**Difficulty level:**☆

# Month: April 2017

## Research – Colin MacLaurin

**Difficulty level:**★

My research area is general relativity. These papers are drafts not yet ready for *arXiv*, but exhibit my work prior to Europe conferences. — Colin MacLaurin

- 2017, “Distance in Schwarzschild spacetime” (draft). Observers with “energy per mass” measure a radial distance . I overview four different tools to measure spatial distance — spatial projector, tetrads, adapted coordinates, and radar — which are locally equivalent. Though spatial distance is foundational, it remains underdeveloped. I clarify subtleties, and counteract the Newton-esque over-reliance on the static distance .

- 2017, “Cosmic cable” (draft). A cosmic-length cable could be used to mine energy from the expansion of the universe. Beyond sci-fi, this is instructive for relativity pedagogy. The dynamics include motion-dependent distance, and time-dilation which reduces the force, effects which are missed in most existing treatments.

- 2015, “Expanding space, redshifts and rigidity: Conceptual issues in cosmology“. My Master’s thesis in general relativity.