An offset that arrives
Worth reading first: The organ that was taken away.
The question was where the family a cut keeps changes on the Lucas 7/11 rung. It is answered to one step of the grid: between 0.00640 and 0.00639, with the counted pair, the settled divergence and the ordering of the two hops identical on both sides.
What happens there is not a cut changing its mind. It is a cut appearing.
The two sides
At 0.00640 the offsets that wreck are 5, 6 and 7, and all three keep a lag of 7.
At 0.00639 they are 5, 6, 7 and 9. Offsets 5, 6 and 7 still keep 7. Offset 9, which recovers at 0.00640 and at every rise above it in the search, wrecks — and keeps 11.
So the lattice’s set of surviving families goes from {7} to {7, 11} because a new row appeared in the table, not because an existing row moved.
Which changes what the located rise means
The rise located to one grid step is the rise at which the lattice first keeps 11 anywhere. That is the quantity the fine-end search was asking about — it went looking for a lattice whose cuts keep a lag outside the census’s four — and it is the quantity the exchange’s fifth hop cluster depends on.
It is not the rise at which any particular cut changes its answer. Those are different questions and only the first has a sharp answer here.
Nothing was lost by the distinction being noticed late. The number is the same and it means something slightly different from what the question implied.
The offsets that are steady
Five, six and seven wreck at nearly every rise of the search and keep 7 at every one. Across twenty rises spanning a sixth of the rung, with the divergence moving two tenths of a degree, those three cuts do the same thing throughout.
That is worth stating because it is the control. If everything moved from rise to rise, the arrival of offset 9 would be one more piece of noise in a noisy table. It is not: three of the four offsets that matter are constant across the whole search.
So the table has a steady part and a moving part, and the moving part is the membership of the wrecking set.
The one that does change its mind
Offset 8. It wrecks at 0.0068 keeping 7, at 0.0065 keeping 7, and at 0.00637 keeping 11.
And it cannot be located. It does not wreck at 0.0064, 0.00639 or 0.00638, so its change is bracketed across thirteen steps of the grid — a bracket that happens to contain the transition without that meaning anything.
That is the same limit the third band ran into on a different object: an offset’s answer exists only where its cut wrecks, and the wrecking set moves faster than the answer does.
The wrecking set across the search
At 0.0070 it is {4, 5, 7}. At 0.0069, {5, 6, 7}. At 0.0068, {5, 7, 8}. At 0.0067, {5, 7}. At 0.0066, {5, 6, 7}. At 0.0065, {5, 6, 7, 8}. At 0.0064, {5, 6, 7}.
Seven consecutive rises, seven different sets, each rise one part in a hundred and forty from the next in the rise. Offsets 4, 6, 8 and 9 each appear and disappear; only 5 and 7 are in every one.
The band sweeps found the same instability over stretches of rise. Here it is visible between adjacent readings, which makes it harder to read as a slow drift.
Why an arrival is a different kind of event
A cut wrecks when the pattern above the hole never returns to the arrangement it had. Whether it does is a boundary in a continuous problem: the removed organ’s absence propagates, and whether the pattern recovers depends on how much of the front the hole was carrying.
So does this cut wreck is a yes-or-no reading of a continuous situation, and a yes-or-no reading can flip under an arbitrarily small change. That is what an arrival is.
What does the cut keep is different in kind. It is a choice among integers, and there is no continuous quantity underneath it that could be crossing a threshold. Its changes are not the same kind of event as an arrival, and the search found one of each.
What the arriving cut keeps, and why 11
Because 11 is available there and 7 is not, for that offset. The surviving family is the smallest lag whose hop the wrecked run holds rigid, and on offset 9’s wrecked run the 7-hop is not held.
That is a positive reading rather than an absence: the 7-hop is measured on that run and it moves, while the 11-hop does not. So offset 9 is not keeping 11 because 7 was unavailable in some formal sense; it is keeping 11 because that is what its own run holds.
Which makes the two families genuinely coexisting at the same rise, on the same lattice, under different offsets. That is the shape the census’s own rows show elsewhere on the ladder, and it is why the offset is in every rule about survivors.
How the new family fills in
Below the transition the set of offsets keeping 11 grows unevenly. {9} at 0.00639 and 0.00638. {8, 9} at 0.00637. {9, 10} at 0.00636. {8, 9} again for four rises. Then {8, 9, 10} from 0.00631 down to 0.0060.
