So much has happened, thanks to so many, that National Geographic’s writers and editors decided not to whittle down the last decade into just a handful of discoveries. Instead, we’ve put our heads together to identify 20 trends and milestones that we found especially noteworthy, and that we think will set the stage for more amazing finds in the decade to come.
Detecting the first gravitational waves
In 1916, Albert Einstein proposed that when objects with enough mass accelerate, they can sometimes create waves that move through the fabric of space and time like ripples on a pond’s surface. Though Einstein later doubted their existence, these spacetime wrinkles—called gravitational waves—are a key prediction of relativity, and the search for them captivated researchers for decades. Though compelling hints of the waves first emerged in the 1970s, nobody directly detected them until 2015, when the U.S.-based observatory LIGO felt the aftershock of a distant collision between two black holes. The discovery, announced in 2016, opened up a new way to “hear” the cosmos.
In 2017, LIGO and the European observatory Virgo felt another set of tremors, this time made when two ultra-dense objects called neutron stars collided. Telescopes around the world saw the related explosion, making the event the first ever observed in both light and gravitational waves. The landmark data have given scientists an unprecedented look at how gravity works and how elements such as gold and silver form….[ ]