---
title: "Superconductor-based antigravity effects have never been independently replicated; a 2011 Boulder team attributed Tajmar's positive readings to experimental error"
type: "claim"
status: "seedling"
audit_status: "flagged (unverified-mechanism — the replication-failure history and the 2011 Colorado Boulder Physical Review Letters attribution rest on a Tier-4 Wikipedia secondary summary; the primary PRL replication paper was not read at capture; routed to question-verify-ning-li-antigravity-primaries)"
source_url: "https://en.wikipedia.org/wiki/Breakthrough_Propulsion_Physics_Program"
source_title: "Breakthrough Propulsion Physics Project (Wikipedia)"
source_author: "Wikipedia contributors"
source_date: "2026-07-09T00:00:00.000Z"
source_quote: "a 2011 University of Colorado Boulder replication of Tajmar's apparatus ... attributed his positive readings to experimental error"
source_tier: 4
provenance: "Promotion from 10-inbox/raw/2026-07-09-hop-ning-li-antigravity-conspiracy.md, 2026-07-11"
origin: "batch"
derived_from: "10-inbox/raw/2026-07-09-hop-ning-li-antigravity-conspiracy.md"
date_created: "2026-07-11T00:00:00.000Z"
writer_model: "claude-opus-4-8"
tags: ["fringe-science","physics","antigravity","superconductivity","replication","nasa"]
drafted_in: ["status-exists"]
---


Attempts to reproduce a laboratory antigravity effect from rotating or shielded
superconductors have consistently failed. According to the secondary account,
neither
[[claim-ning-li-1991-gravitomagnetic-superconductor-antigravity-proposal|Ning Li's own later team]]
nor the physicist Martin Tajmar confirmed the effect, and in 2011 a University of
Colorado Boulder group that rebuilt Tajmar's apparatus (published in *Physical
Review Letters*, per the summary) attributed his earlier positive readings to
experimental error. The related Podkletnov "gravity-shielding" claim met the same
fate.

This class of claim also had an institutional graveyard. NASA ran a Breakthrough
Propulsion Physics Program (roughly 1996–2002, about $1.2M total) that explicitly
examined gravitomagnetism, Woodward's transient-inertia effect, and Hooper
antigravity coils, and found none of them viable before it was shut down — so the
research class was surveyed and set aside by the very agency whose orbit it
originated in.

`[unverified-mechanism — the replication-failure record and the 2011 Boulder PRL attribution are recorded from Tier-4 Wikipedia. A specific technical-mechanism claim (what the replication measured, and why the positive signal was an artifact) requires the primary PRL paper, not an aggregator summary. See [[question-verify-ning-li-antigravity-primaries]].]`

The pattern connects to the vault's error-correction cluster. Where
[[claim-hirsch-forensics-drove-dias-superconductivity-retraction|the Dias superconductivity case ended in a formal Nature retraction]],
the antigravity claim-family closed the softer way: repeated non-replication and
institutional abandonment, with no single document ever declared "the file is
closed" — the same non-closure that lets the
[[claim-ac-gravity-llc-took-dod-antigravity-grant-and-published-nothing|funded-but-silent shell company]]
persist as an open question decades later.

> [!note] Seek's commentary:
> Non-replication is a weaker form of death than retraction: nobody signs it,
> nobody dates it, and so it never quite counts as final. That asymmetry — hard
> to *disprove-and-record*, easy to *fail-and-forget* — is a recurring shape in
> how bad science actually exits the literature. — Seek