The north magnetic pole has wandered as much since 2000 as it did through the whole of the 20th century, and it seems to be racing ever more quickly. What does this mean, other than screwing up the adjustments for anyone still using a compass to navigate in this GPS age? Potentially, quite a lot.
Occasionally, the Earth’s magnetic poles swap ends, trading north for south and south for north (in a magnetic sense, it’s not an actual planetary flip). It’s rare, but not too rare — it’s happened 180 reversals over the last 80 million years. The last time this happened was around 41,000 years ago when the pole flipped, then abruptly flipped back again after a couple of centuries of a weak and fluttering field. That’s a big concern. Not so much because of what it would to have a flip, it’s that “indecisive” field around the time of the flip. The Earth’s magnetic field does the lion’s share of work in protecting the planet from high energy particles that come sleeting in from space. If not intercepted, those particles would be very bad for our electronics, and for every living thing that is exposed to them — including us. A weak field would be … bad.
Does the wandering magnetic pole indicate a flip? Probably not. Almost definitely not. However, there is some evidence that previous flips have been preceded by shifts in the location of the poles. That’s probably not what’s happening here. This is likely to be something more like a “front” coming through in the “weather” of the systems that drive the magnetic field inside the Earth’s core. But truthfully, we don’t understand those systems well enough to know.
The partial U.S. government shutdown, now in its third week, is creating chaos for tens of thousands of U.S. scientists. The shutdown, which began on 22 December 2018, began after Congress refused to give President Donald Trump the $5.7 billion he wants for a wall along the U.S.-Mexico border. The impasse has all but halted work at more than a half-dozen agencies that fund or conduct research, including NASA, the National Science Foundation, the U.S. Department of Agriculture, the National Oceanic and Atmospheric Administration, and parts of the Smithsonian Institution. Many of the scientists at those shuttered agencies have been furloughed without pay, barred from working at home, and prohibited from checking their government email. A travel ban has hurt attendance at several major conferences and caused organizers to cancel other events. The shutdown is also creating chaos for university researchers, private contractors, and others who collaborate with idled federal scientists, or depend on affected agencies for funding, facilities, and data.
That’s a cost that’s not included in the more than $1B a week that’s being lost to the shutdown directly. It’s a hidden cost, but one that will compound, and have a major impact, over time. In an era where the United States is fighting to get and keep STEM resources, Trump’s tantrum might as well be a recruiting poster for every other nation doing research.
Discover Magazine: We could determine if we’re in a simulation … if we really want to know.
Once it becomes possible to build a computer in which a simulated reality can exist, there is no reason that the same technology can’t be used to create a near infinite number of such realities. So, in any universe where any civilization has reached the technological level to create a simulated reality, the number of simulated realities should outnumber the number of “real” realities by factor of … a bunch. So are we living in some other civilization’s iPad 20? There may be ways to tell.
In the 1999 sci-fi film classic The Matrix, the protagonist, Neo, is stunned to see people defying the laws of physics, running up walls and vanishing suddenly. These superhuman violations of the rules of the universe are possible because, unbeknownst to him, Neo’s consciousness is embedded in the Matrix, a virtual-reality simulation created by sentient machines.
The action really begins when Neo is given a fateful choice: Take the blue pill and return to his oblivious, virtual existence, or take the red pill to learn the truth about the Matrix and find out “how deep the rabbit hole goes.”
Physicists can now offer us the same choice, the ability to test whether we live in our own virtual Matrix, by studying radiation from space. …
So should we say yes to the offer to take the red pill and learn the truth — or are the implications too disturbing?
If you’re interested in the philosophy, implications, and testibility of this theory, read this article. Personally, I’m betting this is why quantum and the Standard Model contain so many bits that just seem … messy. Resolution issues in the simulation.
Science: Ocean temperatures show that global warming is far more advanced than most realize.
Lijing Cheng, John Abraham, Zeke Hausfather, Kevin E. Trenberth4
Climate change from human activities mainly results from the energy imbalance in Earth’s climate system caused by rising concentrations of heat-trapping gases. About 93% of the energy imbalance accumulates in the ocean as increased ocean heat content (OHC). The ocean record of this imbalance is much less affected by internal variability and is thus better suited for detecting and attributing human influences than more commonly used surface temperature records. Recent observation-based estimates show rapid warming of Earth’s oceans over the past few decades. This warming has contributed to increases in rainfall intensity, rising sea levels, the destruction of coral reefs, declining ocean oxygen levels, and declines in ice sheets; glaciers; and ice caps in the polar regions. Recent estimates of observed warming resemble those seen in models, indicating that models reliably project changes in OHC.
