{
  "abstract": "In teaching special relativity, John Bell emphasised the value of pre-relativistic intuitions. His famous spaceship puzzle showed that, in certain cases, the older heuristics of Lorentz and FitzGerald get the right answer to a genuinely relativistic problem more reliably than the principles of special relativity themselves. In teaching general relativity, John Wheeler emphasised the value of simplicity, illustrating curved-spacetime geometry with capsules boomeranging through a tunnel along the Earth's diameter. Here I put the two ideas together. I share a simple thought experiment, involving genuinely general-relativistic effects, in which the standard GR heuristic -- ``freely falling observers maximise proper time'' -- gives the wrong answer, while the older heuristic of velocity and gravitational time dilation, applied in a single frame, gets it right immediately. The resolution involves conjugate points and the distinction between local and global extremality of geodesics, but the moral is the same as Bell's: do not let a newer slogan overwrite a perfectly sound older intuition.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.04231",
  "author_total": 1,
  "authors": [
    {
      "name": "Henrique Gomes"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2d803bc9b8wd6.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.04231",
  "fulltext_url": null,
  "id": "2d803bc9b8wd6",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.04231",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.gen-ph"
    ],
    [
      "arxiv",
      "physics.hist-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2609.04231",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2d803bc9b8wd6.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:14Z",
      "native_id": "2609.04231",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.04231"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.gen-ph",
      "subfield": "general"
    }
  ],
  "title": "Boomeranging through the Earth: when free fall doesn't maximize proper time",
  "title_text": "Boomeranging through the Earth: when free fall doesn't maximize proper time",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:14Z",
  "url": "https://research.draconitic.com/paper/2d803bc9b8wd6",
  "venue": "arXiv",
  "versions": []
}