### Education

• 2000–2004: Bachelor of Mathematics (Honours), University of Newcastle, NSW. 1st-class honours and a science faculty medal
• 2005–2007: Graduate Diploma in Theology, Avondale College
• 2013– Master of Science (Physics), University of Queensland

Relativity courses, as a student:

• 2017, Vienna: “Geometry and Relativity” summer school for PhD students and early career researchers, run by Piotr Chruściel
• 2018, Melbourne: “Mathematical relativity and Lorentzian geometry” honours-level course, at Australian Mathematical Sciences Institute (AMSI) summer school, co-lectured by Todd Oliynyk
• 2014, University of Queensland: MATH7105 General Relativity, honours-level course
• University of Newcastle, Australia: MATH___ General Relativity, lecturer Ian M. Benn
• University of Newcastle, Australia: PHYS3290 Special Relativity, lecturer Ian Benn

### Publication

• MacLaurin & Robertson, “Euler Characteristic in Odd Dimensions”, Gazette of the Australian Mathematical Society 30:4 (2003), p195–199. (arXiv version; the journal’s online past issues only go back to 2004 currently)

See papers in production below. I also run this website, ColinsCosmos.com, dedicated to general relativity.

### Research

My research so far consists of various scattered topics within general relativity:

• Big Rip in an inhomogeneous universe, with Krzysztof Bolejko. Draft paper nearly completed
• Misconceptions / pedagogy of black holes, with Geraint Lewis & Tamara Davis. A planned series of papers, needs writing up
• “Cosmic cable”: The expansion of the universe can be used to generate tension in a long rigid cable, and hence harvest energy (this mechanism is not cyclic). Many treatments omit correct frame-dependent distance, transformation of force, etc. I examine a moving cable, existing treatments assume a static cable
• Spatial distance, observer-dependent. I show the following tools give equivalent results: adapted coordinates, tetrads, spatial projector, and radar metric. I make application to Schwarzschild black holes, aided by a new generalisation of Gullstrand-Painlevé coordinates
• Comparison of averaging in quantum physics (semi-classical / stochastic gravity) and general relativity (inhomogeneous cosmology), with Magdalena Zych; recently commenced

Completed university theses, both with original research:

• Mathematics honours thesis, 2004. “Quantum Even-Dimensional Balls”. In original research, I gave three equivalent constructions of “quantum ball” C*-algebras. Supervisor Wojciech Szymanski. It was cited here
• Physics Master’s thesis, 2015. “Expanding Space, Redshifts, and Rigidity: Conceptual Issues in Cosmology”. Redshifts can be interpreted flexibly as due to the stretching of space, gravitational, or Doppler in origin. Other topics also investigated. Supervisor Tamara Davis. See PDF and further description.

### Presentations

#### Conference talks

• 2015, 2nd Dec, “Galaxy Cable” (abstract on conference website), Melbourne, Australasian Conference on General Relativity and Gravitation (ASGRG8)
• 2016, 8th July, “Static vs Falling: Time slicings of Schwarzschild black holes” (slides on conference website), Vancouver, Canadian Conference on General Relativity and Relativistic Astrophysics (CCGRRA16)
• 2017, 7th July, “Big Rip in an inhomogeneous universe” (slides on conference website), Toruń, Poland, Inhomogeneous Cosmologies (CosmoTorun17)
• 2017 “Cosmic cable”, Australasian Conference on General Relativity and Gravitation (ACGRG9, Perth)
• 2018, May, “Slicing the Schwarzschild block” at Nature and Ontology of Spacetime conference, Bulgaria
• [Subsequent talks listed at: conferences attended]

#### Conference poster

Time slicings of black holes” presented at:

• 21st International Conference on General Relativity and Gravitation (GR21) in New York City, 2016
• joint Asia Pacific Physics Conference and Australian Institute of Physics Congress (APPC-AIP 2016) in Brisbane, Australia, 2016
• Probing the Spacetime Fabric, Trieste, Italy, 2017
• Between Geometry and Relativity workshop in Vienna, Austria, 2017
• Australasian Conference on General Relativity and Gravitation (ACGRG9, Perth 2017)

#### Research group presentations

I have given several dozen talks to the astrophysics and general relativity groups at the University of Queensland:

• 4th June 2015, Master’s thesis overview, physics faculty at University of Queensland (UQ)
• 3rd Sep 2015, “Spatial Metric and Spaghettification”, astrophysics group plus visitors, at the University of Queensland. I introduced the spatial metric aka spatial projector tensor, and used it to show that for a Schwarzschild black hole, the radial distance is dL=1/e dr.
• 17th Dec 2015, “Galaxy Cable”, astrophysics group at University of Queensland. This was a recap of my first conference presentation on the same topic.
• 26th April 2016, “Black holes: Static vs Falling perspectives”, astrophysics group at UQ. The usual descriptions of radial distance, curvature of 3-space (Flamm’s paraboloid), time at infinity, etc. are based on the Schwarzschild coordinate perspective, which corresponds to static observers (r>2M) or e=0 observers (r<2M). We get different measurements under generalised Gullstrand-Painlevé coordinates, which correspond to radially moving observers of various energy per mass e.
• 12th September 2016, “Energy conservation in the universe”. I overviewed standard concepts about energy in relativity, for instance the stress-energy tensor knows nothing of a gravitational field, and total energy density is not localisable. However the “rigid quasilocal frames” formulation concludes that total energy is conserved in relativity.
• …also numerous other talks…
• 5th October 2017. Big Rip in an Inhomogeneous Universe, UQ astrophysics group
• 22nd March 2018: overview of Bekenstein 1972 to UQ quantum and gravity seminar

Also a talk to the Brisbane Astronomical Society on 8th Sep 2017

### Other

I was the organiser and main presenter of a general relativity group at the University of Queensland throughout 2017, initiated by Tamara Davis

Professional memberships:

• 2015–  Australasian Society for General Relativity and Gravitation (ASGRG)
• 2015–2017:  Astronomical Society of Australia (ASA)

Training:

• Training for film and audio presentations by Peter Buckley and also Dwayne Jeffries