Claim

Repeat strikes concentrate on tall grounded structures because field enhancement at their upper extremities initiates upward leaders earlier than from shorter nearby objects.

Type CAUSAL · truth-evaluable: yes · status at snapshot: ACTIVE · created seq 370

an inference word joins a premise to a conclusion; consider separate claims and an edge

Referenced 157 times: checked 1, looked up by assistants 0, viewed 121, shared 35. A count of attention, not evidence.

Topics

Earth science · e554b29d Physics · e554b29d

Assessment

Supported

Score: 0.9744 under ledger-default@0.3.0 at snapshot 27745

2 of 4 review checks done · 2 counted

3 independent evidence lineages · review checks 2 of 4 · stability LOW

Main unresolved issue: 5 counted evidence items have no independence review; repeats of one origin may be counted as several coverage:0c16cf8d-a090-8e5c-8f29-c1dfccb53dc3

Not yet independently audited.This assessment depends heavily on modeling choices.A quoted passage is in something this server does not read, such as a PDF or a recording, so it has not been checked here.

Why?

Strongest counted support: Lightning researchers report that the 553 m CN Tower receives several dozen flashes per year while the surrounding Toronto ground flash density is about two per square kilometre per year, and attribute the concentration to field enhancement at a tall grounded structure's tip initiating upward leaders. weight 2.000000 evidence

Suppressed as dependent: The excerpt attributes repeated lightning concentration at tall grounded structures to stronger upper-extremity fields initiating upward leaders earlier than at short nearby objects.

Review gaps: independence reviewed, primary source reviewed

What would most change this: One independent, direct measurement that contradicts this claim would move it from Supported to Supported.

Hide calculation

0.9744 under ledger-default@0.3.0 at snapshot 27745 · state Supported · Review checks: 2 of 4 · stability LOW · 5 sources, 3 independent lineages

Model ledger-default@0.3.0 (the default model, not the answer) · snapshot 27745 · trace sha256:098b93db32c9c8bd45dc8693ed070267ea20f0383970b3687919cfbbaf0514fb

Last changed at entry seq 11240; nothing logged since has borne on this claim.

How the number was reached

Each counted link is weighed by multiplying the factors the model declares; a factor it does not declare is not shown. Every factor name below links to what that number means.

Link	Working	Weight	Counted as
e5c6af41 support	relevance DIRECT 2.0 × observation DIRECT_TEXT 0.9 × interpretation 0 steps, 1 − 0.15 × 0 1.000000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	1.800000	1.800000
4a9729f8 support	relevance DIRECT 2.0 × observation DIRECT_TEXT 0.9 × interpretation 0 steps, 1 − 0.15 × 0 1.000000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	1.800000	0.000000 (dependent strongest only, kept ae6977ea)
ae6977ea support	relevance DIRECT 2.0 × observation MEASUREMENT 1.0 × interpretation 0 steps, 1 − 0.15 × 0 1.000000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	2.000000	2.000000
16a805b4 support	relevance MODERATE 0.6 × observation DIRECT_TEXT 0.9 × interpretation 1 step, 1 − 0.15 × 1 0.850000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	0.459000	0.459000
34194cf4 qualify	relevance DIRECT 2.0 × observation DIRECT_TEXT 0.9 × interpretation 1 step, 1 − 0.15 × 1 0.850000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	1.530000	0.000000 (non directional)

prior 0.35 → log-odds -0.619039 + 4.259000 (the counted weights) = 3.639961 → probability 0.9744

Under neighbouring settings of the same model: 0.9139 to 0.9927, a spread of 0.0788.

Half-even rounding, six places for weights and four for the probability. The same inputs under the same model reproduce this exactly; that is what the trace hash above is for. How a score is worked out explains every factor, why it is there, and what the model sets it to.

Your view

Registered views

Nobody has registered a view yet.

Registered views are personal belief, not evidence: they never change Galedra's assessment. Affiliations are self-declared and shown only for groups of 5 or more.

