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Posts Tagged ‘Science

“To be overly concerned with the original materials, which are merely sentimental souvenirs of the past, is to fail to see the living building itself”*…

The human body replaces its own cells regularly. Scientists at the Weizmann Institute of Science in Rehovot, Israel, have finally pinned down the speed and extent of this “turnover.” About a third of our body mass is fluid outside of our cells, such as plasma, plus solids, such as the calcium scaffolding of bones. The remaining two thirds is made up of roughly 30 trillion human cells. About 72 percent of those, by mass, are fat and muscle, which last an average of 12 to 50 years, respectively. But we have far more, tiny cells in our blood, which live only three to 120 days, and lining our gut, which typically live less than a week. Those two groups therefore make up the giant majority of the turnover. About 330 billion cells are replaced daily, equivalent to about 1 percent of all our cells. In 80 to 100 days, 30 trillion will have replenished—the equivalent of a new you…

Our Bodies Replace Billions of Cells Every Day: “A New You in 80 Days.”

* Douglas Adams, Last Chance to See

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As we sail on the Ship of Theseus, we might spare a thought for Hans Ernst August Buchner; he died on this date in 1902. A bacteriologist, he was a pioneer in the field of immunology, the first to discover a substance in blood, gamma globulins, natural bactericides capable of destroying bacteria.  He also worked with his brother Eduard Buchner, a chemist who won the Nobel Prize in 1907 for his work on fermentation (which helped pave the way for our understanding of the work of enzymes); Ernst had died in 1902, and so did not share in the honor.

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“In the landscape of extinction, precision is next to godliness”*…

There is a portion of the sky where no spacefarer wants to go. It causes Astronauts to see shooting stars in front of their eyes, sets off emergency sensors and renders satellites useless. This Bermuda Triangle of space isn’t just a cause for concern for our future of space exploration, it could be the sign of something far more deadly. This may herald an event that last happened 42,000 years ago, which wiped out our closest relative, the Neanderthals. Welcome to the terrifying world of the South Atlantic Anomaly.

In the 80s engineers noticed that most satellite errors happened over South America and the South Atlantic. These errors ranged from minor glitches, wiped data to full-blown crashed satellites. But they couldn’t quite pinpoint what was causing these troubling errors, they named this mysterious area the South Atlantic Anomaly (SAA).

We didn’t understand the dangers of this region for a long time. When the Hubble Space Telescope first turned on in 1990 they found that the computers kept crashing and data was corrupted almost every time it flew over the South Atlantic. Not wanting their billion-dollar telescope to crash to Earth, the engineers had no choice but to switch it off every time it passed over this deadly patch of sky, and still do today. Not ideal, but it saves the telescope from this mysteriously dangerous part of space.

So what makes the South Atlantic Anomaly so dangerous? It turns out it is all down to the Sun and a crack in Earths armour caused some very bizarre geophysics.

So what does struggling satellites means for us here on Earth? Well, quite a lot really. It could be a sign of something much more deadly, a geomagnetic reversal.

When we picture the Earth’s magnetic field we often think of it as unchanging. It is our eternal armour from deadly solar radiation as well as the guide for our sailors. Even some birds have evolved iron-rich cells in their eyes, enabling them to ‘see’ the magnetic field and navigate the globe. But the magnetic north pole hasn’t always been in the north.

The magnetic poles have flipped repeatedly over the millennia. The field weakens, disappears and then reappears in the opposite direction. We know this because iron-rich lava aligns to the magnetic field and then sets, so we can look at ancient rocks and see what direction magnetic north was when it formed.

We don’t have a complete understanding of how the magnetic field is generated and why it flips. We know that convection currents of iron-rich mantle create the field, but the interactions between these immense systems are complex and hidden from us. What’s more, there are no patterns to the past flipping events, so it is very hard to predict when one will happen.

