# astro: aprops of horrific encounters, how to survive inside a (virtual) black hole

<< As (eight stars skirt a black hole 1m times the mass of the Sun) approach, all are stretched and deformed by the black hole's gravity. Some are completely pulled apart into a long stream of gas, a cataclysmic phenomenon called a tidal disruption event. Others are only partially disrupted, retaining some of their mass and returning to their normal shapes after their horrific encounters. >>

<< These simulations, (..) are the first to combine the physical effects of Einstein's general theory of relativity with realistic stellar density models. The virtual stars range from about one-tenth to 10 times the Sun's mass. >>

<< The division between stars that fully disrupt and those that endure isn't simply related to mass. Instead, survival depends more on the star's density. >>

Jeanette Kazmierczak. Scientists fling model stars at a virtual black hole to see who survives. NASA's Goddard Space Flight Center. Nov 26, 2021.

https://phys.org/news/2021-11-scientists-stars-virtual-black-hole.html

<< This paper introduces a series of papers presenting a quantitative theory for the tidal disruption of main-sequence stars by supermassive black holes (the pericenter-dependence of tidal disruption properties for eight stellar masses (..) and six black hole masses (..). >>

Taeho Ryu, Julian Krolik, et al. Tidal Disruptions of Main-sequence Stars. I. Observable Quantities and Their Dependence on Stellar and Black Hole Mass. ApJ 904 98. Nov 25, 2020.

https://iopscience.iop.org/article/10.3847/1538-4357/abb3cf

Also

keyword 'black hole' | 'astro' in FonT

https://flashontrack.blogspot.com/search?q=black+hole

https://flashontrack.blogspot.com/search?q=astro

keywords: astro, blackhole, tidal disruption, survival, surviving

# ecol: when a predator could help his prey to adapt to an uncertain future (among the fly Iteomyia salicisverruca) ...

<< The loss of biodiversity is rewiring the web of life; however, it is uncertain how this will affect the ability of remaining populations to evolve and adapt to future environments. >>

AA << conducted a field experiment that either maintained a natural community of predators or removed all but one of the predators that was able to impose selection on a common prey. (They) found that the loss of predators acted to constrain prey evolution toward a particular combination of traits. Moreover, (they) found that the loss of predators could make it more difficult for prey to adapt to uncertain future environments. Taken together, (these) results suggest that the simplification of the web of life may constrain the adaptive potential of remaining populations. >>

Matthew A. Barbour, Christopher J. Greyson‐Gaito, et al. Loss of consumers constrains phenotypic evolution in the resulting food web. Evolution Letters. doi: 10.1002/ evl3.170. Apr 20, 2020. 

https://onlinelibrary.wiley.com/doi/full/10.1002/evl3.170

<< Thinking about the big picture, our study hints at a potential insidious side effect of extinctions, (..) The extinction of natural enemies may compromise the ability of remaining species to adapt and persist in an uncertain and changing world. If this is true, this would put many ecosystems at even greater risk than we currently realize. >> Matthew A. Barbour.

Predators help prey adapt to an uncertain future. University of Zurich. 

 May 4, 2020

https://phys.org/news/2020-05-predators-prey-uncertain-future.html