The nine steps, in reading order
- Step 1 of 9 T.00 The hub Ends with: Is any of this physics? Live
- Step 2 of 9 T.02 Everyone moves at one rate Ends with: Why can nothing opt out? Live
- Step 3 of 9 T.01 Gravity as a slope in the rate of time Ends with: What sets the slope? Live
- Step 4 of 9 T.03 What sets the slope Ends with: What if the mass is in two places? Live
- Step 5 of 9 T.04 A clock in two places Ends with: Which time does the clock read? Live
- Step 6 of 9 T.05 Does gravity entangle, and would that settle it? Ends with: If a classical slope can entangle, what would count as quantum gravity? Live
- Step 7 of 9 T.06 Does gravity collapse the wave? Ends with: If gravity neither collapses nor is shown to entangle, what is a superposition of slopes? Live
- Step 8 of 9 T.07 The equation with no time Ends with: Whose clock? Live
- Step 9 of 9 T.10 Page's counting argument Ends with: Where does the information go, in our universe? Live
How to read a T page
Every page in this track ships six things, and the build refuses a page that lacks one: a hand-written instrument whose knockout is the argument; a standard-library verifier that recomputes the page's central number and fails on a planted defect; a grounding ledger whose every DOI resolves in the site's offline Crossref cache; a label on every claim, derived from the ledger by a lint and decided by a person; a SKILL.md so any agent can rebuild the toy; and a Mexican Spanish twin in the same commit.
- At least two collaborations, peer-reviewed DOIs, older than the replication window.
- Follows by mathematics from a named MEASURED parent row.
- An exclusion limit: what the data rule out, not what they show.
- One collaboration, or anything inside the last twenty-four months.
- A proposal or a preprint; a preprint can never be more.
- A question the field has not closed.
The labels describe evidence, not confidence. MEASURED needs at least two collaborations with peer-reviewed results. BOUND is an exclusion limit. DERIVED follows by mathematics from a named MEASURED parent. SINGLE RESULT is one collaboration, or anything published inside the last twenty-four months. PROPOSED is a proposal, and a preprint can never be more. OPEN is a question the field has not closed. A lint checks the mechanics: rows, dates, collaborations, DOIs, the same label sequence in both languages. A human checklist decides the label itself.
This hub carries no claims at all, and the lint asserts that. It states the intuition once, above, as a question in the third person, and that sentence is banned on every other page of the track.
What would change this page
This page ends with one open question
Is any of this physics?
Everyone moves at one rate