But, models and simulations show that when the field gets weaker at the beginning of a magnetic flip, it seems to happen in a random area and then grows from there. The poles also start to drift quite dramatically and chaotically. This is worrying because not only does the South Atlantic Anomaly look like the weakening in a simulation, it is also growing, and the North pole is drifting further each year.

… So, it seems at least plausible that the South Atlantic Anomaly is the start of the next geomagnetic flip. If so, it could have enormous consequences for us!

The last time a flip happened was 42,000 years ago, but it was only a temporary event, and the poles returned to their previous locations, this is known as the Laschamps Excursion, and it lasted for about a thousand years. That meant Earth was without its essential protective shield for an awfully long time.

Now, 42,000 years ago is a significant time. This was when Neanderthals died out. We (Homo Sapiens) also started using caves, red ochre body paint, and the global craze of cave painting started. It was also when a lot of ice-age megafauna died out. All of which has been linked to the flipping of the poles during this period. This extinction event and Sapien revolution has been called the Adams Event (after Douglas Adams and the infamous 42).  

This theory suggests that when the poles flipped, the Earth had a thousand years without its protective layer, so the planet was bombarded with radiation. This depleted ozone, increased radiation on the surface, messed with weather patterns and caused abrupt climate change.

Scientist even suggests that this is why we suddenly took to living in caves and using red ochre. We had to hide from the deadly rays of the Sun, and if we ventured out, we needed a powerful suncream, like powdered red ochre. This is why red ochre hand paintings became so widespread around this time.

But these immense changes hit one species particularly hard. Neanderthals were likely red-headed, light-skinned and mostly dwelt in steppes (grassy plains) and woodlands. They probably got sunburnt a lot. Unlike Homo Sapiens, it seems as though Neanderthals didn’t use red ochre much at all! All of this means that cancers would have been a deadly problem for them.

To make all this even worse, the radiation increased the strength of electrical storms, changed the weather patterns and screwed up many ecosystems. So the food that the Neanderthals hunted my have been driven away or gone extinct. It seems Neanderthals died out because they starved to death while being baked by the Sun. Meanwhile, we Homo Sapiens hid from the Sun, used weird sunscreen and adapted to new foods…

These flipping events take hundreds or thousands of years to pass due to the amount of heavy magma that needs to shift to cause a flip (however it is hypothesised it could take as little as a month in extreme circumstances). So we aren’t in any danger of waking up to a new direction for North. But, over the next few decades or hundreds of years, we will see the South Atlantic Anomaly grow and potentially be joined by many other areas of weak magnetism. We may even see some local flips in a few hundred years.

So, it seems at least plausible that the South Atlantic Anomaly is the start of the next geomagnetic flip. If so, it could have enormous consequences for us!

The South Atlantic Anomaly: Earth’s deadly weakness: “Do Failing Satellites Foretell An Imminent Extinction?” From Will Lockett (@welockett).

* Samuel Beckett

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As we search for true north, we might send charged birthday greetings to a man whose life work could be at risk if there’s a flip (or an intense solar storm), Elihu Thomson; he was born on this date in 1853. An engineer and inventor, he was instrumental in developing the practical applications of electricity, especially alternating current. He invented electric welding and other important advances in electric lighting and power (among his lifetime total of about 700 patents). Thomson was also a cofounder of the General Electric Company (in 1892, in a merger of his Thomson-Houston Electric Company with the Edison Company.

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“He was a killer, a thing that preyed, living on the things that lived, unaided, alone, by virtue of his own strength and prowess, surviving triumphantly in a hostile environment where only the strong survive”*…

One notes that there are only three states with unique predators: two with apex predators– Alaska (the polar bear); Florida (the crocodile)– and Hawaii (the domestic cat). A ‘o ia!

The largest land predators in each state. (TotH to @simongerman600)

* Jack London, The Call of the Wild

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As we watch our backs, we might spare a thought for Alexander Emmanuel Rodolphe Agassiz; he died on this date in 1910. Following in his father‘s footsteps, he made important contributions to systematic zoology, serving as curator of Harvard’s Museum of Comparative Zoology (1873-85), which was founded by his father.

