Saturday Quotes: Goldilocks’ First Black Hole; Metabolism of Toxoplasma gondii; Pumping at Muscle Speed

This week: Physicists conducted a biological study, engineers built a waste-recycling suit for astronauts (and worm riders), and astronomers identified the first known intermediate-mass black hole, and it’s right here in our own galactic backyard.

Pumping water

Observing that human muscle tissue is composed of 70% water, physicists at the University of Michigan created a theoretical model of the role of water in muscle contraction and reported that the speed of a fluid through a muscle fiber determines the speed of muscle contraction. But they also discovered a strange type of elasticity, which they call strange elasticity, consistent with the principle of “snakes on a plane.” This allows the muscle to generate energy through three-dimensional deformations, as observed by the perpendicular swelling of muscles when contracted lengthwise, often while posing in front of the mirror and referencing the price of admission to the gun show.

UM physicist Suraj Shankar says, “Our results suggest that even questions as fundamental as how fast a muscle can contract or how many ways a muscle can generate energy find new and unexpected answers when we take a more integrated and holistic view of muscle as a complex, hierarchically organized material rather than just a bag of molecules. Muscle is more than the sum of its parts.”

Spacewalk without rhythm

Ideally, astronauts would enjoy spacewalks as observers of the unfolding majesty of the universe without having to wear adult diapers, which is undignified and degrading. The unsanitary reality of life in space is that human biological needs supersede our evolution into free-floating, transdimensional star children, and astronauts wear diapers exclusively. Another drawback is that urination during spacewalks bypasses the recycling system on the International Space Station and represents waste in a resource-limited environment.

Researchers at Cornell University, inspired by the waste-recycling suits worn by the Fremen in the films “Dune Part One” and “Dune Two: The Squeakquel,” have developed a suit that could solve both of these problems for future astronauts. It incorporates an external vacuum catheter that directs urine to a combined forward and reverse osmosis unit and provides a continuous supply of drinking water. This is a simplified description of a much more technical piece of equipment, the details of which you can read here.

Parasitic Eve

Toxoplasma gondii is a parasite that causes an incurable and potentially behavior-altering disease called toxoplasmosis. It reproduces in felines and seeks to infect rodents to make them more receptive to cats. There is no vaccine for toxoplasmosis, in part because the biological mechanisms of infection are poorly understood. So a team at the University of Wisconsin-Madison conducted an optical imaging study to better understand it. They used a noninvasive technology called optical metabolic imaging to monitor metabolic activity within cells in real time.

They reported that during infection, host cells became more oxidized and the lifetime of NAD(P)H increased, which provides energy to the parasite during replication. They also discovered a dynamic in the interaction of T. gondii with the host cell surface, to which they applied the vaguely revolting name of “kiss and spit.”

“A cell can be infected while the cells around it are not,” says scientist Gina Gallego-Lopez. “It seems as if the parasite is ‘kissing’ these cells and then injecting proteins, kissing them and spitting them out,” she explains. “To our surprise, we were able to see changes similar to those of a full infection. So it seems that a simple ‘kiss’ from the parasite is enough to induce changes in the host cell.”

A new black hole has just appeared

Omega Centauri is a globular cluster located in the Milky Way galaxy, 17,090 light-years from the Sun and visible from the southern sky. This gravitationally bound collection of 10 million stars is the most massive globular cluster in our galaxy. Scientists believe it is the surviving core of another galaxy that was captured by the Milky Way and stripped of its outer star populations. For years, astronomers have speculated that if it is indeed the core of a galaxy, Omega Centauri could contain a central black hole.

Researchers at the Max Planck Institute for Astronomy confirmed this hypothesis by studying stellar trajectories within the cluster in detail. They compiled a massive catalog of the motions of Omega Centauri’s stars, calculating the velocities of 1.4 million stars from 500 Hubble images. They ultimately focused their attention on seven fast-moving stars in the central region, whose speeds and motions could only be explained by an invisible gravitational body.

Here’s the interesting part: This black hole represents a missing link between stellar-mass black holes and supermassive black holes—an intermediate-mass black hole, which has been predicted but never observed before. The reason it’s much smaller than the black holes normally found in the cores of galaxies is that Omega Centauri itself is frozen in time—with its stable population of central stars and the absence of a population of outer stars, the black hole can’t feed and increase its mass.

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