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ENERGY. “A number of anthropologists believe fire actually refashioned our biology.” An interesting essay. https://lnkd.in/d7wb_xr View in LinkedIn

SLOW SPIN CORES. “Asteroseismic data for low-mass stars have convincingly demonstrated that the cores of low-mass stars rotate at least an order of magnitude slower than predicted by most prior stellar models. Their predictions of compact object rotation rates are unreliable. We predict extremely slow rotation a ~ 10−2 for BHs born from single stars.” (BH = black hole). https://lnkd.in/dApxk5K View in LinkedIn

FUEL. “However, engine-driven transients such as long gamma-ray bursts, broad-lined SNe Ic, and superluminous SNe Ic do not show evidence for any hydrogen in their progenitor stars. These transients are likely driven by a rapidly rotating central engine from a (mostly) carbon–oxygen progenitor star.” (SNe Ic = soecific superluminous black hole transient). https://lnkd.in/dApxk5K View in LinkedIn

MURKY ORIGINS. “However, because collapsing blue supergiants likely formed as a result of a prior binary interaction, few binary scenarios predict them to be the progenitors of BH mergers or XRBs, though they could plausibly be progenitors of ultra-long gamma-ray bursts.” (BH = black hole; XRBs = X-ray binaries). https://lnkd.in/dApxk5K View in LinkedIn

SPINNING INFINITY. “Rotating blue supergiants, such as the progenitor of SN 1987A, may also give rise to rapidly rotating BHs. For these stars, neutrino-mediated mass loss will fail to unbind most of the hydrogen envelope, and a rapidly rotating BH will be produced if the AM in the hydrogen envelope is accreted by the BH.” (BH = black hole; AM = angular momentum). https://lnkd.in/dApxk5K View in LinkedIn

BLACK HOLE SPIN. “Spin is one of only three fundamental properties of black holes (BHs), but there are few reliable predictions of natal BH spins. The BH spin is determined by the angular momentum (AM) content of the core of the star that collapses into the BH. Yet our ability to predict internal stellar rotation rates and AM content has been limited by sparse observational constraints and the complex magnetohydrodynamics of differentially rotating stars.” (BH = black hole; AM = angular momentum). https://lnkd.in/dApxk5K View in LinkedIn

EVOLUTION OF BLACK HOLES. “Because so few philosophers have worked on these issues, many questions and problems of great possible interest have not been investigated philosophically at all; others have had only the barest starts made on them; consequently, several sections discussed in this article merely raise questions and point to problems that deserve philosophical attention. The field is wide open for expansive and intensive exploration.” https://lnkd.in/dPXn5gh View in LinkedIn

A Girona artesenal bookbinder who still occaisionally works in velum. Another dying breed. Extraordinary workshop of old tools. View in LinkedIn

LEWIS CARROLL’S THE SNARK. “The poem describes " with infinite humor, the impossible journey of an improbable crew, to find an inconceivable creature ". (Sidney Williams and Falconer Madan: Handbook of the Literature of the Rev. CL Dodgson , cited in Martin Gardner: The Annotated Snark , Penguin Books, 1974.). https://lnkd.in/dCZKzN4 View in LinkedIn

INCREASING ENTROPY? “Finally, the evolution of black holes is apparently in conflict with standard quantum evolution, for such evolution rules out the sort of increase in entropy that seems to be required when black holes are present. Indeed, as purely gravitational entities with striking quantum properties, what we know about black holes lies at the heart of and guides many attempts to formulate a theory of quantum gravity. This has led to a debate over what seemingly fundamental physical principles are likely to be preserved in, or violated by, a full quantum theory of gravity.” https://lnkd.in/dPXn5gh View in LinkedIn