At an archaeological site in northeastern Jordan, researchers have discovered the charred remains of a flatbread baked by hunter-gatherers 14,400 years ago. It is the oldest direct evidence of bread found to date, predating the advent of agriculture by at least 4,000 years. The findings suggest that bread production based on wild cereals may have encouraged hunter-gatherers to cultivate cereals and, thus, contributed to the agricultural revolution in the Neolithic period.
A team of researchers from the University of Copenhagen, University College London, and University of Cambridge has analyzed charred food remains from a 14,400-year-old Natufian hunter-gatherer site—a site known as Shubayqa 1 located in the Black Desert in northeastern Jordan. The results, which were published in July of 2018 in the journal Proceedings of the National Academy of Sciences, provide the earliest empirical evidence for the production of bread:
“The presence of hundreds of charred food remains in the fireplaces from Shubayqa 1 is an exceptional find, and it has given us the chance to characterize 14,000-year-old food practices. The 24 remains analyzed in this study show that wild ancestors of domesticated cereals such as barley, einkorn, and oat had been ground, sieved, and kneaded prior to cooking. The remains are very similar to unleavened flatbreads identified at several Neolithic and Roman sites in Europe and Turkey. So we now know that bread-like products were produced long before the development of farming. The next step is to evaluate if the production and consumption of bread influenced the emergence of plant cultivation and domestication at all,” said University of Copenhagen archaeobotanist Amaia Arranz Otaegui, who is the first author of the study.
University of Copenhagen archaeologist Tobias Richter, who led the excavations at Shubayqa 1 in Jordan, explained: “Natufian hunter-gatherers are of particular interest to us because they lived through a transitional period when people became more sedentary and their diet began to change. Flint sickle blades as well as ground stone tools found at Natufian sites in the Levant have long led archaeologists to suspect that people had begun to exploit plants in a different and perhaps more effective way. But the flat bread found at Shubayqa 1 is the earliest evidence of bread making recovered so far, and it shows that baking was invented before we had plant cultivation. So this evidence confirms some of our ideas. Indeed, it may be that the early and extremely time-consuming production of bread based on wild cereals may have been one of the key driving forces behind the later agricultural revolution where wild cereals were cultivated to provide more convenient sources of food.”
The charred food remains were analyzed with electronic microscopy at a University College London lab by Ph.D. candidate Lara Gonzalez Carratero (UCL Institute of Archaeology), who is an expert on prehistoric bread: “The identification of ‘bread’ or other cereal-based products in archaeology is not straightforward. There has been a tendency to simplify classification without really testing it against identification criteria. We have established a new set of criteria to identify flat bread, dough, and porridge like products in the archaeological record. Using Scanning Electron Microscopy we identified the microstructures and particles of each charred food remain,” said Gonzalez Carratero.
“Bread involves labor intensive processing that includes dehusking, grinding of cereals and kneading and baking. That it was produced before farming methods suggests it was seen as special, and the desire to make more of this special food probably contributed to the decision to begin to cultivate cereals. All of this relies on new methodological developments that allow us to identify the remains of bread from very small charred fragments using high magnification,” said Professor Dorian Fuller (UCL Institute of Archaeology).
Effects Come Before Causes in Quantum Computers
Watch a movie backwards and you’ll likely get confused—but a quantum computer wouldn’t. That’s the conclusion of researcher Mile Gu at the Center for Quantum Technologies (CQT) at the National University of Singapore and Nanyang Technological University and collaborators.
In research published in July 2018, in Physical Review X, the international team show that a quantum computer is less in thrall to the arrow of time than a classical computer. In some cases, it’s as if the quantum computer doesn’t need to distinguish between cause and effect at all.
The new work is inspired by an influential discovery made almost ten years ago by complexity scientists James Crutchfield and John Mahoney at the University of California, Davis. They showed that many statistical data sequences will have a built-in arrow of time. An observer who sees the data played from beginning to end, like the frames of a movie, can model what comes next using only a modest amount of memory about what occurred before. An observer who tries to model the system in reverse has a much harder task—potentially needing to track orders of magnitude more information.
This discovery came to be known as ‘causal asymmetry.’ It seems intuitive. After all, modeling a system when time is running backwards is like trying to infer a cause from an effect. We are used to finding that more difficult than predicting an effect from a cause. In everyday life, understanding what will happen next is easier if you know what just happened, and what happened before that.
However, researchers are always intrigued to discover asymmetries that are linked to time-ordering. This is because the fundamental laws of physics are ambivalent about whether time moves forwards or in reverse.
“When the physics does not impose any direction on time, where does causal asymmetry—the memory overhead needed to reverse cause and effect—come from?” asks Gu.
The first studies of causal asymmetry used models with classical physics to generate predictions. Crutchfield and Mahoney teamed up with Gu and collaborators Jayne Thompson, Andrew Garner, and Vlatko Vedral at CQT to find out whether quantum mechanics changes the situation.
