Measured, not asserted

One line in 5 has nobody under it

A planetary line is a curve most of whose length crosses ocean, ice or empty desert. Across 600 charts and 24,000 chart-lines, 19.4% of lines have no settlement of any size within 80 km of them. Every tool in this category answers “where are my lines?” with somewhere. This is how often the true answer is nowhere.

The corpus, before the result

What was counted

600 charts, 40 lines each, against all 3,114 settlements of the pinned public-domain gazetteer this product ships. A line counts as quiet when no settlement lies within 80 km of it: the innermost band, the only one this engine allows to say a line is over a place, and the one figure in that scheme that is ours rather than borrowed from the literature.

The charts are synthetic instants rather than real birth data, because the question is about where the forty lines fall and that is set entirely by the moment. They are spaced by intervals like 9d 5h 07m rather than by whole days on purpose: a sidereal day is 23h 56m, so stepping a whole number of days would hold the sky nearly fixed and sample almost the same longitudes forever, a corpus of one dressed up as a corpus of hundreds.

Everything below is computed from that record at build time. Nothing on this page is a figure somebody typed.

The finding

Widen the orb and the silence almost disappears

Each row asks the same question at a different radius: what share of lines have nothing at all inside this distance? The answer falls by a factor of about 28 between the innermost published orb and the outermost.

Share of 24,000 chart-lines with no settlement inside the given radius. Radii are the four bands this engine reads, each a published mile figure converted.
BandNothing insideLinesShare
Under the line80 km4,65919.4%
Peak320 km1,8637.8%
Background565 km7793.2%
Faint805 km1750.7%

That last row is the commercially interesting one. A tool reading at 805 km, the widest orb anyone in the literature publishes, can offer you somewhere 99.3% of the time. It is not finding more than a stricter tool does. It is counting further away as near. Both tools are looking at the same sky and the same cities; the only difference is the radius at which one of them stops calling a city “yours”.

The bands are cumulative, not rings: the 320 km row counts lines with nothing inside 320 km at all, which is why the numbers fall as the radius grows. That is the form that answers the reader's actual question. Would a tool with a wider orb have found me something?

The extreme case

Some lines pass nowhere anybody lives, at any orb

0.7% of chart-lines, 175 of 24,000, have no settlement within 805 km along their entire length. Not a small town, not a distant one: nothing in the gazetteer, anywhere on the curve, at the widest radius any practitioner has published.

Those are rare per line and common per person, because a chart has forty of them: 22.5% of charts have at least one. Roughly one reader in 4 has a line that runs the whole way round the Earth without passing near anybody.

Checkable examples

Quiet lines on charts you can open

The corpus above is synthetic, so here are the same facts on the three published charts this site shows complete readings for. Every row is reproducible: open the reading, open the line page, measure.

Lines with nothing inside 80 km on the three showpiece charts, and the nearest settlement of any size to each.
ChartLineNearest settlement of any size
Frida KahloSun Ascendantnothing within 805 km, anywhere
Frida KahloJupiter Ascendantnothing within 805 km, anywhere
Albert EinsteinNeptune AscendantSt. John's, Canada, 728.8 km away
Jimi HendrixNeptune MidheavenAnchorage, United States, 385.5 km away
Albert EinsteinPluto DescendantMajuro, Marshall Islands, 90.5 km away

Frida Kahlo's Sun and Jupiter Ascendant lines are the striking pair. They are lines a tool would ordinarily be delighted to talk about, and on her chart they cross open Pacific for their entire usable length. The last row is the opposite kind of case: Einstein's Pluto Descendant line misses Majuro by 90.5 km, just outside the 80 km band, and reported as quiet rather than rounded in, because a threshold that bends for a near miss is not a threshold.

Across all three charts: Einstein 4, Kahlo 9, Hendrix 7 quiet lines of 40 each. That is 20 of 120, on a corpus far too small to carry a page, and it lands inside this study's interval of 1919.8%.

The rest of this site quotes 21 of 120, or 18%, and the extra line is not a discrepancy but a different question. This study asks whether anything is there. The product asks whether there is anywhere it can name. Jimi Hendrix's Mercury Imum Coeli line passes 1 km from Mandalay, Myanmar with 9 settlements inside the band, and every one of them is in Myanmar, which sits on the US State Department's Level 4 list. A reading withholds those, so the line is geometrically busy and has nothing to offer. It is one line in 120, and it accounts for the whole difference between the two counts.

The part that is about a person

How much of one map is quiet varies enormously

Nobody has a mean chart. The average is 19.4% of forty lines, but the middle eighty per cent of charts fall between 12.5% and 27.5%, and the full corpus runs from 5% to 45%, that top figure being 18 lines of 40 landing nowhere anybody lives.

The three published charts show the same spread in miniature: Albert Einstein 4, Frida Kahlo 9, Jimi Hendrix 7. Same method, same gazetteer, more than double the quiet lines on one chart as on another.