So there is no second transition at which the thing settles. It fills in over about ten grid steps, with membership moving as it goes, and only at the bottom of the search does it stabilise.
That is the shape a wrecking set has everywhere in this thread, and it means the useful statement is about the first arrival rather than about the final set.
What the census row at the bottom is
At 0.0060 the lattice wrecks at six offsets: 5, 6 and 7 keeping 7, and 8, 9 and 10 keeping 11. That is the row the exchange’s fifth hop cluster came from, and it is the only lattice on this ladder that produces a lag of 11.
Read against this search, that row is not exotic. It is the state the rung is in over its bottom seventy grid steps, and the census simply had not cut anywhere in that stretch.
The search that found it reported it as one rise below where the census stops, which is true and understates it: it is one rise below the census and eighty steps below the transition.
What would have been found by cutting a band
Nothing. The band around this rung’s handover runs from 0.00922 to 0.00721, and the transition is at 0.00640 — eighty-one grid steps below the band’s fine end.
So the Lucas 7/11 band’s clean negative is a negative about the band and not about the rung. Every rise it holds is above the transition, and every cut on it keeps 7 because every cut in that stretch keeps 7.
That reframes the band result usefully rather than undermining it. The band was cut to ask whether the survivor changes with the divergence held still, and the answer there is no. The survivor does change on the rung, where the divergence is not held still.
Which of the two designs is right
Both, for different questions. A band answers does the survivor change when nothing else does. A rung answers where does the survivor change.
The first is the better-controlled question and the second is the one with an answer here. Neither subsumes the other, and running only bands would have missed this transition entirely while running only rungs would leave every change confounded with a moving divergence.
That is an argument for keeping both designs rather than for preferring one, and it is worth recording because the band design is the more expensive and has been the default.
What the offset is, physically
The number of places back from the growing front at which the organ is removed. Offset 5 means the fifth-newest organ; offset 9 means the ninth-newest.
Past the front every cut recovers, because the removed organ is no longer one of the neighbours the next organ is placed against. How far back the front reaches is a measurement and it deepens as the rise falls, which is part of why offsets 9 and 10 become available at the fine end of this search and not at the coarse end.
So the arrival has a candidate explanation of a sort: the front is deepening, and offset 9 comes inside it. What that does not explain is why the new arrivals keep 11 rather than 7.
The explanation that is not available
That the deeper offsets keep 11 because they are deeper. It is a natural reading and the table refuses it: offset 8 keeps 7 at 0.0068 and 0.0065 and keeps 11 at 0.00637, so depth alone does not decide it.
What the table supports is weaker: at rises below the transition, the offsets that keep 11 are the deep ones and the offsets that keep 7 are the shallow ones, and the boundary sits between 7 and 8.
Above the transition there are no offsets keeping 11 at any depth. So depth sorts the answers where both answers exist and does not produce them.
What the round could not do
Locate offset 8’s own change. That would need it to wreck at adjacent rises across its bracket, and it does not — three rises of silence sit in the middle of it.
Nothing available forces a cut to wreck. Whether it does is decided by the rise and the offset together, and both are already fixed by the question.
So the honest report is one located rise for the lattice and a thirteen-step bracket for the one offset that changed, with the reason for the second stated rather than smoothed.
What a control is, here
Every cut is grown beside an intact stem with the same rise, the same seed angle and the same history below the hole, and the displacement of every organ is the difference between the two runs. Without that there is no way to tell a stem that was disturbed from a stem that was always going to sit where it sits.
The control is also what makes recovers meaningful. A cut recovers when the displacement falls back to nothing and stays there; it wrecks when it does not. Both are readings against the control rather than properties of the cut run alone.
So an offset arriving in the wrecking set is the displacement on that offset’s run failing to return, at a rise one step finer than the last. Nothing about the control changed: it is the same stem at a rise one hundred-thousandth away.
The reading window, and why it is not the issue here
A surviving family is read over the top hundred and twenty organs of a three-hundred-organ run, and that window is one of the instrument settings this collection has learned to distrust — varying it moved three periodicity verdicts and revealed a drift.
It bites less on this reading. Rigidity is a boolean per lag, and across the census the rigid lags hold their angle to within a fraction of a degree while the others miss by tens, so the verdict is a separation rather than a line.
Where it would bite is on a survivor large enough that a hundred and twenty organs gives few repeats. At 11 that is eleven samples a class, which is comfortable; the readings that have to be declined are the ones at much larger lags.
