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THE APPROACH. “Could systems biology approaches help achieve a more systematic and quantitative understanding of the biosynthetic potential of a putative pre-phosphate metabolic network? Is it at all possible that a phosphate-independent geochemical setting could support the emergence of a rich and complex organized biochemistry?” https://lnkd.in/dcwZe7b View in LinkedIn

THE QUESTION. “Phosphate is essential for all living systems, serving as a building block of genetic and metabolic machinery. However, it is unclear how phosphate could have assumed these central roles on primordial Earth, given its poor geochemical accessibility.” https://lnkd.in/dcwZe7b View in LinkedIn

FRAGMENT FROM NATURE features an article entitled Remnants of an Ancient Metabolism without Phosphate, by Joshua E.Goldford et al. This is a brilliant analysis using computer modeling of metabolic pathways; even forty five years ago, when I was a graduate student, such tools were essentially unknown in biochemistry. Just like in many aspects of astronomy, probing the evolution of metabolism largely relies on sophisticated theoretical modeling. https://lnkd.in/dcwZe7b View in LinkedIn

AFTER THE INTERPRETATION OF DREAMS (1899). “I have always been amazed at the way an ordinary observer lends so much more credence and attaches so much more importance to waking events than to those occurring in dreams... Man... is above all the plaything of his memory.” (Andre Breton, First Manifesto of Surrealism, 1924). https://lnkd.in/dwEZcPh View in LinkedIn

THE EDGE OF INFINITY. “A spacetime singularity is a breakdown in spacetime, either in its geometry or in some other basic physical structure. It is a topic of ongoing physical and philosophical research to clarify both the nature and significance of such pathologies. When it is the fundamental geometry that breaks down, spacetime singularities are often viewed as an end, or “edge”, of spacetime itself.” https://lnkd.in/dPXn5gh View in LinkedIn

CRITICAL MASS NEEDED. “Even if the accretion rate onto small PBHs happened to be large enough, there would be smaller PBHs that would accrete enough to reach Mcr anyway, filling the void of critical mass holes.” (PBHs = primordial black holes; Mcr = critical mass of a PBH). https://lnkd.in/dggABMY View in LinkedIn

LACK OF BLACK HOLE BURSTS. “Second, it might be possible for the critical mass holes to accrete enough to no longer evaporate in the current era. However, the accretion rate is too small and this would not explain the non-detection of PBH bursts.”(PBHs = primordial black holes). https://lnkd.in/dggABMY View in LinkedIn

LACK OF BLACK HOLE BURSTS. “The non-detection of such an event has a few explanations. First, the fraction of PBHs that make up the dark matter must be quite low for PBHs of the relevant mass scale. Thus it is plausible that not enough of these PBHs exist to subsequently evaporate and trigger gamma-ray detectors.” (PBHs = primordial black holes). https://lnkd.in/dggABMY View in LinkedIn

BLACK HOLE FOOTPRINTS. “Searches for PBH bursts are ongoing. Although there are candidates for such events, no confirmed PBH burst event has been detected. The spectral properties of such bursts should be distinguishable from the ‘normal’ GRBs.” (PBHs = primordial black holes; GRBs = gamma ray bursts). https://lnkd.in/dggABMY View in LinkedIn

FIRST PARTICLES. “Table 1. Standard model elementary particles and other mass thresholds important in the early universe. Listed are the particles that freeze out below each temperature threshold, the mass of each particle or threshold, the effective relativistic degrees of freedom at the temperature corresponding to that mass threshold, and the change in the degrees of freedom as the radiation temperature of the universe crosses the threshold.” https://lnkd.in/dggABMY View in LinkedIn