One rise below the census
Worth reading first: The organ that was taken away · Counting the spirals.
The ablation census cuts ten lattices at every offset out to the front and two past it, and the lags its wrecked cuts keep are 4, 5, 7 and 8. Four numbers over thirty rows.
One of its lattices is the Lucas branch at a rise of 0.008, on the 7/11 rung, and its four wrecked cuts all keep 7. One rise below it, at 0.006, on the same rung, three cuts keep 11.
What the lattice is
A stem grown at a rise of 0.006 from the Lucas seed angle. It settles to a divergence of 99.344 degrees, which is 0.158 degrees from the Lucas angle itself, and its counted pair is 7 and 11.
There is nothing unusual about it. It is on a rung the ladder found, it settles onto its branch as firmly as anything in the census, and its pair is the pair the rung is named for. The only thing distinguishing it is that it had never been cut.
That is worth saying because the search was expected to end somewhere strange. A lag the census has never seen sounds like it should live at the edge of what the rule can do, and the edge is thirty to ninety degrees off the branch where nothing settles at all. This one is in the middle of an ordinary rung.
What its cuts do
Six offsets wreck. Offsets 5, 6 and 7 keep a lag of 7, which is what the census’s lattice at 0.008 does at the same rung. Offsets 8, 9 and 10 keep a lag of 11.
So the lattice answers both ways depending on the offset, which is not itself unusual — five of the census’s ten lattices keep two different families at different offsets. What is unusual is which two.
The split is clean as well. It is not that some high offsets keep 11 and some do not: the three lowest wrecking offsets keep 7 and the three highest keep 11, with no interleaving. On a lattice whose answers are decided by the offset and not entirely by it, a clean split is the more surprising arrangement.
Eleven is the larger counted number
That is the part worth pausing on. On every other row of the census the surviving family is the smaller of the counted pair or a sub-multiple of it: an 8/13 lattice keeps 8 or 4, a 5/8 lattice keeps 5, a 4/7 lattice keeps 4 or 7.
Here a 7/11 lattice keeps 11. The larger number survives, which is something no golden rise on this ladder does at any offset — the survivor there ranks second or worse by hop length every time.
And it is the shortest hop
At this lattice the 11-hop is the shortest step on the surface, and the three cuts that keep 11 are keeping the shortest hop. The three that keep 7 are keeping the second-shortest.
That is worth setting against the census’s own reading. The survivor is not the shorter of the two contact steps is stated there as a refutation, and the honest version of it in that file is that neither reading is the account — at many offsets the survivor is the second-shortest and at many others it is the shortest. This lattice does both, at different offsets, on one stem.
Why nobody had cut it
The census’s ten lattices were chosen so that the same counted pair appears at more than one rise. That is what makes its decisive negative available: 4/7 appears twice and 5/8 four times, so the pair and the offset decide the survivor is a claim with rows on both sides of it rather than a summary of one run.
Spanning the lags was not a design goal because nobody had noticed the lags were spanned by four numbers. The list looked like a consequence of the table rather than a fact worth testing.
Where on the rung it sits
The Lucas 7/11 rung runs from a rise of 0.00947 down to 0.0057. The census’s lattice sits at 33 per cent of it and the new one at 76 per cent.
Between them the family the cut leaves standing changes. The search stepped from 0.0070 to 0.0060 in one move, so the rise at which it changes is located to within a sixth of the rung and no better.
That is coarse by the standards of this thread, which has located a transition to one part in a thousand elsewhere. The difference is that this was a search rather than a sweep: it was looking for whether such a lattice exists at all, and a search that resolved every step finely enough to place a transition would have cost ten times what it did.
And where the band sits
The band around that rung’s handover covers rises from 0.00922 down to 0.00721, and it was cut at every one of its 124 rises. Every cut on it keeps 7.
So the band holds the survivor fixed across its whole width and the survivor changes twenty rises below its fine end. That is a coincidence of construction rather than a finding — a band is grown outwards from its handover until the settled divergence moves a twentieth of a degree, and this one happens to stop above the change.
What the change is not
It is not a change of counted pair. The pair is 7 and 11 at 0.0070 and 7 and 11 at 0.0060, and it is 7 and 11 everywhere on the rung by definition of a rung.
It is not a change of branch either: 99.141 degrees at 0.0070 and 99.344 at 0.0060, both within a quarter of a degree of the Lucas angle. So whatever moves between those two rises, it is not the lattice’s identity.
What it might be
No account is offered and the honest reason is that the search has one case. Two observations are available: the offsets that keep 11 are the three highest that wreck here, and the 11-hop is the shortest step at this rise and not at the coarser ones.
The second is checkable and would be the thing to check. If the 11-hop becomes shortest between 0.0070 and 0.0060, then the survivor follows the ordering of the hops on this rung, which is a claim the census’s own decisive negative would then have to be read against.
Nine rises would settle it
The rise at which the 11-hop overtakes the 7-hop is arithmetic on the geometry and costs nothing. Whether the surviving family changes at that rise is nine cut stems at nine rises, about five minutes.
That is the cheapest open question in this thread and it is worth naming precisely so that it does not get lost: does the survivor change at the rise where the hop ordering does? If it does, this rung has a second kind of handover in it.
Three rows, and they are one measurement
The three cuts that keep 11 are at offsets 8, 9 and 10 of the same lattice, and their exchanges are 97.25, 97.25 and 97.28 degrees.
That is one number three times. The offsets differ and nothing else does — same rise, same seed angle, same history below the hole — so the three rows are three cuts and one observation, and any arithmetic quantified over rows should say so.
Which is the same caveat the exchange makes about itself
The exchange’s own file says the honest denominator is four hops rather than seventeen rows, because the hop is nearly constant inside a lag. That argument applies to its extension unchanged.
