Explore the vast range of titles available.

Cosmic-ray muon radiography has been used to non-invasively visualize the voids in the Great Pyramid (Khufu’s Pyramid), revealing a large void situated above the Grand Gallery. Cosmic discovery at Giza The Great Pyramid of Giza holds many secrets. There is no consensus on how it was built and most of its internal structure, besides three chambers, is not known. Kunihiro Morishima and colleagues used cosmic-ray muons, which are weakly deflected and absorbed by stone, as a natural imaging probe to investigate the possibility of hidden chambers. They installed a muon detector—a nuclear emulsion film—in one of the chambers and collected data over several months. They observed a clear increase in the flux of muons for specific positions above the known chambers, which indicates the presence of a previously unknown void. The findings are supported by data from two other detection techniques. This is the first major inner structure found in the Great Pyramid since the 19th century. The Great Pyramid, or Khufu’s Pyramid, was built on the Giza plateau in Egypt during the fourth dynasty by the pharaoh Khufu (Cheops) 1 , who reigned from 2509 bc to 2483 bc . Despite being one of the oldest and largest monuments on Earth, there is no consensus about how it was built 2 , 3 . To understand its internal structure better, we imaged the pyramid using muons, which are by-products of cosmic rays that are only partially absorbed by stone 4 , 5 , 6 . The resulting cosmic-ray muon radiography allows us to visualize the known and any unknown voids in the pyramid in a non-invasive way. Here we report the discovery of a large void (with a cross-section similar to that of the Grand Gallery and a minimum length of 30 metres) situated above the Grand Gallery. This constitutes the first major inner structure found in the Great Pyramid since the nineteenth century 1 . The void, named ScanPyramids’ Big Void, was first observed with nuclear emulsion films 7 , 8 , 9 installed in the Queen’s chamber, then confirmed with scintillator hodoscopes 10 , 11 set up in the same chamber and finally re-confirmed with gas detectors 12 outside the pyramid. This large void has therefore been detected with high confidence by three different muon detection technologies and three independent analyses. These results constitute a breakthrough for the understanding of the internal structure of Khufu’s Pyramid. Although there is currently no information about the intended purpose of this void, these findings show how modern particle physics can shed new light on the world’s archaeological heritage.

Societal upheaval occurred across Eurasia in the sixth and seventh centuries. Tree-ring reconstructions suggest a period of pronounced cooling during this time associated with several volcanic eruptions. Climatic changes during the first half of the Common Era have been suggested to play a role in societal reorganizations in Europe 1 , 2 and Asia 3 , 4 . In particular, the sixth century coincides with rising and falling civilizations 1 , 2 , 3 , 4 , 5 , 6 , pandemics 7 , 8 , human migration and political turmoil 8 , 9 , 10 , 11 , 12 , 13 . Our understanding of the magnitude and spatial extent as well as the possible causes and concurrences of climate change during this period is, however, still limited. Here we use tree-ring chronologies from the Russian Altai and European Alps to reconstruct summer temperatures over the past two millennia. We find an unprecedented, long-lasting and spatially synchronized cooling following a cluster of large volcanic eruptions in 536, 540 and 547  AD (ref.  14 ), which was probably sustained by ocean and sea-ice feedbacks 15 , 16 , as well as a solar minimum 17 . We thus identify the interval from 536 to about 660  AD as the Late Antique Little Ice Age. Spanning most of the Northern Hemisphere, we suggest that this cold phase be considered as an additional environmental factor contributing to the establishment of the Justinian plague 7 , 8 , transformation of the eastern Roman Empire and collapse of the Sasanian Empire 1 , 2 , 5 , movements out of the Asian steppe and Arabian Peninsula 8 , 11 , 12 , spread of Slavic-speaking peoples 9 , 10 and political upheavals in China 13 .

All of statistics and much of science depends on probability — an astonishing achievement, considering no one’s really sure what it is. All of statistics and much of science depends on probability — an astonishing achievement, considering no one’s really sure what it is.

But some are now challenging the vote, saying there were ‘procedural irregularities’. But some are now challenging the vote, saying there were ‘procedural irregularities’. Credit: The Canadian Press/Alamy An aerial view of Crawford Lake in Milton, Ontario.

A large scholarship currently holds that before the onset of anthropogenic global warming, natural climatic changes long provoked subsistence crises and, occasionally, civilizational collapses among human societies. This scholarship, which we term the ‘history of climate and society’ (HCS), is pursued by researchers from a wide range of disciplines, including archaeologists, economists, geneticists, geographers, historians, linguists and palaeoclimatologists. We argue that, despite the wide interest in HCS, the field suffers from numerous biases, and often does not account for the local effects and spatiotemporal heterogeneity of past climate changes or the challenges of interpreting historical sources. Here we propose an interdisciplinary framework for uncovering climate–society interactions that emphasizes the mechanics by which climate change has influenced human history, and the uncertainties inherent in discerning that influence across different spatiotemporal scales. Although we acknowledge that climate change has sometimes had destructive effects on past societies, the application of our framework to numerous case studies uncovers five pathways by which populations survived—and often thrived—in the face of climatic pressures. This Review proposes an interdisciplinary framework for researching climate–society interactions that focuses on the mechanisms through which climate change has influenced societies, and the uncertainties of discerning this influence across different spatiotemporal scales.

Hundreds of scientists had worked on mRNA vaccines for decades before the coronavirus pandemic brought a breakthrough. Hundreds of scientists had worked on mRNA vaccines for decades before the coronavirus pandemic brought a breakthrough.

The biochemist introduced the first heel-prick tests for newborn babies in Spain, protecting infants from life-changing metabolic conditions. The biochemist introduced the first heel-prick tests for newborn babies in Spain, protecting infants from life-changing metabolic conditions.

The Nobel prizewinner worked tirelessly with wife Rosalynn Carter to eradicate Guinea-worm disease. The Nobel prizewinner worked tirelessly with wife Rosalynn Carter to eradicate Guinea-worm disease.