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Written by LW

March 27, 2021 at 1:01 am

“Do you think that the soul first shows itself by a gnashing of teeth?”*…

In January 2020, as a new plague began to upend life on Earth, a small research team from Tufts, the University of Vermont, and Harvard announced that they, too, had turned life on Earth upside-down. Their discovery wasn’t quite so dramatic at first glance. Any regular person peering through a microscope at their creation would see little more than a few globs of dirty pond water in a petri dish. But those globs were alive; in fact, they were alive in a way that nothing has ever been alive before, in an uncharted space between biology and technology. They called them Xenobots, the world’s first living robot—the world’s first programmable organism.

Xenobot: Xeno as in Xenopus laevis, a voracious frog native to the wetlands of Sub-Saharan Africa; bot, of course, as in robot. It’s an unconventional name for an unconventional organism, so novel that even its makers struggle to conceptualize it. “The terminology that has served us well for many years is just not any good anymore,” concedes Michael Levin, the team’s iconoclastic biologist. His collaborator Josh Bongard, a computer scientist and robotics expert, has called Xenobots “novel living machines.” Sam Kriegman—the team’s postdoc—prefers the term “Computer Designed Organism,” although he’s been trying on “living deepfake” for size recently.

And they’re all right, in a way. Xenobots are deepfakes in the sense that they aren’t what they seem. They’re robots in the sense that they’re autonomous, programmable agents. They’re Computer Designed in the sense that their morphology—the form their tiny bodies take—was designed by an evolutionary computer algorithm in Bongard’s UVM lab. They’re living in the sense that they’re made of embryonic frog cells, and they’re machines in the sense that humans are machines: biological mechanisms made up of constituent parts.

Xenobots are the first living creatures whose immediate evolution occurred inside a computer and not in the biosphere. The result is a simple organism. Xenobots have no brains; the shape of their bodies is what determines how they behave. And yet, Levin and Bongard do not fully understand why Xenobots behave the way they do. “What you’re seeing de novois a completely novel creature with new proto-cognitive capacities, preferences, capabilities, IQ,” Levin explains. “All of those things appear out of nowhere.” Sometimes a Xenobot will head in one direction and then abruptly double back, as though changing its mind. What force guides such behaviors? Can a frog’s cells, in some way, think? Xenobots seem to have “nano free-will,” Levin jokes.

And this is where the can of worms—or tadpoles, maybe—pops open…

The word “robot” recently celebrated its centennial. It comes from the Czech playwright Karel Čapek’s 1920 play “Rossum’s Universal Robots,” about a worker uprising in a robot factory. Čapek’s robots are biological, the result of a vaguely alchemical process involving “albumen” with a “raging thirst for life.” Our conception of a robot as being something metallic, with clanging gears and servo-motors, is more recent baggage, a consequence of the science-fiction stories and films of the mid-twentieth century. In order to understand what Xenobots might mean for our future, we’ll have to divest ourselves from the idea that a robot—or any kind of autonomous being—can be wholly defined by its materiality…

As Norbert Weiner, the father of cybernetics, observed: “Let us remember that the automatic machine is the precise economic equivalent of slave labor. Any labor which competes with slave labor must accept the economic consequences of slave labor.”

Claire Evans (@TheUniverse) explains how “Xenobots may change how we think about intelligence.”

For apposite background, see also “The Link Between Bioelectricity and Consciousness.”

Karel Čapek, R.U.R. (Rossumovi Univerzální Roboti, or in English, Rossum’s Universal Robots)

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As we ponder life itself, we might recall (with, perhaps, a touch of nostalgia) that it was on this date in 1959 that Texas Instruments (TI) demonstrated the first working integrated circuit (IC), which had been invented by Jack Kilby. Kilby created the device to prove that resistors and capacitors could exist on the same piece of semiconductor material. His circuit consisted of a sliver of germanium with five components linked by wires. It was Fairchild’s Robert Noyce, however, who filed for a patent within months of Kilby and who made the IC a commercially-viable technology. Both men are credited as co-inventors of the IC. (Kilby won the Nobel Prize for his work in 2000; Noyce, who died in 1990, did not share.)

