Hear this week’s science news, with Nick Howe and Shamini Bundell. This week, a new 3D printer allows quick shifting between many materials, and understanding the link between gut microbes and liver disease.
Most historical accounts of slavery were written by colonists and planters. Researchers are now using the tools of archaeology to learn more about the day-to-day lives of enslaved Africans—how they survived the conditions of slavery, how they participated in local economies, and how they maintained their own agency. Host Sarah Crespi talks with Contributing Correspondent Lizzie Wade about a Caribbean archaeology project based on St. Croix in the U.S. Virgin Islands and launched by the founders of the Society for Black Archaeologists that aims to unearth these details. Watch a related video here.
Sarah also talks with Jonathan Schulz, a professor in the Department of Economics at George Mason University in Fairfax, Virginia, about a role for the medieval Roman Catholic Church in so-called WEIRD psychology—western, educated, industrialized, rich, democratic. The bulk of psychology experiments have used participants that could be described as WEIRD, and according to many psychological measures, WEIRD subjects tend to have some extreme traits, like a stronger tendency toward individuality and more friendliness with strangers. Schulz and colleagues used historical maps and measures of kinship structure to tie these traits to strict marriage rules enforced by the medieval Catholic Church in Western Europe. Read related commentary.
There was a massive shift in Roman residents’ ancestry, the researchers found, but that ancestry came primarily from the Eastern Mediterranean and Near East, possibly because of denser populations there relative to the Roman Empire’s western reaches in Europe and Africa.
The next several centuries were full of turmoil: the empire split in two, diseases decimated Rome’s population and a series of invasions befell the city. Those events left a mark on the city’s population, which shifted toward western European ancestry. Later, the rise and reign of the Holy Roman Empire brought an influx of central and northern European ancestry.
Scholars have been studying Rome for hundreds of years, but it still holds some secrets—for instance, relatively little is known about the ancestral origins of the city’s denizens. Now, an international team led by researchers from Stanford University, the University of Vienna and Sapienza University of Rome is filling in the gaps with a genetic history that shows just how much the Eternal City’s populace mirrored its sometimes tumultuous history.
We conclude that Pollock avoided the appearance of the hydrodynamic instabilities, contrary to what was argued by previous studies. Pollock selected the physical properties of the paint to prevent filament fragmentation before deposition, and applied it while moving his hand sufficiently fast and at certain heights to avoid fluid filaments from coiling into themselves. An understanding of the physical conditions at which these patterns were created is important to further art research and it can be used as a tool in the authentication of paintings.
Considered one of the most prominent American painters of the 20th century, the life and work of Jackson Pollock have been the subject of books, movies, and documentaries [1–3]. His paintings can be broadly categorized as being abstract-expressionist. Although his painting style evolved during his sometimes tormented life, the so-called ‘dripping’ technique is certainly the most widely recognized both by experts and the general public.
Jackson Pollock described the technique himself . In summary, Pollock would lay a canvas horizontally and pour paint on top of it, in a controlled manner. To regulate the flow of paint, he either used an instrument (a stick, knife or a brush), poured it directly from a can and in some instances he also used a syringe. Viscous fluid filaments were produced and laid over the canvas while ‘rhythmically moving’ around it. It is believed that Pollock developed this technique strongly influenced by an experimental painting workshop, organized in New York by Mexican muralist David Alfaro Siqueiros in 1936 . Interestingly, Siqueiros himself also developed the ‘accidental painting’ technique during this workshop, which was recently analyzed by Zetina et al. .
Measles is a dangerous infection that can kill. As many as 100,000 people die from the disease each year. For those who survive infection, the virus leaves a lasting mark—it appears to wipe out the immune system’s memory. News Intern Eva Fredrick joins host Sarah Crespi to talk about a pair of studies that looked at how this happens in children’s immune systems.
In our second segment this week, Sarah talks with Todd Thompson, of Ohio State University in Columbus, about his effort to find a small black hole in a binary pair with a red giant star. Usually black holes are detected because they are accruing matter and as the matter interacts with the black hole, x-rays are released. Without this flashy signal, black hole detection gets much harder. Astronomers must look for the gravitational influence of the black holes on nearby stars—which is easier to spot when the black hole is massive. Thompson talks with Sarah about a new approach to finding small, noninteracting black holes.
Scientists believe they have located the ancestral home of one of humanity’s early ancestors—in northern Botswana. Tom Siebel, a Silicon Valley veteran and the founder of C3.ai, explains how digital transformation stops companies from going extinct. And, host Kenneth Cukier takes a trip to the Natural History Museum in London to learn about bias in species collection