So the right way to report this is that the denominator has gone from four to five, not that the table has gone from seventeen rows to twenty. Both sentences are true and only one of them is about evidence.
How it was added to the census
By passing the census a longer list of lattices, not by editing the list. The extended table is the old ten plus one, so every number the old table reported is answered from the same cache rather than measured again.
That is the same discipline as keeping the six original lattices inside the larger slot table. A comparison between a table and a table with one more row in it is worth nothing if the two are also two implementations.
What the three new rows are like
All three are balanced pairs: two adjacent chains displaced in opposite directions by the same amount, which is the shape seventeen of the census’s thirty rows have and thirteen do not.
So all three enter the exchange table rather than the set it sets aside. That was not guaranteed and it is what makes the fifth cluster usable: a lattice whose cuts all came back unpaired would have found a new lag and tested nothing.
And what the other three rows are like
The other three cuts at this lattice — offsets 5, 6 and 7, keeping a lag of 7 — are not balanced pairs. They carry four, four and five exceptional chains.
They therefore belong to the excluded set, and they arrive as an out-of-sample test of a rule about that set which was fitted without them. That is a piece of luck: one search produced a positive for one thread and a test for another.
What the search covered
Twenty rises, ten on each branch, from inside the two rungs that carry an 11 or a 13 down past the ladder’s finest rise. Four of the Lucas rises are on a rung and six are below it.
Below the rung the settled divergence leaves the branch — 129.4, 129.5, 165.6, 165.7, 129.7 and 129.7 degrees, thirty to sixty-six degrees from the Lucas angle — on pairs like 3/11, 11/13 and 11/14. Those are not lattices this collection would call lattices.
So the positive is one lattice, and that is not nothing
Twenty rises returned one usable case. That is a thin harvest for eight minutes of stems and it is the right harvest for a search whose target is rare.
The alternative reading — that a search returning one case has found nothing much — is wrong here for a specific reason. The case is the only one on this ladder, so a search that found two would have been finding the same thing twice.
What it changes
Three claims of the exchange are re-scored on twenty rows rather than seventeen and all three survive. The correction’s fitted coefficient moves from 0.188 to 0.184, which is a change in the third digit.
That is the least dramatic outcome available and it is the one worth having. A rule that moved when a new cluster arrived would have been a fit; a rule that does not is a rule with one more observation behind it.
The other two claims are the direction the exchange runs, which is now right on twenty rows rather than seventeen, and where it sits, which goes from ten of seventeen at the hole to thirteen of twenty.
What a search has to report that a sweep does not
A sweep visits every point of a stated range and its report is its output. A search goes looking, and its report has to include where it looked, because a negative from a search is only as strong as its coverage.
So the twenty rises are named in full and the six that could not be counted as lattices are in the table with the reason attached. A search that dropped its unreadable points would be reporting its own reach, which is the failure this collection has caught in three separate instruments already.
The banked search, and why it lives on its own
The twenty rises cost about eight minutes of stems, and the analysis that reads them costs nothing. Those two are kept in separate files on purpose: a cached sweep is keyed on the code that produced it, so a file holding both would discard eight minutes every time a sentence in the analysis changed.
That is not a hypothetical. It happened once during this work — an edit to a comment above the reading function invalidated the whole search — and the split is what stops it happening again.
What would make this two cases instead of one
The Lucas 7/11 rung supplies one lattice that keeps 11. A second case would have to come from somewhere the ladder does not obviously offer.
The rung’s own fine end is the first place to look: below 0.006 there are rises down to 0.0057 that were not cut, and if the whole lower quarter of the rung keeps 11 then there are several lattices rather than one, though they would be several rises of one rung and so not independent in the way two rungs would be.
The honest statement is that this ladder has one rung whose larger number can survive, and that a second would need a subject with a longer ladder in it.
What a reader should carry
That a census’s answers can be bounded by its own sampling in a way nobody notices, because a list of four numbers attached to ten lattices reads like a fact about lattices.
And that the repair here cost eight minutes and one extra row. The lattice was on a rung the collection already sweeps, one rise below one already in the table, with nothing about it out of the ordinary except that it had not been cut.
What the picture at the top shows
Ten rows, one per Lucas rise searched, coarse at the top. Each names the counted pair, the settled divergence, whether the rise is on a rung, and the lags its wrecking cuts leave standing.
The top three rows keep 7. The fourth — the rise at 0.006 — keeps 7 and 11, and is the only row in either branch’s block that keeps a lag outside the census’s four while still on its branch. The six below it are pale, at divergences thirty to sixty-six degrees off.
The one line
A Lucas lattice at a rise of 0.006, on the 7/11 rung, settled divergence 99.344 degrees: three of its six wrecking cuts keep a lag of 11, which is the larger counted number and the shortest hop, and no other lattice on either branch does.
It is one rise below a lattice the census already holds, and the whole search that found it was eight minutes.
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.
- The wrecking set moves again — both name ablation, census design, claim testing, contact family, lattice offset, replication, rise, rung, sampling
- A band with nothing inside it — both name ablation, claim testing, contact family, lattice offset, replication, rise, rung, sampling
- Every rise of a band — both name ablation, claim testing, lattice offset, parastichy pair, rise, rung, sampling
- The offsets that never change — both name ablation, claim testing, lattice offset, parastichy pair, rise, rung, sampling
- The side the census sat on — both name ablation, claim testing, lattice offset, parastichy pair, rise, rung, sampling
- Three offsets, three crossings — both name ablation, claim testing, lattice offset, parastichy pair, rise, rung, sampling
Named objects
A flat tag is an object no other essay names yet.
AblationCensus designClaim testingContact familyHop lengthLattice offsetParastichy pairReplicationRiseRungSamplingSearch