Temperature models based entirely, or almost entirely, on land-air temperatures, have seriously overlooked the amount of heat going into, and being stored by, the oceans. But models that have taken this into account turn out to be quite accurate. In fact, observations of ocean heat are at “90 percent confidence levels” in predictions running out to 2100. One of the knocks that professional skeptics use against climate science is that predictions made from models don’t match results — but that is simply not true of more recent models using a larger data set.
Smithsonian: A fleck of pigment could rewrite the history of a medieval town.
In 2011, a team of scientists decided to study the teeth of a medieval woman who had been buried in Germany sometime between 1000 and 1200 A.D. The researchers were interested in taking a closer look at the woman’s dental calculus—plaque that hardens on the teeth during a person’s lifetime—in the hopes of learning more about her diet. But when they examined the calculus under a microscope, they discovered something entirely surprising: as the plaque dissolved, it released hundreds of tiny blue particles.
In a new study published in Science Advances, the researchers reveal that they have identified the blue pigments as lapis lazuli, a brilliant blue rock that, in the medieval era, was used to color illuminated manuscripts. And the team has a theory about how fragments of this precious stone ended up in the woman’s mouth: She was, they suggest, a highly skilled painter tasked with illustrating luxurious texts, who repeatedly licked the tip of brushes that were saturated with lapis lazuli pigments.
It’s known that monks who worked in monasteries illuminating manuscripts sometimes had similar evidence of working with pigments and dyes. But researchers describe finding evidence that a woman was trusted to work with a pigment so rare and expense as lapis lazuli, as a “bombshell” that could upend their understanding of women’s roles in this European community.
Nature: Machine learning bumps up against an ‘unsolvable problem’
[Mathematicians] working on a machine-learning problem show that the question of ‘learnability’ — whether an algorithm can extract a pattern from limited data — is linked to a paradox known as the continuum hypothesis. Gödel showed that the statement cannot be proved either true or false using standard mathematical language.
Why have you been getting challenged to “click all the images containing bicycles” to prove you are human in the latest version of bot-busters? It’s related to this problem. For machine learning, “compression” — turning a potentially infinite set into a neat rule — can be difficult. In fact, may be genuinely impossible, at least in the mathematical sense.
Georg Cantor, the founder of set theory, demonstrated in the 1870s that not all infinite sets are created equal: in particular, the set of integer numbers is ‘smaller’ than the set of all real numbers, also known as the continuum. (The real numbers include the irrational numbers, as well as rationals and integers.) Cantor also suggested that there cannot be sets of intermediate size — that is, larger than the integers but smaller than the continuum. But he was not able to prove this continuum hypothesis, and nor were many mathematicians and logicians who followed him.
There’s a big infinity, and a small infinity. Cantor says all infinities have to be one or the other. But in 1940, Gödel showed that this statement can’t be proven. And while this may seem like an exceedingly esoteric discussion, it has big implications for set theory, which in turn has been implications for the mathematical foundations of at least a small infinity of other things. Probably a big infinity.
PNAS: Brazil doubles its cropland in less than two decades.
Viviana Zalles, et. al.
Brazil has become a global leader in the production of commodity row crops such as soybean, sugarcane, cotton, and corn. Here, we report an increase in Brazilian cropland extent from 26.0 Mha in 2000 to 46.1 Mha in 2014. The states of Maranhão, Tocantins, Piauí, Bahia (collectively MATOPIBA), Mato Grosso, Mato Grosso do Sul, and Pará all more than doubled in cropland extent. The states of Goiás, Minas Gerais, and São Paulo each experienced >50% increases. The vast majority of expansion, 79%, occurred on repurposed pasture lands, and 20% was from the conversion of natural vegetation. Area of converted Cerrado savannas was nearly 2.5 times that of Amazon forests, and accounted for more than half of new cropland in MATOPIBA.
The only good news out of this report is that the majority of new row crops in Brazil are being grown on land that had already been cleared for pasture. However, even 20 percent of cropland coming from slashing down forest regions is a huge concern when the area is measured in thousands of square miles and the savanna regions lost to cropland also represent the lose of an important, diverse, and vanishing ecosystem.
Two factors stand ready to make this situation far worse. Brazil’s new president, Jair Bolsonaro, ran on a platform of removing protection from natural areas, displacing remaining indigenous peoples, and opening vast new regions to agriculture. At the same time, Donald Trump’s trade war with China is making Brazil much more attractive overseas as a source of agricultural goods. That combination is likely to result in much greater planting of new cropland in the immediate future.