Fat bears, a new kilogram, and the stunning power of trees: our favorite science stories from 2018.
As science journalists, we cover a huge range of phenomena — from the minute to the outer reaches of the universe. But the best stories of 2018 all had one thing in common: They hit us in the gut with a sense of awe.
These stories taught us about the incredible scale and power of distant objects in the universe, like a special type of galaxy called a blazar. They showed the ingenuity and compassion of fellow humans, like vaccinators trying to stop a deadly Ebola outbreak amid a war in central Africa and divers navigating a flooded Thai cave for a daring rescue.
Here are some of our favorite stories from the past year that, very simply, made us say “whoa.” They fan our excitement of science and the natural world and give us a glimpse into the future. We hope they’ll do the same for you.
The kilogram was redefined in terms of the Planck constant
In November, scientists from around the world met at the General Conference on Weights and Measures in Versailles, France, and voted to change the definition of a kilogram, tying it to the Planck constant, a universal, foundational concept in quantum mechanics.
That sounds incredibly nerdy. And it is. But what made us go “whoa” was not exactly the science behind this change (which is enormously impressive) but the philosophical victory it represents.
Until the change goes into effect in May, the kilogram has a very simple definition: It’s the mass of a hunk of platinum-iridium alloy, called “Big K,” that’s been housed at the International Bureau of Weights and Measures in Sèvres, France, since 1889. That artifact is imperfect. It can get lost or stolen. There’s even evidence that it’s lost some mass over the years.
The kilogram is the world’s standard unit of mass, recognized universally, even in the United States. (The US’s pounds are technically defined in terms of kilograms.) By affixing the definition of it to a universal force of nature, we make it permanent — celestial even.
Scientists estimated the weight of all life on Earth
By weight, human beings are insignificant.
There are an estimated 550 gigatons of carbon of life in the world, according to a study published in May in PNAS. We humans make up less than 1 percent of that. (A gigaton is equal to 1 billion metric tons. A metric ton is 1,000 kilograms, or about 2,200 pounds.)
The “whoa” factor really kicks in when you see this data visualized. The graphic, by Vox’s Javier Zarracina, is a bit too large to post here, but you should check it out.