8. The Bridge and sealed predictions
The flame-stretch-rate hypothesis, the FM2 balance and the sealed statements.
The Bridge in plain words
On the Envelope page, gravity is a regime barrier: a test in microgravity cannot be compared with a condition in lunar gravity, and the verdict says so. But NASA's own literature relates gravity levels through a quantity called flame stretch rate.
The Bridge page takes that idea and asks: in which PSI tests was the flame stretched by about as much as a flame would be by buoyancy on the Moon? Those tests are called transfer analogs.
It is a hypothesis, not evidence. It never changes a verdict and it does not predict how a flame behaves on the Moon.
Stretch rate, in plain words
Stretch rate, in reciprocal seconds, is how hard the surrounding gas flow pulls on a flame. In orbit there is no buoyancy, so a weak forced airflow sets the stretch. On the Moon there is a little buoyancy. The two can stretch a flame by similar amounts. That is the bridge.
The formulas used are for curved bodies in flow, such as a rod tip. Flat sheets have no radius, so no stretch is computed for them.
The FM2 oxygen balance
FM2 is the Flammability of Materials on the Moon experiment. It burns samples in a closed chamber, and each burn uses up oxygen. The balance on the Bridge page answers a narrow question: how much oxygen can a burn use before the chamber falls to an assumed limiting oxygen concentration?
It is a mass balance, not a flame model. The chamber volume and the starting atmospheres come from NASA's plan. The temperature and the limit are assumptions you can change, shown with their ranges. It does not say where the real limit is.
Sealed predictions
Before any FM2 result exists, PYRION wrote down what it will and will not say about FM2: for example, that it commits to no value for the lunar limiting oxygen of the planned fabric, because PSI holds no test of it.
The fingerprint of that text, a SHA-256, was stamped with OpenTimestamps, which anchors it in the Bitcoin blockchain. When FM2 reports, anyone can check the statements against the results and check that the text did not change. The proof may show as pending until the blockchain confirms it.
The Bridge (a hypothesis, not evidence)
In PYRION, gravity is a regime barrier: a microgravity test and a lunar-gravity target are not comparable. The Bridge page explores a labelled hypothesis from NASA literature: that partial gravity can be related to other gravity levels through flame stretch rate.
It points at PSI tests whose stretch rate is closest, with a gravity dial and a stretch map. It never changes a verdict, and nothing there predicts flame behaviour on the Moon.
Sealed predictions before FM2 flies
Before any FM2 result exists, PYRION wrote down what it will and will not say about FM2. The fingerprint (SHA-256) of that text was stamped with OpenTimestamps, which anchors it in the Bitcoin blockchain, so anyone can later check that the text was not changed after results appeared.
The statements are in the predictions README of the repository, linked from the Bridge page.
Bridge page overview
What it is. The page that explores a hypothesis relating gravity levels through flame stretch rate.
What it shows. A gravity dial, a stretch map, the transfer analogs, limits, the FM2 instrument balance and the sealed predictions.
How to use it. Move the dial, read the map, check the limits.
Example. Set the Moon and see which PSI tests have a similar stretch.
What it does not do. It is labelled a hypothesis and never changes a verdict.
Hypothesis tag
What it is. The label "HYPOTHESIS — NOT EVIDENCE".
What it shows. That the page's content is a hypothesis.
How to use it. Keep it in mind while reading.
Example. Read it before quoting any analog.
What it does not do. It cannot be turned off.
Bridge introduction
What it is. The first card.
What it shows. Stretch rate in one sentence, then NASA's own words about equivalence of flame stretch rates and the gravity values PYRION uses.
How to use it. Read it first.
Example. Moon 0.165 g, Mars 0.38 g, with sources.
What it does not do. It does not claim any prediction.
NTRS source link
What it is. A link in the Bridge text.
What it shows. An NTRS record of a NASA paper.
How to use it. Click to open it.
Example. Open the Olson and T'ien paper.
What it does not do. It opens NASA's page, not our summary.
Gravity dial card
What it is. The card with the gravity control.
What it shows. Four stops: microgravity, Moon, Mars, Earth, with their sources.
How to use it. Move the slider or click a stop.
Example. Click Moon.
What it does not do. It has four stops, not a continuous scale.
Gravity dial slider
What it is. The range control.
What it shows. The selected gravity stop.
How to use it. Drag it or use the arrow keys.
