Akhet Khufu: archaeo-astronomical hints at a common project of the two main pyramids of Giza, Egypt

Giulio Magli

Home/Archive/arXiv

arXiv · 0708.3632

Akhet Khufu: archaeo-astronomical hints at a common project of the two main pyramids of Giza, Egypt

Giulio Magli

View original source ↗Read source document ↗Export metadata ↓

Abstract

The architectural complexes composed by the two main pyramids of Giza together with their temples are investigated from an inter-disciplinary point of view, taking into account their astronomical alignments as well as their relationships with the visible landscape. Combining already known facts together with new clues, the work strongly supports the idea that the two complexes were conceived as parts of a common project.

Explore related subjects

physics.hist-ph

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Giulio Magli. 2007-09-04. Akhet Khufu: archaeo-astronomical hints at a common project of the two main pyramids of Giza, Egypt. https://arxiv.org/abs/0708.3632

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

On Algebraic Background-Independence

It has recently been claimed that algebraic methods can be used to give a background-independent description of semiclassical gravity. This paper aims to provide an entry point into recent algebraic approaches to quantum gravity and to analyse and critically assess the conception of background-independence here involved. We discuss an algebraic framework for formulating an algebra of observables along the worldline of an observer in a cosmological setting. By 'gravitationally dressing' the observables to the observer's worldline, the reference to the spacetime background can be set aside at the level of the abstract *-algebra. Thus this *-algebra is taken to be independent of any particular spacetime realisation, with different states on the algebra corresponding to different backgrounds. We compare this algebraic framework to three influential notions of background-independence in the literature and argue that none of these fully captures the sense in which the *-algebra is taken to be background-independent. Building on this, we extract a novel notion of algebraic background-independence tied to the representation-independence of the *-algebra. This algebraic conception motivates two further concepts of background-independence tailored to semiclassical theories: semiclassical background-independence and perturbative background-independence. We suggest that these provide useful tools for evaluating the scope and limitations of semiclassical approaches to quantum gravity.

physics.hist-ph↗

arXiv2026

Ghosts that Connect

What is a Faddeev--Popov ghost? The textbook answer is that it is a trick: a way of writing a functional determinant as a term in the action, and nothing more. Dougherty 2021 and Dougherty and Read 2026 have argued that this undersells the ghost, which on their account encodes classical structure of the configuration space, viz. the degree-one generators of the Chevalley--Eilenberg complex of the action Lie algebroid. I agree with them that the ghost encodes classical structure. But I think the structure is bigger than they say. The ghost, I argue, is a principal connection $\varpi$ on the bundle $F \to F/G$ of gauge potentials over physical configurations; the BRST operator is the exterior derivative along the orbits; and the Chevalley--Eilenberg ghost coincides with $\varpi$ restricted to the orbits (and every $\varpi$ has the same restriction). The restriction drops the horizontal complement, and I show that gauge-fixed quantisation needs that complement. A gauge-fixing installs it as a pairing of configurations across orbits (a counterpart relation, in Lewis's sense); dressed observables and local counterfactuals rely on this pairing, but it is discarded by the quotient $\F/\G$. In the non-Abelian case Singer's theorem forbids a flat $\varpi$, and there the pairing exists only as parallel transport. Finally, BRST survives gauge-fixing because it is vertical and rigid, and so leaves any such pairing unchanged.

physics.hist-ph↗

arXiv2026

Schrödinger's unpublished hidden-variable model in the 1944-45 debate over the "Collapse of Determinism"

In the mid-1940s, the question of whether quantum mechanics could be supplemented by deterministic hidden variables resurfaced in a debate in ^textit{Nature}. I show that Erwin Schrödinger drafted a hitherto unpublished response to this controversy. In it, Schrödinger provided an explicit hidden-variable model, thereby showing that such models could not be ruled out. I reconstruct the historical context of this forgotten manuscript and publish here the first transcription and analysis. Importantly, Schrödinger's proposal should be understood as a proof of principle rather than as evidence of his commitment to determinism.

physics.hist-ph↗