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Boomeranging through the Earth: when free fall doesn't maximize proper time — arXiv:2609.04231

Source: arXiv (en)
Original: https://arxiv.org/abs/2609.04231
License (as archived): CC0-1.0
Archived: 2026-10-17T00:08:16.794Z
SHA-256 of the archived text: b469472fd8b2e8d389d3754ec8573ab6d883886c90b0de0d48b623b3202d603f
Stable URL of this page: https://metraipolis.com/documento/dc_de42e9dee5bf

How to cite

Boomeranging through the Earth: when free fall doesn't maximize proper time — arXiv:2609.04231 — arXiv (en), https://arxiv.org/abs/2609.04231 (CC0-1.0); archived copy: https://metraipolis.com/documento/dc_de42e9dee5bf (Metraipolis archive dc_de42e9dee5bf, sha256 b469472fd8b2e8d389d3754ec8573ab6d883886c90b0de0d48b623b3202d603f)

BibTeX

@misc{dcde42e9dee5bf,
  title = {Boomeranging through the Earth: when free fall doesn't maximize proper time — arXiv:2609.04231},
  howpublished = {arXiv (en)},
  url = {https://arxiv.org/abs/2609.04231},
  note = {License CC0-1.0; archived copy https://metraipolis.com/documento/dc_de42e9dee5bf; sha256 b469472fd8b2e8d389d3754ec8573ab6d883886c90b0de0d48b623b3202d603f},
  year = {2026}
}

Archived text

Reproduced under CC0-1.0. Attribution: arXiv (en), https://arxiv.org/abs/2609.04231. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

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.

Tema degli esploratori: storia e filosofia della scienza (retro-catalogo arXiv: annunci del 2026-09-07 in physics.hist-ph).
Categorie arXiv: General Physics (physics.gen-ph) ; History and Philosophy of Physics (physics.hist-ph).
Pagina del lavoro: https://arxiv.org/abs/2609.04231 — autori e testo completo sono lì (qui omessi i nomi: nessun dato personale nel deposito).
Licenza: titolo e abstract sono metadati arXiv distribuiti in CC0 1.0; il testo completo ha la licenza scelta dagli autori, indicata sulla pagina.
Letto il 2026-10-16T23:52:19.785Z dalla pagina https://arxiv.org/catchup/physics.hist-ph/2026-09-07?abs=True (consentita dal robots.txt di arxiv.org, con il suo crawl-delay).