Month: September 2022

THE WORLD AS INFO. “Holography may be a guide to a better theory. What is the fundamental theory like? The chain of reasoning involving holography suggests to some, notably Lee Smolin of the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, that such a final theory must be concerned not with fields, not even with spacetime, but rather with information exchange among physical processes. If so, the vision of information as the stuff the world is made of will have found a worthy embodiment.” https://lnkd.in/draqjTW View in LinkedIn

GOD IS A GEOMETER. “Tool-use, with its Subject (the tool), Verb (movement of the tool), and Object (the workpiece), and manipulation of mental images, is an extension of the sentence. The sense of truth and falsity shares a common source with the right and wrong answers of arithmetic.” (The human mind’s origins in geometry, an unusual viewpoint) https://lnkd.in/drepKdh View in LinkedIn

Hazy days of summer with high contrasts of light and shadow, blazing heat and relief. View in LinkedIn

JACOB D. BEKENSTEIN has contributed to the foundation of black hole thermodynamics and to other aspects of the connections between information and gravitation. He is Polak Professor of Theoretical Physics at the Hebrew University of Jerusalem, a member of the Israel Academy of Sciences and Humanities, and a recipient of the Rothschild and the Israel prizes. Bekenstein dedicates this article to John Archibald Wheeler (his Ph.D. supervisor 30 years ago). https://lnkd.in/draqjTW View in LinkedIn

WE START a new paper on the Origin of the antihierarchical growth of black holes, by an international group of collaborators. These important observations about black holes will conclude this lengthy section of black holes and we will transition into how black hokes make white holes, and their properties. https://lnkd.in/d9JV8md View in LinkedIn

DOWNSIZING. “Observational studies have revealed a ‘downsizing’ trend in black hole (BH) growth: the number densities of luminous active galactic nuclei (AGN) peak at higher redshifts than those of faint AGN. This would seem to imply that massive BHs formed before low-mass BHs, in apparent contradiction to hierarchical clustering scenarios.” https://lnkd.in/d9JV8md View in LinkedIn

GOALS. “We investigate whether this observed ‘downsizing’ in BH growth is reproduced in a semi-analytic model for the formation and evolution of galaxies and BHs, set within the hierarchical paradigm for structure formation.” (BH = black hole) https://lnkd.in/d9JV8md View in LinkedIn

HIERARCHICAL MODEL. “In this model, BHs evolve from light seeds (∼100 M⊙) and their growth is merger driven. The original Somerville et al. model (baseline model) reproduces the number density of AGN at intermediate redshifts and luminosities, but underproduces luminous AGN at very high redshift (z > 3) and overproduces them at low redshift (z < 1).” (BH = black hole; AGN = active galactic nuclei). https://lnkd.in/d9JV8md View in LinkedIn

WARP SPEED. “When the Chinese released the sequence of the SARS-CoV-2 virus, we started the process of making RNA the next day. A couple weeks later, we were injecting animals with the vaccine." A very long time to until the acceptance of mRNA vaccines, whose promises for the future are considerable. See my TEDx talk. https://lnkd.in/dc32WbP View in LinkedIn