Category: Uncategorized

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

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

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

ENTROPY. “Furthermore, even if the infinity is tamed, the mysterious dependence of information on surface area must be somehow accommodated.” https://lnkd.in/draqjTW View in LinkedIn

FLAW OF STRING. “Superstring theory also embraces an infinite number of degrees of freedom. Holography restricts the number of degrees of freedom that can be present inside a bounding surface to a finite number; field theory with its infinity cannot be the final story.” https://lnkd.in/draqjTW View in LinkedIn

HOLOGRAPHIC PRINCIPLE. “And with it comes a realization that the fundamental belief, prevalent for 50 years, that field theory is the ultimate language of physics must give way. Fields, such as the electromagnetic field, vary continuously from point to point, and they thereby describe an infinity of degrees of freedom.” https://lnkd.in/draqjTW View in LinkedIn

EXPLAINING THE HEAVENS. “Our best-fitting model suggests a scenario in which disc instabilities are the main driver for moderately luminous Seyfert galaxies at low redshift, while major mergers are the main trigger for luminous AGN.” (AGN = active galactic nuclei). https://lnkd.in/d9JV8md View in LinkedIn

DOWNSIZING EXPLANATION. “With these three modifications, the models can explain the observed downsizing, successfully reproduce the bolometric AGN luminosity function and simultaneously reproduce galaxy and BH properties in the local Universe.” (BH = black hole; AGN = active galactic nuclei). https://lnkd.in/d9JV8md View in LinkedIn

The waxy magnolia comes forh in the growing summer heat, flawless in the growing energy and commotion. View in LinkedIn