They found that it did. The team proved that models using quantum physics can entirely mitigate the memory overhead. A quantum model forced to emulate the process in reverse-time will always outperform a classical model modeling the process in forward time.
The work has some profound implications. “The most exciting thing for us is the possible connection with the arrow of time,” says Thompson, first author on the work. “If causal asymmetry is only found in classical models, it suggests our perception of cause and effect, and thus time, can emerge from enforcing a classical explanation on events in a fundamentally quantum world,” she says.
Next the team wants to understand how this connects to other ideas of time. “Every community has their own arrow of time, and everybody wants to explain where they come from,” says Vedral. Crutchfield and Mahoney called causal asymmetry an example of time’s ‘barbed arrow.’
Most iconic is the ‘thermodynamic arrow.’ It comes from the idea that disorder, or entropy, will always increase—a little here and there, in everything that happens, until the Universe ends as one big, hot mess. While causal asymmetry is not the same as the thermodynamic arrow, they could be interrelated. Classical models that track more information also generate more disorder. “This hints that causal asymmetry can have entropic consequence,” says Thompson.
The results may also have practical value. Doing away with the classical overhead for reversing cause and effect could help quantum simulation. “Like being played a movie in reverse time, sometimes we may be required to make sense of things that are presented in an order that is intrinsically difficult to model. In such cases, quantum methods could prove vastly more efficient than their classical counterparts,” says Gu.
Center for Quantum Technologies at the National University of Singapore: https://www.quantumlah.org/about/highlight.php?id=308
CAPTION: Quantum computers can more easily model the reversal of cause and effect—like following a movie played backwards—than classical computers. (Credit: Aki Honda/Centre for Quantum Technologies, National University of Singapore.)
Mystery of the Basel Papyrus Said Solved
Since the sixteenth century, Basel, Switzerland, has been home to a mysterious papyrus. With mirror writing on both sides, it has puzzled generations of researchers. A research team from the University of Basel has now discovered that it is an unknown medical document from late antiquity. The famous Roman physician Galen likely wrote the text.
The Basel papyrus collection comprises 65 papers in five languages, which were purchased by the university in 1900 for the purpose of teaching classical studies—with the exception of two papyri. These arrived in Basel back in the sixteenth century, and likely formed part of Basilius Amerbach’s art collection.
One of these Amerbach papyri was regarded until now as unique in the world of papyrology. With mirror writing on both sides, it has puzzled generations of researchers. It was only through ultraviolet and infrared images produced by the Basel Digital Humanities Lab that it was possible to determine that this 2,000-year-old document was not a single papyrus at all but, rather, several layers of papyrus glued together. A specialist papyrus restorer was brought to Basel to separate the sheets, enabling the Greek document to be decoded for the first time.
“This is a sensational discovery,” says Sabine Huebner, Professor of Ancient History at the University of Basel. “The majority of papyri are documents such as letters, contracts, and receipts. This is a literary text, however, and they are vastly more valuable.”
What’s more, it contains a previously unknown text from antiquity. “We can now say that it’s a medical text from late antiquity that describes the phenomenon of ‘hysterical apnea,’ ” says Huebner. “We therefore assume that it is either a text from the Roman physician Galen, or an unknown commentary on his work.” After Hippocrates, Galen is regarded as the most important physician of antiquity.
The decisive evidence came from Italy—an expert saw parallels to the famous Ravenna papyri from the chancery of the Archdiocese of Ravenna. These include many antique manuscripts from Galen, which were later used as palimpsests and written over. The Basel papyrus could be a similar case of medieval recycling, as it consists of multiple sheets glued together and was probably used as a book-binding. The other Basel Amerbach papyrus, in Latin script, is also thought to have come from the Archdiocese of Ravenna. At the end of the fifteenth century, it was then stolen from the archive and traded by art collectors as a curiosity.
Huebner made the discovery in the course of an editing project funded by the Swiss National Science Foundation. For three years, she has been working with an interdisciplinary team in collaboration with the University of Basel’s Digital Humanities Lab to examine the papyrus collection, which in the meantime has been digitalized, transcribed, annotated, and translated. The project team had already presented the history of the papyrus collection through an exhibition in the University Library last year. They plan to publish all their findings at the start of 2019.
With the end of the editing project, the research on the Basel papyri will enter into a new phase. Huebner hopes to provide additional impetus to papyrus research, particularly through sharing the digitalized collection with international databases. As papyri frequently only survive in fragments or pieces, exchanges with other papyrus collections are essential. “The papyri are all part of a larger context. People mentioned in a Basel papyrus text may appear again in other papyri, housed for example in Strasbourg, London, Berlin, or other locations. It is digital opportunities that enable us to put these mosaic pieces together again to form a larger picture.”