Example. Move to Mars.
What it does not do. Only four stops exist.
Gravity stop button
What it is. A button under the dial.
What it shows. One gravity level and its label.
How to use it. Click it.
Example. Click Earth.
What it does not do. It sets the view of the stretch map only.
Stretch map card
What it is. The chart of stretch rate versus oxygen.
What it shows. Solid lines are PSI BASS-II rod tests; the hatched band is the hypothesised buoyant stretch at the selected gravity.
How to use it. Choose a formula and read where lines meet the band.
Example. Read how many tests overlap at the Moon.
What it does not do. The formulas are for curved bodies in flow; flat sheets are excluded.
Rod-tip formula
What it is. A toggle.
What it shows. The stretch formula for a rod tip.
How to use it. Click to select.
Example. Compare with the cylinder formula.
What it does not do. The table does not say how each rod sat in the flow, so the formula is a choice shown with every result.
Cylinder formula
What it is. A toggle.
What it shows. The stretch formula for a cylinder in flow.
How to use it. Click to select.
Example. Switch and watch the band change.
What it does not do. It is a different assumption, not a better one.
Test segment on the map
What it is. A horizontal line on the map.
What it shows. One PSI test's forced stretch range at its oxygen.
How to use it. Click or press Enter to open its detail.
Example. Select a BASS-II test.
What it does not do. It is computed from flow readings and rod radius.
Transfer analog test
What it is. A link in the analog lists.
What it shows. A PSI test whose stretch falls inside the band, or only partly.
How to use it. Click it to open its detail.
Example. Open the first analog.
What it does not do. Analogs are hypotheses; they are never counted as applicable.
Partly overlapping tests
What it is. A collapsible list.
What it shows. Tests whose stretch passes through the band for part of their flow readings.
How to use it. Click to open.
Example. Open it to see the six partial overlaps.
What it does not do. Partial overlap is weaker than an analog.
Close the detail
What it is. A link in the test detail.
What it shows. Nothing.
How to use it. Click it.
Example. Close after reading.
What it does not do. It does not change the selection of the dial.
Bridge receipt
What it is. A collapsible receipt.
What it shows. Inputs, sources, assumptions and limits of the stretch calculation.
How to use it. Click to open.
Example. Read the assumptions.
What it does not do. It shows the calculation, not a validation.
Bridge limits
What it is. A card of limits.
What it shows. Geometry, material dependence, scale and time, pressure.
How to use it. Read it before using an analog.
Example. Check "Material dependence".
What it does not do. The limits are part of the result.
FM2 instrument balance
What it is. A card with a closed-chamber oxygen balance.
What it shows. How much oxygen a burn can use before the chamber reaches a hypothesised limit, using FM2's stated volume and start conditions.
How to use it. Move the two sliders.
Example. Set a limit of 25 %.
What it does not do. It is a mass balance, not a flame model; it does not say where the limit is.
FM2 temperature slider
What it is. A slider.
What it shows. The assumed chamber temperature (the plan does not state it).
How to use it. Drag it.
Example. Set 22 °C.
What it does not do. It is an assumption shown with its range.
FM2 hypothesised limit slider
What it is. A slider.
What it shows. A hypothesised limiting oxygen concentration.
How to use it. Drag it.
Example. Set 25 %.
What it does not do. It is a hypothesis, not a measurement.
FM2 formulas and assumptions
What it is. A collapsible list.
What it shows. The formulas and assumptions of the balance.
How to use it. Click to open.
Example. Check the fuel stoichiometry note.
What it does not do. The PMMA numbers illustrate the balance; FM2 burns a different fabric.
Sealed before FM2 flies
What it is. A card about the sealed predictions.
What it shows. That PYRION wrote down what it will and will not say about FM2 and stamped its fingerprint with OpenTimestamps.
How to use it. Click the links to read the statements.
Example. Open the predictions README.
What it does not do. It does not claim a Bitcoin confirmation that is not shown.
Predictions README link
What it is. A link.
What it shows. The sealed statements on GitHub.
How to use it. Click it.
Example. Read statement 1.
What it does not do. It is a text file, not a result.
OpenTimestamps proof link
What it is. A link.
What it shows. The proof file SHA256SUMS.ots.
How to use it. Click it.
Example. Check it with an OpenTimestamps tool.
What it does not do. The proof may be pending until Bitcoin confirms it.