Kenneth Arnold 1947: Visualisation · Signals from the Periphery

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THE RIDGE

Assumed distance

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Implied

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Regime

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KENNETH ARNOLD · 24 JUN 1947
nine objects · Rainier to Adams · 46.7 mi
timed on an instrument clock: 1 min 42 s
the distance was never measured, only assumed
speed is exactly linear in that assumption
drag the distance · read the speed · check the eye

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Evidence

fact ⇄ what kind of claim · live

1 min 42 s, on the instrument-panel clock, Rainier flank to Adams crest

his own report, repeated verbatim in 1977; the stop mark was the LAST object

REPORTED

Summit to summit 46.73 mi at 164° true; the reported course was 170°

published coordinates, closed form; the press's "fifty miles" is 7% long

EXACT

v = d / 102 s: 77 mph per mile of assumed distance, subsonic below 9.6 mi

exact arithmetic on an assumption nobody measured; ISA sound speed at 9,200 ft

EXACT

A shape at 23 mi needs ~106 ft; the file's 45-50 ft subtends 1.4′

three acuity thresholds kept apart; the DC-4 control is drawn beside them

EXACT

The visible horizon lies 1.57° below true level from 9,200 ft

refracted dip, closed form: "level with the horizon" puts them near 7,000 ft

EXACT

The foothills between the summits, and the objects' drawn outline

terrain is shaped noise, not a DEM; the outline is his June 1947 sketch

MODELLED

Every quotation in the Word view, with its date and publication

saucer is a shape word in all of them; the misquote claim first appears in 1950

REPORTED

What the nine objects were

the one thing this bench prices nothing of

READING

View

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The one dial that decides everything

Assumed distance23.0 mi

Nothing in the record measures this. Arnold called 20 to 25 miles; Shough reconstructs 16 to 20; Hynek needed under 6. Speed is exactly linear in it.

The ridge

The clock28.6 s

The real 102 seconds, Rainier's southern flank to the crest of Adams. Time-lapsed six to one.

Horizon referencedraw true level and the 1.57° visible horizon

Labels

The ledger

Chain correctionhe stopped the clock on the LAST object, so the leader had already flown a chain length further. The bench opens on his own arithmetic; switch this on to add it back.

The eye

Object span100 ft

The ATIC file says 45 to 50 ft, which was really a DC-4's engine span. Arnold said 100. Ruppelt records a faction at 210.

The word

Timelineflat disc

Thirteen dated entries, June 1947 to June 1977: the press, Arnold himself, and the record.

Readout · live

Implied speed

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Mach at 9,200 ft

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Angular size

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Chain

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Travelled span

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Height on the horizon

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What is exact vs modelled here

Exact: the geodesy (46.73 mi at 164°), the speed arithmetic and its linear coupling to distance, the ISA speed of sound at 9,200 ft, the 1.57° horizon dip, every angular size, and the sun's position that afternoon. Reported: the 102 seconds, every size and distance Arnold gave, the chain length, all quotations with their dates, Hynek's memo, Ruppelt's factions, the Air Force filing, and the 1947 wave counts. Modelled: the foothills between the published summits, the objects' drawn outline and glint cycle, and their staged altitude. There is no fitted constant anywhere on this bench.

The model, in full

Distance and bearing come from published coordinates in closed form. Speed is the travelled span over 102 s, where the span is the summit-to-summit line scaled by the assumed distance, plus one chain length when the stop mark is the last object. Mach uses the ISA speed of sound at 9,200 ft. Angular size is span/range in arcminutes, against three separately labelled acuity thresholds. The horizon dip is √(2h/kR) with k = 7/6 for standard refraction. The sun is a Meeus low-precision solution for 24 June 1947, computed for both Pacific standard and daylight time because Arnold could not say which his clock kept. Every anchor is checked in scripts/arnold-tune.mjs.

Where this instrument takes liberties

The Cascade terrain between the summits is shaped noise, not a digital elevation model: it exists so the eye reads distance, and the peaks that carry arguments stand on their real coordinates and 1947 heights. The objects are drawn to Arnold's June 1947 description, not the crescent he drew from August onward, because the drift is the Word view's subject. Their staged altitude puts them on the apparent horizon, which is an argument this bench makes rather than a fact the record contains. The sky is the standard three.js Preetham scattering model driven by the computed sun, at clear-as-crystal turbidity because that is the weather Arnold logged; the sparse cumulus east of the crest are staging anchored on the Stampede Pass record for that afternoon (1/10 Cu). The timing uncertainty of ±5 s is this bench's own reasonable figure, labelled as such.

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