The interval is computed across charts rather than across lines because the chart is the unit that was sampled. The expected reason, that forty lines of one chart share one sky and so are not forty independent observations, was checked and is not true here: the observed spread between charts is 5.4 points against a binomial expectation of 6.3 for forty independent lines. Correcting for clustering that is not there would have made this interval narrower, not wider.

Does it hold up?

The same measurement, four independent corpora

The study is always computed four ways rather than once, over corpora starting decades apart with unrelated step intervals. The headline moves by 1 percentage point across all four, which is what entitles it to be stated as a single number.

Each corpus computed separately. Quiet share at 80 km.
CorpusFirst instantStepChartsQuiet
A1940-01-019d 5h 07m15019.7%
B1975-06-1413d 2h 41m15019.9%
C1902-09-035d 19h 23m15019.2%
D2001-03-2221d 7h 53m15018.9%
What predicts a quiet line

Almost nothing about the line does

The planet does not matter. The whole spread across the ten bodies is 0.9 percentage points, from sun at 20% to pluto at 19.1%, which is about the same as the 1-point wobble the headline itself shows between corpora. There is no effect here to report, and reporting the null is the point: silence is a fact about where the oceans and the empty quarters are, not a fact about the body. No rival method computes it away.

The angle matters slightly, and the effect survives checking. Meridian lines are quiet 20.2% of the time against 18.6% for horizon lines, a gap of 1.6 points. A meridian line is one north-south sweep through a single longitude, so it gets fewer chances to pass near anybody than a curve crossing many latitudes does. The gap comes out +1.7, +1.1, +2.2, +1.3 points in the four corpora, the same sign every time, which is the whole reason it is stated here and the finding below is not.

Limits

A finding this study threw away

The first corpus computed here showed Ascendant lines quiet 21.5% of the time against 16% for Descendant lines. A 5.5-point gap, larger than the angle-class effect above, with a story ready to explain it and a standard error that made it look decisive. It is noise.

The Ascendant-minus-Descendant gap, computed separately in each corpus.
CorpusASC quietDSC quietGap
A21.5%16%+5.5 pp
B19.8%18.9%+0.9 pp
C17.2%19.1%-1.9 pp
D17.5%19%-1.5 pp

The gap changes sign. What produced it was sampling a single corpus and then trusting a standard error computed as though the lines in it were independent draws from the sky. They are not, and the size of that mistake is measurable rather than a matter of opinion: the naive standard error for this gap is 1.4 points, while its actual spread across the four corpora is 3.4, about 2.4 times larger. A corpus of instants stepped at a fixed interval is not a random sample of skies, so a statistic that keys on where lines fall inherits structure from the step. No mechanism beyond that is claimed here, and none is needed: the comparison is the reason the fix is four corpora with unrelated steps rather than a better formula applied to one.

It is on this page rather than deleted from history because it is the most useful thing the study can show about how to weigh the rest of it. The four corpora exist so that this class of finding dies here instead of on your screen. Everything above passed that test; this did not.

Two further limits worth stating. The gazetteer holds settlements of about 100,000 people or a national capital, so “nothing is near this line” means no settlement of that size. A line over a village of four thousand reads as quiet here. And the corpus is synthetic instants, uniform in time, whereas real birth data is not: it clusters in populated longitudes and recent decades, so a population of real charts would not be expected to match this exactly.

Questions

Common questions

Why does my astrocartography map have no lines near me?
Usually because there is genuinely nothing there, and that is common rather than a defect. Across 600 charts and 24,000 chart-lines, 19.4% of lines, about one in 5, have no settlement of any size within 80 km of them. A line spends most of its length over ocean, ice or empty desert, so the honest answer to "what is under this line?" is often "nobody lives there".
Doesn't every other astrocartography tool find something near me?
Widening the orb is what makes that possible. The same corpus measured at each published band: nothing inside 80 km for 19.4% of lines, but nothing inside 805 km for only 0.7%. A tool reading at the widest orb in the literature can offer you somewhere about 99.3% of the time. It is not finding more; it is counting further away as near.
Is a quiet line a problem with my chart?
No, though how much of your map is quiet varies a great deal. The mean chart has 19.4% of its forty lines quiet and the middle eighty per cent of charts fall between 12.5% and 27.5%, but the corpus runs from 5% to 45%, and that top figure is 18 of forty lines landing nowhere anybody lives. Separately, 22.5% of charts have at least one line with no settlement inside even 805 km, the widest orb published by anyone.
Does it depend on which planet or which angle?
Not on the planet: the whole spread across the ten bodies is 0.9 points, comparable to the 1-point wobble the headline itself shows between corpora. Angle matters slightly. Meridian lines (MC and IC) are quiet 20.2% of the time against 18.6% for horizon lines (ASC and DSC), a gap of 1.6 points that holds in all four sub-corpora. A meridian line is one north-south sweep through a single longitude, so it gets fewer chances to pass near anybody than a curve crossing many latitudes does.

See which of your own lines are quiet

The free map draws all 40 of your lines and names the band for each. Where nothing is inside 80 km, it says so rather than widening the band until something appears.

19.4% of lines quiet at 80 km, across 24,000 chart-lines. The number is recomputed from the committed corpus on every build.