The Sciences

More than 40 of the birds, in coalitions of three or four, may fight for days over oak trees in which to store their acorns.

Jigsaw-puzzle-shaped seams that hold a notoriously tough insect’s wing cases together could inspire engineers

A high mountain in China turns into a safe haven for the declining insects

The volatile compounds released by microbial communities on cheese rinds shape and shift a cheese’s microbiome. Christopher Intagliata reports. 

Creating a sustainable human presence beyond low-Earth orbit requires a clear-eyed view of the risks—and rewards—inherent in spaceflight

The mass-extinction asteroid happened to strike an area where the rock contained a lot of organic matter and sent soot into the stratosphere, where it could block sunlight for years.

The spacecraft attempted to collect samples from the asteroid for eventual return to Earth

Biologists who study acorn woodpeckers’ power struggles are not the only ones watching—so are rival woodpecker groups

Life’s up and downs may seem as inevitable as gravity, but somehow 2020 feels worse than usual. Just as a thought experiment, what if this year actually did get so weird that it even ushered in a change in how gravity affects our material universe?

In the video Did the Universe Have to Be the Way That It Is? we examine what our universe—and more specifically, our lives—might look like with some tweaks to the physics responsible for the world as we know it.

If gravity were just a little stronger in our own three-dimensional world, the curvature of spacetime would be greater, and matter could more easily collapse in on itself. This arrangement would make stars, galaxies and planets extremely diminutive, compared with the ones in our reality. Not only would we have less space on Earth, but our sun would deplete its nuclear fuel much more rapidly—meaning that evolution, and life itself, would be greatly curtailed.

If gravity were weaker, Earth would be gigantic, and it might be oddly shaped like some asteroids—or a potato. And rather than walking on the surface of our planet, we might find ourselves, say, jumping to grab a rebound in a basketball game, only to accidentally end up in the upper atmosphere or orbiting the globe as a tiny human space station.

What if we weren’t three-dimensional at all? (Imagine people as paper cutouts.) If we lived in two dimensions, gravity would act very differently. Although we would still have the spacetime curvature noted in Einstein’s general theory of relativity, such curvature would no longer produce gravitational forces. For this sort of flattened universe, we could instead have “scalar gravity,” in which Newton’s description of gravity would have been the final word, and black holes would be relegated to science fiction.

Thankfully, even though 2020 seems topsy-turvy, we still have gravity to keep us grounded.

Planners returned water to the dry bed of Arizona’s Santa Cruz River in 2019, and various species began showing up on the same day.

The upcoming debate between Joe Biden and Donald Trump may be one of the least consequential in decades, experts say

Any extraterrestrial organisms we find will be made of the same atoms we are—yet their existence will be profoundly important to us nonetheless