Science

A pigeon-inspired robot has solved the mystery of how birds fly without the vertical tail fins that human-designed aircraft rely on. Its makers say the prototype could eventually lead to passenger aircraft with less drag, reducing fuel consumption. Tail fins, also known as vertical stabilisers, allow aircraft to turn from side to side and help avoid changing direction unintentionally. Some military planes, such as the Northrop B-2 Spirit, are designed without a tail fin because it makes them less visible to radar. Instead, they use flaps that create extra drag on just one side when needed, but this is an inefficient solution. Birds have no vertical fin and also don’t seem to deliberately create asymmetric drag. David Lentink at the University of Gronin...

Billions, perhaps trillions, of years from now, long after the sun has engulfed Earth, cosmologists expect the universe will end. Some wrestle with whether it is more likely to collapse under its weight in a big crunch or keep on expanding forever into an infinitely empty big freeze. Others reckon our cosmic endgame will be decided by a mysterious kind of energy that shatters the universe in a big rip. But there is a more immediate cataclysm that may already be barrelling towards us at the speed of light: they call it the big slurp. The slurp in question starts with a quantum fluctuation that sets a bubble rolling across the universe like a cosmic tidal wave, obliterating everything in its path. We should take this possibility seriously, says John Ellis at King’s Coll...

Columbia’s Sabin Center for Climate Change Law focuses on four program areas: cross-cutting issues and initiatives, energy law, environmental and land use law, and international and foreign law. As the number of legal efforts involving each of these categories continues to grow, the center has positioned itself as a resource hub for tracking and analyzing global climate change litigation. In a lecture at the Columbia Climate School Research Seminar Series, Michael Burger, executive director of the Sabin Center, discussed the direction climate change cases have taken in the courtroom in recent years—and what these lawsuits may mean for current and future regulation, policy and response. Burger began his presentation with an overview of significant developments in climate litigation,...

Artificial intelligence is here, but we are still guessing what its future holds. Hollywood has been imagining the impact AI might have on our lives for decades, but how accurate are these portrayals? AI researcher Beth Singler is assistant professor in digital religion(s) at the University of Zurich, Switzerland, and a lifelong sci-fi fan. Thinking about “what you think about machines that might think”, she explores cultural depictions of technology, including AI, and how they might shape our fears and expectations. In this latest iteration of our sci-fi series, Singler dives into some of the best and worst examples of AI in film and TV. Take 1986’s Short Circuit: did it really get AI right? Surprisingly, yes, in some ways...

The shadow of a laser beam appears as a horizontal line against the blue backgroundAbrahao et al. (2024) Light normally makes other objects cast shadows – but with a little help from a ruby, a beam of laser light can cast a shadow of its own. When two laser beams interact, they don’t clash together like lightsabers in Star Wars, says Raphael Abrahao at Brookhaven National Laboratory in New York. In real life, they will simply pass through each other. Abrahao and his colleagues, however, found a way for one laser beam to block another – and make its shadow appear. The crucial ingredient was a ruby cube. The researchers hit this cube with a beam of green laser light while illuminating it with a blue laser from the side. As the green light passed through the ruby ato...