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Written by LW

March 24, 2021 at 1:01 am

“People seemed to believe that technology had stripped hurricanes of their power to kill. No hurricane expert endorsed this view.”*…

Tropical Storm Bertha approaching the South Carolina coast, May 27, 2020

For six straight years, Atlantic storms have been named in May, before [hurricane] season even begins. During the past nine Atlantic hurricane seasons, seven tropical storms have formed between May 15 and the official June 1 start date. Those have killed at least 20 people, causing about $200 million in damage, according to the WMO.

Last year, the hurricane center issued 36 “special” tropical weather outlooks before June 1, according to center spokesman Dennis Feltgen. Tropical Storms Arthur and Bertha both formed before June 1 near the Carolinas.

torms seem to be forming earlier because climate change is making the ocean warmer, University of Miami hurricane researcher Brian McNoldy said. Storms need warm water as fuel — at least 79 degrees (26 degrees Celsius). Also, better technology and monitoring are identifying and naming weaker storms that may not have been spotted in years past, Feltgen said…

With named storms coming earlier and more often in warmer waters, the Atlantic hurricane season is going through some changes with meteorologists ditching the Greek alphabet during busy years…

A special World Meteorological Organization committee Wednesday ended the use of Greek letters when the Atlantic runs out of the 21 names for the year, saying the practice was confusing and put too much focus on the Greek letter and not on the dangerous storm it represented. Also, in 2020 with Zeta, Eta and Theta, they sounded so similar it caused problems.

The Greek alphabet had only been used twice in 2005 and nine times last year in a record-shattering hurricane season. 

Starting this year, if there are more than 21 Atlantic storms, the next storms will come from a new supplemental list headed by Adria, Braylen, Caridad and Deshawn and ending with Will. There’s a new back-up list for the Eastern Pacific that runs from Aidan and Bruna to Zoe.

Meanwhile, the National Oceanic Atmospheric Administration is recalculating just what constitutes an average hurricane season… But the Atlantic hurricane season will start this year on June 1 as traditionally scheduled, despite meteorologists discussing the idea of moving it to May 15…

With so much activity, MIT’s [Kerry] Emanuel said the current warnings are too storm-centric, and he wants them more oriented to where people live, warning of specific risks such as floods and wind. That includes changing or ditching the nearly 50-year-old Saffir Simpson scale of rating hurricanes Category 1 to 5. 

That wind-based scale is “about a storm, it’s not about you. I want to make it about you, where you are,” he said. “It is about risk. In the end, we are trying to save lives and property”… Differentiating between tropical storms, hurricanes and extratropical cyclones can be a messaging problem when a system actually has a cold core, because these weaker storms can kill with water surges rather than wind… For example, some people and officials underestimated 2012’s Sandy because it wasn’t a hurricane and lost its tropical characteristic… 

Rethinking hurricanes in a time of climate change: “Bye Alpha, Eta: Greek alphabet ditched for hurricane names.”

* Erik Larson, Isaac’s Storm: A Man, a Time, and the Deadliest Hurricane in History

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As we accommodate climate change, we might spare a thought for George Alfred Leon Sarton; he died on this date in 1956. A chemist by training, his primary interest lay in the past practices and precepts of his field…an interest that led him to found the discipline of the history of science as an independent field of study. His most influential work was the Introduction to the History of Science (three volumes totaling 4,296 pages). Sarton ultimately aimed to achieve an integrated philosophy of science that connected the sciences and the humanities– what he called “the new humanism.” His name is honored with the prestigious George Sarton Medal, awarded by the History of Science Society.

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