Two ways the table could have come out
A cut changes its mind. Some offset keeps 7 above a rise and 11 below it, at adjacent rises, with everything else held. That would have been the cleanest possible answer and would have made the transition a property of a single run.
A cut arrives. Which is what happened, and it makes the transition a property of the wrecking set — a quantity that moves everywhere in this thread and has no account attached to it anywhere.
The second is the less satisfying and it is what the table says. Writing down which of the two was expected, before the cutting, is what makes it possible to say that afterwards.
What this does to the exchange’s fifth cluster
Nothing, and the check is worth making. The exchange gained three rows from the lattice at 0.006, at a hop of 12.78 degrees, which is smaller than any it was fitted over — and that is what made it a test rather than a restatement.
Those three rows are offsets 8, 9 and 10, which are exactly the arrivals. So the fifth cluster comes from cuts that do not exist at rises eighty steps higher, and the row is a row of the rung’s fine end rather than of the ladder generally.
That is a limit on how far it generalises, not a doubt about the numbers. The three rows are measured the same way as the seventeen before them and they are the only rows of their kind available.
Where the arrivals sit relative to the front
Offsets 9 and 10 are the ninth- and tenth-newest organs, which on this lattice is near the back of the front. A removal there is a removal of an organ that is only just still one of the neighbours the next placement is computed against.
That is where wrecking is marginal by construction: at offset 11 and beyond nothing wrecks at all, so 9 and 10 sit at the boundary between wrecking and recovering.
An arrival at the boundary is therefore the expected shape. What is not expected is that a cut that only just wrecks holds a longer hop rigid than the cuts that wreck comfortably.
Why the arrival is the awkward answer
Because it moves the question one step and leaves it there. Where does the survivor change has a sharp answer; why does offset 9 start wrecking at that rise does not, and the wrecking set is a quantity nothing in this thread accounts for.
It moves from rise to rise on every band cut whole, in stretches on some offsets and single rises on others, with the counted pair and the settled divergence held. Three rounds have measured it and none has predicted it.
So the chain of explanation here is: the lattice first keeps eleven because an offset arrives; the offset arrives because it starts wrecking; and it starts wrecking for no reason anybody has written down. That is where it stops, and saying so is better than the alternative, which is a story about the front deepening that the table refuses.
The reason it refuses that story
Depth would be the natural account — offsets 9 and 10 are near the back of the front, the front deepens as the rise falls, and so the deep offsets come inside it and bring the new family with them.
Offset 8 kills it. It keeps 7 at 0.0068 and at 0.0065 and keeps 11 at 0.00637, at a depth that does not change. So depth cannot be what decides which family a cut keeps, because one offset at one depth gives both answers at different rises.
What the table does support is weaker and worth keeping: below the transition, the offsets that keep 11 are the deep ones and the offsets that keep 7 are the shallow ones, with the boundary between 7 and 8. Depth sorts the answers where both exist. It does not produce them.
What is claimed
That at the located transition on the Lucas 7/11 rung, the offsets already wrecking keep the same family on both sides and a new offset begins to wreck; that what the new offset keeps is the larger member of the counted pair; and that the located rise is therefore the rise at which the lattice first keeps that family anywhere.
That one offset does change its own answer somewhere in the search and cannot be located, because it does not wreck at three consecutive rises inside its own bracket.
And that the set of offsets keeping the new family fills in over about ten further steps of the grid rather than arriving at once.
What links here
Computed from the collection, not written here: the essays that point at this one.
Shares its objects with
Essays that name at least two of the same things, and that neither author linked.
- Which chains changed places — both name ablation, claim testing, discretisation, honest limits, lattice offset, measurement, resolution, rigid hop
- A period the grid invented — both name ablation, claim testing, discretisation, honest limits, measurement, refusal, resolution
- A step of one organ — both name ablation, claim testing, honest limits, lattice offset, measurement, resolution, rigid hop
- Every rise of a band — both name ablation, claim testing, honest limits, lattice offset, measurement, resolution, rigid hop
- One way round, seventeen times — both name ablation, claim testing, honest limits, lattice offset, measurement, resolution, rigid hop
- The alternation is not a period — both name ablation, claim testing, honest limits, lattice offset, measurement, resolution, rigid hop
Named objects
A flat tag is an object no other essay names yet.
AblationCensus designClaim testingContact familyDiscretisationHonest limitsLattice offsetMeasurementRefusalResolutionRigid hopTransition