Ancient Footprints

Footprints found at White Sands National Park in New Mexico. (National Park Service)



Dozens of awe-inspiring ancient footprints left on the shores of an ice age lake have reignited a long-running debate about when the first people arrived in the Americas.


Two years ago, a team of scientists came to the conclusion that human tracks sunk into the mud in White Sands National Park in New Mexico were more than 21,000 years old. The provocative finding threatened the dominant thinking on when and how people migrated into the Americas. 

Soon afterward, a technical debate erupted about the method used to estimate the age of the tracks, which relied on an analysis of plant seeds embedded with the footprints.


Now, a study published in the journal Science confirms the initial finding with two new lines of evidence: thousands of grains of pollen and an analysis of quartz crystals in the sediments.


“It’s more or less a master class in how you do this,” said Edward Jolie, an anthropological archaeologist at the University of Arizona who has studied the White Sands footprints in the field but was not involved in the new study. “As Carl Sagan said, ‘Extraordinary claims require extraordinary evidence.’ They have some extraordinary evidence.”


Lorena Becerra-Valdivia, a fellow at the Oxford Radiocarbon Accelerator Unit, said that the results support her modeling work, which suggested that people first crossed into present-day North America before 29,000 years ago, possibly traveling via the ocean.


“If anything, early findings like the White Sands footprints should inspire further scientific investigation in what is a dynamic and changing field,” Becerra-Valdivia said.


Some critics who raised concerns about the initial study said that they were encouraged by the follow-up analyses but remained unconvinced.  READ MORE...

The Giant Magellan Telescope

Artist’s concept of the completed Giant Magellan Telescope. The Giant Magellan Telescope is finalizing its last primary mirror, with the goal to surpass current space telescopes in sensitivity and resolution. Leveraging U.S. manufacturing, it promises unparalleled astronomical insights and aims for operation by the decade’s end. Credit: GMTO Corporation






Seven of the world’s largest mirrors will search the Universe for life beyond Earth

The Giant Magellan Telescope begins the four-year process to fabricate and polish its seventh and final primary mirror, the last required to complete the telescope’s 368 square meter (3,961 square foot) light collecting surface, the world’s largest and most challenging optics ever produced. 

Together, the mirrors will collect more light than any other telescope in existence, allowing humanity to unlock the secrets of the Universe by providing detailed chemical analyses of celestial objects and their origin.

Last week, the University of Arizona Richard F. Caris Mirror Lab closed the lid on nearly 20 tons of the purest optical glass inside a one-of-a-kind oven housed beneath the stands of the Arizona Wildcats Football Stadium. 

The spinning oven will heat the glass to 1,165°C (2,129°F) so as it melts, it is forced outward to form the mirror’s curved paraboloid surface. Measuring 8.4 meters (26.7 feet) in diameter—about two stories tall when standing on edge—the mirror will cool over the next three months before moving into the polishing stage.  READ MORE...

Decrease Your Risk of Dementia

Research demonstrated that what older adults do when they are sitting influences their risk of dementia.

According to a recent study by the University of Southern California and University of Arizona researchers, those 60 and older who spend a lot of time watching TV or partaking in other passive, sedentary behaviors may be more likely to develop dementia.

Additionally, their research demonstrated that the risk is reduced for those who engage in activities while seated, such as reading or using a computer.

The study was published recently published in Proceedings of the National Academy of Sciences. It also revealed that even among those who engaged in physical activity, the connection between sedentary behavior and the risk of dementia persisted.

“It isn’t the time spent sitting, per se, but the type of sedentary activity performed during leisure time that impacts dementia risk,” said study author David Raichlen, professor of biological sciences and anthropology at the University of Southern California Dornsife College of Letters, Arts and Sciences.

“We know from past studies that watching TV involves low levels of muscle activity and energy use compared with using a computer or reading,” he said. “And while research has shown that uninterrupted sitting for long periods is linked with reduced blood flow in the brain, the relatively greater intellectual stimulation that occurs during computer use may counteract the negative effects of sitting.”   READ MORE...