Month: June 2021

Enlarge (credit: Gimranov et al. 2021)

During the last Ice Age, more than 100 cave bears died in Imanay Cave, a 100-meter-long corridor of stone in Russia’s southern Ural Mountains. The dead bears, along with a cave lion and a few other Pleistocene mammals, left behind nearly 10,000 bones, which have mostly worn down to small fragments over the millennia. Most of them were so-called small cave bears, Ursus spelaeus eremus, notable for being smaller than the so-called large cave bear, Ursus spelaeus—and for their apparent habit of dying en masse while hibernating through the harsh Pleistocene winters, leaving behind huge assemblages of bones for modern paleontologists to find.

Most of the cave bear bones found in Eurasia, including the ones at Imanay Cave, show no signs of violence, butchering, or gnawing. They seem to have died quietly, perhaps of cold, starvation, or illness. But while cleaning one cave bear skull from Imanay, Dmitry Gimranov of the Ural Branch of the Russian Academy of Sciences and his colleagues noticed a rather suspicious hole in the parietal bone, near the back of the skull.

The hole in the parietal bone (left side of photo) matches the cross-section of stone projectile points also found in the cave. (credit: Gimranov et al. 2021)

The lower edge of the hole is a gentle curve with a flattened base, while the upper edge is more uneven and widens sharply in the middle. Its shape is strikingly similar to the cross-section of stone projectile points unearthed in the same layer of cave sediment as most of the bear bones. Those points tend to have a flat ventral (or lower) side and a more curved dorsal (or upper) side with a sharp rib of stone sticking up along the center. And they're about the same size as the hole in the bear skull.

In December 2019, astronomers noticed a strange, dramatic dimming in the light from Betelgeuse, a bright red star in the Orion constellation. They puzzled over the phenomenon and wondered whether it was a sign that the star was about to go supernova. Several months later, they had narrowed the most likely explanations to two: a short-lived cold patch on the star's southern surface (akin to a sun spot), or a clump of dust making the star seem dimmer to observers on Earth. We now have our answer, according to a new paper published in the journal Nature. Dust is the primary culprit, but it is linked to the brief emergence of a cold spot.

As Ars' John Timmer reported last year, Betelgeuse is one of the closest massive stars to Earth, about 700 light years away. It's an old star that has reached the stage where it glows a dull red and expands, with the hot core only having a tenuous gravitational grip on its outer layers. The star has something akin to a heartbeat, albeit an extremely slow and irregular one. Over time, the star cycles through periods when its surface expands and then contracts.

One of these cycles is fairly regular, taking a bit over five years to complete. Layered on that is a shorter, more irregular cycle that takes anywhere from under a year to 1.5 years to complete. While they're easy to track with ground-based telescopes, these shifts don't cause the sort of radical changes in the star's light that would account for the changes seen during the dimming event.

Enlarge / Lordstown Motors' factory in Lordstown, Ohio.

Lordstown Motors has been having a tough time recently. The Ohio-based electric truck startup was accused of misleading investors about the extent of its order books, leading to an investigation by the US Securities and Exchange Commission. This in turn led the company to issue a "going concern" warning, followed by the departure of its CEO and CFO.

But on Tuesday, a day after the executive resignations, the company stated that limited production of its Endurance work truck will begin later this year. Lordstown's president Rich Schmidt told journalists at a press event that there were enough "binding orders" to fund this limited production until May 2022, according to TechCrunch.

Schmidt said that Lordstown has more than $400 million in the bank, but it will need extra investment to produce more than 20,000 EVs or continue operations beyond next May. The company raised $675 million in October 2020 after merging with a special-purpose acquisition company.