Along Antarctica’s west coast near the Amundsen Sea, great white glaciers the size of U.S. states slowly slide into the ocean. In the early ’80s, scientists dubbed it the continent’s “weak underbelly” after learning that ice here — which helps hold back the entire West Antarctic Ice Sheet — is anchored below sea level.
If oceans warmed, this unfortunate topography could cause rapid and irreversible retreat. In decades past, glaciologists had assumed thes ...read more
In the year 1006, our ancestors witnessed the biggest natural light show in recorded history. A new “guest star,” as Chinese astronomers called it, appeared one night without warning. It was brighter than a crescent moon and visible in daytime. As months passed, the star dimmed until it was no longer visible over a year later.
Today, we know the guest star of 1006 was a supernova. The most violent explosions known, supernovas can briefly outshine the rest of a galaxy. The most common ...read more
The bomb arrived in pieces. Workers assembled the device behind steel-reinforced concrete walls in the desert, mating radioactive materials with high explosives. It was called Kearsarge.
And on a hot August day in 1988, a crew lowered the bomb through a hole drilled thousands of feet into the Nevada Test Site, then entombed it beneath millions of pounds of sand.
Thirty miles away, Los Alamos Director Siegfried Hecker sat nervously in the control room. Seven top Soviet nuclear scientists watched ...read more
10. When the researchers aimed a laser at the graphene sponge, it moved. In subsequent experiments, they found they could propel, rotate and even levitate the sponge using light.
11. In a 2015 Nature Photonics study, the researchers explained that sunlight or a moderate laser beam caused the graphene sponge to throw off a trail of excited electrons that pushed the material, which may prove ideal for light-powered sails that could one day propel spaceships. Talk about exciting ...read more
When it comes to species, says biological anthropologist Rebecca Ackermann, “forget everything you learned in high school.”
The classic textbook definition, known as the biological species concept, is a group of organisms that only produce fertile offspring with one another. By this rule, domesticated dogs are a single species — whether dachshund or Great Dane — but a donkey and a horse are not.
Ackermann, a professor at South Africa’s University of Cape Town, favor ...read more
Author Vishay SinghPosted on Categories Discover Magazine