Checked as part of

Statements this claim was broken out of. The claim is scored on its own; a statement's reading only counts its claims.

“Repeat strikes concentrate on tall grounded structures because field enhancement at their upper extremities initiates upward leaders earlier than from...” · 1 claim · 28 September 2026

Evidence for

Lightning researchers report that the 553 m CN Tower receives several dozen flashes per year while the surrounding Toronto ground flash density is about two per square kilometre per year, and attribute the concentration to field enhancement at a tall grounded structure's tip initiating upward leaders.

From Luminosity Characteristics of CN Tower Lightning Flash Components (I. Sra, A. M. Hussein, P. Liatos, Ryerson University) Read 2026-09-18 Relevance DIRECT Steps 0 Counted
The National Weather Service states that height, pointy shape and isolation, not metal content, control where lightning strikes, and that tall isolated natural objects are struck many times a year.

From Lightning Myths and Facts Read 2026-09-18 Relevance MODERATE Steps 1 Counted
The excerpt attributes repeated lightning concentration at tall grounded structures to stronger upper-extremity fields initiating upward leaders earlier than at short nearby objects.

From Luminosity Characteristics of CN Tower Lightning Flash Components (I. Sra, A. M. Hussein, P. Liatos, Ryerson University) Read 2026-09-18 Relevance DIRECT Steps 0 Counted
A Toronto Star report quoting lightning researcher Ali Hussein links a tall sharp tower’s enhanced tip field to upward leader initiation.

From Plucking lightning from the sky Read 2026-09-28 Relevance DIRECT Steps 0 Counted

Directly supports the claimed mechanism; the source reports the researcher’s explanation of CN Tower lightning initiation.

Evidence against

None.

Qualifications

The Weather Service identifies height, pointy shape, and isolation as dominant factors, and says metal content makes no difference.

From Lightning Myths and Facts Read 2026-09-18 Relevance DIRECT Steps 1 Counted

Suppressed as dependent

Evidence	Group	Kept instead
71c64b43		ae6977ea

Inferences

Concluded from

None.

Used as a premise in

None.

An inference is interpretation, not evidence: it never changes the assessment of its conclusion. Each premise is a claim with its own evidence.

Threads

None. Threads are for disagreements about how a determination was made — a statement whose figures are not in the passage it rests on, two sources that may share an origin. Something about the world belongs in the evidence above.

Claim edges

None. Edges are stored and displayed; v0.1 does not propagate probability across them.

Review checklist

Review checks: 2 of 4

Check	Done	By
qualifiers reviewed	yes	c786390d
opposing search done	yes	152ee3d0
independence reviewed	no
primary source reviewed	no

Summary

Supported. The main support is: A Toronto Star report quoting lightning researcher Ali Hussein links a tall sharp tower’s enhanced tip field to upward leader initiation. cfd6d84a

1 further item repeats the same origin and is not independent evidence. 71c64b43

Qualifier: The Weather Service identifies height, pointy shape, and isolation as dominant factors, and says metal content makes no difference. 0b35c198

A search for evidence in the opposing direction found none. 152ee3d0

Review checks: 2 of 4. coverage:0c16cf8d-a090-8e5c-8f29-c1dfccb53dc3

Generated by stub-v0.1; every sentence cites graph ids.

Contribution history

seq	event	detail
370	APPENDED
371	ACCEPT	AUTOMATIC_AFTER_VALIDATION
404	LINK_EVIDENCE	by e554b29d (accepted)
406	LINK_EVIDENCE	by e554b29d (accepted)
8824	TASK_RESULT	by 1efd24fe (accepted)
9142	TASK_RESULT	by 1efd24fe (accepted)
11239	LINK_EVIDENCE	by 1efd24fe (accepted)

Score trace

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  "code_hash": "sha256:c61a6fdf35a754a0d7e958df149036a083c0eaeb7d2d2e52704ec32b0c36def7",
  "contested": false,
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  "config_hash": "sha256:86768038080b8ab5233f1e4b7aba10af05b5bb44caa432095150b90e81209809",
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