HAS-BEEN For 130 years, this metal cylinder was the definition of a kilogram. Now, it's just another hunk of metal, as scientists have instituted a new definition based on a quantity known as the Planck constant.
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In the May 11 & 25 SN: High-tech cricket farming, AI learns from Minecraft, looking for lithium, a new hominid species is named, signs of life in dead pig brains, Cherokee cave texts decoded, water molecules on the moon and more.
CORE STRENGTH Researchers have decoded the genetic composition of important structures called centromeres (colored green in this illustration) in fruit flies’ chromosomes. Centromeres ensure that chromosomes are properly distributed to dividing cells.
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TIED UP Protons contain smaller particles called quarks and gluons (illustrated). Experimental data hint that quantum entanglement links those particles with one another.
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MISERY’S COMPANY Ravens, known for their problem-solving prowess, also act in ways that suggest empathy. New research hints that an ability to share emotions, at least negative ones, may play into their social behavior.
E Lin Photography/Shutterstock
Science News
Feature
Measles erases the immune system’s memory
The measles virus can usher in other infections for months, or even years.
Transparency Project
3 weeks ago
Feature
How the battle against measles varies around the world
Measles is a global health threat. Snapshots of several countries show how stopping its spread depends on local conditions and beliefs.
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Finding common ground can reduce parents’ hesitation about vaccines
Physicians are examining whether discussing shared health goals can bring vaccine-hesitant parents on board.
News in Brief
Signs of red pigment were spotted in a fossil for the first time
For the first time, scientists have identified the chemical fingerprint of red pigment in a fossil.
News
Bad moods could be contagious among ravens
Ravens may pick up and share their compatriots’ negativity, a study on the social intelligence of these animals suggests.
News
The kilogram just got a revamp. A unit of time might be next
After years of preparation, new definitions for the basic units of mass, temperature and more have now gone into effect.
News
This early sauropod went from walking on four legs to two as it grew
A new computer analysis shows how Mussaurus patagonicus’s weight shifted toward its hips as it grew, confirming fossil hints of how its gait changed.
News
How allergens in pollen help plants do more than make you sneeze
A plant’s view of what humans call allergens in pollen grains involves a lot of crucial biology. And sex.
News
Key parts of a fruit fly’s genetic makeup have finally been decoded
Jumping genes may make it possible to divvy up chromosomes.
News
An experiment hints at quantum entanglement inside protons
Particles inside protons seem to be linked on a scale smaller than a trillionth of a millimeter.
News
Vaccines may help bats fight white nose syndrome
Researchers are developing an oral vaccine that helps little brown bats survive the fungal disease white nose syndrome.
News
Does eating ultraprocessed food affect weight gain? It’s complicated
Laying off ultraprocessed foods and switching to whole foods may help some people manage their weight, a small study finds.
News in Brief
Some dog breeds may have trouble breathing because of a mutated gene
Norwich terriers don’t have flat snouts, but can suffer the same wheezing as bulldogs. It turns out that a gene mutation tied to swelling could be to blame.
News
Bloodthirsty bedbugs have feasted on prey for 100 million years
Research sheds light on the evolutionary history of the bloodsucking bedbugs. The first species evolved at least as early as the Cretaceous, scientists say.
News
Fossil teeth push the human-Neandertal split back to about 1 million years ago
A study of fossilized teeth shifts the age of the last common ancestor between Neandertals and humans.
News
China’s lunar rover may have found minerals from the moon’s mantle
The Chang’e-4 mission spotted material on the lunar surface that appears to contain bits originating from the moon’s interior.
Science Visualized
Peacock spiders’ superblack spots reflect just 0.5 percent of light
By manipulating light with tiny structures, patches on peacock spiders appear superblack, helping accentuate the arachnids’ bright colors.
News
Tweaking one gene with CRISPR switched the way a snail shell spirals
The first gene-edited snails confirm which gene is responsible for the direction of the shell’s spiral.
News
Apollo-era moonquakes reveal that the moon may be tectonically active
Moonquakes recorded decades ago suggest the moon is tectonically active. Knowing more about that activity could help scientists identify where to land future spacecraft.
News
A new AI acquired humanlike ‘number sense’ on its own
A new artificial intelligence seems to share our intuitive ability to estimate numbers at a glance.
News
Deep-sea fishes’ eye chemistry might let them see colors in near darkness
An unexpected abundance of proteins for catching dim light evolved independently in three groups of weird deep-sea fishes.
News in Brief
Only a third of Earth’s longest rivers still run free
Mapping millions of kilometers of waterways shows that just 37 percent of rivers longer than 1,000 kilometers remain unchained by human activities.
News in Brief
Ancient South American populations dipped due to an erratic climate
Scientists link bouts of intense rainfall and drought around 8,600 to 6,000 years ago to declining numbers of South American hunter-gatherers.
50 Years Ago
50 years ago, scientists tried to transplant part of a human eye
In 1969, a doctor tried and failed to restore a 54-year-old man’s vision. Fifty years later, scientists are still struggling to make eye transplants work.